Posted on by John Williams

Early Black Holes were Grazers Rather than Glutonous Eaters

Faint quasars powered by black holes. Image credit NASA/ESA/Yale

Black holes powering distant quasars in the early Universe grazed on patches of gas or passing galaxies rather than glutting themselves in dramatic collisions according to new observations from NASA’s Spitzer and Hubble space telescopes.

A black hole doesn’t need much gas to satisfy its hunger and turn into a quasar, says study leader Kevin Schawinski of Yale “There’s more than enough gas within a few light-years from the center of our Milky Way to turn it into a quasar,” Schawinski explained. “It just doesn’t happen. But it could happen if one of those small clouds of gas ran into the black hole. Random motions and stirrings inside the galaxy would channel gas into the black hole. Ten billion years ago, those random motions were more common and there was more gas to go around. Small galaxies also were more abundant and were swallowed up by larger galaxies.”

Quasars are distant and brilliant galactic powerhouses. These far-off objects are powered by black holes that glut themselves on captured material; this in turn heats the matter to millions of degrees making it super luminous. The brightest quasars reside in galaxies pushed and pulled by mergers and interactions with other galaxies leaving a lot of material to be gobbled up by the super-massive black holes residing in the galactic cores.

Schawinski and his team studied 30 quasars with NASA’s orbiting telescopes Hubble and Spitzer. These quasars, glowing extremely bright in the infrared images (a telltale sign that resident black holes are actively scooping up gas and dust into their gravitational whirlpool) formed during a time of peak black-hole growth between eight and twelve billion years ago. They found 26 of the host galaxies, all about the size of our own Milky Way Galaxy, showed no signs of collisions, such as smashed arms, distorted shapes or long tidal tails. Only one galaxy in the study showed evidence of an interaction. This finding supports evidence that the creation of the most massive black holes in the early Universe was fueled not by dramatic bursts of major mergers but by smaller, long-term events.

“Quasars that are products of galaxy collisions are very bright,” Schawinski said. “The objects we looked at in this study are the more typical quasars. They’re a lot less luminous. The brilliant quasars born of galaxy mergers get all the attention because they are so bright and their host galaxies are so messed up. But the typical bread-and-butter quasars are actually where most of the black-hole growth is happening. They are the norm, and they don’t need the drama of a collision to shine.

“I think it’s a combination of processes, such as random stirring of gas, supernovae blasts, swallowing of small bodies, and streams of gas and stars feeding material into the nucleus,” Schawinski said.

Unfortunately, the process powering the quasars and their black holes lies below the detection of Hubble making them prime targets for the upcoming James Webb Space Telescope, a large infrared orbiting observatory scheduled for launch in 2018.

You can learn more about the images here.

Image caption: These galaxies have so much dust enshrouding them that the brilliant light from their quasars cannot be seen in these images from the NASA/ESA Hubble Space Telescope.

Posted on by John Williams

Huge Wildfires Burn on Opposite Sides of the Planet

The latest views of Earth from NASA’s Aqua and Terra satellites are looking a bit hazy from wildfires burning in wilderness areas of the United States and Siberia.

The above image acquired July 18 from the Moderate Resolution Imaging Spectroradiometer, or MODIS, aboard the Terra satellite, shows a whopping 198 wildfires burning across Siberia. You can view more of this huge fire at NASA’s Earth Observatory website. The fires have charred an area of more than 83 square kilometers. Some of the fires were started by people who lost control of agricultural fires but some fires were started by lightning.

High Park Fire from NASA's Aqua MODIS
Another NASA earth-observing satellite, Aqua, has taken dramatic images of the High Park Fire just west of Fort Collins, Colorado and the Whitewater-Baldy Complex Fire in southwestern New Mexico. The High Park Fire has grown to more than 235 square kilometers, burning 180 structures and leading to the death of one person. It has become one of the most destructive and largest fires in Colorado history. Thankfully, the

Besides measuring the smoke plume and fire extent, much can be learned using satellite images of wildfires. Types of vegetation can affect the type and color of smoke emitted by the wildfire. Grassland fires tend to burn quickly and give off carbon-rich black smoke. Forest fires where moisture is higher give off thicker smoke; a combination of organic rich ash and water vapor, that ranges in color from brown to bright white.

Pyrocumulus cloud from High Park Fire, ColoradoOn the plus side for weather buffs, each of the fires have produced rare pyrocumulus, or fire clouds. Wildfires and volcanos can produce these dramatic clouds as intense heating causes the air to rise. As the rising air cools, water vapor in the ash cloud condenses just like a normal cloud. The ash particles provide nuclei for water to condense. Sometimes this moisture will fall back on the fire as rain. Dave Lipson, a meteorologist with the National Oceanic and Atmospheric Administration told the Denver Post that calm and clear weather along Colorado’s Front Range made the towering pyrocumulus cloud look especially menacing Tuesday. Tuesday afternoon, the lone fire cloud could be seen from 40 miles away from Denver.

Lead image caption: NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response. Instrument: Terra – MODIS

Second image caption: High Park Fire, Colorado from NASA’s Aqua MODIS

Third image caption: Looking north near Boulder, Colorado at the pyrocumulus cloud produced from the High Park Fire. Photo: John Williams

Posted on by Nancy Atkinson

Loads of Ice Waiting for Explorers at the Moon’s Shackleton Crater

Shackleton crater on the Moon’s south pole has been somewhat of an enigma, as its permanently shadowed interior has made it difficult to detect what is inside. But with new observations using the laser altimeter on the Lunar Reconnaissance Orbiter (LRO) spacecraft, a team of researchers has essentially illuminated the crater’s interior with laser light, measuring its albedo, or natural reflectance. The scientists found that the crater’s floor is quite bright, an observation consistent with the presence of ice. In fact, ice may make up 22 percent of the material on the crater floor, with possibly more ice embedded within the crater walls.

“We decided we would study the living daylights out of this crater,” said Maria Zuber from the Massachuesetts Institute of Technology, who lead a team to study Shackleton Crater. “From the incredible density of observations we were able to make an extremely detailed topographic map.”

For laser altimeter observations, elevation maps can be created by measuring the time it takes for laser light to bounce down to the Moon’s surface and back to the instrument. The longer it takes, the lower the terrain’s elevation. Using these measurements, the group mapped the crater’s floor and the slope of its walls.

The team used over 5 million measurements to create their detailed map.


While the crater’s floor was relatively bright, Zuber and her colleagues observed that its walls were even brighter. The finding was at first puzzling. Scientists had thought that if ice were anywhere in a crater, it would be on the floor, where no direct sunlight penetrates. The upper walls of Shackleton crater are occasionally illuminated, which could evaporate any ice that accumulates. A theory offered by the team to explain the puzzle is that “moonquakes”– seismic shaking brought on by meteorite impacts or gravitational tides from Earth — may have caused Shackleton’s walls to slough off older, darker soil, revealing newer, brighter soil underneath. Zuber’s team’s ultra-high-resolution map provides strong evidence for ice on both the crater’s floor and walls.

“There may be multiple explanations for the observed brightness throughout the crater,” said Zuber. “For example, newer material may be exposed along its walls, while ice may be mixed in with its floor.”

The crater, named after the Antarctic explorer Ernest Shackleton, is nearly 20 km (more than 12 miles) wide and over 3 km (2 miles) deep — about as deep as Earth’s oceans. Zuber described the crater’s interior as “extremely rugged … It would not be easy to crawl around in there.”

She added that the new topographic map will help researchers understand crater formation and study other uncharted areas of the moon.

“I will never get over the thrill when I see a new terrain for the first time,” Zuber said. “It’s that sort of motivation that causes people to explore to begin with. Of course, we’re not risking our lives like the early explorers did, but there is a great personal investment in all of this for a lot of people.”

Ben Bussey, staff scientist at Johns Hopkins University’s Applied Physics Laboratory, said the new evidence for ice in Shackleton crater may indeed help determine the course for future lunar missions.

“Ice in the polar regions has been sort of an enigmatic thing for some time … I think this is another piece of evidence for the possibility of ice,” Bussey says. “To truly answer the question, we’ll have to send a lunar lander, and these results will help us select where to send a lander.”

And for any humans explorers, a crater like Shackleton at the lunar poles may well be the best location for a base, as the poles contain regions of near-permanent sunlight needed for power, and regions of near-permanent darkness containing ice — both of which would be essential resources for any lunar colony.

The team’s research was published today in the Journal Nature.

Sources: MIT, NASA

Lead image caption: Elevation (left) and shaded relief (right) image of Shackleton, a 21-km-diameter (12.5-mile-diameter) permanently shadowed crater adjacent to the lunar south pole. The structure of the crater’s interior was revealed by a digital elevation model constructed from over 5 million elevation measurements from the Lunar Orbiter Laser Altimeter. Credit: NASA/Zuber, M.T. et al., Nature, 2012

Second image caption: This is an elevation map of Shackleton crater made using LRO Lunar Orbiter Laser Altimeter data. The false colors indicate height, with blue lowest and red/white highest. Credit: NASA/Zuber, M.T. et al., Nature, 2012

Posted on by Nancy Atkinson

Organics Found in Mars Meteorites, But Nothing Biological

Editor’s note: This guest post was written by Andy Tomaswick, an electrical engineer who follows space science and technology.

The search for biologically created organic molecules on Mars goes back at least to the 1970s with the Viking program. Those missions had famously mixed results, and so the search for carbon-based life on Mars continues to this day. Researchers keeping piling on more and more evidence to excite astrobiologists and new results published in a study by the Planetary Science Institute and the Carnegie Institute of Washington may heighten their enthusiasm.

The latest results come from a team led by Andrew Steele of the Carnegie Institution for Science who surveyed meteorites from Mars, which covered a 4.2 billion year time span of Martian geology. While it is no surprise that there are organics on Mars — that Martian meteorites contain carbon-based molecules has been known for years — the team confirmed those findings by detecting organics on ten of the eleven meteorites they examined. However, questions remained as to where exactly the meteorite-bound organic molecules came from and, if they were from Mars, what had created them?

The team set out to answer these questions and came to the conclusion that the molecules are indeed from Mars and not the result of some cross-contamination from Earth’s biosphere. However, they also found that the molecules were not created by any biological process. The organics actually formed in the chunks of rock that later became the meteorites that transported them to earth. Their formation was part of a volcanic process that traps carbon in crystal structures formed by cooling magma. Through a series of non-biological chemical reactions, the complex organics found in the meteorites are created using the carbon trapped in these crystals.

The team also casts doubt on another possible explanation: whether the organics might be caused by emissions from microbes that had migrated into the volcano via tectonic processes similar to those on Earth. They point out that Mars does not have the tectonic activity similar to Earth so there is very little likelihood that the molecules are created by microbial activity.

That might sound like a depressing result for the astrobiologists. But the important finding from this study is that Mars has been natively and naturally creating complex organic molecules for 4.2 billion years and may be still be doing so today. Since the creation of organic molecules on Earth was a precursor to life, scientists can still hold out hope that the same life-creating process might have already happened on the red planet.

Interestingly, one of the Martian meteorites that was studied was the famous ALH84001, the meteorite that some researchers claimed in 1996 might contain fossils from Mars. That claim was subsequently strongly challenged, and studies of the rock are ongoing. ALH84001 is a portion of a meteorite that was dislodged from Mars by a huge impact about 16 million years ago and that fell to Earth in Antarctica approximately 13,000 years ago. The meteorite was found in Allan Hills ice field in Antarctica.

Read the team’s abstract.

Lead image caption: ALH84001 is one of 10 rocks from Mars in which researchers have found organic carbon compounds that originated on Mars without involvement of life. Credit: NASA/JSC/Stanford University

Sources: Planetary Science Institute, LiveScience, NASA

Posted on by Nancy Atkinson

A Close-up Look at the War and Peace Nebula

Take a trip out to the constellation of Scorpius get a close-up look at the War and Peace nebula, courtesy of the Very Large Telescope. This is the most detailed visible-light image so far of this spectacular stellar nursery, which is within NGC 6357. The view shows many hot young stars, glowing clouds of gas and weird dust formations sculpted by ultraviolet radiation and stellar winds.

The unusual name of “War and Peace” was given to this nebula not because of the famous novel by Tolstoy, but because in infrared light, the bright, western part of the nebula resembles a dove, while the eastern part looked like a skull. Unfortunately this effect cannot be seen in this visible-light image, but instead we can see dark disks of gas and young stars wrapped in expanding cocoons of dust.

In fact, the whole image is covered with dark trails of cosmic dust, but some of the most fascinating dark features appear at the lower right and on the right hand edge of the picture. Here the radiation from the bright young stars has created huge columns, similar to the famous “pillars of creation” in the Eagle Nebula and other fascinating structures revealed by the awesome power of the VLT.

Lead image caption: The War and Peace Nebula inside NGC 6357, as seen by the Very Large Telescope. Credit: ESO

Source: ESO

Posted on by Fraser Cain

This Video Will Make You Grateful for the Earth’s Magnetosphere

A newly released video from NASA showcases the space agency’s data visualization skills, as well as the dramatic science behind the Sun’s powerful coronal mass ejections and their interactions with the Earth’s magnetosphere and climate. These ejections stripped the lighter elements away from Venus long ago, leaving the planet with a desolate, hostile environment. But in this animation, you can watch as the particles from the solar wind are redirected around the Earth, keeping us safe – and hydrated.

This video is actually an excerpt from a longer video called Dynamic Earth: Exploring Earth’s Climate Engine, which is playing at the Smithsonian National Air and Space Museum in Washington, D.C; this portion showcases the interaction between the Sun’s solar wind and the Earth’s ocean currents. What’s really amazing about this video is that the underlying data visualizations are based on real satellite observations. The swirling ocean currents were created from real ocean current data.

Still sitting on the fence, finger hovering over the play button, not sure if you should spend a few minutes of your valuable time? You might be interested to know that the video was recently chosen as a “select entry” for the 2012 SIGGRAPH conference, held in Los Angeles on Aug. 5 to 9, 2012. This is the conference where all the film studios showcase their 3D graphics work. A NASA video chosen as a select entry? I like their taste.

Posted on by Nancy Atkinson

Astrophoto: Noctilucent Clouds by Brendan Alexander

It’s Noctilucent Cloud season! And Brendan Alexander in Donegal Ireland captured this beautiful view on the morning of June 18, 2012. “The skies cleared before dawn and I was treated to the best Noctilucent Cloud display I have seen this season so far,” Brendan said on Flickr. We’ve featured Brendan’s work many times on Universe Today.

Details:
Location: Killygordon, Lifford, Co. Donegal, Ireland
Date: 18 June 2012
Time: 02:00-02:30
Camera: Self modded Canon 1000D, Simga 20mm
Exposure: 6sec, ISO 400 F5

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Posted on by Nancy Atkinson

“Alien Prometheus Prominence” Hovers Over the Sun

Seen the movie “Prometheus” yet? If so, you may recognize one of the creatures in an eerie but beautiful prominence eruption from the Sun today. The folks at the Solar Dynamics Observatory noticed the similarity, too. This video covers almost 15 hours from the early hours of June 18, 2012, showing ultraviolet views from the AIA instrument on SDO. In addition to the hovering alien, look for a big blast from the Sun at about 0:15, too.
Continue reading ““Alien Prometheus Prominence” Hovers Over the Sun”

Posted on by Nancy Atkinson

Carnival of Space #254

This week’s Carnival of Space is hosted by our pal John Williams over at Starry Critters!

Click here to read Carnival of Space #254.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

Lead image by John Williams.