Saturday, April 9, 2016

Japan’s Black Hole Telescope Is In Trouble

Japan’s Black Hole Telescope Is In Trouble:



An artist's drawing of Japan's Hitomi observatory. Image Credit: JAXA/Akihiro Ikeshita


The Japanese Aerospace Exploration Agency (JAXA) has lost contact with its X-ray Astronomy Satellite Hitomi (ASTRO-H.) Hitomi was launched on February 17th, for a 3-year mission to study black holes. But now that mission appears to be in jeopardy.Hitomi is a collaboration between JAXA and NASA. Its mission was to investigate how galaxy clusters were formed and influenced by dark matter and dark energy, and to understand how super-massive black holes form and evolve at the center of galaxies. Hitomi was also to "unearth the physical laws governing extreme conditions in neutron stars and black holes," according to JAXA.Japan has managed two very short communications with Hitomi, but they were very brief, and JAXA has not been able to determine the nature of the problem. Now, JSpOC, the US Joint Space Operations Center, say they have detected debris in the vicinity of Hitomi, and in a press release this morning (March 29th), JAXA says "it is estimated that Hitomi separated to five pieces at about 10:42 a.m."Hitomi was going to be an important contribution to the fleet of space telescopes used by astrophysicists and cosmologists. It has a cutting edge instrument called the X-ray micro-calorimeter, which would have observed X-rays from space with the greatest sensitivity of any instrument so far. If all that is lost, it will be quite a blow.There's no definitive word yet on what exactly has happened to Hitomi. Japan is using ground stations in different parts of the world to try to communicate with their observatory. It's important to note that there is no agreement that the craft has broken apart. The press releases are translations from Japanese to English, so the exact meaning of "separated to five pieces" is unclear.It's possible that there was a small explosion of some sort, and that some debris from that explosion is in the vicinity of Hitomi. It's also possible that JAXA will re-establish communications with the craft as time goes on.Other observatories have suffered serious problems, and have eventually been brought back under control and completed their missions. The ESA/NASA Solar and Heliospheric Observatory (SOHO) suffered serious problems at the beginning of its mission in 1995, entering emergency mode 3 times before all contact was lost. Eventually, SOHO was brought under control, and what was supposed to be a 2-year mission has lasted 20.Universe Today will be following this story to see if Hitomi can be made operational. For readers wanting to know more about Hitomi's mission, read JAXA's excellent Hitomi press kit.

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Jupiter Just Got Nailed By Something

Jupiter Just Got Nailed By Something:



Austrian amateur astronomer Gerrit Kernbauer recorded these brief flash of light at Jupiter's limb on March 17, 2016. It was confirmed by another amateur video observation made by John McKeon of Ireland. Credit: Gerrit Kernbauer


Jupiter may be the biggest planet, but it sure seems to get picked on. On March 17, amateur astronomer Gerrit Kernbauer of Mödling, Austria, a small town just south of Vienna, was filming Jupiter through his 7.8-inch (200mm) telescope. 10 days later he returned to process the videos and discovered a bright flash of light at Jupiter's limb.https://www.youtube.com/watch?v=4LiL7RYG7ac Possible asteroid or comet impact on Jupiter on March 17"I was observing and filming Jupiter with my Skywatcher Newton 200 telescope, writes Kernbauer. "The seeing was not the best, so I hesitated to process the videos. Nevertheless, 10 days later I looked through the videos and I found this strange light spot that appeared for less than one second on the edge of the planetary disc. Thinking back to Shoemaker-Levy 9, my only explanation for this is an asteroid or comet that enters Jupiter's high atmosphere and burned up/explode very fast."The flash certainly looks genuine, plus we know this has happened at Jupiter before. Kernbauer mentions the first-ever confirmed reported comet impact that occurred in July 1994. Comet Shoemaker-Levy 9, shattered to pieces from strong tidal forces when it passed extremely close to the planet in 1992, returned two years later to collide with Jupiter — one fragment at a time.  21 separate fragments pelted the planet, leaving big, dark blotches in the cloud tops easily seen in small telescopes at the time.https://www.youtube.com/watch?v=qAJI4gqX3Zg&feature=iv&src_vid=vSfqvAEAZiQ&annotation_id=annotation_3442896559 Video of possible Jupiter impact flash by John McKeon on March 17, 2016Not long after Kernbauer got the word out, a second video came to light taken by John McKeon from near Dublin, Ireland using his 11-inch (28 cm) telescope. And get this. Both videos were taken in the same time frame, making it likely they captured a genuine impact.With the advent of cheap video cameras, amateurs have kept a close eye on the planet, hoping to catch sight of more impacts. Two factors make Jupiter a great place to look for asteroid / comet collisions. First, the planet's strong gravitational influence is able to draw in more comets and asteroids than smaller planets. Second, its powerful gravity causes small objects to accelerate faster, increasing their impact energy.According to Bad Astronomy blogger Phil Plait: "On average (and ignoring orbital velocity), an object will hit Jupiter with roughly five times the velocity it hits Earth, so the impact energy is 25 times as high." Simply put, it doesn't take something very big to create a big, bright bang when it slams into Jove's atmosphere.It wasn't long before the next whacking. 15 years to be exact.On July 19, 2009, Australian amateur Anthony Wesley was the first to record a brand new dark scar near Jupiter's south pole using a low-light video camera on his telescope. Although no one saw or filmed the impact itself, there was no question that the brand new spot was evidence of the aftermath: NASA's Infrared Telescope Facility at Mauna Kea picked up a bright spot at the location in infrared light.https://www.youtube.com/watch?v=0AXSA9rZzrU Jupiter impact event recorded by Christopher Go on June 3, 2010Once we started looking closely, the impacts kept coming. Wesley hit a second home run on June 3, 2010 with video of an impact flash, later confirmed on a second video made by Christopher Go. This was quickly followed by another flash filmed by Japanese amateur astronomer Masayuki Tachikawa on August 20, 2010.https://www.youtube.com/watch?v=jIkr86xKcwQ Jupiter impact flash on August 20, 2010 by Masayuki TachikawaPrior to this month's event, amateur Dan Petersen visually observed a impact flash lasting 1-2 seconds in his 12-inch (30.5 cm) scope on September 10, 2012, which was also confirmed on webcam by George Hall.Keep 'em comin'!

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ALMA Captures Never-Before-Seen Details of Protoplanetary Disk

ALMA Captures Never-Before-Seen Details of Protoplanetary Disk:



ALMA’s best image of a protoplanetary disk to date. This picture of the nearby young star TW Hydrae reveals the classic rings and gaps that signify planets are in formation in this system. Credit: S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)


TW Hydrae is a special star. Located 175 light years from Earth in the constellation Hydra the Water Snake, it sits at the center of a dense disk of gas and dust that astronomers think resembles our solar system when it was just 10 million years old. The disk is incredibly clear in images made using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which employs 66 radio telescopes sensitive to light just beyond that of infrared.  Spread across more than 9 miles (15 kilometers), the ALMA array acts as a gigantic single telescope that can make images 10 times sharper than even the Hubble Space Telescope.Astronomers everywhere point their telescopes at TW Hydrae because it's the closest infant star in the sky. With an age of between 5 and 10 million years, it's not even running on hydrogen fusion yet, the process by which stars convert hydrogen into helium to produce energy. TW Hydrae shines from the energy released as it contracts through gravity. Fusion and official stardom won't begin until it's dense enough and hot enough for fusion to fire up in its belly.

We see most protoplanetary disks at various angles, but TW's has a face-on orientation as seen from Earth, giving astronomers a rare, undistorted view of the complete disk around the star. The new images show amazing detail, revealing a series of concentric bright rings of dust separated by dark gaps. There's even indications that a planet with an Earth-like orbit has begun clearing an orbit.
"Previous studies with optical and radio telescopes confirm that TW Hydrae hosts a prominent disk with features that strongly suggest planets are beginning to coalesce," said Sean Andrews with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, USA and lead author on a paper published today in the Astrophysical Journal Letters.
Pronounced gaps that show up in the photos above are located at 1.9 and 3.7 billion miles (3-6 billion kilometers) from the central star, similar to the average distances from the sun to Uranus and Pluto in the solar system. They too are likely to be the results of particles that came together to form planets, which then swept their orbits clear of dust and gas to sculpt the remaining material into well-defined bands. ALMA picks up the faint emission of submillimeter light emitted by dust grains in the disk, revealing details as small as 93 million miles (150 million kilometers) or the distance of Earth from the sun
"This is the highest spatial resolution image ever of a protoplanetary disk from ALMA, and that won't be easily beaten in the future!" said Andrews.
Earlier ALMA observations of another system, HL Tauri, show that even younger protoplanetary disks — a mere 1 million years old — look remarkably similar.  By studying the older TW Hydrae disk, astronomers hope to better understand the evolution of our own planet and the prospects for similar systems throughout the Milky Way.
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Andromeda’s First Spinning Neutron Star Found

Andromeda’s First Spinning Neutron Star Found:



Andromeda's spinning neutron star. Though astronomers think there are over 100 million of these objects in the Milky Way, this is the first one found in Andromeda. Image: ESA/XMM Newton.


On a clear night, away from the bright lights of a city, you can see the smudge of the Andromeda galaxy with the naked eye. With a backyard telescope, you can take a good look at the Milky Way's sister galaxy. With powerful observatories, it's possible to see deep inside Andromeda, which is what astronomers have been doing for decades.Now, astronomers combing through data from the ESA's XMM Newton space telescope have found something rare, at least for Andromeda; a spinning neutron star. Though these objects are common in the Milky Way, (astronomers think there are over 100 million of them) this is the first one discovered in Andromeda.A neutron star is the remnant of a massive star that went supernova. They are the smallest and most dense stellar objects known. Neutron stars are made entirely of neutrons, and have no electrical charge. They spin rapidly, and can emit electromagnetic energy.If the neutron star is oriented toward Earth in just the right way, we can detect their emitted energy as pulses. Think of them as lighthouses, with their beam sweeping across Earth. The pulses of energy were first detected in 1967, and given the name pulsar." We actually discovered pulsars before we knew that neutron stars existed.Many neutron stars, including this one, exist in binary systems, which makes them easier to detect. They cannibalize their companion star, drawing gas from the companion into their magnetic fields. As they do so, they emit high energy pulses of X-ray energy.The star in question, which astronomers, with their characteristic flair for language, have named 3XMM J004301.4+413017, spins rapidly: once every 1.2 seconds. It's neighbouring star orbits it once every 1.3 days. While these facts are known, a more detailed understanding of the star will have to wait for more analysis. But 3XMM J004301.4+413017 does appear to be an exotic object.“It could be what we call a ‘peculiar low-mass X-ray binary pulsar’ – in which the companion star is less massive than our Sun – or alternatively an intermediate-mass binary system, with a companion of about two solar masses,” says Paolo Esposito of INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, Milan, Italy. “We need to acquire more observations of the pulsar and its companion to help determine which scenario is more likely.”“We’re in a better position now to uncover more objects like this in Andromeda, both with XMM-Newton and with future missions such as ESA’s next-generation high-energy observatory, Athena,” added Norbert Schartel, ESA’s XMM-Newton project scientist.This discovery is a result of EXTraS, a European Project that combs through XMM Newton data. “EXTraS discovery of an 1.2-s X-ray pulsar in M31” by P. Esposito et al, is published in the Monthly Notices of the Royal Astronomical Society, Volume 457, pp L5-L9, Issue 1 March 21, 2016.

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Don’t Want Aliens Dropping By? Engage Laser Cloaking Device

Don’t Want Aliens Dropping By? Engage Laser Cloaking Device:



Lasers like this one, at the VLT in Paranal, help counteract the blurring effect of the atmosphere. Powerful arrays of much larger lasers could hide our presence from aliens. (ESO/Y. Beletsky)


Of course we all know that aliens want to take over Earth. It's in all the movies. And after they take over, they could do whatever they want to us puny, weak Earthlings. Enslavement? Yup. Forced breeding programs? Sure. Lay eggs in our bellies and consume our guts for their first meal? Why not.But here at Universe Today, we're science-minded types. We love the science fiction, but don't take it too seriously. But someone we do take seriously when he has something to tell us is Stephen Hawking. And when he warned us that aliens might want to conquer and colonize us, it lent gravity to the whole discussion around contact with aliens. Should we reach out to alien civilizations? Will we be safe if they find us? Or should we try to conceal our presence?If we choose concealment, then a new paper from two astronomers at New York's Columbia University have good news for humanity. The authors of the paper, Professor David Kipping and graduate student Alex Teachey, say that lasers could be used to hide Earth from alien prying eyes.At the heart of this whole idea are transits. When a planet passes in between its star and a distant observer, the star's light is dimmed, and that's called a transit. This is how the Kepler spacecraft detects exo-planets, and it's been remarkably successful. If alien species are using the same method, which makes sense, then Earth would be easily detectable in the Sun's habitable zone.According to Kipping and Teachey, lasers could be used to mask this effect. A 30 MW laser would be enough to counter the dimming effect of Earth's transit in front of the Sun. And it would only need to be turned on for 10 hours, once every year, since that's how long Earth's transit takes.But that would only take care of the dimming effect in visible light. To counter-act the transit dimming across the whole electromagnetic spectrum would require much more energy: a 250 MW cloak of lasers tuned all across the spectrum. But there might be a middle way.According to an interview with the paper's authors in Science Daily, it might take only 160 MW of lasers to mask biological signatures in the atmosphere. Any prying alien eyes would not notice that life had ever come into being on Earth.Should we decide that we do indeed want to be colonized, or forced to take part in breeding programs, or be enslaved, then the same system of lasers could be used to amplify the transit effect. This would make it easier, rather than harder, for aliens to detect us. In fact, according to the authors, these lasers could even be used to communicate with aliens, by transmitting information.Of course, there's one other element to all this. For this to work, we have to know where to aim the lasers, which means we have to know where the alien civilization is. And if we're worried about them coming to get us, they will have more advanced technology than us. And if they have more advanced technology than us, they will for sure already have laser cloaking like the type talked about here.So who'll be the first to blink, and turn off their laser cloaking and allow detection?You first, aliens.

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The Constellation Ara

The Constellation Ara:



The Ara Constellation, one of the 88 recognized by the IAU. Credit: jedi-counsel.net


Welcome back to another Constellation Friday, another series dedicated to the memory of the late, great Tammy Plotner. And today, we take a look at Ara, one of the classic southern constellation.In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) released one of the most influential books in the history of astronomy. Known as the Almagest, this book included the 48 then-known constellation into a system of cosmology that would remain influential for over a thousand years. Among the 48 constellations listed in this book was Ara, a constellation in the southern sky that is crossed by the Milky Way.Also known as "The Altar", Ara is best visible the month of July in the southern hemisphere (latitudes between +25° and -90°). It is bordered by Corona Australis, Scorpius, Norma, Triangulum Australe, Apus, Pavo and Telescopium, and its primary stars form a notable asterism which seems to represent the figure H. Ara belongs to the Hercules family of constellations, together with Aquila, Centaurus, Corona Australis, Corvus, Crater, Crux, Cygnus, Hercules, Hydra, Lupus, Lyra, Ophiuchus, Sagitta, Scutum, Serpens, Sextans, Triangulum Australe, and Vulpecula.

Name and Meaning:

In Greek mythology, Ara represented the altar used by Zeus and other Greek gods to swear a vow of allegiance before they went to war against Cronus and the Titans. According to legends, it is believed the Cyclopes originally built the altar as a place to sacrifice to the Olympian gods. It was also upon this altar that Centaurus the centaur sacrificed Lupus the wolf.The altar was normally depicted as upside down, but sometimes it was shown as erect with the smoke drifting away as the Milky Way. Some legends have it that a child was once sacrificed, whereupon Zeus then turned the child into a wolf and immortalized it in stars forming the constellation of Lupus. In another Greek myth, Ara represents the altar of King Lycaon of Arcadia.

Notable Features:

Since Ara contains part of the Milky Way to the south of Scorpius, it therefore has rich star fields. Its major stars include Alpha Arae, a blue-white hued star of magnitude 2.8 that is the closest of Ara's stars, located approximately 242 light-years from Earth. Beta Arae, its brightest star, is an orange-hued supergiant of magnitude 2.8, which is located 600 light-years from Earth.Gamma Arae is a blue-hued supergiant of magnitude 3.3, located 1140 light-years from Earth, while Delta Arae has a blue-white hue, a magnitude of 3.6, and is located 187 light-years from Earth. Zeta Ara is an orange-hued giant of magnitude 3.1, and is located 574 light-years from Earth. Ara is also home to several Deep Sky Objects.For instance, the northwest corner of Ara is crossed by the galactic plane of the Milky Way, and therefore contains several open clusters and diffuse nebulae. For instance, there is the NGC 6397 globular cluster, which is the brightest in the Ara constellation. It is also one of the closest to our Solar System, being 6,500 light-years from Earth.Ara also contains Westerlund 1, a super star cluster that contains the red supergiant Westerlund 1-26, one of the largest stars known. Ara is also home to two spiral galaxies - NGC 6215 and NGC 6221 - which are visible near the star Eta Arae.

History of Observation:

Ara was first described by Ptolemy and was included in the 48 constellations listed in the Almagest. Today, it is one of the 88 constellations that is recognized by the International Astronomical Union (IAU).

Finding Ara:

For those using binoculars,Ara can be located by looking for Beta Arae, the brightest star of the constellation. Beta is an orange class K (K3) supergiant with a luminosity of about 4600 times that of the Sun. It also rotates on its axis at about 5.4 kilometers per second at it equator, it takes around 2.33 years for Beta to make a full rotation. As a result, any sunspots on Beta would be visible for a very long time! Beta is also an unusual "super metal-rich" star, with high iron content, over three times more than that of Sol.Then there's a Alpha Arae, a spectroscopic binary that is a hot, blue, luminous class B (B2) dwarf star. Just because it's called a dwarf doesn't mean it's small, though. Alpha is still about 8 times the mass of our own Sun. It's a very special star, too. It's known as "Be" (B-emission") star, who's emission lines come from from hydrogen located in a thick disk that surrounds it. Alpha is a "shell star" and the disk is nearly edge on, obscuring part of the star, and superimposing absorptions on the star's spectrum.Now move on to R Arae - a variable star. Its magnitude ranges from 6 to 7.1 in a period of 4.4 days. R Arae or HD 149730 is eclipsing binary of Algol type and well worth watching for its quick changes!Need a little more sparkle in your binoculars? Then head on to NGC 6193. At a distance of only 7200 light years away, it's one of the nearest globular clusters to our solar system and on a clear dark night, it can even be seen with the unaided eye! Binoculars or a small telescope show it as a misty patch with a diameter close to 20 arc minutes. Or try open cluster NGC 6193 located eight degrees west of Alpha Arae. This widely scattered group will show about 30 stars, the brightest of which is about 6th magnitude.For telescopes, the binary star Gamma Arae offers a great opportunity for stargazing. Located 1140 light years from Earth, this 3.5 and 10th magnitude pair is separated by 18 arc seconds and was found to be binary by John Herschel in 1835. The primary component, Gamma Arae A, is a blue-white B-type supergiant and the companion Gamma Arae B, is a white A-type main sequence dwarf star.Now locate 4th magnitude Epsilon1 Arae and go 1.5 degrees west for NGC 6208. This 7.5 combined magnitude open cluster presents a nice challenge for the telescope! Three new spectroscopic binaries were discovered recently among the red giants of NGC 6208. It contains about 60 stars and the brightest is about magnitude 10. We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?What Is The Zodiac?, and Zodiac Signs And Their Dates.Be sure to check out The Messier Catalog while you’re at it!For more information, check out the IAUs list of Constellations. and the Students for the Exploration and Development of Space page on Apus and Constellation Families.

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Is Planet X Linked to Mass Extinctions?

Is Planet X Linked to Mass Extinctions?:



This artwork shows a rocky planet being bombarded by comets. Image credit: NASA/JPL-Caltech


Planet Nine, the massive orb proposed to explain the clustered orbits of a half dozen remote Kuiper Belt asteroids, may have a darker side. Periodic mass extinctions on Earth, as indicated in the global fossil record, could be linked to the hypothetical planet according to research published by Daniel Whitmire, a retired professor of astrophysics and faculty member of the University of Arkansas Department of Mathematical Sciences.Planet Nine is estimated to be 10 times more massive than Earth and currently orbiting about 1,000 times farther away from the Sun. Astronomers have been searching for a potential large planet — for years called "Planet X" — that might be implicated in a handful of major mass extinctions over the past 500 million years. During those times, between 50 and more than 90% of species on Earth perished in a geological heartbeat. The worst, dubbed the Permian-Triassic event or the Great Dying, occurred 250 million years ago and saw the disappearance of more than 90% of the planet's life in a geological heartbeat.Whitmire and his colleague, John Matese, first published research on the connection between Planet X and mass extinctions in the journal Nature in 1985 while working as astrophysicists at the University of Louisiana at Lafayette. They proposed that perturbations from a 10th planet (Pluto was considered a planet back then) could fling a shower of comets from the Kuiper Belt beyond Neptune in Earth's direction every 28 million years in sync with recorded mass extinctions.Two other ideas also proposed at the time they wrote their paper — a sister star to the Sun and vertical oscillations of the Sun as it orbits the galaxy — have since been ruled out because the timing is inconsistent with the extinction record. Only Planet X remained as a viable theory, and it's now gaining renewed attention.https://www.youtube.com/watch?v=hSXNE0pNtr8 Neil deGrasse Tyson explains precession and Mercury's orbitWhitmire and Matese proposed that as Planet X orbits the Sun, its tilted orbit slowly rotates, causing the location of its perihelion (closest point to the Sun) to slowly precess or shift position along its orbit instead of remaining in the same place. Every planet precesses, so no surprises here.But location can make a huge difference. The team proposed that Planet X's slow orbital gyration directs it into the Kuiper Belt approximately every 27 million years, knocking comets into the inner Solar System. The dislodged comets not only smash into the Earth, they also vaporize and break apart in the inner Solar System as they get nearer to the Sun, reducing the amount of sunlight that reaches the Earth. Add it up, and you have a recipe for cyclic destruction.One thing to keep in mind is that their research led them to conclude that Planet X was only 5 times as massive as Earth and 100 times farther from the Sun. This doesn't jive with the size and mass particulars for Planet Nine inferred by researchers Konstantin Batygin and Michael E. Brown at Caltech earlier this year, but until someone tracks the real planet down, there's room for argument.Comet and asteroid showers are often cited as possible bad guys in extinction episodes. And why not? We have hard evidence of the asteroid impact that sealed the dinosaurs's fate 65 million years ago and have seen some six impacts at Jupiter since 1994. It's cosmic billiards out there folks, and the game's not over.

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Ten Interesting Facts About Jupiter

Ten Interesting Facts About Jupiter:



Jupiter's Red Spot, seen by Voyager 1. Image credit: NASA/JPL


Jupiter was appropriately named after the king of the gods. It's massive, has a powerful magnetic field, and more moons that any planet in the Solar System. Though it has been known to astronomers since ancient times, the invention of the telescope and the advent of modern astronomy has taught us so much about this gas giant.In short, there are countless interesting facts about this gas giant that many people just don't know about. And we here at Universe Today have taken the liberty of compiling a list of ten particularly interesting ones that we think will fascinate and surprise you. Think you know everything about Jupiter? Think again!

1. Jupiter Is Massive:

It's no secret that Jupiter is the largest planet in the Solar System. But this description really doesn't do it justice. For one, the mass of Jupiter is 318 times as massive as the Earth. In fact, Jupiter is 2.5 times more massive than all of the other planets in the Solar System combined. But here's the really interesting thing...If Jupiter got any more massive, it would actually get smaller. Additional mass would actually make the planet more dense, which would cause it to start pulling it in on itself. Astronomers estimate that Jupiter could end up with 4 times its current mass, and still remain about the same size.

2. Jupiter Cannot Become A Star:

Astronomers call Jupiter a failed star, but that's not really an appropriate description. While it is true that, like a star, Jupiter is rich in hydrogen and helium, Jupiter does not have nearly enough mass to trigger a fusion reaction in its core. This is how stars generate energy, by fusing hydrogen atoms together under extreme heat and pressure to create helium, releasing light and heat in the process.This is made possible by their enormous gravity. For Jupiter to ignite a nuclear fusion process and become a star, it would need more than 70 times its current mass. If you could crash dozens of Jupiters together, you might have a chance to make a new star. But in the meantime, Jupiter shall remain a large gas giant with no hopes of becoming a star. Sorry, Jupiter!https://youtu.be/v9HtCAHv54E

3. Jupiter Is The Fastest Spinning Planet In The Solar System:

For all its size and mass, Jupiter sure moves quickly. In fact, with an rotational velocity of 12.6 km/s (~7.45 m/s) or 45,300 km/h (28,148 mph), the planet only takes about 10 hours to complete a full rotation on its axis. And because it's spinning so rapidly, the planet has flattened out at the poles a little and is bulging at its equator.In fact, points on Jupiter's equator are more than 4,600 km further from the center than the poles. Or to put it another way, the planet's polar radius measures to 66,854 ± 10 km (or 10.517 that of Earth's), while its diameter at the equator is 71,492 ± 4 km (or 11.209 that of Earth's). This rapid rotation also helps generate Jupiter's powerful magnetic fields, and contribute to the dangerous radiation surrounding it.

4. The Clouds On Jupiter Are Only 50 km Thick:

That's right, all those beautiful whirling clouds and storms you see on Jupiter are only about 50 km thick. They're made of ammonia crystals broken up into two different cloud decks. The darker material is thought to be compounds brought up from deeper inside Jupiter, and then change color when they reacted with sunlight. But below those clouds, it's just hydrogen and helium, all the way down.

5. The Great Red Spot Has Been Around For A Long Time:

The Great Red Spot on Jupiter is one of its most familiar features. This persistent anticyclonic storm, which is located south of its equator, measures between 24,000 km in diameter and 12–14,000 km in height. As such, it is large enough to contain two or three planets the size of Earth's diameter. And the spot has been around for at least 350 years, since it was spotted as far back as the 17th century.The Great Red Spot was first identified in 1665 by Italian astronomer Giovanni Cassini. By the 20th century, astronomers began to theorize that it was a storm, one which was created by Jupiter's turbulent and fast-moving atmosphere. These theories were confirmed by the Voyager 1 mission, which observed the Giant Red Spot up close in March of 1979 during its flyby of the planet.However, it appears to have been shrinking since that time. Based on Cassini's observations, the size was estimated to be 40,000 km in the 17th century, which was almost twice as large as it is now. Astronomers do not know if or when it will ever disappear entirely, but they are relatively sure that another one will emerge somewhere else on the planet.

6. Jupiter Has Rings:

When people think of ring systems, Saturn naturally comes to mind. But in truth, both Uranus and Jupiter have ring systems of their own. Jupiter's were the third set to be discovered (after the other two), due to the fact that they are particularly faint. Jupiter's rings consist of three main segments - an inner torus of particles known as the halo, a relatively bright main ring, and an outer gossamer ring.These rings are widely believed to have come from material ejected by its moons when they're struck by meteorite impacts. In particular, the main ring is thought to be composed of material from the moons of Adrastea and Metis, while the moons of Thebe and Amalthea are believed to produce the two distinct components of the dusty gossamer ring.This material fell into orbit around Jupiter (instead of falling back to their respective moons) because if Jupiter's strong gravitational influence. The ring is also depleted and replenished regularly as some material veers towards Jupiter while new material is added by additional impacts.

7. Jupiter's Magnetic Field Is 14 Times Stronger Than Earth's:

Compasses would really work on Jupiter. That's because it has the strongest magnetic field in the Solar System. Astronomers think the magnetic field is generated by the eddy currents - i.e. swirling movements of conducting materials - within the liquid metallic hydrogen core. This magnetic field traps particles of sulfur dioxide from Io's volcanic eruptions, which producing sulfur and oxygen ions. Together with hydrogen ions originating from the atmosphere of Jupiter, these form a plasma sheet in Jupiter's equatorial plane.Farther out, the interaction of the magnetosphere with the solar wind generates a bow shock, a dangerous belt of radiation that can cause damage tos spacecraft. Jupiter's four largest moons all orbit within the magnetosphere, which protects them from the solar wind, but also make the likelihood of establishing outposts on their surface problematic. The magnetosphere of Jupiter is also responsible for intense episodes of radio emission from the planet's polar regions.

8. Jupiter Has 67 Moons:

As of the penning of this article, Jupiter has a 67 confirmed and named satellites. However, it is estimated that the planet has over 200 natural satellites orbiting it. Almost all of them are less than 10 kilometers in diameter, and were only discovered after 1975, when the first spacecraft (Pioneer 10) arrived at Jupiter.However, it also has four major moons, which are collectively known as the Galilean Moons (after their discovered Galileo Galilei). These are, in order of distance from Jupiter, Io, Europa, Ganymede, and Callisto. These moons are some of the largest in the Solar System, with Ganymede being the largest, measuring 5262 km in diameter.

9. Jupiter Has Been Visited 7 Times By Spacecraft:

Jupiter was first visited by NASA's Pioneer 10 spacecraft in December 1973, and then Pioneer 11 in December 1974. Then came the Voyager 1 and 2 flybys, both of which happened in 1979. This was followed by a long break until Ulysses arrived in February 1992, followed by the Galileo space probe in 1995. Then Cassini made a flyby in 2000, on its way to Saturn. And finally, NASA's New Horizons spacecraft made its flyby in 2007. This was the last mission to fly past Jupiter, but it surely won't be the last.

10. You Can See Jupiter With Your Own Eyes:

Jupiter is the third brightest object in the Solar System, after Venus and the Moon. Chances are, you saw Jupiter in the sky, and had no idea that's what you were seeing. And here at Universe Today, we are in the habit of letting readers know when the best opportunities for spotting Jupiter in the night sky are.Chances are, if you see a really bright star high in the sky, then you're looking at Jupiter. Get your hands on a pair of binoculars, and if you know someone with a telescope, that's even better. Using even modest magnification, you might even spot small specks of light orbiting it, which are its Galilean Moons. Just think, you'll be seeing precisely what Galileo did when he gazed at the planet in 1610.We have written many interesting articles about Jupiter here at Universe Today. Here's The Gas Giant Jupiter, How Strong Is Jupiter's Gravity?, Does Jupiter Have A Solid Core?, and Jupiter Compared To Earth.And here are 10 Interesting Facts About Planet Earth, and 1o Interesting Facts About Mars.For more information, check out the Hubblesite's News Releases about Jupiter, and NASA's Solar System Exploration.We've also recorded an entire show just on Jupiter for Astronomy Cast. Listen to it here, Episode 56: Jupiter, and Episode 57: Jupiter's Moons.

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Huygens Spots Methane Fog On Saturn’s Moon Titan

Huygens Spots Methane Fog On Saturn’s Moon Titan:



Titan's dense, hydrocarbon rich atmosphere remains a focal point of scientific research. Credit: NASA


Titan is a moon shrouded in mystery. Despite multiple flybys and surface exploration conducted in the past few decades, this Cronian moon still manages to surprise us from time to time. In addition to having a dense atmosphere rich in hydrocarbons, which scientists believe may be similar to what Earth's own atmosphere was like billions of years ago, it appears that methane is to Titan what water is to planet Earth.In addition, methane fog was also observed by the Cassini space probe back in 2009 as it conducted a flyby of Titan. But recent findings by a team of researchers from York University indicates that the Huygens lander also detected fog during its descent towards the surface in 2005. This evidence, combined with the data obtained by Cassini, have helped to shed light on the weather patterns of this mysterious moon.In a paper that appeared in arXiv on March 14th, Dr. Christina Smith - a postdoctoral researcher from York University's Center for Research in Earth and Space Sciences (CRESS) - described how the Huygens probe's Side Looking Imager (SLI) obtained information that has since been analyzed to identify potential atmospheric features. These features show that Titan experiences meteorological phenomena which were not previously known.In total, the team looked over 82 SLI images, which were all taken after the lander reached the surface. These were then calibrated, processed and examined for signs of atmospheric features. Of these, six showed evidence of an extended horizontal feature that differed in radiance from what was predicted at higher and lower regions. No other discernible features were detected.The team concluded that this feature most likely originated from the presence of a fog bank close to the horizon that rose and fell during the period of observation. This indicated that it had recently rained in the area, which was a rather surprising find. Much like the observations made in 2009, the presence of methane fog shows that Titan has an active methane hydrological cycle.In essence, this means that methane on Titan is subject to the same transfer process as water is here on Earth. Basically, liquid methane on the surface evaporates and is exchanged with the atmosphere, where it condenses to form fog banks and rain clouds. As Christina Smith told Universe Today via email:

"We initially set out to see if we could see features such as clouds from the Huygens SLI data, but the features we found don't seem to be consistent with clouds and more likely are caused by a fog bank rising and falling over the time of observation. Fog had been seen before from orbit but never from the surface of Titan - this is what makes this work so exciting. This work is also a great example of how new insights and new findings can be made from "older" data sets."
Looking over this old data for the sake of making new discoveries was made possible, in part, because of the ongoing investigations conducted by Martian rovers and their respective science teams. Brittney Cooper - an undergraduate research assistant at CRESS and the second author of the paper - explained via email:

"We applied a technique of image analysis developed by Mark Lemmon for use with the Mars Exploration Rovers that was adapted by John Moores for use on the Mars Phoenix lander mission. This analysis method allowed the faint, barely observable atmospheric features captured by the Huygens' probe Side Looking Imager (SLI) on Titan to be amplified and more easily discerned."
For years, scientists have understood that on Titan, methane is analogous to water. It exists in liquid form (especially around the north pole where several large methane lakes exist), and in gaseous form in the atmosphere. However, what they did not know was whether or not there was an active cycle, where liquid methane on the surface was replenished through evaporation, condensation, and rain.But this evidence, combined with the Cassini probe data, shows that on Titan, there is an active transfer process between the liquid methane and the atmospheric methane. And where atmospheric humidity reaches 100%, methane fogs will form. Just the latest in a long line of fascinating discoveries to emerge from this mysterious moon!

Further Reading: arXiv.com
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GRAIL Data Points To Possible Lava Tubes On The Moon

GRAIL Data Points To Possible Lava Tubes On The Moon:



Map showing variations in the lunar gravity field, as measured by NASA's Gravity Recovery and Interior Laboratory (GRAIL) . Credit: NASA/JPL-Caltech/MIT/GSFC


For years, scientists have been hunting for the stable lava tubes that are believed to exist on the Moon. A remnant from the Moon's past, when it was still volcanically active, these underground channels could very well be an ideal location for lunar colonies someday. Not only would their thick roofs provide naturally shielding from solar radiation, meteoric impacts, and extremes in temperature. They could also be pressurized to create a breathable environment.But until now, evidence of their existence has been inferred from surface features such as sinuous rilles - channel-like depressions that run along the surface that indicate the presence of subterranean lava flows - and holes in the surface (aka. "skylights"). However, recent evidence presented at the 47th Lunar and Planetary Science Conference (LPSC) in Texas indicates that one such stable lava tube could exist in the once-active region known as Marius Hills.

The presentation was led by Rohan Sood, a graduate research assistant from the department of Aeronautics and Astronautics at Purdue University in Indiana. For some time now, Sood and his research colleagues have been examining data obtained from NASA's twin Gravity Recovery and Interior Laboratory (GRAIL) mission in order to get a better sense of what the Moon's interior looks like.

Launched in 2011, the purpose of the GRAIL mission - which consists of two orbiters, Ebb and Flow, working in tandem - was to map the Moon's gravity with extreme precision. Over time, the information it gathered has provided scientists with the opportunity to gain a better understanding of the Moon's subsurface features, particularly the buried lava tubes that are believed to exist.

In 2009, the Japan Aerospace Exploration Agency's (JAXA) Kaguya spacecraft (aka. Selene) confirmed the presence of a skylight in the Marius Hills region, which has since come to be known as the "Marius Hole". In 2011, it was photographed in more detail by the Lunar Reconnaissance Orbiter, which showed that it was approximately 65 meters wide and 80 meters deep. The fact that this hole sat between two rilles indicated that it was evidence that lava once flowed beneath the region.Using the GRAIL gravity data that was collected at different altitudes, the Purdue team went about assessing the presence and extent of ancient lava tubes beneath the surface of Marius Hills. What they determined was rather interesting. As Sood told Universe Today via email:

"Thanks to NASA's GRAIL mission, we now have derived the lunar gravity field to an unprecedented resolution and accuracy. The data allows us to dig below the lunar surface, with our objective being to recognize signatures that may correspond to those of empty lava tubes."
To assess the possibility of lava tubes, Sood and his team relied on a two-tiered strategy of gradiometry and cross-correlationon specific regions. Whereas gradiometry calculates the gravitational potential from a spherical harmonics data set, cross-correlation utilizes the individual track data based on the relative acceleration between the two spacecraft as they move along their respective orbits.Much like Earth, the moon’s gravitational field is affected by masses below the surface. "Any gravitational field is affected by the density of material," said Sood. "If you are flying the spacecraft over a block of dense material, it will experience an increase in gravitational pull in contrary to flying over a lava tube void, in which case there will be a decrease in gravitational attraction experienced by the spacecraft."Where the Marius Hole is located, the team spotted a gravitational signature that was indicative of a subsurface cavity. But that was not all. Distributed across the Moon's near side, Sood and his colleagues also noted that the GRAIL data indicated at least ten signatures that could resemble lava tubes. All are located near the dark areas left by ancient volcanic seas, with some measuring more than 100 km long and several kilometers wide.Naturally, there are some doubts as to whether or not the readings are indicative of actual lava tubes. As the team indicated in their paper - "Detection of Buried Empty Lunar Lava Tubes Using Grail Gravity Data", which contains the findings they presented at the 47th Lunar and Planetary Science Conference - the structures they were looking for were similar or smaller in scale than the resolution of the gravity data.As a result, it was difficult to determine whether or not the signals they spotted were in fact a sign of an underground recess, or a numerical artifact in the data. Because of this, proving the existence of stable, subsurface lava tubes will require a next-generation mission, one that has instruments which will be able to penetrate the lunar surface and confirm the presence of recesses."[W]e have to remember that gravity is non-unique," Sood added, "which means, in order to support our findings and to add to our ongoing efforts, our team is considering a ground penetrating radar that will probe the lunar subsurface from orbit. The goal of the radar would be to confirm the presence of the potential lava tube candidates that we have detected so far, and in addition, look for smaller lava tubes that were beyond the resolution of GRAIL gravity data."One possibility is a concept Sood and his colleagues have proposed themselves - the Lunar Advanced Radar Orbiter For Subsurface Sounding (LAROSS) mission. Designed to build upon the success of the GRAIL mission, the concept calls for a spacecraft equipped with ground-penetrating radar to conduct a sounding mission that would potentially confirm both the presence and size of the Moon's buried empty lava tubes.This is not the first time that researchers from Purdue have presented a case for stable lunar lava tubes at the Lunar and Planetary Science Conference. Last year, at the 46th annual conference, a research team from the Department of Earth, Atmospheric and Planetary Sciences (which included Sood) used data similarly provided by the GRAIL mission to determine that some lunar lava tubes could measure up to 1 km in width.These latest findings, which not only produced more evidence of such subsurface spaces, but indicated that they may be even larger than previously expected, is good news for advocates of lunar settlement. It is also worth noting that since it began surveying the moon, the Lunar Reconnaissance Orbiter has imaged over 200 pits that show signs of being skylights.Each of these holes could lead to subsurface voids or caverns, which range in diameter from about 16 feet (5 meters) to more than 2,950 feet (900 m). Assuming that just a fraction of these lead to underground tubes that are large enough to house an entire Earth city, there would be no shortage of possible settlement sites if and when it comes time to colonize the Moon.After all, one of the biggest challenges in settling on a body where there is no atmosphere to speak of is creating a sturdy and airtight protective shelter. Another major challenge is shielding the occupants of these and other shelters from incoming cosmic rays and solar radiation since their is no ozone layer to filter them out.Where better than in an underground tunnel that will not only shield inhabitants from harmful radiation, meteoric impacts, and extremes in temperature, but also has immensely thick walls to keep the air in? In all likelihood, if and when there is such a thing as "Lunies", they will dwell in elongated caverns beneath the Moon's surface.Further Reading: Universities Space Research Assocation

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How Long Does It Take to Get to Jupiter?

How Long Does It Take to Get to Jupiter?:

We’re always talking about Pluto, or Saturn or Mars. But nobody ever seems to talk about Jupiter any more. Why is that? I mean, it’s the largest planet in the Solar System. 318 times the mass of the Earth has got to count for something, right? Right?

Jupiter with Io and Ganymede taken by amateur astronomer Damian Peach. Credit: NASA / Damian Peach

Jupiter with Io and Ganymede taken by amateur astronomer Damian Peach. Credit: NASA / Damian Peach
Jupiter is one of the most important places in the Solar System. The planet itself is impressive; with ancient cyclonic storms larger than the Earth, or a magnetosphere so powerful it defies comprehension.

One of the most compelling reasons to visit Jupiter is because of its moons. Europa, Callisto and Ganymede might all contain vast oceans of liquid water underneath icy shells. And as you probably know, wherever we find liquid water on Earth, we find life.

And so, the icy moons of Jupiter are probably the best place to look for life in the entire Solar System.

And yet, as I record this video in early 2016, there are no spacecraft at Jupiter or its moons. In fact, there haven’t been any there for years. The last spacecraft to visit Jupiter was NASA’s New Horizons in 2007. Mars is buzzing with orbiters and rovers, we just got close up pictures of Pluto! and yet we haven’t seen Jupiter close up in almost 10 years. What’s going on?

Part of the problem is that Jupiter is really far away, and it takes a long time to get there.

How long? Let’s take a look at all the spacecraft that have ever made this journey.

The first spacecraft to ever cross the gulf from the Earth to Jupiter was NASA’s Pioneer 10. It launched on March 3, 1972 and reached on December 3, 1973. That’s a total of 640 days of flight time.

But Pioneer 10 was just flying by, on its way to explore the outer Solar System. It came within 130,000 km of the planet, took the first close up pictures ever taken of Jupiter, and then continued on into deep space for another 11 years before NASA lost contact.

Pioneer 11 took off a year later, and arrived a year later. It made the journey in 606 days, making a much closer flyby, getting within 21,000 kilometers of Jupiter, and visiting Saturn too.

Next came the Voyager spacecraft. Voyager 1 took only 546 days, arriving on March 5, 1979, and Voyager 2 took 688 days.

So, if you’re going to do a flyby, you’ll need about 550-650 days to make the journey.

But if you actually want to slow down and go into orbit around Jupiter, you’ll need to take a much slower journey. The only spacecraft to ever stick around Jupiter was NASA’s Galileo spacecraft, which launched on October 18, 1989.

Instead of taking the direct path to Jupiter, it made two gravitational assisting flybys of Earth and one of Venus to pick up speed, finally arriving at Jupiter on December 8, 1995. That’s a total of 2,242 days.

So why did Galileo take so much longer to get to Jupiter? It’s because you need to be going slow enough that when you reach Jupiter, you can actually enter orbit around the planet, and not just speed on past.

And now, after this long period of Jupiterlessness, we’re about to have another spacecraft arrive at the massive planet and go into orbit. NASA’s Juno spacecraft was launched back on August 5, 2011 and it’s been buzzing around the inner Solar System, building up the velocity to make the journey to Jupiter.

NASA's Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL

NASA’s Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL
It did a flyby of Earth back in 2013, and if everything goes well, Juno will make its orbital insertion into the Jovian system on July 4, 2016. Total flight time: 1,795 days.

Once again, we’ll have a spacecraft observing Jupiter and its moon.s

This is just the beginning. There are several more missions to Jupiter in the works. The European Space Agency will be launching the Jupiter Icy Moons Mission in 2022, which will take nearly 8 years to reach Jupiter by 2030.

NASA’s Europa Multiple-Flyby Mission [Editor’s note: formerly known as the Europa Clipper] will probably launch in the same timeframe, and spend its time orbiting Europa, trying to get a better understand the environment on Europa. It probably won’t be able to detect any life down there, beneath the ice, but it’ll figure out exactly where the ocean starts.

So, how long does it take to get to Jupiter? Around 600 days if you want to just do a flyby and aren’t planning to stick around, or about 2,000 days if you want to actually get into orbit.

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Mysterious Pull On Cassini Probe May Help Find Planet Nine

Mysterious Pull On Cassini Probe May Help Find Planet Nine:



Artist's impression of Planet Nine, blocking out the Milky Way. The Sun is in the distance, with the orbit of Neptune shown as a ring. Credit: ESO/Tomruen/nagualdesign


Finding a ninth planet in our Solar System this late in the game would be fascinating. It would also be somewhat of a surprise, considering our observational capabilities. But new evidence, in the form of small perturbations in the orbit of the Cassini probe, points to the existence of an as-yet undetected planet in our solar system.Back in January, Konstantin Batygin and Mike Brown, two planetary scientists from the California Institute of Technology, presented evidence supporting the existence of a ninth planet. Their paper showed that some Kuiper Belt Objects (KBOs) display unexpected behaviour. It appears that 6 KBOs are affected by their relationship to a large object, but the KBOs in question are too distant from the known gas giants for them to be responsible. They think that a large, distant planet, in the distant reaches of our Solar System, could be responsible for the unexpected orbital clustering of these KBOs.Now, the Ninth Planet idea is gaining steam, and another team of researchers have presented evidence that small perturbations in the orbit of the Cassini spacecraft are caused by the new planet. Agnès Fienga at the Côte d’Azur Observatory in France, and her colleagues, have been working on a detailed model of the Solar System for over a decade. They plugged the hypothetical orbit and size of Planet Nine into their model, to see if it fit.Planet Nine is calculated to be about 4 times as large as Earth, and 10 times as massive. It's orbit takes between 10,000 and 20,000 years. A planet that large can only be hiding in so many places, and those places are a long way from Earth. Fienga found a potential home for Planet Nine, some 600 astronomical units (AU) from here. That much mass at that location could account for the perturbations in Cassini's orbit.There's more good news when it comes to Planet Nine. By happy accident, it's predicted location in the sky is towards the constellation Cetus, in the southern hemisphere. This means that it is in the view of the Dark Energy Survey, a southern hemisphere project that is studying the acceleration of the universe. The Dark Energy Survey is not designed to search for planetary objects, but it has successfully found at least one icy object.There are other ways that the existence of Planet Nine could be confirmed. If it's as large as thought, then it will radiate enough internal heat to be detected by instruments designed to study the Cosmic Microwave Background (CMB). There is also an enormous amount of data from multiple experiments and observations done over the years that might contain an inadvertent clue. But looking through it is an enormous task.As for Brown and Batygin, who initially proposed the existence of Planet Nine based on the behaviour of KBOs, they are already proposing a more specific hunt for the elusive planet. They have asked for a substantial amount of observing time at the Subaru Telescope on Mauna Kea in Hawaii, in order to examine closely the location that Fienga's solar system model predicts Planet Nine to be at.For a more detailed look at Batygin's and Brown's work analyzing KBOs, read Matt Williams' article here.

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Nearby Supernovas Showered Earth With Iron

Nearby Supernovas Showered Earth With Iron:



Visible, infrared, and X-ray light image of Kepler's supernova remnant (SN 1604) located about 13,000 light-years away. Credit: NASA, ESA, R. Sankrit and W. Blair (Johns Hopkins University).


We all know that we are "made of star-stuff," with all of the elements necessary for the formation of planets and even life itself having originated inside generations of massive stars, which over billions of years have blasted their creations out into the galaxy at the explosive ends of their lives. Supernovas are some of the most powerful and energetic events in the known Universe, and when a dying star finally explodes you wouldn't want to be anywhere nearby—fresh elements are nice and all but the energy and radiation from a supernova would roast any planets within tens if not hundreds of light-years in all directions. Luckily for us we're not in an unsafe range of any supernovas in the foreseeable future, but there was a time geologically not very long ago that these stellar explosions are thought to have occurred in nearby space... and scientists have recently found the "smoking gun" evidence at the bottom of the ocean.Two independent teams of "deep-sea astronomers"—one led by Dieter Breitschwerdt from the Berlin Institute of Technology and the other by Anton Wallner from the Australian National University—have investigated sediment samples taken from the floors of the Pacific, Atlantic, and Indian oceans. The sediments were found to contain relatively high levels of iron-60, an unstable isotope specifically created during supernovas.Watch: How Quickly Does a Supernova Happen?The teams found that the ages of the iron-60 concentrations (the determination of which was recently perfected by Wallner) centered around two time periods, 1.7 to 3.2 million years ago and 6.5 to 8.7 million years ago. Based on this and the fact that our Solar System currently resides within a peanut-shaped region virtually empty of interstellar gas known as the Local Bubble, the researchers are confident that this provides further evidence that supernovas exploded within a mere 330 light-years of Earth, sending their elemental fallout our way.“This research essentially proves that certain events happened in the not-too-distant past," said Adrian Melott, an astrophysicist and professor at the University of Kansas who was not directly involved with the research but published his take on the findings in a letter in Nature. (Source)The researchers think that two supernova events in particular were responsible for nearly half of the iron-60 concentrations now observed. These are thought to have taken place among a a nearby group of stars known as the Scorpius–Centaurus Association, some 2.3 and 1.5 million years ago. At those same time frames Earth was entering a phase of repeated global glaciation, the end of the last of which led to the rise of modern human civilization.While supernovas of those sizes and distances wouldn't have been a direct danger to life here on Earth, could they have played a part in changing the climate?Read more: Could a Faraway Supernova Threaten Earth?“Our local research group is working on figuring out what the effects were likely to have been,” Melott said. “We really don’t know. The events weren’t close enough to cause a big mass extinction or severe effects, but not so far away that we can ignore them either. We’re trying to decide if we should expect to have seen any effects on the ground on the Earth.”Regardless of the correlation, if any, between ice ages and supernovas, it's important to learn how these events do affect Earth and realize that they may have played an important and perhaps overlooked role in the history of life on our planet."Over the past 500 million years there must have been supernovae very nearby with disastrous consequences," said Melott. "There have been a lot of mass extinctions, but at this point we don't have enough information to tease out the role of supernovae in them."You can find the teams' papers in Nature here and here.Sources: IOP PhysicsWorld and the University of Kansas

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