Posted on by Astronomy Cast

Podcast: Explosions in Space

We’ve all seen the classic science fiction space explosions, full of flames and loud sounds. Beautiful on the screen but, totally lacking in any kind of… science. What’s wrong with science fiction? What would chemical and nuclear explosions really look like? What would we hear? And what are some natural explosions that nature detonates in space?

Click here to download the episode.

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“Explosions in Space” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:

Posted on by Nancy Atkinson

Geminid Meteor Shower Peaks Tonight

Winter Milky Way Geminids on December 12, 2012. Credit: John Chumack

The Geminid Meteor Shower is underway, with the peak on December 13th and 14th! SpaceWeather.com is reporting that international observers are counting as many as 50 meteors per hour as Earth plunges into a stream of debris from rock comet 3200 Phaethon. Astrophotographer John Chumack in Ohio, USA took the image of a bright fireball last night (Dec. 12/13) and said he was seeing one or two meteors every minute or so, describing the sky show as “definitely one of the best Geminid showers I’ve seen in over 20 years!”

John also compiled a video, below.

So if you’ve got clear skies, get out there and look up! The best time to look will be after dark on Thursday, December 13 and before dawn on Friday, December 14. The Geminids are notably one of the most reliable meteor showers, and this year the timing is great as the new Moon won’t intefer with the shower. Astronomers from McDonald Observatory at the University of Texas predicts skywatchers can expect to see dozens of meteors per hour.


Additionally, NASA says that for the first time, Earth might also pass through the tail of another object, comet Wirtanen, which could possibly provide even more meteors in the sky. No one is really sure what kind of meteor action this comet will produce, but Bill Cooke of NASA’s Meteoroid Environment off says even if the new shower is a dud, the Geminids should be great.

For the Geminids, meteors will appear to originate from the constellation Gemini, although they should be visible all over the sky. If Wirtanen does contribute to the shower, they may appear to come from the constellation Pisces.

If you’ve got cloudy skies or its too cold outside, there are a few alternatives:

NASA TV is going to have a live broadcast from 11:00 pm-3:00 am EST.

You can follow along via Twitter and MeteorWatch. All you need to do is check for the #meteorwatch hashtag, and people will be posting descriptions and images.

You can also “listen” to the meteor shower: The Air Force Space Surveillance Radar is scanning the skies above Texas. When a meteor or satellite passes over the facility–ping!–there is an echo. Check out SpaceWeatherRadio for the broadcast.

Posted on by John Williams

Combining Light to Reveal Monster Black Holes

NGC 3627 glows in the combined light of Hubble, Chandra, Spitzer and the Very Large Telescope in this image. Astronomers conducted a survey of 62 galaxies, including NGC 3627 to study monster black holes at their centers.

It’s not just pretty, it’s science. Like a starry watercolor, astronomers combining light from Earth and space-based observatories found 37 new supermassive black hole candidates lurking in nearby galaxies.

Included in that survey is NGC 3627 pictured above. Astronomers combined X-ray data from NASA’s Chandra X-ray Observatory, infrared data from the Spitzer Space Telescope, and optical data from the Hubble Space Telescope and the Very Large Telescope. The other images give the galaxy context but it’s the ghostly blue images from Chandra that show super bright in the X-ray images; X-ray light powered by material falling into a monster black hole.

Gas and dust slowly spins around the black hole creating a flattened disk, or accretion disk. As material falls inward, it heats up and releases large amounts of energy that shine brightly in the ultraviolet region of the spectrum.

NGC 3627, located about 30 million light-years from Earth, was just one of a survey of 62 nearby galaxies using archived data from Chandra and data from the Spitzer Infrared Nearby Galaxy Survey. Of those, 37 galaxies contained bright X-ray sources, indicating active black holes at their cores. Scientists believe that seven of those sources are new supermassive black hole candidates.

The paper describing the survey results was published in the April 10, 2011 issue of The Astrophysical Journal.

Combining ultraviolet and infrared observations confirm previous Chandra results that found that there may be many more galaxies powered by monster black holes than believed previously through optical surveys. Scientists say in the paper that low-levels of black hole activity previously may have been hidden by dust or washed out by the bright light of the galaxy.

Image caption: Bright X-ray sources glow a ghostly blue in this image in NGC 3627 from NASA’s Chandra X-ray Observatory. A study confirms previous Chandra results that indicate that more galaxies powered by monster black holes populate the cosmos.

Source: Chandra X-ray Observatory website

Posted on by Nancy Atkinson

One Spacecraft Captures Another in Lunar Orbit

moon.thumbnail.gif

This is awesome! It is the first footage of one orbiting robotic spacecraft taken by another orbiting robotic spacecraft at Earth’s moon. “Flow,” one of two satellites making up NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, captured this video of NASA’s Lunar Reconnaissance Orbiter (LRO) as it flew by at a distance of about 20 kilometers (12 miles) on May 3, 2012. LRO is the single bright pixel that moves from top left to bottom right. The Moon’s south polar region is in the background, much of which is in darkness.

This footage was taken by Flow’s “MoonKam” camera, which is an educational camera run by the GRAIL team and Sally Ride Science.

Posted on by Nancy Atkinson

The Truth About 2012: Killer Solar Flares Are a Physical Impossibility

NASA is trying to make sure that no one is taking the 2012 doomsday nonsense seriously, and just put out this video today detailing how a gigantic “killer solar flare” just ain’t gonna happen. Dr. Alex Young from the Goddard Space Flight Center explains how the Sun’s regular 11-year solar cycle is expected to peak in 2013 and 2014, not on December 21 of this year. Plus, this current solar cycle has been kind of a dud as far as wild activity goes, and scientists are not expecting the peak of this cycle to even be as strong as the previous one, which was rather mild.

Solar prominence in H alpha, with Earth scale model. Credit: John Brady.

Not to mention, Earth’s atmosphere keeps us well protected here on Earth. The only thing we do have to be concerned with is how solar flares and coronal mass ejections (CMEs) can damage satellites and even impact the power grid on Earth; additionally astronauts in Space to have to be specially protected as they are outside of the protection of the atmosphere.

You can get more information in our detailed article “2012: No Killer Solar Flare.”

Posted on by Nancy Atkinson

Timelapse: Incredible Northern Lights from the Arctic Circle

Shot from the Arctic Circle in Canada, this beautiful display of the Aurora Borealis will put you in the holiday mood (I’m sure Santa’s workshop is just beyond one of those mountains in the background!) National Geographic photographer Mike Theiss said the northern lights started around 11:30pm and continued on until around 3am. “The lights were dancing, rolling and twisting and at times looked like they were close enough to touch,” he said.

Just beautiful.

Read more about his Arctic Circle adventure here.

Posted on by Nancy Atkinson

NASA’s Version of Mr. Fusion

Researcher Stephen Anthony works with the new reactor prototype that could turn trash into gas. Image credit: NASA/Dmitri Gerondidakis

It probably won’t be able to fuel Doc Brown’s flux capacitor on his DeLorean time machine, but NASA researchers are hoping a new device that will be tested on the International Space Station can turn trash into power. The Trash to Gas Reactor is a miniature version of large waste incineration facilities on Earth that generate electricity or fuel. This could help with the accumulating trash on the ISS and be used on future missions beyond Earth orbit, as well as help the trash problem in areas of the world where there are neither large power plants nor garbage processing facilities.

“Not only will the effort on this help space missions but also on Earth because we have enough problems dealing with our own trash,” said Anne Caraccio, a chemical engineer working on the project.

The prototype of the Trash to Gas Reactor is a meter-long (3 foot-long) device that looks strikingly similar to the “Mr. Fusion” reactor in the second “Back to the Future” movie. Just like Doc Brown and Marty, astronauts can throw in things like food wrappers, used clothing, food scraps, tape, packaging and other garbage accumulated by the crew and the reactor will turn it into potential power, such as methane gas, or even oxygen or water.

The team developing the reactor is hoping to have their prototype ready to fly on the ISS by 2018 – which unfortunately doesn’t fit into the “Back to the Future” timeline: Emmett Brown travels to 2015 where he gets his Mr. Fusion and changes the future. But perhaps its Earth-bound counterpart could be ready in two years, in time for the Doc’s arrival from 1985.

“Back to the Future’s” Mr. Fusion. Via Theme Park Review.

OK, back to reality now, even though this does have a science fiction element to it…

A team led by Paul Hintze at the Kennedy Space Center has built an 80-pound small reactor to test theories about incinerating a variety of trash ranging from used clothes to uneaten food. The reactor holds more than three quarts of material and burns at about 1,000 degrees F, about twice the maximum temperature of an average household oven. It’s expected to take astronauts four hours to burn a day’s worth of trash from a crew of four.

The team estimates that during the course of a year in space – one half the length of time a mission to Mars is expected to take – trash processing for a crew of four would create about 2,200 pounds of methane fuel, enough to power a launch from the lunar surface, Hintze said.

“The longer the mission, the more applicable this technology is,” Hintze said. “If you’re just doing a two-week mission, you wouldn’t want to take along something like this because you wouldn’t get anything out of it.”

Converting garbage into fuel also would keep astronauts from turning their cramped space capsule into an orbiting landfill.

Paul Hintze is the researcher leading the trash-to-gas project at NASA’s Kennedy Space Center in Florida. Image credit: NASA/Dmitri Gerondidakis

The experimental version of the reactor is made of steel, but the team expects to employ a different alloy for future versions, something that might be lighter but just as strong in order to withstand the high temperatures needed to break down the materials and destroy potential microbes.

One of the issues the team is working on is making sure that no smell or potential hazardous gases are created as a by-product in the closed environment of the space station or a spacecraft on its way to deep space.

“On Earth, a little bit of an odor is not a problem, but in space a bad smell is a deal breaker,” Hintze said.

Right now trash in the ISS is stuffed into the Progress resupply ship, which burns up in the atmosphere during re-entry. This new reactor could turn the trash into something valuable in space.

Source: NASA

Posted on by Nancy Atkinson

Cry Me a Nile-Like River of Liquid Hydrocarbons on Titan

This image from NASA’s Cassini spacecraft shows a vast river system on Saturn’s moon Titan. It is the first time images from space have revealed a river system so vast and in such high resolution anywhere other than Earth. Image Credit: NASA/JPL-Caltech/ASI

Titan is appearing more Earth-like all the time (yes, a very cold, and early version of Earth), as now the Cassini spacecraft has spotted what appears to be a miniature extraterrestrial version of the Nile River: a river valley on Saturn’s moon Titan that extends from what looks like ‘headwaters’ out to a large sea. Not only is it a riverbed, but it appears to be filled with liquid; likely very cold hydrocarbons such as ethane or methane.


Scientists deduce that the river is filled with liquid because it appears dark along its entire extent in the high-resolution radar image, indicating a smooth surface.

It is the first time images have revealed a river system this vast and in such high resolution anywhere beyond Earth.

“Though there are some short, local meanders, the relative straightness of the river valley suggests it follows the trace of at least one fault, similar to other large rivers running into the southern margin of this same Titan sea,” says Jani Radebaugh, a Cassini radar team associate at Brigham Young University, USA. “Such faults – fractures in Titan’s bedrock – may not imply plate tectonics, like on Earth, but still lead to the opening of basins and perhaps to the formation of the giant seas themselves.”

While the Earthly Nile River is 6,650 kilometers (4,132 miles) long, Titan’s big river is about 400 km long.

Titan is the only other world we know of that has stable liquid on its surface. While Earth’s hydrologic cycle relies on water, Titan’s equivalent cycle involves hydrocarbons.

Images from Cassini’s visible-light cameras in late 2010 revealed regions that darkened after recent rainfall.

Cassini’s visual and infrared mapping spectrometer confirmed liquid ethane at a lake in Titan’s southern hemisphere known as Ontario Lacus in 2008.

“This radar-imaged river by Cassini provides another fantastic snapshot of a world in motion, which was first hinted at from the images of channels and gullies seen by ESA’s Huygens probe as it descended to the moon’s surface in 2005,” said Nicolas Altobelli, ESA’s Cassini Project Scientist.

See a full-sized image of Titan’s river here.

Source: ESA

Posted on by John Williams

Hubble Census Unveils Galaxies Shining Near Cosmic Dawn

This new image of the Hubble Ultra Deep Field (HUDF) 2012 campaign reveals a previously unseen population of seven faraway galaxies, which are observed as they appeared in a period 350 million to 600 million years after the Big Bang. Credit: NASA, ESA, R. Ellis (Caltech), and the UDF 2012 Team

Astronomers using NASA’s Hubble Space Telescope have spotted some of the most distant, dim and ancient galaxies ever detected in a new survey. The images, taken with Hubble’s Wide Field Camera 3 (WFC 3) looks further back in time than any previous Hubble observation, providing information about the conditions in the early Universe.

“This is like a scientific version of the story of Genesis,” said astronomer Avi Loeb from Harvard University.

The seven distant galaxies represent a previously unseen population of galaxies that formed more than 13 billion years ago, when the Universe was less than 3 percent of its present age. In these deepest images to date from Hubble, astronomers were able to take a sample of the amount of galaxies at the time. The results show a smooth decline in the number of galaxies with increasing look-back time to about 450 million years after the Big Bang.

The data provides the first reliable census of this uncharted period of cosmic history, according to the scientists. As astronomers look even deeper into the Universe, galaxy numbers appear to drop off smoothly leading them to believe that the “cosmic dawn” was gradual, not a dramatic event.

“Observations of the microwave afterglow from the Big Bang tell us that reionization happened more than about 13 billion years ago,” said Brant Robertson of the University of Arizona in Tucson, a member of the survey team. “Our data confirms that reionization was a drawn-out process occurring over several hundred million years with galaxies slowly building up their stars and chemical elements. There wasn’t a single dramatic moment when galaxies formed; it was a gradual process.”

These galaxies were found as part of an ambitious Hubble survey of an intensively studied patch of sky known as the Ultra Deep Field (UDF), which was originally taken in 2003-2004, focusing in on a small area in the sky in the constellation Fornax. In the new 2012 campaign, called UDF 2012, a team of astronomers led by Richard Ellis of the California Institute of Technology used the WFC3 to peer deeper into space in near-infrared light than any previous Hubble observation. The observations were made over a period of six weeks during August and September 2012, and the first scientific results are now appearing in a series of scientific papers. The UDF 2012 team is publicly releasing these unique data, after preparing them for other research groups to use.

“Hubble is achieving just great science,” said John Grunsfeld, former astronaut and NASA’s associate administrator for science, speaking at a briefing about the new survey. “This is an origins story, where we’re going back to the beginning, back to the first stars that appeared in the Universe. This validates that when we get James Webb Space Telescope online it will have a lot to look at and a lot to do.”

The James Webb Space Telescope is slated to launch in 2018.

Astronomers detected seven galaxies in the time period 400-600 million years after the Big Bang. All extremely distant, they ranged in distance with redshifts from 8.6 to nearly 12.

Astronomers study the distant universe in near-infrared light because the expansion of space stretches ultraviolet and visible light from galaxies into infrared wavelengths, a phenomenon called “redshift.” The more distant a galaxy, the higher its redshift.

Notably, one of the galaxies may be a distance record breaker, observed 380 million years after the birth of our universe in the Big Bang, corresponding to a redshift of 11.9. This is the galaxy UDFj-39546284, which was previously detected and was originally suggested as the most distant object ever found nearly two years ago by Hubble. Later observations put it at a redshift of 10.3, but the newly refined observations put it even more distant.

A timeline of the Universe and our observations of it. Credit: University of Arizona.

Scientists think that the universe began with the Big Bang about 13.7 billion years ago. Hydrogen formed about 400,000 years later but with no stars, spacetime was dark. About 200 million years later, hydrogen clouds collapsed forming the first stars and galaxies; what astronomers call the “cosmic dawn.” Light from these new stars began breaking down hydrogen into protons and electrons during a time period called cosmic reionization. In the present universe, scientists see galaxies growing in mass and size with the synthesis of elements, leading to the formation of complex molecules including the components to create life. Our Sun and solar system formed just over 4 billion years ago.

“The team pushed Hubble to its limits. This is probably the farthest back Hubble can look, according to the study leader, Richard Ellis. “We are pushing Hubble well beyond what it was designed to do.”

Read more about the findings and the HUDF 2012 Campaign at the HubbleSite.

Read the team’s paper: The Abundance of Star-Forming Galaxies in the Redshift Range 8.5 to 12: New Results from the 2012 Hubble Ultra Deep Field Campaign

Additional Sources: CalTech ESA Hubble

Posted on by Nancy Atkinson

What Earth Looked like on 12/12/12

Earth, as seen by the GOES15 satellite on December 12, 2012. Credit: NASA/NOAA GOES Project/Dennis Chesters

Although we don’t subscribe to hokum like numerology or think that dates on a man-made calendar could have any sort of cosmic significance, there is something about a little symmetry. The GOES-15 satellite captured this image of Earth today, which is 12/12/12 on the Gregorian calendar, and even added a bonus of taking the image at 1200 UTC.

Too bad the GOES-12 spacecraft had some thruster problems and is currently in a standby mode.

Dennis Chesters, project scientist of NASA’s GOES Project at the NASA Goddard Space Flight Center said this image does something significant, however: the fourth tropical cyclone in the southern Pacific Ocean. Newborn Tropical Storm Evan was born today, Dec. 12, 2012 at 1500 UTC (10 a.m. EST) and appears as a rounded area of clouds in the bottom left corner of the image. Tropical Storm Evan is about 145 nautical miles west of Pago Pago, American Samoa.

See a larger version of this image here.