DYING STARS - Dying Stars May Transform Frozen Worlds Into Havens for Life

Dying Stars May Transform Frozen Worlds Into Havens for Life:

A red giant star will consume planets close to it, but leave others just right for life.

Credit: Science@NASA


When most stars reach old age and begin to run out fuel, they swell up to hundreds of times their normal size, engulfing planets that orbit too close. But can planets that escape this fiery demise still support life? In this state, can planets around the dying star host life? New research says yes.

In about 7.5 billion years, the sun will have begun its march to the grave and will start expanding. Eventually it will swell to about 200 times its current size. It will swallow Mercury and Venus, and make Earth uninhabitable. But currently frigid locations in the solar system, like the icy moons of Saturn and Jupiter, might become just the right temperature for life.

Many stars in the universe become red giants, and some can remain that way for billions of years. The new work provides an in-depth look at how long planets can remain habitable around red giant stars — in some cases, for up to 9 billion years, which is twice Earth's current age. That's sufficiently long for life to form from scratch, or to flourish in a newer, more welcoming environment. It could also provide a lifeboat for humanity. [Video: Earth Will Be Consumed By a Red Giant Star]

When the sun expands into a red giant, it will overtake the current orbits of Mercury, Venus and Earth. The planets will move away from the star as it expands, allowing Earth to just barely escape being engulfed.

Credit: Cornell University


Crazy hot

Earth currently sits in the "habitable zone" of the sun — the distance at which the planet is warm enough to have liquid water on its surface, but not so hot that the water evaporates. (Liquid water is a requirement for all life on Earth, although the universe could very well serve up exceptions to this). This "just right" spot around a star is also sometimes called the "Goldilocks Zone."

The habitable zone is determined by the luminosity of a star — how much total light it emits over time. When most "normal" stars run out of hydrogen fuel, they start burning helium instead. Helium is a more potent fuel, and boosts the star's energy output at its core. As a result, the star swells up like bread in an oven, and becomes a "red giant."

A graph from NASA's Kepler Space Telescope mission shows the size of red giant stars compared to the sun.

Credit: NASA/Kepler/Tim Bedding, University of Sydney


A star's luminosity, or the total amount of light it emits in a given time, is largely responsible for defining the habitable zone. As a star swells up into a red giant, its luminosity increases. The sun's luminosity will increase by over 4,000 times when it becomes a red giant, the new research shows.

"The Earth [will become] a sizzling wasteland. The sun [will be] nearly at the Earth's orbit. It's going to be crazy hot," Lisa Kaltenegger, associate professor of astronomy and director of the Carl Sagan Institute, told Space.com. Kaltenegger is a co-author on the new research, which appears today (May 16) in the Astrophysical Journal.

But other places in the solar system will land in a less extreme temperature zone. The habitable zone of the sun will shift outward to include the orbits of Jupiter and Saturn, according to the new research.

This infographic shows where the sun's habitable zone will be when it turns into a red giant.

Credit: Cornell University


Under the thick icy layers on the surface of Saturn's moon Enceladus and Jupiter's moon Europa, scientists think it's possible that life could exist in liquid water oceans. The discovery of microbial life living in extreme environments on Earth, like under layers of ice in Antarctica, have boosted this hypothesis.

The new research suggests that when the sun becomes a red giant, life on Europa and Enceladus could thaw out, and have a chance to thrive on a planet that would lie in the habitable zone, Kaltenegger said.

For a star like our sun, a planet could potentially sit in the new habitable zone for half a million years. While that might not be enough time on a distant planet, that could be enough time for life buried under the ice to emerge and evolve into something detectable by Earth-based telescopes, Kaltenegger said.

Around the most massive stars considered in the new work (those in the category "A5," which includes stars more massive than the sun, but not the most massive stars in the universe), a planet could potentially be in the "new" habitable zone for up to 200 million years. Big stars burn fast and bright, but small stars can smolder in the red giant phase for much longer. The new work shows that for small stars, a planet could sit in the red giant habitable zone for up to 9 billion years. If life can evolve on Earth in less than 4 billion years, why not on a planet around a red giant?

Kaltenegger said she and her co-author on the paper, Ramses M. Ramirez, a research associate at the Carl Sagan Institute, have submitted a second paper for publication, in which they provide a list of 23 red giant stars within 100 light-years of Earth — potential targets for planet hunters.

"I hope that this will actually spark an effort by people who look for planets, to also look at these old stars now," she said. "Because if you could find signatures of life on such an evolved planet — a de-frozen planet — that would tell you that (life) could get started subsurface, and that would be an amazing part of the story."

Looking even further ahead, it could mean that humans could escape to the moons of Saturn or Jupiter when Earth becomes uninhabitable, she said.

"People keep saying, 'When our sun becomes a big hot star, then we have to move to Mars or other places.' But really for the first time, we have actually calculated where that place is and when," she said. "If you want to go planet-hopping, you'll want to know when you want to be where, and that's basically what we figured out."

The devil is in the details

This infographic illustrates how the habitable zone of a small red star will move out when the star expands into a red giant. Small stars remain in this phase of life longer than large stars, so planets in the "new" habitable zone can remain there for billions of years.

Credit: Cornell University


To determine where the habitable zone of a star will move to be as the star evolves into a red giant, Kaltenegger and Ramirez used models of stars and their evolution that already exist. This made it possible to compute a star's luminosity, as well as its temperature, which also influences the location of the habitable zone.

Planets that live in the habitable zone aren't necessarily habitable to life as we know it. Mars is a prime example. Venus lies just outside the sun's habitable zone, but its ultra-thick atmosphere traps heat on the surface and would likely make the planet uninhabitable, even inside the habitable zone. Still, looking for planets in the habitable zone is a good starting point in the search for life.

Kaltenegger and Ramirez knew that there was one variable in this entire calculation that could render the rest of the research moot — if the star, as it expands into a red giant, strips all nearby planets of their atmospheres.

"This is one of the things we didn't know," Kaltenegger said. In particular, she said the new work is the first time someone has shown whether or not rocky planets slightly less massive than the Earth and those slighty more massive than the Earth, could hold on to their atmospheres as their parent star evolves into a red giant.

Stars lose mass when they become red giants, and that mass gets blasted outward, as part of the so-called stellar wind. The new work shows that some planets will lose their atmospheres during the evolution — those located very close to the star, and those with low gravity (a planet's gravity helps it "hold on" to its atmosphere). But planets with sufficient mass, positioned a safe distance away, can maintain most of their atmosphere, Kaltenegger said.

There were other complicating factors that needed to be factored in, such as the fact that as the star loses mass, its gravitational grip on the planets is reduced. As a result, the orbit of a planet around a star will expand as the star becomes a red giant. (For this reason, the Earth will escape being engulfed by the sun, according to Kaltenegger).

Researchers have worked on the question of habitability around old stars before, but Kaltnenegger said no work has ever been done using models that can reveal details about how both the star and planets will evolve together through such a drastic change to the system.

"This is the first time where we link the model of the star to the model of the planet and see what it does," she said. "The devil is really in the details. The first stabs at it were great work because the idea got started, but it's a lot of work to do, and [Ramirez] actually hunkered down and did it."

Follow Calla Cofield @callacofield.Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

DNA OR RNA ? Molecular 'Midwives' Helped Give Birth to RNA

Molecular 'Midwives' Helped Give Birth to RNA:

Fundamental work on RNA is intended to help assist with probing life's origins.

Credit: NASA/Jenny Mottar


All life on Earth uses DNA to encode and store genes, and to pass them on from one generation to the next. RNA, a close molecular relative of DNA, is used within living cells to carry out a wide variety of important biological functions, including protein synthesis.

DNA and RNA are both extremely complex molecules, a fact that has fueled a long-standing debate about the origins of life. RNA looks potentially older and more versatile than DNA, so many scientists believe that RNA came before DNA. But did life begin with RNA, or was there something even simpler that preceded it?

Scientists have found it difficult to deduce the chemical environment on early Earth when life began. Nevertheless, there have been a number of notable successes in this area of research, including the discovery of reactions that produce the building blocks of RNA. However, a reaction that produces actual polymers of RNA has not been found, causing many scientists to conclude that RNA is the product of evolution. [The Strangest Places Where Life Is Found on Earth]

Artist's impression of RNA.

Credit: Vossman/Wikipedia Commons


"The origin of RNA is something I've been working on for two decades," said Nicholas Hud, head of the Georgia Institute of Technology's Center for Chemical Evolution, where researchers are attempting to figure out how life began. "It is easy to speculate that some other molecule came before RNA, but determining the structure of molecules that might actually have come before RNA is a major challenge for chemists."

A recent paper by Hud and his team found that proflavine, a small planar molecule that binds between adjacent base pairs of a DNA, can dramatically increase the stability of DNA or RNA in the lab when single strands of the complex molecules are synthetically bound to an unnatural nucleic acid. ("Unnatural" means that these are molecules similar to natural DNA or RNA, but with different backbone structures.)

"Proflavine can cause the formation of a duplex from two nucleic acids that otherwise do not form duplexes at all," Hud said.

He added that their results are important for two reasons. The first is that duplexes formed by DNA and an unnatural nucleic acid could be used to create dynamic structures that assemble only when proflavine, or a similar molecule, is present. This property has potential applications in nanotechnology, or the technology of very small things.

A second and more fundamental implication of this work has to do with our understanding of the "RNA World" hypothesis, the theory that RNA was the first molecule of life. After decades of unsuccessful attempts to create RNA in model prebiotic (non-biological) reactions, many chemists that study the origin of life believe that there must have been some other RNA-like polymer before RNA. Hud said the first of these polymers could be called a "proto-RNA" and each evolutionary step between proto-RNA and current RNA is a "pre-RNA." [10 Exoplanets That Could Host Alien Life]

"There have been many proposals for possible pre-RNA structures," he said. "While it may not be possible to determine the exact structure of any of the molecules that served as the ancestors of RNA, researchers generally agree that the ability to form a duplex with RNA is an important criterion that must be met for a molecule to be considered a possible ancestor of RNA."

Back in 2000 Hud and his collaborator Frank Anet proposed that small molecules might have helped the synthesis of RNA, or the original ancestor of RNA, if RNA came later. They called these hypothetical small molecules "molecular midwives," to reflect that these molecules would have helped give birth to RNA. They proposed that molecular midwives would have been similar to molecules that are currently known to bind DNA and RNA, such as fluorescent dye molecule known as "intercalators" that are used to visualize DNA in the laboratory.

Most recently, Hud and his collaborators have discovered that proflavine, a particular intercalator, is able to cause the formation of a double helix, like that formed by two DNA molecules, but between RNA and a non-natural RNA-like molecule that has a "backbone" structure distinct from RNA and DNA. In the absence of proflavine these molecules do not form double helixes.

This result has important implications regarding the origin of the first RNA-like molecules of life. In particular, the number of molecules that could have served as the first genetic molecules of life might have been much greater than previously expected if intercalator molecules we present on the early Earth. Hud notes that proflavine is not a potentially prebiotic molecule, but was used in their study as a model for the type of intercalator molecules that may have been available on early Earth.

Scientists have also found evidence of asteroids bringing the building blocks of life, such as amino acids, to Earth.

Credit: NASA/Mary Pat Hrybyk-Keith

Other alternatives

Hud has spent years studying the potential role of intercalators in the origin of RNA. Very few studies have investigated the ability of intercalators to bind non-natural RNA-like molecules, and no previous studies had investigated the possibility that intercalators might allow RNA to pair with polymers that would otherwise be "incompatible" with RNA.

Connections made within the Center for Chemical Evolution (or CCE) allowed these studies to move to a whole new level. Ram Krishnamurthy, a fellow member of the CCE who is at The Scripps Research Institute in La Jolla, Calif., was synthesizing with his co-workers a polymer called iso-GNA that is in some ways simpler than RNA, and they thought this polymer might shed light on the structural requirements for the simplest informational system RNA. Their observation that iso-GNA has limited base-pairing with RNA made them question the currently accepted requirements for ancestors of RNA. Conversations within the CCE resulted in Hud’s group testing the ability of an intercalator to facilitate the pairing of Krishnamurthy’s molecule (iso-GNA) with RNA. [The Strangest Alien Planets (Gallery)]

"In our earlier work on iso-GNA revealed that this molecule did not form duplexes that are stable as those of DNA or RNA," Krishnamurthy said. "We proposed that this limitation of iso-GNA could be overcome by the use of intercalators since they are known to stabilize base-pairing within a duplex structure by enhancing base-stacking. What is fascinating in this study is that the increase we observed for the stability of iso-GNA duplexes in the presence of proflavine is much larger than the increased stability those observed when proflavine binds DNA or RNA, far exceeding our expectations. This study should allow for a greater flexibility when searching for possible prebiotic polymers that are able to interact with RNA (or DNA)."

These latest results have caused Hud and Krishnamurthy to broaden their view of which molecules might have come before RNA. These two researchers and their co-workers are currently trying to find a possible ancestor of RNA that is able to spontaneously form from molecules that were present on the early Earth. They remain more open than ever to the idea that some molecules not seen in life today may have been necessary to get life started, perhaps molecules that we could view as the "midwives" that helped give "birth" to RNA.

Funding for the research was provided by the National Science Foundation (which funds CCE more generally) and a grant from the NASA Astrobiology Institute element of the Astrobiology Program at NASA.

This story was provided by Astrobiology Magazine, a web-based publication sponsored by the NASA astrobiology program. Follow Space.com @Spacedotcom, Facebook and Google+.

YOUNG STARS - Superbubble! Young Stars Highlight Glowing Gas Cloud (Photo, Video)

Superbubble! Young Stars Highlight Glowing Gas Cloud (Photo, Video):

A glowing gas cloud full of young stars shines brightly in a new picture from the European Southern Observatory's Very Large Telescope (VLT) in Chile.

The gas cloud, a nebula called LHA 120-N55, is about 163,000 light-years away from Earth and is situated in the Large Magellanic Cloud, a nearby dwarf galaxy that's one of the Milky Way's satellites. The image was taken by the VLT's FOcal Reducer and low dispersion Spectrograph (FORS2), and its location in space is pinpointed in a new video.

The gaseous N55 is inside of a superbubble, a vast structure which occurs when winds from new stars and shockwaves from supernova explosions, caused by dying stars, blow away the gas and dust those stars used to possess. The process carves bubble-shaped holes in the gas. [50 Fabulous Deep-Space Nebula Photos]

Emission nebula LHA 120-N55 shines in this image from the European Southern Observatory's Very Large Telescope.

Credit: ESO "The material that became N55, however, managed to survive as a small remnant pocket of gas and dust," ESO officials said in a statement. "It is now a standalone nebula inside the superbubble and a grouping of brilliant blue and white stars — known as LH 72 — also managed to form hundreds of millions of years after the events that originally blew up the superbubble."


Those brilliant stars are quite young — too young to have created the superbubble — but they are responsible for the bright colors in the image. Their radiation is stripping away electrons inside the hydrogen atoms of N55, which makes the gas glow; that vibrant glow is seen as an indication of new stars.

This region will see a lot of upheaval in a few million years, ESO officials added, when some of these young stars begin to go supernova. "In effect, a bubble will be blown within a superbubble, and the cycle of starry ends and beginnings will carry on in this close neighbour of our home galaxy," they said.

Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. We're also on Facebook and Google+. Original article on Space.com.

ASTRONAUTS IN MARS - Send Astronauts to Mars to Find Evidence of Life, NASA's Top Scientist Says

Send Astronauts to Mars to Find Evidence of Life, NASA's Top Scientist Says:

This detailed view of Mars was created using 1,000 photos taken by NASA’s Viking 1 orbiter.

Credit: NASA/JPL/USGS


The chances are good that microbial life existed on Mars long ago, and sending astronauts to the Red Planet is the best way to find the evidence, NASA's chief scientist said.

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Though Mars is cold and dry today, the planet hosted liquid water on its surface for extended periods more than 3 billion years ago, Ellen Stofan pointed out during a talk Tuesday (May 17) at the Humans to Mars Summit in Washington, D.C.


"Those conditions on Mars, we know, were not that different from the conditions on Earth from when life evolved," she said. "And life evolved so quickly here on Earth, and in the oceans, that it gives the scientific community a fair amount of confidence that the same conditions did exist on Mars, and that life did evolve there. So how are we going to find it?" [The Search for Life on Mars (A Photo Timeline)]

Scientists know that life had evolved on Earth by 3.8 billion years ago, and a recent study suggested that the first microbes actually might have appeared by 4.1 billion years ago — just 440 million years after the planet formed.

Earth life-forms stayed simple for a long time after that; complex, multicellular organisms didn't get a firm foothold here until 800 million years ago or so. By that time, the Red Planet had long since lost most of its atmosphere, as well as its stable surface water. So the hunt for life on Mars should think small, Stofan said.

"We're not looking for skeletons; we're looking for fossil microbes — if [Mars] life did indeed go extinct," she said. "And those are going to be hard to find."

Indeed, field geologists here on Earth can study rocks rich in fossil microbes but never see the tiny structures, said Stofan, who is a geologist. Therefore, she thinks robots won't be able to do the job by themselves on Mars, especially considering how high the burden of proof will be for such an epochal discovery.

"I strongly believe we will never settle this question of determining whether or not there's life on Mars unless we get human scientists down onto the surface of the Red Planet," Stofan said.

No planet is more steeped in myth and misconception than Mars. This quiz will reveal how much you really know about some of the goofiest claims about the red planet.

0 of 10 questions complete

Mars Myths & Misconceptions: Quiz

No planet is more steeped in myth and misconception than Mars. This quiz will reveal how much you really know about some of the goofiest claims about the red planet.

0 of questions complete

The search for Mars life is, therefore, a strong motivation for putting boots on the Red Planet, which NASA aims to do by 2040. But there are other drivers as well, Stofan said.

"Every time I go out into a classroom — whether it was a D.C. high school I went to last week, elementary schools around the world — you ask those kids, 'Do you want to go to Mars?' And over half the room raises their hand," she said. "So let's get this done. Let's go to Mars."

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

JUPITER PLANET - Jupiter Fireballs: Big Impacts Occur 6 to 7 Times Per Year

Jupiter Fireballs: Big Impacts Occur 6 to 7 Times Per Year:

The Jupiter fireball of March 17, 2016, captured by Gerrit Kernbauer and John McKeon.

Credit: G. Kernbauer, J. McKeon, S. Voltmer


Jupiter doesn't get whacked by asteroids and comets quite as often as scientists had thought.

Objects big enough to generate a fireball visible from Earth — such as the spectacular one that occurred on March 17 — slam into Jupiter about 6.5 times per year, according to a new study based on the pooled observations of amateur astronomers around the world.

"In three years since our program started, amateur contributors from Europe, the U.S. and Australia have analyzed the equivalent of more than 56 days of videos — around 53,000 videos — without discovering an impact," Marc Delcroix, who coordinates a group of about 60 skywatchers worldwide, said in a statement. [Jupiter Collision! Impact Captured by Amateur Astronomer (Video)]

"This is a result in itself and, together with the reports of amateur astronomer John McKeon, has helped us come up with our preliminary estimate, which slightly reduces previous estimates of the flux of impacting objects [at] Jupiter," Delcroix added.

McKeon captured the March 17 Jupiter fireball on video. (Another amateur astronomer, Gerrit Kernbauer, spotted the impact first; McKeon went through his observations from that night after learning of Kernbauer's find.)

Researchers think that the March 17 event was caused by an object 33 to 66 feet (10 to 20 meters) wide. Skywatchers have observed three other such Jupiter strikes since June 2010; all of them likely involved impactors in the same general size range, scientists have said.

But bigger objects hammer the gas giant fairly frequently as well. A 1,650-foot-wide (500 m) asteroid barreled into Jupiter in 2009, for example, and the big chunks of broken-apart Comet Shoemaker-Levy 9 pummeled the huge planet in July 1994, leaving dark scars that were visible in Jupiter's cloud tops for months.

Jupiter is much bigger and more massive than Earth, so the giant planet gets hit by cosmic objects thousands of times more often than our planet does. (Asteroids and comets are drawn in more frequently by Jupiter's powerful gravity.)

Nailing down Jupiter's precise impact rate is of interest to astronomers and planetary scientists as well as skywatchers.

"Unfortunately, we are still dealing with the statistics of a very few number of impacts detected, but plans to improve our detection methods and perform systematic searches will help us to detect more of these objects," Ricardo Hueso Alonso, of the University of the Basque Country in Spain, said in the same statement. "That will allow us to know more about the current architecture of the outer solar system and the role of Jupiter in protecting the Earth from comparable impacts."

The study team presented its results at a workshop on Jupiter for professional and amateur astronomers at the Observatoire de la Côte d’Azur in Nice, France. The workshop was organized by the Europlanet 2020 Research Infrastructure, a project designed to support planetary-science activities throughout Europe.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

MARS PLANET - Hubble Telescope Captures Incredible Up-Close View of Mars

Hubble Telescope Captures Incredible Up-Close View of Mars:

An amazing new Mars image captured by the Hubble Space Telescope shows clouds, craters, ice caps and other features on the Red Planet.

Hubble took the photo on May 12, when Mars was just 50 million miles (80 million kilometers) from Earth. That's quite close in the cosmic scheme of things; Mars is nearly at "opposition" — when the planet and the sun are on exact opposite sides of Earth from each other — which will come on May 22.  

Mars as it was observed shortly before opposition in May 2016 by the Hubble Space Telescope. Some prominent features are clearly visible, including the heavily eroded Arabia Terra in the center of the image and the small southern polar cap.

Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (ASU), and M. Wolff (Space Science Institute)


Opposition "marks the planet's closest approach to Earth, so that Mars appears bigger and brighter in the sky than usual," European Space Agency officials wrote today (May 19) in a description of the newly released photo. (The Hubble mission is run jointly by NASA and ESA). "This event allows astronomers using telescopes in space and on the ground to see more details on the Martian surface." [The 7 Biggest Mysteries of Mars]

The dates of closest approach and opposition don't mesh exactly. The closest approach will actually come on May 30, when Earth and Mars are separated by 46.8 million miles (75.3 million km).

The average time between Mars oppositions is about 780 days; the last time Earth, the Red Planet and the sun all lined up was in April 2014. And some closest approaches are closer than others. In 2003, for example, Mars came within 34.65 million miles (55.76 million km) of Earth — the closest the two planets had been in 60,000 years, ESA officials said.  

The new Hubble photo, which the telescope took with its Wide Field Camera 3 instrument, shows a natural-color view of Mars in which mountains, plains, canyons, craters and many other geological features are visible.

Annotated view of Mars as it was observed shortly before opposition in May 2016 by the NASA/ESA Hubble Space Telescope.

Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (ASU), and M. Wolff (Space Science Institute)


"The orange area in the center of the image is Arabia Terra, a vast upland region," ESA officials wrote. "The landscape is densely cratered and heavily eroded, indicating that it could be among the oldest features on the planet."

"South of Arabia Terra, running east to west along the equator, are the long, dark features known as Sinus Sabaeus (to the east) and Sinus Meridiani (to the west)," they added. "These darker regions are covered by bedrock from ancient lava flows and other volcanic features."

Clouds blanket the dark volcanic plains of Syrtis Major, on the right side of Mars, and cover the extensive south polar ice cap as well. (The northern ice cap is quite small, because it's currently summer in Mars' northern hemisphere.)

Hubble launched in April 1990 aboard the space shuttle Discovery. Spacewalking astronauts repaired its flawed primary mirror in December 1993, and the famous telescope has been helping astronomers make big discoveries ever since. Barring any unforeseen events, Hubble should keep operating through at least 2020, and perhaps longer, NASA officials have said.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

JAPAN AEROSPACE - JAXA: Japan's Aerospace Exploration Agency

JAXA: Japan's Aerospace Exploration Agency:

Earth return of Japan's Hayabusa asteroid probe and release of its sample capsule.

Credit: C. Waste and T. Thompson (NASA/JPL-Caltech)


The Japan Aerospace Exploration Agency (JAXA) was formed in 2003 after the merger of three government space organizations into one. JAXA is responsible for all civilian space activities in Japan, with activities ranging from basic space research to ongoing space missions.

Japan's human exploration program long predates the beginning of JAXA, including numerous contributions to the International Space Station. Its work on station includes the Kibo research module (including a robotic arm) and regular cargo flights to ISS using the H-II Transfer Vehicle (HTV).

The country is also noted for several robotic exploration missions – Hayabusa's sample return mission from asteroid 25143 Itokawa and the lunar mission SELENE are examples – and its new self-checking rocket, Epsilon.

Early Japanese space research

Prior to JAXA, Japan pursued space through three different agencies. The Institute of Space and Astronautical Science (ISAS) and the National Aerospace Laboratory of Japan (NAL) were both created in 1955, while the National Space Development Agency of Japan (NASDA) was formed in 1969.

ISAS focused on robotic space missions, including the PENCIL suborbital rocket launch in 1955 and the first satellite, OHSUMI, which launched in 1970. (The entity was previously known by other names, but was called ISAS after a research agreement was forged between Japanese universities in 1981.)

NAL (first called the National Aeronautical Laboratory) worked on rockets, aircraft, aerospace transportation and related technology. NASDA also performed work in satellites and launch vehicles, and was the hub for Japan's early astronaut program.

Japanese authorities elected to merge the three groups into one in 2003. The goal was to form "one independent administrative institution to be able to perform all their activities in the aerospace field as one organization, from basic research and development to utilization," JAXA stated.

It's important to note that much of the work carried out by JAXA today originates from research performed at these three agencies. One example is work on the ISS.

Japan human spaceflight and the ISS

Japan's first astronaut selection took place in 1985 under NASDA, with three candidates selected: Mamoru Mohri, Chiaki Mukai and Takao Doi. Mohri was the first one to fly into space, riding aboard STS-47 in 1992. The mission on space shuttle Endeavour included Spacelab-J, a scientific module that included numerous Japanese experiments.

The aim of the early Japanese spaceflights was to accumulate research experience that would be useful on the ISS. Then they learned about other station duties: on STS-72 in 1996, for example, Koichi Wakata (part of the 1992 astronaut class) became the first Japanese astronaut to operate robotics in space.

The first spacewalk took place in 1997, when Takao Doi did procedure evaluations for station aboard STS-87. More astronauts were selected in several rounds to fill the demand for orbital slots. JAXA's most recent astronaut selection was in 2009.

For the station, NASDA and JAXA created cargo spaceships and the Kibo – the first Japanese module for human spaceflight. "We will finally be able to conduct experiments in such fields as new material development, which require a lot of preparation time, and to study the impact of long stays in space on the human body," stated Tetsuo Tanaka, director of JAXA's space environment utilization center, in 2006.

A newer JAXA mission to station is a "talking robot", Kirobo, intended to interact with astronauts and gain information about their mental health.

Robotic missions

Hayabusa is one of Japan's most famous robotic missions. The spacecraft launched in 2003 and successfully arrived at the asteroid in September 2005. It deployed a lander, MINERVA, that was supposed to hop from place to place on the surface, but MINERVA never made it. Hayabusa itself made a successful landing in November 2005, attempted to scoop up material, and returned to Earth safely in 2010 after encountering many failures along the way (including two of its four ion engines). [Photos: Hayabusa: Japan's Asteroid Mission]

JAXA launched a successor mission called Hayabusa2 in December 2014. The spacecraft is en route to a carbonaceous asteroid called Ryugu, where it will arrive in mid-2018 and deploy several small robots on the surface. Hayabusa2 will also scoop up a bit of the asteroid itself for sample return. The spacecraft is expected to leave the asteroid in late 2019 and come back to Earth in late 2020.

Another prominent effort is SELenological and ENgineering Explorer (SELENE, also known as Kayuga), a mission to explore the moon. The lunar mission launched in 2007 and operated for well over a year before SELENE was steered into the lunar surface as planned. The mission aimed to learn about the moon's "elemental and mineralogical composition, its geography, its surface and sub-surface structure, the remnant of its magnetic field, and its gravity field," JAXA stated on its website.

Other prominent missions

The Hinode (SOLAR-B) spacecraft launched in September 2006 to do solar observations. Its focus is on understanding more about the solar corona, which is the sun's atmosphere. The aim is to better predict solar weather and its effect on Earth.

The Venus orbiter Akatsuki was supposed to arrive at the cloudy planet in 2010, but didn't make it due to an engine failure. The spacecraft was in an orbit that allowed it to make another close pass by Venus in December 2015, close enough for JAXA to push it into orbit using the attitude control engine. Observations started in April 2016.

JAXA has been periodically testing a solar sail demonstrator called Ikaros, which launched in 2010. The spacecraft has periods of operations broken up by planned hibernations, the latest of which took place in 2015.

JAXA launched the ASTRO-H/Hitomi X-ray observatory in early 2016, but the mission lost contact with Earth and was declared lost in April of that year.

A more recent technology demonstrator is the Epsilon rocket, which is intended to perform its own health checks and relieve the work burden off of ground controllers. The aim is to launch the rocket from the equivalent of a couple of desktop computers, rather than large mainframes, and to cut costs.

"You may doubt that artificial intelligence can be used in a rocket, but nowadays a self-inspection function is something commonly seen in machinery," stated Yasuhiro Morita, Epsilon's launch vehicle project manager. "Another example is a medical device such as the electrocardiograph, which uses artificial intelligence to diagnose heart abnormalities."

Additional resource

SKY IN GAMMA-RAYS The HAWC Has Landed — Observatory Maps the High Energy Sky

The HAWC Has Landed — Observatory Maps the High Energy Sky:

"A view of two-thirds of the entire sky with very high-energy gamma-rays observed by HAWC during 340 days of data taking between November 2014 and November 2015. Clearly visible are many sources in the Milky Way and the extragalactic objects Markarian 421 and 501. Several well-known constellations are shown as a reference."

Credit: HAWC collaboration


In a remote section of desert in southern Mexico, on the slopes of the dormant Sierra Negra volcano, lies a collection of 300 steel tanks, each the size of a small house. Together, they take up an area that's a little less than four football fields. In the otherwise uninhabited area, the glistening metal structures look like a futuristic city tried to take root there.

These metal tanks make up the High-Altitude Water Cherenkov Gamma-Ray Observatory, or HAWC for short, which is being used to map the sky in high-energy gamma-rays. The new map reveals a cosmic landscape that resembles the isolated desert where HAWC's detectors make their home, sparsely littered with sources of light.

The release of HAWC's first complete sky map last month effectively signified that HAWC is now a participating member of the observing community, and has already begun to perform one of its primary functions: alerting other telescopes when strange and sporadic bursts of gamma-rays appear in the sky. [Gamma-Ray Universe: Photos by NASA's Fermi Space Telescope]

Cosmic treasure maps

Water tanks for the HAWC detector with Picode Orizaba in the background.

Credit: Zig Hampel-Arias, HAWC/WIPAC


Earthlings who look up at the night sky see a background of blackness littered with millions of points of light, and the hazy band of the Milky Way.

HAWC's view of the sky is decidedly different. The map released by the collaboration in April shows a sky that is mostly dark; there are only about 40 distinct sources of light, and most of those line up along the plane of the Milky Way Galaxy, which looks bright in any wavelength, simply because of its proximity to the Earth.

The longer HAWC observes the sky, the more sources it will discover, but a high-energy, gamma-ray map of the sky will never look quite like the cosmic skyline that human eyes see. Compared to the number of stars that radiate visible light, there just aren't very many cosmic objects that emit the high-energy gamma-rays that HAWC detects.

But quantity isn't everything. The view of the sky in high-energy gamma-rays is part of the cosmic puzzle, and without it, humanity's view of the cosmos is incomplete.

Consider the different types of maps that can be made of a single city: there are those that show the location of roads, buildings, rivers and lakes; but there are also topological maps that show the rise and fall of the land, or geological maps that reveal the materials buried under the ground. Maps that show gas and power lines are essential for construction projects — even though they don't help people find their way to the grocery store. Different maps can show the same location in a different light.

Maps of the universe show the same location in, literally, different kinds of light — there are telescopes and observatories that have mapped the sky in just about every wavelength of light: radio, infrared, optical, microwave, X-ray and gamma-ray HAWC is not the first).

HAWC's map covers two-thirds of the night sky. (Because it is located on the ground, and not in space, part of its view is blocked by the Earth.) No other observatory has ever mapped such a large section of the sky in such high-energy gamma-rays, and over such a long period of time (which lets HAWC pick up fainter sources), said Brenda Dingus, the principal investigator for the U.S. Department of Energy for HAWC. Comparing the locations in HAWC's map with those same locations on maps of other wavelengths can reveal more about the objects that lurk there, and the processes going on there. These multiwavelength investigations can solve mysteries or create new ones.

Cosmic accelerators

This view shows the entire sky in gamma-rays, based on five years of data from the LAT instrument on NASA's Fermi Gamma-ray Space Telescope. Brighter colors indicate brighter gamma-ray sources.

Credit: NASA/DOE/Fermi LAT Collaboration


Stars and most other objects in the universe radiate energy because they are hot, Dingus told Space.com. That thermal energy is responsible for most of the illumination in the universe. But gamma-rays don't form so easily.

"You can't just get something hot and make gamma-rays," Dingus said. "You actually have to have a particle accelerator."

One such cosmic accelerator is a supernova — a massive star that runs out of fuel, collapses under its own weight and explodes. As the stellar mass collapses, the in-falling material can bounce off the star's core, creating a shockwave that slams through nearby dust clouds like a wrecking ball. The dust particles get kicked so hard they spit out gamma-rays. While the initial explosion releases visible light and other wavelengths for a few days, the gamma-rays from the shockwave remain visible for centuries, allowing long-term study of the remains of the supernova. [Supernova Photos: Great Images of Star Explosions]

When a gamma-ray from a distant source collides with a particle in the Earth's atmosphere, it's like a particle piñata got cracked open: the energy from the collision creates a shower of new particles (including more gamma-rays). Those 300 massive steel tanks that make up the HAWC observatory don't look like most instruments that observe the cosmos; they bear no resemblance to a telescope. The tanks are full of purified water, and when those showers of particles speed through the H2O, they generate more light, which is picked up by detectors. Working backward, scientists can trace the path of the original particle.

HAWC isn't the only telescope that uses this approach to capture gamma-rays, but it is currently the only detector of this type surveying such a large portion of the sky. The Fermi Gamma-ray Space Telescope also surveys the sky in gamma-rays (using a different method), but the highest-energy light it collects is fifty times weaker than HAWC's maximum, and HAWC covers an energy range that's over 65 times larger than what Fermi covers.

Despite such a broad reach, HAWC's map effectively reveals a cosmic desert. Maps in other wavelengths — even the lower-energy gamma-ray maps from Fermi — are lush with light sources and diffuse glow. By comparison, the creators of these powerful gamma-rays sparsely populate the cosmic landscape. But quantity isn't everything.

New discoveries

This full-sky map from the Planck mission shows matter between Earth and the edge of the observable universe. Each sky map of the universe can reveal different information about the same area. Image released March 21, 2013.

Credit: ESA/NASA/JPL-Caltech


Of the 40 high-energy gamma-ray sources seen in the HAWC map, about 25 percent have not been seen before in this wavelength range, said Michelle Hui, a researcher at NASA's Marshall Space Flight Center and a member of the HAWC collaboration. Hui spoke about the new HAWC map at The American Physical Society April Meeting, held this year in Salt Lake City. The meeting brings together scientists from the field of astrophysics, as well as from particle and nuclear physics, to discuss current trends and new results.

It's likely that some of the sources in the new HAWC map are associated with pulsars, another example of a cosmic particle accelerator, Hui said. Pulsars are the dense cores of material that are often left behind after a star explodes, and their incredibly strong magnetic fields and fierce spinning (up to hundreds of times per second) sometimes generate gamma-rays.

Many pulsars also emit radio waves — the least energetic form of light — all the way at the other end of the spectrum from gamma-rays. So HAWC scientists can consult a radio map of the sky, and see if their gamma-ray sources line up with a known pulsar.

"That will be our next step … to correlate with the other wavelengths to see exactly what is generating these high-energy photons," Hui said.

One of the most interesting revelations in the new map is a region nicknamed "the executioner," which has previously been spotted by other gamma-ray telescopes, Hui said. HAWC's map revealed that there might be three di

stinct sources in this bright spot, which could mean the discovery of a brand-new gamma-ray emitter. [NASA's Top 10 Gamma-Ray Sources in the Universe]

Alert!

The universe seen in infrared light, captured by NASA's Wide-field Infrared Survey Explorer (WISE).

Credit: NASA/JPL-Caltech/UCLA


On April 6, 10 days before the start of the APS meeting, HAWC saw a known gamma-ray source rapidly brighten for about one day, and then nearly disappear again. The team sent out an astronomer's telegram, which is a community-wide alert that lets other telescope observatories know if a bright flash of light appears, or if something else strange is happening. The HAWC scientists still don't know what's causing the flare-up.

This is one of the primary roles that HAWC would like to serve, Dingus said — to be an alert system to let other telescopes know when an object releases a short-lived burst of gamma-rays. The Fermi telescope also performed this function in lower energies.

"We have other [observatories] that also look at this source daily … with the Fermi gamma-ray satellite in lower-energy gamma-rays, down to X-rays," Robert Lauer, a research assistant professor in physics and astronomy at the University of New Mexico and a member of the HAWC collaboration, said at the press conference. "And then we can compare all these measurements and see if we see the same type of fluctuation and learn much more about the processes and the source."

"You get a whole lot of new information by studying variability," Dingus told Space.com. "If you look at something and it stays the same all the time, you can make a theory about it. But then if it actually changes, that adds a lot more constraints to your theory."

Outside the room where the three scientists discussed these findings, another 20 HAWC members showed up just to cheer on their colleagues. The hallway buzzed with excitement — it felt more like a red carpet debut than a scientific announcement. But the release of the map is a major milestone for the experiment.

"This is our announcement that we work, and we work as advertised," Dingus told Space.com at the APS April Meeting. "This is the first map with the full detector. And it promises that the next five years are going to be really exciting."

Follow Calla Cofield @callacofield. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

BLUE MOON - 'Blue Moon' Rises Saturday — But It Won't Be Blue: A Full Moon History

'Blue Moon' Rises Saturday — But It Won't Be Blue: A Full Moon History:

The "blue moon" full moon of July 31, 2015 rises behind the dome the U.S. Capitol in this image from NASA photographer Bill Ingalls. The May 21, 2016 full moon is the fourth full moon in spring, which is also known as a "blue moon."

Credit: NASA/Bill Ingalls


This weekend, a full moon will rise in the night sky, a so-called "Blue Moon."

Typically, a Blue Moon is defined as the second full moon that occurs during a calendar month, but the full moon this Saturday (May 21) will be the only full moon of May 2016. So, how can it be called a Blue Moon?

The explanation points back to a somewhat obscure rule. In fact, the current rule of two full moons in one month has superseded the rule that would allow this month's full moon to be called "blue." [Video: What's a Blue Moon — Is It REALLY Blue?]

If you're confused, don't worry. Here's the rest of the story. 

Credit: Karl Tate, SPACE.com

The almanac rule

In a question-and-answer column from the July 1943 issue of Sky & Telescope magazine, writer Lawrence J. Lafleur referenced the term "Blue Moon." Lafleur cited the unusual term from a copy of the 1937 edition of the now-defunct "Maine Farmers' Almanac" (not to be confused with the "Farmers' Almanac," which is still published in Lewiston, Maine).

On the page for August 1937, the "Maine Farmer's Almanac" gives the calendrical meaning for the term "Blue Moon." [Blue Moon Photos of 2015: Amazing Full Moon Views]

That explanation said that the moon "usually comes full 12 times in a year, three times for each season." Occasionally, however, there will come a year when there are 13 full moons during a year, not the usual 12.

The almanac explanation continued: "This was considered a very unfortunate circumstance, especially by the monks who had charge of the calendar of thirteen months for that year, and it upset the regular arrangement of church festivals. For this reason, thirteen came to be considered an unlucky number."

And that extra full moon also meant that one of the four seasons would contain four full moons instead of the usual three.

"There are seven Blue Moons in a lunar cycle of 19 years," the almanac said, ending on the comment that, "In olden times, the almanac makers had much difficulty calculating the occurrence of the Blue Moon, and this uncertainty gave rise to the expression 'once in a Blue Moon.'"

An unfortunate oversight

While LaFleur correctly quoted the almanac's account, he made one important omission: He never specified any date for the Blue Moon.And as it turned out, in 1937, the Blue Moon occurred on Aug. 21. This was the third full moon in the summer of 1937, a summer season that would see a total of four full moons.

Names were assigned to each full moon in a season. For example, the first moon of summer was called the early summer moon, the second was the midsummer moon, and the last was called the late summer moon. But when a particular season has four moons, the third was apparently dubbed a "Blue Moon," so that the fourth and final one can continue to be called the late moon.

So where did the two-full-moons-in-a-month rule that is so popular today come from?

Pruett's mistake

Once again, the answer hails from the pages of Sky & Telescope magazine. This time, on Page 3 of the March 1946 issue, James Hugh Pruett wrote an article titled "Once in a Blue Moon." Here, he used the term "Blue Moon" and referenced LaFleur's article from July 1943. But because Pruett had no specific dates to fall back on, his interpretation of the ruling given by the "Maine Farmers' Almanac" was highly subjective.

Pruett ultimately came to the following conclusion: "Seven times in 19 years there were — and still are — 13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a month, so I interpret it, was called Blue Moon."

It's unfortunate that Pruett did not have a copy of that 1937 almanac at hand, or else he almost certainly would have noticed that his two-full-moons-in-a-single-month assumption was wrong. That's because the Blue Moon date of Aug. 21 was notthe second full moon that month. [Moon Master: An Easy Quiz for Lunatics] 

Going viral

Pruett's 1946 explanation was, of course, wrong, and it might have been completely forgotten were it not for science journalist Deborah Byrd. She cited Pruett's interpretation on the Jan. 31, 1980, episode of her popular National Public Radio program "StarDate." It could be said that in the aftermath of her radio show, the incorrect Blue Moon rule "went viral."

Over the next decade, this new Blue Moon definition appeared in such diverse places such as the kids' edition of "The World Almanac" and the board game "Trivial Pursuit."

I must confess that even I helped perpetuate the new Blue Moon phenomenon. Nearly 34 years ago, in the Dec. 1, 1982, edition of The New York Times, I made reference to the erroneous Blue Moon explanation in the "New York Day by Day" column.

And by 1988, the new definition had started receiving international press coverage.

Today, Pruett's misinterpreted two-full-moons-in-a-month rule is recognized worldwide. Indeed, Sky & Telescope turned a literary lemon into lemonade, proclaiming later that the magazine had, however unintentionally, changed pop culture and the English language in unexpected ways.

Meanwhile, the original "Maine Farmers' Almanac" rule has been all but forgotten.

For most of human history, the moon was largely a mystery. It spawned awe and fear and to this day is the source of myth and legend. But today we know a lot about our favorite natural satellite. Do you?

0 of 10 questions complete

Moon Master: An Easy Quiz for Lunatics

For most of human history, the moon was largely a mystery. It spawned awe and fear and to this day is the source of myth and legend. But today we know a lot about our favorite natural satellite. Do you?

0 of questions complete

Credit: Karl Tate, SPACE.com

Playing by the (old) rules

Now, let's come back to this month's full moon.

Under the "old" almanac rule, this Saturday's moon would be a Blue Moon.

In spring 2016, there are four full moons, occurring on March 23, April 22, May 21 and June 20.

June 20, 2016, is the first day of summer if you live north of the equator, but south of the equator, that date is the first day of winter. In 2016, the summer solstice comes at 2234 GMT or 6:34 p.m. EDT on June 20. But the moon turns full at 1103 GMT or 7:03 a.m. EDT. That's 11 hours and 31 minutes before the solstice occurs. So the June 20 full moon occurs during the waning hours of spring and qualifies as the fourth full moon of the season.

This means that under the original "Maine Almanac" rule — the one promoted by Lafleur and later misinterpreted by Pruett — the third full moon of the 2016 spring season on May 21 would be a Blue Moon.

Final thoughts

So which Blue Moon definition tickles your fancy? Is it the second full moon in a calendar month or (as is the case on Saturday) the third full moon in a season with four? Maybe it's both. The final decision is solely up to you.

Saturday's full moon will look no different than any other full moon — it won't likely be blue. But the moon cantake on such a color in certain conditions. After forest fires or volcanic eruptions, Earth's satellite can appear to take on a bluish or even lavender hue. Soot and ash particles, deposited high in the Earth's atmosphere, can sometimes make the moon appear bluish.

For instance, in the aftermath of the massive eruption of Mount Pinatubo in the Philippines in June 1991, there were reports of a blue-colored moon (and even a blue sun) worldwide. .

If bad weather ruins your "Blue Moon" experience this weekend, don't worry. The online Slooh Community Observatory will offer a free live webcast of the May full moon beginning at 8 p.m. EDT (0000 GMT). You can follow the Slooh webcast at Slooh.com.

You can also watch the Blue Moon webcast on Space.com here, courtesy of Slooh.

Editor's note: If you snap an amazing photo of May's Blue Moon full moon and would like to share with Space.com and our news partners for a possible story or image gallery, send images and comments in to managing editor Tariq Malik at spacephotos@space.com.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y. Follow us@Spacedotcom, Facebook or Google+. Originally published on Space.com.

GALAXY - Spring Skywatching: The Top 5 Objects to See

Spring Skywatching: The Top 5 Objects to See:

This spectacular image of the Omega Centauri cluster was captured by the VLT Survey Telescope at the European Southern Observatory's Paranal Observatory in Chile.

Credit: ESO/INAF-VST/OmegaCAM. Acknowledgement: A. Grado/INAF-Capodimonte Observatory


We're now more than halfway through spring. If you head outside during the evening hours and look skyward, you'll notice that the spring night sky is not as dazzling as the winter sky. Indeed, the brilliant stars associated with Orion and his retinue are all but gone, having disappeared into the sunset fires, not to reappear again until the predawn hours of mid-August.

Summertime will bring a brighter firmament compared to spring, with the most spectacular parts of the Milky Way in view. In contrast, at this time of the year, the Milky Way is all but invisible as it runs all around the horizon — and is usually hidden in the haze that lies close to the horizon.

Still, there are a few things that are worth looking for with binoculars or small telescopes in the spring. With the bright moon shifting out of the evening sky during this upcoming week, here is my subjective list of five objects that you might want to look for in the night sky. [Jupiter, Virgo Cluster and More: May 2016 Skywatching Video]

The Beehive, or Praesepe — The late Walter Scott Houston, who spent much of his life observing deep-sky objects, once wrote that this beautiful open star cluster is "symbolic of spring."

The Beehive lies within the dim constellation of Cancer (The Crab), which currently is located about one-third of the way up above the western horizon as darkness falls. Cancer, which is located between the stars Pollux and Castor in Gemini (The Twins) and the Sickle of Leo, is the least conspicuous of the 12 zodiacal constellations; some call Cancer the "empty space in the sky." Aside from being in the Zodiac, The Crab is probably only noteworthy because it contains one of the brightest galactic star clusters in the sky.

This cluster appears to the eye as a fuzzy patch of light, although, under exceptionally clear and dark skies, those with better-than-average vision can almost resolve the cluster using just their eyes. Binoculars will reveal the cluster's stellar nature. In fact, through good binoculars and low-power telescopes, this cluster appears brilliant, with no sharp boundaries.

But what to call it? Some astronomy texts speak of Praesepe (The Manger), referring to a trough in which feed for donkeys or other livestock is placed. The cluster was apparently first called Praesepe 20 centuries ago. Indeed, two nearby stars, Gamma and Delta Cancri, are also known as Asellus Borealis and Asellus Australis, the northern and southern donkey colts, and they appear to be feeding from a manger. Using his crude telescope in 1610, Galileo Galilei first resolved Praesepe into 36 stars. Using binoculars or a small telescope, observers can see more than 100 stars, and they seem to be spread out over an area that's about three times the apparent diameter of the moon. [Best Night Sky Events of May 2016 (Stargazing Maps)]

The cluster's relatively new moniker — "The Beehive" — apparently first appeared almost four centuries ago, perhaps when some anonymous person, upon seeing so many stars revealed in one of the first crude telescopes, exclaimed: "It looks just like a swarm of bees!"

Coma Berenices — Nearly overhead at around 10 p.m. local daylight time is the constellation that owes its name to a theft: Coma Berenices (Berenice's Hair). According to the story, Berenice was an Egyptian Queen in the third century B.C. who said that she would cut off her beautiful blonde hair if the gods would bring her husband home safely from a war.

After her husband returned, Berenice kept her word, cut off her hair and placed it in a temple. But the hair was stolen and the queen was very upset, until local priests managed to convince her that Zeus had taken her golden locks and placed them in the sky as a constellation to honor her sacrifice.

The Greek astronomer and mathematician Eratosthenes was among the first to notice this faint group of stars, which is a large, loose galactic cluster some 250 light-years away that appears as a faint shimmering patch of light on clear, moonless nights. In many ways, Coma Berenices seems to resemble a larger and more spread-out version of the famous Pleiades star cluster, which is also known as The Seven Sisters.

As a cluster, Coma Berenices is by far at its best in a pair of good binoculars. If you attempt to observe it with a high-powered telescope, the impression of a cluster will become totally lost because of the telescope's narrower field of view.

Algieba (The Lion's Mane) is in the curve or the blade of the Sickle of Leo, halfway up in the west-southwest sky at nightfall, and appears as a single star to the naked eye. However, as a moderate-size telescope (4 to 6 inches; 100- to 150-power magnification) will clearly show, Algieba is actually one of the most beautiful double stars in the sky.

The Lion's Mane should really be observed in twilight or bright moonlight to reveal the contrasting colors; one star has been said to be greenish, the other a delicate yellow. Other observers, however, have described different hues, such as pale yellow; orange; reddish and golden yellow; and even pale red and white! Check it out for yourself: What colors do you see?

Messier 3 — This is a beautiful and bright globular cluster, thought by many to be one of the most splendid in the sky. Messier 3 is located roughly midway between the brilliant orange star Arcturus and the third-magnitude star Cor Caroli in the constellation of Canes Venatici (The Hunting Dogs) and is currently soaring high in the south at around 10 p.m. local daylight time.

The cluster was first seen by Charles Messier in 1764 and was listed as No. 3 ("M3") in his famous catalog of deep-sky objects. In a good pair of binoculars, M3 looks like a fuzzy sixth-magnitude star. But with a small telescope, it appears as a circular, nebulous object. The outer parts can be resolved into stars with a 4-inch (10 centimeters) telescope. Larger instruments will bring out the cluster's full glory: An 8-inch (20 cm) telescope at 200 to 300 power reveals a beautiful ball of countless tiny stars, with streams of stars seemingly running out from all sides. The 19th-century British astronomer William H. Smyth wrote: "A noble object . . . it blazes splendidly toward the center, with many outliers." Perhaps 40,000 light-years away, the cluster's diameter is estimated to be 220 light-years.

Omega Centauri — In the southern constellation of Centaurus (The Centaur), we have the brightest and most splendid globular star cluster in the entire sky. Shining at a moderately dim magnitude +4, Omega Centauri is easy to glimpse with the naked eye under good sky conditions. It has, in fact, been known since ancient times (albeit as a star), and it appeared in the star catalog of Ptolemy more than 18 centuries ago. The cluster even received the Greek letter designation of Omega from German astronomer Johann Bayer, who lived from 1572 until 1625.

Though they look serene and silent from our vantage on Earth, stars are actually roiling balls of violent plasma. Test your stellar smarts with this quiz.

0 of 10 questions complete

Star Quiz: Test Your Stellar Smarts

Though they look serene and silent from our vantage on Earth, stars are actually roiling balls of violent plasma. Test your stellar smarts with this quiz.

0 of questions complete

Edmond Halley (of comet fame) called Omega a nebula in 1677, but it was not until 1835 that its true glory as a cluster was revealed by the 18.25-inch (46.4 cm) telescope that Sir John Herschel took to South Africa to survey the southern skies. Of Omega, Herschel wrote: "It is beyond all comparison the richest and largest object of its kind in the heavens; the stars are literally innumerable." Omega Centauri is about 17,000 light-years away and probably contains more than 1 million stars. It has an apparent diameter equal to the moon — 0.5 degrees — but only appears about half as large as that to the unaided eye.

In 1986, I saw Omega from Easter Island and the Andes of Chile. I brought with me a homemade 3.1-inch (7.9 cm) refracting telescope, and my views through that small instrument rivaledthe views I had of the Great Globular Cluster in Hercules through a much larger (12-inch, or 30-cm) telescope. What a pity that it's positioned so far south! If Omega were visible from farther north, it would be as popular and well known a sky object as the Great Orion Nebula and the Great Andromeda Galaxy. [See amazing photos of the Andromeda galaxy]

This week this splendid object is almost due south at 10 p.m. local daylight time. Theoretically, Omega Centauri can be seen from places as far north as New York or Philadelphia. But I can offer no encouragement to those residents of the Big Apple or City of Brotherly Love, because even if all of their streetlights were somehow to be extinguished and a fresh, clean Canadian air mass were to position itself directly over the Northeastern U.S., the thick haze that is perpetually evident along and near the horizon almost always hides Omega. Furthermore, even if one were to somehow get it in view through a telescope, the cluster would be robbed of its full glory.

To see this globular cluster properly, one should be no farther north than about 35 degrees north latitude, although a far better view can be obtained from the tropics, and especially near, or south of, the equator.

Editor's note: If you have an amazing skywatching photo you'd like to share with Space.com and our news partners for a possible story or image gallery, send images and comments in to managing editor Tariq Malik at spacephotos@space.com.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

METEOR - Fireball! Brilliant Meteor Streaks Over Northeastern US (Video)

Fireball! Brilliant Meteor Streaks Over Northeastern US (Video):

A huge fireball lit up the night sky over the northeastern United States Tuesday (May 17), sparking hundreds of reports by skywatchers lucky enough to have witnessed the dazzling meteor event. And if you want to go meteorite hunting, there may be a rich reward if you find a piece of the object.

Views of the fireball, including these awesome videos from police car dashcams in Maine and New York, show a brilliant streak across the late-night sky (it occured at 12:50 a.m. EDT, or 0450 GMT, on Tuesday). One particularly striking photo, included in this report, shows the fireball over the Piscataqua River in Portsmouth, New Hampshire, and was captured by a Portsmouthwebcam.com camera by Mike McCormack.

A dazzling fireball lights up the night sky over the Piscataqua River in Portsmouth, New Hampshire on May 17, 2016 in this stunning still image captured by a camera with Portsmouthwebcam.com and provided by Mike McCormack. The meteor was widely visible across the U.S. northeast and the Maine Mineral and Gem Museum is offering a reward for any meteorites from the event.

Credit: Mike McCormack portsmouthwebcam.com



According to the American Meteor Society (AMS), two separate objects entered the Earth's atmosphere. The AMS posted screenshots on its website showing the fireball streaking across the sky. The fireball was best visible in Maine, but nearly 700 reports also poured in from eight neighboring states and two Canadian provinces (Ontario and Quebec).  [Related: 5 Amazing Fireballs Caught on Video]

"Fireball detected by @westernu meteor cameras last night. Probable meteorite fall," planetary astronomer Peter Brown of Western University wrote on Twitter; his institution is based in London, Ontario, in Canada. In an interview he conducted later with CBC News, Brown estimated the fireball to be between a basketball and a shopping cart in size.

Fireball detected by @westernu meteor cameras last night. Probable meteorite fall https://t.co/gGuKSr8ldb #meteor pic.twitter.com/vlQgTDxqgm

— Peter Brown (@pgbrown) May 17, 2016

The Maine Mineral and Gem Museum of Bethel, Maine, offered $20,000 to anyone who can find the first chunk of the meteorite that weighs at least a kilogram (2.2 lbs.). That meteorite, once confirmed, will be put on display in the museum's Meteorite Hall.

"It's clear that the meteoroid entered Earth's atmosphere over Maine and its terminal explosion occurred about 30 kilometers [18.6 miles] west of Rangeley, Maine, in Franklin County," the museum wrote in the press release.

"This is an exciting opportunity, and we need the public's help," Museum Director Barbra Barrett said in the statement. Coincidentally, the museum is working on implementing a statewide network of cameras to capture fireballs and better pin down their locations. The network will be ready in 2017, the museum said.

This still image from a Plattsburgh Police Department car dashboard camera video shows the brilliant fireball over Plattsburgh, New York on May 17, 2016. The fireball was visible across the northeastern U.S. and parts of eastern Canada.

Credit: Plattsburgh Police Department


Fireballs occur when small objects (such as space rocks) break up high in the Earth's atmosphere. In this case, the fireball was too small to pose a threat to people or property. A much larger object caused broken glass and injuries after crashing down in Chelyabinsk, Russia, in February 2013.

A meteor is a small space rock that streaks through Earth's atmosphere as a dazzling fireball. Meteoroids are small objects in space, while any pieces that reach the Earth are called meteorites.

Most meteors burn up before reaching the ground. Periodically, the Earth goes through a dust cloud left behind by a comet, which produces a series of meteors known as a meteor shower.

Editor's note: If you captured an awesome photo of Tuesday's meteor and would like to share it with Space.com and our news partners for a story or gallery, send images and comments in to Managing Editor Tariq Malik at: spacephotos@space.com. If you believe you have found a piece of a meteorite from the fireball, you can contact the Maine Mineral and Gem Museum at (207) 824-3036 or bbarrett@mainemineralmuseum.org.

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