Across the Universe - Venus at Night in Infrared from Akatsuki

Venus at Night in Infrared from Akatsuki:

Discover the cosmos!
Each day a different image or photograph of our fascinating universe is
featured, along with a brief explanation written by a professional astronomer.


2018 January 30

Venus at Night in Infrared from Akatsuki

Image Credit:
JAXA,
ISAS,
DARTS;
Processing & Copyright:
Damia Bouic



Explanation:
Why is Venus so different from Earth?

To help find out,
Japan launched the robotic
Akatsuki spacecraft which
entered orbit around Venus late
in 2015 after an unplanned five-year adventure around the inner
Solar System.

Even though Akatsuki was past its original planned lifetime,
the spacecraft and instruments were operating
so well that much of its original mission was
reinstated.

Also known as the
Venus
Climate Orbiter,
Akatsuki's
instruments
investigated unknowns about Earth's sister planet, including whether
volcanoes are still active,
whether lightning occurs in the dense atmosphere, and why wind speeds
greatly exceed the planet's rotation speed.

In the featured image taken by
Akatsuki's
IR2 camera, Venus's night side shows a jagged-edged equatorial band
of high dark clouds absorbing infrared light from hotter layers deeper in
Venus' atmosphere.

The bright orange and black stripe on the upper right is a false digital
artifact that covers part of the much brighter day side of
Venus.

Analyses of
Akatsuki images
and data has shown that Venus has
equatorial jet similar to
Earth's jet stream.



Watch:
Lunar Extravaganza

Tomorrow's picture: The First Explorer

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Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell (UMCP)
NASA Official: Phillip Newman
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Across the Universe - Here Are Some Amazing Pictures of the January 2018 Lunar Eclipse

Here Are Some Amazing Pictures of the January 2018 Lunar Eclipse:

On Wednesday, January 31st (i.e. today!), a spectacular celestial event occurred. For those who live in the western part of North America, Alaska, and the Hawaiian islands, it was visible in the wee hours of the morning – and some people were disciplined enough to roll out of bed to see it! This was none other than the highly-anticipated “Super Blue Moon“, a rare type of full moon that on this occasion was special for a number of reasons.

For one, it was the third in a series of “supermoons”, where a Full Moon coincides with the Moon being closer in its orbit to Earth (aka. perigee) and thus appears larger. It was also the second full moon of the month, which is  otherwise known as a “Blue Moon“. Lastly, for those in right locations, the Moon also passed through the Earth’s shadow, giving it a reddish tint (known as a “Red Moon” or “Blood Moon”).

The super blue moon, taken by Kevin Gill in Los Angeles, CA, with a Canon EOS 60D mounted on a Celestron NexStar 6se. Credit: @apoapsys

In short, you could say that what was occurred this morning was a “super blue blood moon.” And as you can see, some truly awesome pictures were taken of this celestial event from all over the world. Here is a collection of pictures that a number of skilled photographers and star gazers have chosen to share with us. Enjoy!

A collage of images showing the transition of the super blue moon, taken by Braden Ottenbreit of Saskatchewan, Canada. Credit: @bradenottenbreit

Long exposure photo of the super blue moon, taken by Marc Leatham in Cypress, CA. Credit: @marcleatham

Early morning photo snapped outside of Pucklechurch, Bristol, by photographer Tim Graham. Credit: @timgrahamphotorgraphy

The lunar eclipse captured in Shiraz, Iran, by Alireza Nadimi using a Nikon D610A – Sigma 120-400 Apo. Credit: @ar.nadimi

The phases of the lunar eclipse of the Super Blue Blood Moon, taken by astrophographer Rami Ammoun. Credit: @rami_ammoun

Super blue moon taken by Bray Falls in Arizona. Credit: @astrofalls

The super blue moon, as photographed from Los Angeles by Tom Masterson using a Tamron 150-600mm and Canon 6D Hutech UV/IR mod. Credit: @transientastro

A long-exposure shot of the super blue moon above San Francisco by Taylor Meehan. Credit: @tm18210

Composite image showing the sequence of the eclipse, as seen from downtown Houston. Credit: @sergiorill

A composite of the phases of our super blue moon lunar eclipse. Credit: @jeffycan

“Thanks to everyone who used the #universetoday hashtag on Instagram to let us know about your pictures. There are many many more in there, so check it out.”

The post Here Are Some Amazing Pictures of the January 2018 Lunar Eclipse appeared first on Universe Today.

Across the Universe - Curiosity has Lasted More than 2,000 Days on Mars, Triple its Original Mission Plan

Curiosity has Lasted More than 2,000 Days on Mars, Triple its Original Mission Plan:

On August 5th, 2012, after spending over 8 months in space, NASA’s Curiosity rover landed on Mars. As part of the NASA Mars Science Laboratory (MSL) mission, and the latest in a series of rovers deployed to the Martian surface, Curiosity had some rather ambitious research goals. In addition to investigating Mars’ climate and geology, the rover was also tasked with revealing more about Mars’ past and determining if it ever supported microbial life.

And recently, the Curiosity rover hit another major milestone in its exploration of the Red Planet. As of January 26th, 2018 the rover has spent a total of 2,000 days on Mars, which works out to 5 years, 5 months and 21 days – or 1947 Martian days (sols). That’s especially impressive when you consider that the mission was only meant to last 687 days (668 sols), or just little under 2 years.

In all that time, the Curiosity rover has accomplished some major feats and has the scars to prove it! Some of it’s wheels have become teared, holed and cracked and its drill has been pushed almost to the point of breaking. And yet, Curiosity is still hard at work pushing itself up a mountain – both literally and figuratively! The rover has also managed to exceed everyone’s expectations.

MRO image of Gale Crater illustrating the landing location and trek of the Rover Curiosity. Credits: NASA/JPL, illustration, T.Reyes

As Ashwin Vasavada, the MSL Project Scientist, told Universe Today via email:

“In terms of challenges, the first 2000 days of Curiosity’s mission went better than I could have hoped. For much of the time, the rover remained as capable as the day it landed. We had a scare in the first year when a memory fault triggered additional problems and nearly resulted in the loss of the mission. We famously wore down our wheels pretty early, as well, but since then we’ve kept that under control. In the last year, we’ve had a major problem with our drill. That’s the only major issue currently, but we believe we’ll be back to drilling in a month or so. If that works out, we’ll amazingly be back to having all systems ready for science!”

As of the penning of this article, the rover is climbing Mount Sharp in order to collect further samples from Mars’ past. Also known as Aeolis Mons, this mountain resides in the center of the Gale Crater where Curiosity landed in 2012 and has been central to Curiosity’s mission. Standing 5,500 meters (18,000 ft) above the valley floor, Mount Sharp is believed to have formed from sediment that was slowly deposited by flowing water over billions of years.

This is all in keeping with current theories about how Mars once had a denser atmosphere and was able to sustain liquid water on its surface. But between 4.2 and 3.7 billion years ago, this atmosphere was slowly stripped away by solar wind, thus turning Mars into the cold and desiccated place that we know today. As a result, the study of Mount Sharp was always expected to reveal a great deal about Mars’ geological evolution.

Image of Mount Sharp taken by the Curiosity rover on Aug. 23rd, 2012. The layers at the base of Mt. Sharp show the geological history of Mars. Credit: NASA/JPL-Caltech/MSSS.

In it’s first year, Curiosity achieved a major milestone when the rover obtained drill samples from low-lying areas that indicated that lakes and streams existed in the Gale Crater between 3.3 to 3.8 billion years ago. In addition, the rover has also obtained ample evidence that the crater once had all the chemical elements and even a chemical source of energy needed for microbial life to exist.

“NASA’s charge to our mission was to determine whether Mars ever had conditions suitable for life,” said Vasavada. “Success was not a foregone conclusion. Would we arrive safely? Would the scientific instruments work? Would the area we chose for the landing site hold the clues we were looking for? For me, meeting each of these objectives are the highlights of the mission. I’ll never forget witnessing the launch, or nervously waiting for a safe touchdown. Discovering an ancient, freshwater lake environment at Gale crater was profound scientifically, but also was the moment that I knew that our team had delivered what we promised to NASA.”

Basically, by scaling Mount Sharp and examining the layers that were deposited over the course of billions of years, Curiosity is able to examine a living geological record of how the planet has evolved since then. Essentially, the lower layers of the mountain are believed to have been deposited 3.5 billion years ago when the Gale Crater was still a lakebed, as evidenced by the fact that they are rich in clay minerals.

The upper layers, meanwhile, are believed to have been deposited over the ensuing millions of years, during which time the lake in the Gale Crater appears to have grown, shrunk, disappeared and then reappeared. Basically, by scaling the mountain and obtaining samples, Curiosity will be able to illustrate how Mars underwent the transition from being a warmer, wetter place to a frozen and dry one.

Image taken of drill sample obtained at the ‘Lubango’ outcrop target on Sol 1320, Apr. 23, 2016. Lubango is located in the Stimson unit on the lower slopes of Mount Sharp inside Gale Crater. Credit: NASA/JPL/MSSS/Ken Kremer/kenkremer.com/Marco Di Lorenzo

As Vasavada explained, this exploration is also key to answering a number of foundational questions about the search for life beyond Earth:

“Curiosity established that Mars was once a suitable home for life; it had liquid water, key chemical building blocks, and energy sources required by life in the lake and groundwater environment within Gale crater. Curiosity also has detected organic molecules in ancient rocks, in spite of all the degradation that could have occurred in three billion years. While Curiosity cannot detect life itself, knowing that Mars can preserve organic molecules bodes well for missions that will explore ancient rocks, looking for signs of past life.”

At this juncture, its not clear how much longer Curiosity will last. Considering that it has already lasted over twice as long as originally intended, it is possible the rover will remain in operation for years to come. However, unlike the Opportunity rover – who’s mission was intended to last for 90 days, but has remained in operation for 5121 days (4984 sols) – Curiosity has a shelf life.

Whereas Opportunity is powered by solar cells, Curiosity is dependent on its Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). Eventually, this slow-fission reactor will exhaust its supply of nuclear fuel and the rover will be forced to come to a halt. And considering how the rover has been put through its paces in the past 5 years, there’s also the chance that it will suffer a mechanical failure.

But in the meantime, there’s plenty of work to be done and lots of opportunities for vital research. As Vasavada put it:

“Curiosity won’t last forever, but in the years we have left, I hope we can complete our traverse through the lowermost strata on Mount Sharp. We’re well over halfway through. There are changes in the composition of the rocks ahead that might tell us how the climate of Mars changed over time, perhaps ending the era of habitability. Every day on Mars still counts, perhaps even more than before. Now every new discovery adds a piece to a puzzle that’s more than halfway done; it reveals more given all the other pieces already around it.”

And be sure to check out this retrospective of the Curiosity rover’s mission, courtesy of NASA:



Further Reading: Forbes, NASA

The post Curiosity has Lasted More than 2,000 Days on Mars, Triple its Original Mission Plan appeared first on Universe Today.

Across the Universe - Astronomers Find One of the Oldest Stars in the Milky Way

Astronomers Find One of the Oldest Stars in the Milky Way:

According to modern cosmological models, the Universe began in a cataclysm event known as the Big Bang. This took place roughly 13.8 billion years ago, and was followed by a period of expansion and cooling. During that time, the first hydrogen atoms formed as protons and electrons combined and the fundamental forces of physics were born. Then, about 100 million years after the Big Bang, that the first stars and galaxies began to form.

The formation of the first stars was also what allowed for the creation of heavier elements, and therefore the formation of planets and all life as we know it. However, until now, how and when this process took place has been largely theoretical since astronomers did not know where the oldest stars in our galaxy were to be found. But thanks to a new study by a team of Spanish astronomers, we may have just found the oldest star in the Milky Way!

The study, titled “J0815+4729: A chemically primitive dwarf star in the Galactic Halo observed with Gran Telescopio Canarias“, recently appeared in The Astrophysical Journal Letters. Led by David S. Aguado of the Instituto de Astrofisica de Canarias (IAC), the team included members from the University of La Laguna and the Spanish National Research Council (CSIC).

Artist’s impression of the Milky Way Galaxy. Credit: NASA/JPL-Caltech/R. Hurt (SSC-Caltech)

This star is located roughly 7,500 light years from the Sun, and was found in the halo of the Milky Way along the line of sight to the Lynx constellation. Known as J0815+4729, this star is still in its main sequence and has a low mass, (around 0.7 Solar Masses), though the research team estimates that it has a surface temperature that is about 400 degrees hotter – 6,215 K (5942 °C; 10,727 °F) compared to 5778 K (5505 °C; 9940 °F).

For the sake of their study, the team was looking for a star that showed signs of being metal-poor, which would indicate that it has been in its main sequence for a very long time. The team first selected J0815+4729 from the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS) and then conducted follow-up spectroscopic investigations to determine its composition (and hence its age).

This was done using the Intermediate dispersion Spectrograph and Imaging System (ISIS) at the William Herschel Telescope (WHT) and the Optical System for Imaging and low-intermediate-Resolution Integrated Spectroscopy (OSIRIS) at Gran Telescopio de Canarias (GTC), both of which are located at the Observatorio del Roque de los Muchachos on the island of La Palma.

Consistent with what modern theory predicts, the star was found in the Galactic halo – the extended component of our galaxy that reaches beyond the galactic disk (the visible portion). It is in this region that the oldest and most metal-poor stars are believed to be found in galaxies, hence why the team was confident that a star dating back to the early Universe would be found here.

The William Herschel Telescope, part of the Isaac Newton group of telescopes, located on Canary Island. Credit: ing.iac.es

As Jonay González Hernández – a professor from the University of La Laguna, a member of the IAC and a co-author on the paper – explained in an IAC press release:

“Theory predicts that these stars could use material from the first supernovae, whose progenitors were the first massive stars in the galaxy, around 300 million years after the Big Bang. In spite of its age, and its distance away from us, we can still observe it.”

Spectra obtained by both the ISIS and OSIRIS instruments confirmed that the star was poor in metals, indicating that J0815+4729 has only one-millionth of the calcium and iron that the Sun contains. In addition, the team also noticed that the star has a higher carbon content than our Sun, accounting for almost 15% percent of its solar abundance (i.e. the relative abundance of its elements).

In short, J0815+4729 may be the most iron-poor and carbon-rich star currently known to astronomers. Moreover, finding it was rather difficult since the star is both weak in luminosity and was buried within a massive amount of SDSS/BOSS archival data. As Carlos Allende Prieto, another IAC researcher and a co-author on the paper, indicated:

“This star was tucked away in the database of the BOSS project, among a million stellar spectra which we have analysed, requiring a considerable observational and computational effort. It requires high-resolution spectroscopy on large telescopes to detect the chemical elements in the star, which can help us to understand the first supernovae and their progenitors.”

In the near future, the team predicts that next-generation spectrographs could allow for further research that would reveal more about the star’s chemical abundances. Such instruments include the HORS high-resolution spectrograph, which is presently in a trial phase on the Gran Telescopio Canarias (GTC).

“Detecting lithium gives us crucial information related to Big Bang nucleosynthesis,” said Rafael Rebolo, the director of the IAC and a coauthor of the paper. “We are working on a spectrograph of high-resolution and wide spectral range in order to measure the detailed chemical composition of stars with unique properties such as J0815+4719.”

These future studies are sure to be a boon for astronomers and cosmologists. In addition to being a chance to study stars that formed when the Universe was still in its infancy, they could provide new insight into the early stages of the universe, the formation of the first stars, and the properties of the first supernovae. In other words, they would put us a step closer to know how the Universe as we know it formed and evolved.

Further Reading: IAC, The Astrophysical Journal Letters

The post Astronomers Find One of the Oldest Stars in the Milky Way appeared first on Universe Today.

Across the Universe - Outflows From Black Holes are Creating New Molecules Where There Should Only be Destruction

Outflows From Black Holes are Creating New Molecules Where There Should Only be Destruction:

During the 1960s, scientists discovered a massive radio source (known as Sagittarius A*) at the center of the Milky Way, which was later revealed to be a Supermassive Black Holes (SMBH). Since then, they have learned that these SMBHs reside at the center of most massive galaxies. The presence of these black holes is also what allows the centers of these galaxies to have a higher than normal luminosity – aka. Active Galactic Nuclei (AGNs).

In the past few years, astronomers have also observed fast molecular outflows emanating from AGNs which left them puzzled. For one, it was a mystery how any particles could survive the heat and energy of a black hole’s outflow. But according to a new study produced by researchers from Northwestern University, these molecules were actually born within the winds themselves. This theory may help explain how stars form in extreme environments.

The study recently appeared in The Monthly Notices of the Royal Astronomical Society under the title “The origin of fast molecular outflows in quasars: molecule formation in AGN-driven galactic winds.” The study was conducted by Lindheimer post-doctoral fellow Alexander J Richings and assistant professor Claude-André Faucher-Giguère from Northwestern University’s Center for Interdisciplinary Research and Exploration in Astrophysics (CIERA).

Artist’s impression of a black hole’s wind sweeping away galactic gas. Credit: ESA

For the sake of their study, Richings developed the first-ever computer code capable of modeling the detailed chemical processes in interstellar gas which are accelerated by a growing SMBH’s radiation. Meanwhile, Claude-André Faucher-Giguère contributed his expertise, having spent his career studying the formation and evolution of galaxies. As Richings explained in a Northwestern press release:

“When a black hole wind sweeps up gas from its host galaxy, the gas is heated to high temperatures, which destroy any existing molecules. By modeling the molecular chemistry in computer simulations of black hole winds, we found that this swept-up gas can subsequently cool and form new molecules.”

The existence of energetic outflows form SMBHs was first confirmed in 2015, when researchers used the ESA’s Herschel Space Observatory and data from the Japanese/US Suzaku satellite to observe the AGN of a galaxy known as IRAS F11119+3257. Such outflows, they determined, are responsible for draining galaxies of their interstellar gas, which has an arresting effect on the formation of new stars and can lead to “red and dead” elliptical galaxies.

This was followed-up in 2017 with observations that indicated that rapidly moving new stars formed in these outflows, something that astronomers previously thought to be impossible because of the extreme conditions present within them. By theorizing that these particles are actually the product of black hole winds, Richings and Faucher-Giguère have managed to address questions raised by these previous observations.

Artist’s concept of Sagittarius A, the supermassive black hole at the center of our galaxy. Credit: NASA/JPL

Essentially, their theory helps explain predictions made in the past, which appeared contradictory at first glance. On the one hand, it upholds the prediction that black hole winds destroy molecules they collide with. However, it also predicts that new molecules are formed within these winds – including hydrogen, carbon monoxide and water – which can give birth to new stars. As Faucher-Giguère explained:

“This is the first time that the molecule formation process has been simulated in full detail, and in our view, it is a very compelling explanation for the observation that molecules are ubiquitous in supermassive black hole winds, which has been one of the major outstanding problems in the field.”

Richings and Faucher-Giguère look forward to the day when their theory can be confirmed by next-generation missions. They predict that new molecules formed by black hole outflows would be brighter in the infrared wavelength than pre-existing molecules. So when the James Webb Space Telescope takes to space in the Spring of 2019, it will be able to map these outflows in detail using its advance IR instruments.

One of the most exciting things about the current era of astronomy is the way new discoveries are shedding light on decades-old mysteries. But when these discoveries lead to theories that offer symmetry to what were once thought to be incongruous pieces of evidence, that’s when things get especially exciting. Basically, it lets us know that we are moving closer to a greater understanding of our Universe!

Further Reading: Northwestern University, MNRAS

The post Outflows From Black Holes are Creating New Molecules Where There Should Only be Destruction appeared first on Universe Today.

Tropical Storm Harvey is bringing catastrophic flooding to Houston, Texas

Tropical Storm Harvey is bringing catastrophic flooding to Houston, Texas:

After making landfall on Friday night, Hurricane Harvey has since been downgraded to a tropical storm but it is still wreaking damage throughout southeast Texas. Massive flooding is being reported in the Houston area, thanks to two bands of rain that merged and strengthened on top of the city overnight. In the last 24 hours, Houston and nearby Galveston have received 24 inches of rain, and it looks like it’s not letting up any time soon.

“We’re really dealing with a disaster that’s just now beginning in terms of rainfall and flooding,” Patrick Burke, a lead forecaster with the National Weather Service, tells The Verge. Harvey was an incredibly powerful Category 4 storm when it first hit Texas, and though it weakened after making...

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Catastrophic flooding: all the updates as Harvey makes landfall

Catastrophic flooding: all the updates as Harvey makes landfall:

‘We’re really dealing with a disaster that’s just now beginning’

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Korean astronomers saw a distant explosion 600 years ago — and we just found the stars that caused it

Korean astronomers saw a distant explosion 600 years ago — and we just found the stars that caused it:

In March of 1437, Korean astronomers in Seoul saw what they thought was a new, bright star appear in the night sky. Now, nearly 600 years later, astronomers have figured out what those stargazers actually saw: a thermonuclear explosion caused by the interaction of two distant stars. The new research pinpoints the location of those two stars in the sky, solving a mystery that’s plagued astronomers for decades and providing clues about what happens to pairs of stars centuries after they explode.

The event that the Korean astronomers saw lasted 14 days, leading modern astronomers to suspect it was something known as a classical nova. This is a type of explosion caused by an ordinary star similar to our Sun and a white dwarf — a small,...

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Jupiter's vividly glowing auroras have a mysterious power source

Jupiter's vividly glowing auroras have a mysterious power source:

For the first time ever, NASA’s Juno spacecraft has spotted electrons being fired down into Jupiter’s atmosphere at up to 400,000 volts. That’s an enormous amount of energy that gives rise to the planet’s glowing auroras. These incredibly high voltages, however, are only spotted occasionally — and that’s raising questions about what exactly is behind some of the planet’s most vivid glows at the poles.

The discovery, detailed in a study published today in Nature, was made possible by the instruments on board Juno, which has been orbiting Jupiter for a little over a year, passing by the poles closer than any other spacecraft has before. It confirms, in part, what astronomers expected, but it also shows that Jupiter’s auroras behave...

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Free walkie-talkie app tops App Store charts ahead of Hurricane Irma

Free walkie-talkie app tops App Store charts ahead of Hurricane Irma:

With the Category 5 Hurricane Irma, now one of the strongest hurricanes ever recorded in the Atlantic, on its way toward the Caribbean and possibly the southeastern tip of the US, a little-known walkie-talkie app has shot to the top of Apple’s App Store. The free app, called Zello Walkie Talkie, lets your phone communicate as a two-way radio so long as you have a network or Wi-Fi connection. What makes it useful is that it allows immediate voice communication to others in a shared channel, as opposed to having to place a phone call and hope someone on the other end picks up. The ad-free service can also be used to send texts and photos.

Zello first began rising in the top free chart as Tropical Storm Harvey made landfall in Texas as a...

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Record-breaking Galaxy Five Billion Light-Years Away Shows We Live in Magnetic Universe

Record-breaking Galaxy Five Billion Light-Years Away Shows We Live in Magnetic Universe:

A team of astronomers has observed the magnetic field of a galaxy five billion light-years from Earth. The galaxy is the most distant in which a coherent magnetic field has been observed and provides important insight into how magnetism in the Universe formed and evolved.

The observation shows a magnetic field of a similar strength and configuration to that seen in our own Milky Way Galaxy, even though the distant galaxy is five billion years younger than ours. This is evidence that galactic magnetic fields form early in a galaxy’s life and remain relatively stable.

“This finding is exciting,” says Dr. Sui Ann Mao, an astronomer and Minerva Research Group leader at the Max Planck Institute for Radio Astronomy and lead author of the paper describing the observation. “It is now the record holder of the most distant galaxy for which we have this magnetic field information.” The paper was published August 28 in Nature Astronomy.

Galaxies have their own magnetic fields, but they are incredibly weak—a million times weaker than the Earth’s magnetic field. One theory suggests that the magnetic field of a young galaxy starts off weak and tangled, becoming stronger and more organized over time.

But, because the magnetic field of the observed galaxy is not much different from the fields we observe in our own Milky Way Galaxy and nearby galaxies, the detection is evidence that galactic magnetism appears relatively early, rather than growing slowly over time.

“This means that magnetism is generated very early in a galaxy’s life by natural processes, and thus that almost every heavenly body is magnetic,” says Prof. Bryan Gaensler, Dunlap Institute for Astronomy & Astrophysics, University of Toronto, and a co-author of the paper. “The implication is that we need to understand magnetism to understand the Universe.”

Studying the evolution of galactic magnetic fields requires observations of galaxies at different distances from us because such observations show us galaxies at different ages.

But these observations are difficult to make, in part because a magnetic field can’t be detected directly. Instead, we can only detect one by observing the magnetic fingerprint it leaves on light passing through it—an effect referred to as Faraday Rotation.

Mao, Gaensler and their colleagues were able to make their observation because a quasar—a very bright and distant galaxy—lies beyond the galaxy being studied, along the same line of sight. Thanks to this chance alignment, the quasar’s light passes through the galaxy’s magnetic field on its way to us, picking up the tell-tale Faraday Rotation fingerprint.

The observation was made using the Karl G. Jansky Very Large Array, an array of radio telescope dishes in Plains of San Agustin in the New Mexico desert, operated by the National Radio Astronomy Observatory.

“Nobody knows where cosmic magnetism comes from or how it was generated,” says Gaensler. “But now, we have obtained a major clue needed for solving this mystery, by extracting the fossil record of magnetism in a galaxy billions of years before the present day.”

Credit: dunlap.utoronto.ca

Giant Asteroid to Swoosh by Earth on September 1

Giant Asteroid to Swoosh by Earth on September 1:

A massive asteroid over four kilometers wide is expected to fly by our planet on Friday, September 1. The space rock, designated 1981 ET3 (also known as Florence), will miss the Earth at a safe distance of 18.5 lunar distances (LD), or seven million kilometers.

Detected by Schelte "Bobby" Bus at Siding Spring Observatory in Australia in March 1981, Florence was named in honor of Florence Nightingale (1820-1910), the founder of modern nursing. 

Measurements made by NASA's Spitzer Space Telescope and NEOWISE mission indicate that Florence is about 4.4 kilometers in size, what makes it one of the largest known near-Earth asteroids. It is also the largest object to pass by our planet this close since NASA’s program to detect and track near-Earth asteroids began.

“While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller,” said Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies (CNEOS) at the agency's Jet Propulsion Laboratory in Pasadena, California.

Florence has an absolute magnitude of 14.1 and a rotation period of approximately 2.36 hours. The asteroid has a semimajor axis of about 1.77 AU and orbits the sun every 2.35 years.

The close approach of Florence on September 1 will take place at 12:06 UTC, when it will pass by our planet with a relative velocity of 13.53 km/s. The upcoming fly-by will offer an excellent opportunity to conduct radar observations of this object. Radar imaging is planned at NASA's Goldstone Solar System Radar in California and at the National Science Foundation's Arecibo Observatory in Puerto Rico. These images could show the real size of Florence and could also reveal surface details as small as about 10 meters.

Florence is classified as one of the 1,803 Potentially Hazardous Asteroids (PHAs) currently known. PHAs are asteroids larger than 100 meters that can come closer to Earth than 19.5 LD. None of the known PHAs is on a collision course with our planet.

Lunar Reconnaissance Orbiter Captures Solar Eclipse as Seen From the Moon

Lunar Reconnaissance Orbiter Captures Solar Eclipse as Seen From the Moon:

During the total solar eclipse on Aug. 21, NASA’s Lunar Reconnaissance Orbiter, or LRO, captured an image of the Moon’s shadow over a large region of the United States, centered just north of Nashville, Tennessee. As LRO crossed the lunar south pole heading north at 3,579 mph (1,600 meters per second), the shadow of the Moon was racing across the United States at 1,500 mph (670 meters per second).

A few minutes later, LRO began a slow 180-degree turn to look back at Earth, capturing an image of the eclipse very near the location where totality lasted the longest. The spacecraft’s Narrow Angle Camera began scanning Earth at 2:25:30 p.m. EDT (18:25:30 UTC) and completed the image 18 seconds later.

The Narrow Angle Camera is part of the Lunar Reconnaissance Orbiter Camera system. Two Narrow Angle Cameras capture high-resolution black and white images, and a third, the Wide Angle Camera, captures moderate-resolution images using filters to provide information about the properties and color of the lunar surface. 

The Narrow Angle Camera builds up an image line by line rather than the more typical “instantaneous” framing that occurs with digital or cell-phone cameras. Each line of the image is exposed for less than one-thousandth of a second; the exposure time was set as low as possible to prevent bright clouds from saturating the sensor. It takes about 18 seconds to acquire all 52,224 lines for the image.

While the thrill of the total eclipse was in experiencing the shadow of the Moon sweep across us on Earth, on the Moon this was just another day. The lunar nearside was one week into its two-week night, while the Sun shone on the far side in the middle of its two-week day. Because solar eclipses do not affect the health or power supply of the spacecraft, LRO operated normally during the total solar eclipse.

Launched on June 18, 2009, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the Moon and reminding us, through these eclipse images, of the beauty of our Earth. 

LRO is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, as a project under NASA's Discovery Program. The Discovery Program is managed by NASA's Marshall Spaceflight Center in Huntsville, Alabama, for the Science Mission Directorate at NASA Headquarters in Washington.

The Lunar Reconnaissance Orbiter Camera was developed at Malin Space Science Systems in San Diego, California and Arizona State University.

Credit: NASA

Weightlessness Affects Health of Astronauts at Molecular Level

Weightlessness Affects Health of Astronauts at Molecular Level:

A team of scientists from Russia and Canada has analyzed the effect of space conditions on the protein composition in blood samples of 18 Russian cosmonauts. The results indicated many significant changes in the human body caused by space flight. These changes are intended to help the body adapt and take place in all the major types of human cells, tissues, and organs. The results of the research have been published in the prestigious scientific journal Nature Scientific Reports. Skoltech and MIPT Professor Evgeny Nikolaev initiated this research, and he is a corresponding author of the study.

The effects of spaceflight on the human body have been studied actively since the mid-20th century. It is widely known that space conditions influence metabolism, thermoregulation, heart biorhythms, muscle tonus, the respiration system and other physiological aspects of the human body function. However, the molecular mechanisms which drive the physiological changes caused by space flights remain unknown.

Proteins are key players in the adaptive processes in an organism, so the scientists decided to focus on them. To gain a deeper understanding of the changes in human physiology during space travel, the research team quantified concentrations of 125 proteins in the blood plasma of 18 Russian cosmonauts who had been on long-duration missions to the International Space Station. The blood was initially taken from them 30 days prior to their flights, and again immediately after their return to Earth and finally seven days after that. This timing was chosen as it helped the scientists to identify trends in protein concentration changes and see how fast the protein concentrations returned to their normal levels prior to the flight.

Protein concentrations were measured using a mass spectrometer. This technology makes it possible to identify a particular molecule and perform a quantitative analysis of a mixture of substances (count the exact number of molecules).

As a result of the study, the scientists found proteins whose concentrations remained unchanged, as well as those whose concentrations did change, but recovered rapidly to their pre-flight levels and those whose levels recovered very slowly after the cosmonaut's return to Earth.

“For the research, we took a set of proteins – non-infectious diseases biomarkers. The results showed that in weightlessness, the immune system acts like it does when the body is infected because the human body doesn’t know what to do and tries to turn on all possible defense systems. For this study, we began by using quantitative proteomics to study the cosmonauts’ blood indicators, so we detected not only the presence of a protein but its amount as well. We plan to use a targeted approach in the future to detect more specific proteins responsible for the human response to space conditions. To do this, the cosmonauts will have to take blood tests while in orbit,” said Professor Nikolaev.

The factors that affect the human body during spaceflight are very interesting because they are different to those that influenced human evolution on Earth. It is not known if the human body has mechanisms responsible for rapidly adapting to such major changes. The results of the study indicate that such mechanisms probably do not exist because, during space flight, these adaptations take place in all the major types of human cells, tissues, and organs. This indicates that the human body does not know what to do and is trying to do everything in its power.

Credit: mipt.ru

Artificial Intelligence Analyzes Gravitational Lenses 10 Million Times Faster

Artificial Intelligence Analyzes Gravitational Lenses 10 Million Times Faster:

Researchers from the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University have for the first time shown that neural networks – a form of artificial intelligence – can accurately analyze the complex distortions in spacetime known as gravitational lenses 10 million times faster than traditional methods.

“Analyses that typically take weeks to months to complete, that require the input of experts and that are computationally demanding, can be done by neural nets within a fraction of a second, in a fully automated way and, in principle, on a cell phone’s computer chip,” said postdoctoral fellow Laurence Perreault Levasseur, a co-author of a study published today in Nature.

The team at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), a joint institute of SLAC and Stanford, used neural networks to analyze images of strong gravitational lensing, where the image of a faraway galaxy is multiplied and distorted into rings and arcs by the gravity of a massive object, such as a galaxy cluster, that’s closer to us. The distortions provide important clues about how mass is distributed in space and how that distribution changes over time – properties linked to invisible dark matter that makes up 85 percent of all matter in the universe and to dark energy that’s accelerating the expansion of the universe.

Until now this type of analysis has been a tedious process that involves comparing actual images of lenses with a large number of computer simulations of mathematical lensing models. This can take weeks to months for a single lens.

But with the neural networks, the researchers were able to do the same analysis in a few seconds, which they demonstrated using real images from NASA’s Hubble Space Telescope and simulated ones.

To train the neural networks in what to look for, the researchers showed them about half a million simulated images of gravitational lenses for about a day. Once trained, the networks were able to analyze new lenses almost instantaneously with a precision that was comparable to traditional analysis methods. In a separate paper, submitted to The Astrophysical Journal Letters, the team reports how these networks can also determine the uncertainties of their analyses.

“The neural networks we tested – three publicly available neural nets and one that we developed ourselves – were able to determine the properties of each lens, including how its mass was distributed and how much it magnified the image of the background galaxy,” said the study’s lead author Yashar Hezaveh, a NASA Hubble postdoctoral fellow at KIPAC.

This goes far beyond recent applications of neural networks in astrophysics, which were limited to solving classification problems, such as determining whether an image shows a gravitational lens or not.

The ability to sift through large amounts of data and perform complex analyses very quickly and in a fully automated fashion could transform astrophysics in a way that is much needed for future sky surveys that will look deeper into the universe – and produce more data – than ever before.

The Large Synoptic Survey Telescope (LSST), for example, whose 3.2-gigapixel camera is currently under construction at SLAC, will provide unparalleled views of the universe and is expected to increase the number of known strong gravitational lenses from a few hundred today to tens of thousands.

“We won’t have enough people to analyze all these data in a timely manner with the traditional methods,” Perreault Levasseur said. “Neural networks will help us identify interesting objects and analyze them quickly. This will give us more time to ask the right questions about the universe.”

Neural networks are inspired by the architecture of the human brain, in which a dense network of neurons quickly processes and analyzes information.

In the artificial version, the “neurons” are single computational units that are associated with the pixels of the image being analyzed. The neurons are organized into layers, up to hundreds of layers deep. Each layer searches for features in the image. Once the first layer has found a certain feature, it transmits the information to the next layer, which then searches for another feature within that feature, and so on.

“The amazing thing is that neural networks learn by themselves what features to look for,” said KIPAC staff scientist Phil Marshall, a co-author of the paper. “This is comparable to the way small children learn to recognize objects. You don’t tell them exactly what a dog is; you just show them pictures of dogs.”

But in this case, Hezaveh said, “It’s as if they not only picked photos of dogs from a pile of photos, but also returned information about the dogs’ weight, height and age.”

Although the KIPAC scientists ran their tests on the Sherlock high-performance computing cluster at the Stanford Research Computing Center, they could have done their computations on a laptop or even on a cell phone, they said. In fact, one of the neural networks they tested was designed to work on iPhones.

“Neural nets have been applied to astrophysical problems in the past with mixed outcomes,” said KIPAC faculty member Roger Blandford, who was not a co-author on the paper. “But new algorithms combined with modern graphics processing units, or GPUs, can produce extremely fast and reliable results, as the gravitational lens problem tackled in this paper dramatically demonstrates. There is considerable optimism that this will become the approach of choice for many more data processing and analysis problems in astrophysics and other fields.”

Credit: slac.stanford.edu

ALMA Finds Huge Hidden Reservoirs of Turbulent Gas in Distant Galaxies

ALMA Finds Huge Hidden Reservoirs of Turbulent Gas in Distant Galaxies:

ALMA has been used to detect turbulent reservoirs of cold gas surrounding distant starburst galaxies. By detecting CH+ for the first time in the distant Universe this research opens up a new window of exploration into a critical epoch of star formation. The presence of this molecule sheds new light on how galaxies manage to extend their period of rapid star formation. The results appear in the journal Nature.

A team led by Edith Falgarone (Ecole Normale Supérieure and Observatoire de Paris, France) has used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect signatures of the carbon hydride molecule CH+ in distant starburst galaxies. The group identified strong signals of CH+ in five out of the six galaxies studied, including the Cosmic Eyelash (eso1012). This research provides new information that helps astronomers understand the growth of galaxies and how a galaxy’s surroundings fuel star formation.

“CH+ is a special molecule. It needs a lot of energy to form and is very reactive, which means its lifetime is very short and it can’t be transported far. CH+ therefore traces how energy flows in the galaxies and their surroundings,” said Martin Zwaan, an astronomer at ESO, who contributed to the paper.

How CH+ traces energy can be thought of by analogy to being on a boat in a tropical ocean on a dark, moonless night. When the conditions are right, fluorescent plankton can light up around the boat as it sails. The turbulence caused by the boat sliding through the water excites the plankton to emit light, which reveals the existence of the the turbulent regions in the underlying dark water. Since CH+ forms exclusively in small areas where turbulent motions of gas dissipates, its detection in essence traces energy on a galactic scale.

The observed CH+ reveals dense shock waves, powered by hot, fast galactic winds originating inside the galaxies’ star forming regions. These winds flow through a galaxy, and push material out of it, but their turbulent motions are such that part of the material can be re-captured by the gravitational pull of the galaxy itself. This material gathers into huge turbulent reservoirs of cool, low-density gas, extending more than 30 000 light-years from the galaxy’s star forming region.

“With CH+, we learn that energy is stored within vast galaxy-sized winds and ends up as turbulent motions in previously unseen reservoirs of cold gas surrounding the galaxy,” said Falgarone, who is lead author of the new paper. “Our results challenge the theory of galaxy evolution. By driving turbulence in the reservoirs, these galactic winds extend the starburst phase instead of quenching it.”

The team determined that galactic winds alone could not replenish the newly revealed gaseous reservoirs and suggests that the mass is provided by galactic mergers or accretion from hidden streams of gas, as predicted by current theory.

“This discovery represents a major step forward in our understanding of how the inflow of material is regulated around the most intense starburst galaxies in the early Universe,” says ESO’s Director for Science, Rob Ivison, a co-author on the paper. “It shows what can be achieved when scientists from a variety of disciplines come together to exploit the capabilities of the world's most powerful telescope.”

Credit: ESO

Heavy Stellar Traffic, Deflected Comets, and a Closer Look at the Triggers of Cosmic Disaster

Heavy Stellar Traffic, Deflected Comets, and a Closer Look at the Triggers of Cosmic Disaster:

As stars pass close by our solar system, they can nudge comets from the distant Oort cloud into the inner regions around the Sun. Thus, stellar encounters are an important factor in determining the risk of large cosmic impacts on Earth. Now, Coryn Bailer-Jones from the Max Planck Institute for Astronomy has used data from the ESA satellite Gaia to give the first systematic estimate of the rate of such close stellar encounters. Every million years, up to two dozen stars pass within a few light-years of the Sun, making for a near-constant state of perturbation. The results have been published in the journal Astronomy & Astrophysics.

Comets colliding with Earth are among the more violent and extensive cosmic catastrophes that can befall our home planet. The best known such impact is the one which, 66 million years ago, caused or at least hastened the demise of the dinosaurs (although it is not known whether the blame in this case falls on a comet or an asteroid).

It must be said that, to the best of current knowledge, impacts with regional or even global consequences are exceedingly rare, and occur at a rate of no more than one per million years. Also, monitoring systems give us a fairly complete inventory of larger asteroids and comets, none of which is currently on a collision course with Earth.

Still, the consequences are serious enough that studies of the causes of comet impacts are not purely academic. The prime culprits are stellar encounters: stars passing through our Sun's cosmic neighborhood. The outskirts of our solar system are believed to host a reservoir of cold and icy objects – potential comets – known as the Oort cloud. The gravitational influence of passing stars can nudge these comets inwards, and some will begin a journey all the way to the inner solar system, possibly on a collision course with Earth. That is why knowledge of these stellar encounters and their properties has a direct impact on risk assessment for comet impacts.

Now, Bailer-Jones has published the first systematic estimate of the rate of such stellar encounters. The new result uses data from the first data release (DR1) of the Gaia mission that combines new Gaia measurements with older measurements by ESA's Hipparcos satellite. Crucially, Bailer-Jones modeled each candidate for a close encounter as a swarm of virtual stars, showing how uncertainties in the orbital data will influence the derived rate of encounters.

Bailer-Jones found that within a typical million years, between 490 and 600 stars will pass the Sun within a distance of 16.3 light-years (5 parsecs, to use a unit more common in professional astronomy) or less. Between 19 and 24 stars will pass at 3.26 light-years (1 parsec) or less. All these hundreds of stars would be sufficiently close to nudge comets from the Oort cloud into the solar system. The new results are in the same ballpark as earlier, less systematic estimates that show that when it comes to stellar encounters, traffic in our cosmic neighborhood is rather heavy.

The current results are valid for a period of time that reaches about 5 million years into the past and into the future. With Gaia's next data release, DR2 slated for April 2018, this could be extended to 25 million years each way. However, astronomers intending to go even further and search for the stars that might be responsible for hurling a comet towards the dinosaurs will need to know our home galaxy and its mass distribution in much more detail than we currently do – a long-term goal of the researchers involved in Gaia and related projects.

Credit: mpia.de