Universe Today

April 10, 2014March 8, 2017 by Fraser Cain

Can Tatooine Be Real?

We’re familiar with the sky on Tatooine with its twin suns. But could a planet actually orbit two stars at the same time? Could you have a planet in a multiple star system with 4, 6 or more suns?

Hey kids, you remember Star Wars right? Tatooine ring any bells? Lots of sand Tusken raiders walking single file. Banthas sweating all over the place like some crazy mammoth-goat breeding experiment gone horribly awry?
Tatooine was an arid desert planet, it had 2 suns and 3 moons. It’s not the only fictional planet to orbit multiple suns. In Nightfall by Isaac Asimov, planet Lagash had 6 suns. Could something like this be possible?

Interestingly, most stars in the Milky Way are in multiple star systems. You can easily have double, triple, or quadruple systems. There are even star clusters with hundreds or even thousands of stars. Just imagine the crazy chaotic gravitational interactions in a multiple star system.

So, could they have planets? Yes. There are circumbinary systems, where stars orbit each other their planets orbit outside, circling them both. Since the stars orbit one another so closely, it’s the gravitational equivalent of a single star. From an orbiting planet, the stars would always appear together in the sky.

To date, we have discovered 17 of these systems. Then there are wide binary systems, which are far more dangerous for planets. Here the planets orbit one main star, and there’s another star which maintains a distant orbit much further out. You don’t want to live there. The gravitational interactions are chaotic and lead to mayhem. In simulations, planets which aren’t tightly orbiting a star are ejected out of the system, or crashed into other planets or stars.

Artist's impression of the Cygnus-X1 binary. Credit: NASA / Honeywell Max-Q Digital Group / Dana Berry — Artist’s impression of the Cygnus-X1 binary. Credit: NASA / Honeywell Max-Q Digital Group / Dana Berry

We might already be detecting highly elliptical orbits from disrupted planets just like these. A triple star system was recently discovered in the constellation Cygnus: HD 188753. Here, a pair of stars are tightly bound, and these are in a wide binary arrangement with a sun-mass star. A planet closely orbits the primary star, but all other planets were likely ejected.

In the year 2012, a planet was found around Alpha Centauri B, and PH1 was the first quadruple star system to be discovered to have a planet. Kepler 47 is a multi-star, multi-planet system. Two stars orbit one another every 7.45 days. Here, the gas giant Kepler 47c orbits the stars every 303 days and is even located in the habitable zone. This sounds like perfect concept art for a Vin Diesel film, or artwork airbrushed on the side of a van.

Kepler-16b is but one example of an uncanny world. It orbits two suns. Credit: Discovery

Finally, In 2011, the Kepler-16 system was found to have a circumbinary planet in the habitable zone. So, two stars, closely orbiting each other and a Saturn-mass, Kepler 16b orbiting the two. Astronomers informally called this a real Tatooine.

What do you think? Would you want to live on a desert world like Tatooine or Arrakis? Tell us your thoughts in the comments below.

April 10, 2014December 23, 2015 by David Dickinson

Two Observing Challenges: Catch Venus Passing Neptune And Occulting a Bright Star

The Milky Way, The Large and Small Magellanic Clouds, Zodiacal Light, and Venus as seen from the Karoo Desert in South Africa early this month. Credit: Cory Schmitz.

Have you been following the planet Venus this season? 2014 sees the brightest planet in our Earthly skies spend a majority of its time in the dawn. Shining at magnitude -3.8, it’s hard to miss in the morning twilight. But dazzling Venus is visiting two unique celestial objects over the next week, and both present unique observing challenges for the seasoned observer.

First up is an interesting close conjunction of the planets Venus and Neptune on the morning of Saturday, April 12^th. Closest conjunction occurs at 3:00 Universal Time (UT) April 12th favoring Eastern Europe, the Middle East and eastern Africa, when the two worlds appear to be just 40 arc minutes apart, a little over – by about 10’ – the apparent size of a full Moon. Shining at magnitude +7.8 and 30,000 times fainter than Venus, you’ll need a telescope to tease out Neptune from the pre-dawn sky. Both objects will, however, easily fit in a one degree field of view, in addition to a scattering of other stars.

Looking to the east the morning of April 12th from the U.S. East Coast near latitude 30 degrees north. Nearby stars are annotated in red by magnitude with decimals omitted. Created using Stellarium, click to enlarge.

At low power, Venus will display a 59% illuminated gibbous phase 20” across on the morning of the 12^th, while Neptune will show a tiny disk barely 2” across. Still, this represents the first chance for viewers to recover Neptune since solar conjunction behind the Sun on February 23^rd, 2014, using dazzling Venus as a guide.

Both sit 45 degrees west of the Sun and currently rise around 3 to 4 AM local dependent on latitude.

This is one of the closest planet-planet conjunctions for 2014. The closest is Venus and Jupiter at just 0.2 degrees apart on August 18^th. This will represent the brightest planet versus planet conjunction for the year, and is sure to illicit multiple “what’s those two bright stars in the sky?” queries from morning commuters… hopefully, such sightings won’t result in any border skirmishes worldwide.

Now, for the mandatory Wow factor. On the date of conjunction, Earth-sized Venus is 0.84 Astronomical Units (A.U.s) or over 130 million kilometres distant. Ice giant Neptune, however, is 30.7 AUs or 36 times as distant, and only appears tiny though it’s almost four times larger in diameter. Sunlight reflected from Venus takes 7 minutes to reach Earth, but over four hours to arrive from Neptune. We’ve visited Venus lots, and the Russians have even landed there and returned images from its smoldering surface, but we’ve only visited Neptune once, during a brief flyby of Voyager 2 in 1989.

From Neptune looking back on April 12th, Earth and Venus would appear less than 1 arc minute apart…. though they’d also be just over one degree from the Sun!

The "shadow path" of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0. — The “shadow path” of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0.

But an even more bizarre event happens a few days later on April 16^th, though only a small region of the world in the South Pacific may bare witness to it.

Next Wednesday from 17:59 to 18:13 UT Venus occults the +3.7 magnitude star HIP 112961 also known as Lambda Aquarii on the morning of April 16^th 2014.

Venus will be a 61% illuminated gibbous phase 19” in diameter. Unfortunately, although North America is rotated towards the event, it’s also in the middle of the day.

The best prospects to observe the occultation are from New Zealand and western Pacific at dawn. The star will disappear behind the bright limb of Venus in dawn twilight before emerging on its dark limb 5 minutes later as seen from New Zealand.

The path of Lambda Aquarii behind Venus as seen from New Zealand the morning of the 16th. Created in Starry Night.

Note: New Zealand switched back to standard time on April 6^th – it’s currently Fall down under – and local sunrise occurs around ~7:40 AM.

Lambda Aquarii is a 3.6 solar mass star located 390 light years distant. As far as we know, it’s a solitary star, though there’s always a chance that a companion could make itself known as it emerges on the dark limb of Venus. Such an observation will, however, be extremely difficult, as Venus is still over 700 times brighter than the star!

North Americans get to see the pair only 20’ apart on the morning of the 12^th.

And further occultation adventures await Venus in the 21^st century. On October 1^st, 2044 it will occult Regulus… and on November 22^nd, 2065 it will actually occult Jupiter!

Such pairings give us a chance to image Venus with a “pseudo-moon.” Early telescopic observers made numerous sightings of a supposed Moon of Venus, and the hypothetical object even merited the name Neith for a brief time. Such sightings were most likely spurious internal reflections due to poor optics or nearby stars, but its fun to wonder what those observers of old might’ve seen.

… and speaking of moons, don’t miss a chance to see Venus near the daytime Moon April 25^th. Follow us as @Astroguyz on Twitter as we give shout outs to these and other strange pairings daily!

April 10, 2014December 23, 2015 by Elizabeth Howell

European Satellite Dodged Space Debris Hours After Reaching Orbit

Artist's conception of Sentinel-1, an environment-monitoring satellite from the European Space Agency. Credit: ESA/ATG medialab

Yesterday, the European Space Agency disclosed a serious problem early in the Sentinel-1A mission, which lifted off April 3 on a mission to observe the Earth. The spacecraft — which reportedly cost 280 million Euros ($384 million) to launch — came close to a collision in orbit.

“At the end of the first day after the launch (4 April): all deployments have been executed during the night and completed early in the morning at the beginning of the first ‘day shift’,” read a blog post from the Sentinel-1A team on the European Space Agency’s website.

“As the first day shift nears its end, a serious alert is received: there is a danger of a collision with a NASA satellite called ACRIMSAT, which has run out of fuel and can no longer be maneuvered. Not much information at the beginning, we are waiting for more information, but a collision avoidance maneuver may be needed. ‘Are you kidding? A collision avoidance maneuver during LEOP [launch and early orbit phase]? This has never been done before, this has not been simulated!’ ”

Worse, as controllers looked at the data they realized there was not one, but two possible points of collision. Cue the inevitable Gravity reference, and then a solution: to essentially move the satellite out of the way. The maneuver took about 39 seconds, and safely skirted Sentinel-1A out of danger.

You can read more about the situation in the blog post. ESA’s main Twitter feed and the ESA Operations Twitter feed also first reported the near-collision yesterday, nearly a week after it occurred. It should also be noted that the Europeans (among many other space agencies) are looking at ways to reduce space debris.

The successful liftoff of Sentinel-1A in April 2014. Credit: ESA-S.Corvaja, 2014

April 10, 2014December 23, 2015 by Elizabeth Howell

Do You Know 80s Kid Who Inspired Virgin Galactic? Branson Asks For Help Ahead Of First Spaceflight

New Mexico Governor Susana Martinez and Sir Richard Branson pose for photographer on the balcony of the new Spaceport Hangar, Monday October 17, 2011 near Las Cruces, New Mexico. It was part of a dedication and christening of the hangar to Virgin Galactic. Credit: Mark Greenberg

As Virgin Galactic aims for a spaceflight this year, founder Richard Branson is asking the public to help track down the kid (now an adult) who prompted him to start the company 26 years ago.

Above you can see a Virgin video showing an 1988 clip from an old BBC show called “Going Live!” Branson answered a question from a young fan, Shihan Musafer, asking if he’d go to space. Of course, you all know what his answer was.

“After that call, I set about registering the name Virgin Galactic,” Branson wrote in a blog post. “We’d love to track down Shihan to say a personal thank you for helping to inspire the idea with that phone call. We want to offer Shihan the chance to join Virgin Galactic as a VIP guest to witness a spaceflight.”

If you have any information, Branson encourages you to tweet @richardbranson and @virgingalactic with the hashtag #shihanmusafer. (Early results on Twitter show a lot of retweets and few ideas of how to find him.) Meanwhile, his company has been busy putting SpaceShipTwo through its paces, making powered test flights — such as this one you can see from January.

April 9, 2014April 26, 2016 by Ken Kremer

US Spy Sat and SpaceX Set for Double Barreled Blastoffs After Critical Cape Canaveral Radar Revitalized

Atlas V rocket and Super Secret NROL-67 intelligence gathering payload following rollout to Space Launch Complex 41 at Cape Canaveral Air Force Station, FL, on March 24, 2014. Credit: Ken Kremer - kenkremer.com

The Florida Space Coast is about to ignite with a doubled barreled dose of spectacular rocket launches from Cape Canaveral over the next few days that were suddenly postponed two weeks ago amidst final launch preparations when an electrical short completely knocked out use of the US Air Force’s crucial tracking radar that is mandatory to insure public safety.

A pair of liftoffs vital to US National Security and NASA/SpaceX are now slated for April 10 and April 14 from Cape Canaveral Air Force Station after revitalizing the radar systems.

The tracking radar is an absolutely essential asset for the Eastern Range that oversees all launches from Cape Canaveral Air Force Station and the Kennedy Space Center in Florida.

The United Launch Alliance Atlas V is now slated to launch on Thursday, April 10 at 1:45 p.m. EDT.

Artwork for Super Secret NROL-67 payload launching on Atlas V rocket. Credit: NRO/ULA

The Atlas V rocket is carrying the super secret NROL-67 intelligence gathering spy satellite for the National Reconnaissance Office (NRO).

The SpaceX Falcon 9 is slated to launch on Monday, April 14 at 4:58 p.m. EDT.

The Falcon 9 is lofting a SpaceX Dragon cargo ship and delivering some 5000 pounds of science experiments and supplies for the six man space station crew – under a resupply contract with NASA.

The pair of liftoffs of the Atlas V and Falcon 9 boosters for the NRO and SpaceX/NASA had been slated just days apart on March 25 and March 30, respectively.

Falcon 9 and Dragon static fire test on March 8, 2014. Credit: SpaceX

I was on site at Cape Canaveral Launch Pad 41 photographing the Atlas V rocket carrying the NRO payload in anticipation of the launch.

Shortly thereafter a fire of unexplained origin in the radar equipment unexpected occurred and knocked the tracking radar off line. When no quick fix was possible, both launches were delayed indefinitely pending repairs.

“The tracking radar experienced an electrical short, overheating the unit and rendering the radar inoperable,” said the USAF in a statement I received from the 45th Space Wing that controls the critical launch control systems, communications, computers and radar elements at the Eastern Range.

On Monday, April 7, the Air Force announced that range repairs were on target and that a retired, inactive radar had been brought back online.

“A radar that was previously in standby status has been brought back to operational status while the repair work is being accomplished,” said the USAF in a statement.

A fully functional tracking radar is an absolute requirement to ensure the success and safety of every rocket launch.

Insufficient maintenance and antiquated equipment due to a lack of US government funding and investment in infrastructure may be at fault for the electrical short.

The Eastern range radar must function perfectly in order to destroy any rocket in a split second in the event it abruptly veers off course towards the nearby populated areas along the Florida Space Coast.

The Atlas V rocket was rolled out earlier today to Space Launch Complex 41 in preparation for Thursday’s NROL-67 launch. The weather forecast shows a 90 percent chance of favorable weather conditions for launch.

The Dragon spacecraft, filled with about 4,600 lbs of cargo bound for the space station, is mated with Falcon 9. Credit: SpaceX

Stay tuned here for Ken’s continuing Atlas V NROL 67, SpaceX, Orbital Sciences, commercial space, Orion, Chang’e-3, LADEE, Mars rover, MAVEN, MOM and more planetary and human spaceflight news.

Learn more at Ken’s upcoming presentations at the NEAF astro/space convention, NY on April 12/13.

Ken Kremer

April 9, 2014December 23, 2015 by Elizabeth Howell

Did A Lake Once Cover Spirit Rover’s Landing Site On Mars?

Mosaic images of Comanche outcrop from NASA's Spirit rover, which ceased communications to Earth in 2010. Credit: NASA/JPL-Caltech/Cornell University/Arizona State University

Science is an iterative process, with each discovery building on those made before. This means that as new evidence comes into play, you need to examine the evidence in context of what you know now, and what you knew before. Sometimes the evidence points to new theories. And sometimes, like in this case concerning Mars, it points to older ones.

The Spirit rover spent six years (2004-2010) exploring Gusev Crater, which is just a little south of the Martian equator. Scientists have been back and forth about whether it once was a vast lake of water, but some new research could swing the pendulum towards the water hypothesis.

The water track hinges on magnesium-iron carbonate minerals found in Columbia Hills, a 300-foot (91-meter) feature about two miles (3.2 kilometers) away from Spirit’s landing site. When the minerals were first found in the hills’ Comanche outcrop in 2010, scientists (which included the lead author of the study) attributed this to ancient hot springs activity.

It was a bit of a disappointment for those who had picked Gusev as a landing site from the belief that it was indeed an ancient lake. “From orbit, Gusev looked, with its southern rim breached by a meandering river channel, as if it once held a lake – and water-deposited rocks were the rover mission’s focus,” Arizona State University stated.

Spirit, however, initially found that the crater was lined with volcanic rocks and not the sediments scientists needed to support the lake theory. When it did find evidence of water in the hills, it was linked to hydrothermal activity.

A 2004 image of an outcrop at Columbia Hills on Mars, taken by the rover Spirit. Credit: NASA/JPL

The new analysis suggests that Comanche (and other outcrops in the vicinity) got their liquid from water on the surface that was of a much lower temperature than what you would find in a hot spring –which originates underground.

This is because Comanche and the surrounding area are believed to have started as a buildup of volcanic ash (called a tephra) from eruptions somewhere around Gusev. As the theory goes, waters penetrated Gusev at the south, lingered, and created a “briny solution”. Over time, the brine evaporated and what remained was carbonate minerals residue that coated the rocks.

“The lake didn’t have to be big,” stated Steve Ruff, an associate research professor at Arizona State University who led the research. “The Columbia Hills stand 300 feet high, but they’re in the lowest part of Gusev. So a deep, crater-spanning lake wasn’t needed.”

Locator image for Comanche outcrops in the Columbia Hill of Gusev Crater, Mars. Yellow line marks Spirit’s traverse. Pancam panoramic images were taken near the true summit of Husband Hill (Everest Pan) and at the location of the Seminole outcrop. Spirit is currently located on the left side of Home Plate. Image width is ~1000 m. Image courtesy of NASA/UA/HiRISE using PSP_001513_1655_red image. After Arvidson et al. [2008] — Locator image for Comanche outcrops in the Columbia Hill of Gusev Crater, Mars. Yellow line marks Spirit’s traverse. Pancam panoramic images were taken near the true summit of Husband Hill (Everest Pan) and at the location of the Seminole outcrop. Spirit was then located on the left side of Home Plate. Image width is ~1000 m. Image courtesy of NASA/UA/HiRISE using PSP_001513_1655_red image. After Arvidson et al. [2008]

Getting more information, however, would be one way to add credence to the theory. That’s why the team is also pushing for the forthcoming NASA Mars 2020 rover to land in Gusev Crater, which would be unprecedented among Mars missions as each lander and/or rover has gone to a different spot. Site selection has not been finalized yet.

“Going back to Gusev would give us an opportunity for a second field season there, which any terrestrial geologist would understand,” stated Ruff. “After the first field season with Spirit, we now have a bunch more questions and new hypotheses that can be addressed by going back.”

You can read more about the research in the journal Geology.

Source: Arizona State University

April 9, 2014December 23, 2015 by David Dickinson

Mars Opposition Season 2014: Images From Around the World

Mars as seen on from Aguadilla, Puerto Rico on Mars 25th, 2014, two weeks prior to opposition. Credit-Efrain Morales Rivera.

Did you see it? Last night, the Red Planet rose in the east as it passed opposition for 2014, and astrophotographers the world over were ready to greet it. And although Mars gets slightly closer to us over the coming week, opposition marks the point at which Mars is 180 degrees “opposite” to the setting Sun in Right Ascension as viewed from our Earthly vantage point and denotes the center of the Mars observing season. Opposition only comes around once about every 26 months, so it’s definitely worth your while to check out Mars through a telescope now if you can. We’ve written about prospects for observing Mars this season, and the folks at Slooh and the Virtual Telescope Project also featured live views of the Red Planet last night. We also thought we’d include a reader roundup of pics from worldwide:

Mars and Spica rising over the telescope domes at Kitt Peak, Arizona. The 2.1 metre dome is on the left, and the 0.9 metre dome is to the right. Credit-Rob Sparks @halfastro.

Even near opposition, Mars presents a challenge to observers. In 2014, Mars only reaches 15 arc seconds maximum in apparent size, a far cry from its 25″ appearance during the historic 2003 opposition. Now for the good news: we’re in a cycle of improving oppositions… the next one on May 22nd, 2016 will be better still, and the 2018 opposition will be nearly as favorable as the 2003 appearance!

Mars as seen from the Netherlands at 0:26 UT... about 3 hours past opposition. Credit- Christian Fröschlin. — Mars as seen from the Netherlands at 0:26 UT… about 3 hours past opposition. Credit- Christian Fröschlin @chrfde.

And you can see just how technology in the amateur astronomy community has improved with each successive appearance of Mars over the years. Early observers were restricted to sketching features glimpsed during fleeting moments of steady seeing. Even during the film era of photography, absurdly long focal lengths were required to yield even a tiny speck of a dot. And even then, the “graininess” of the film tended to smear and yield a blurry image with few details to be seen.

The advent of digital photography opened new vistas on planetary imaging. Now backyard astrophotographers are routinely taking images using stacking techniques and processing to “grab” and align those moments of good seeing. These images are often now better that what you’d see in a text book taken from professional observatories only a few decades ago!

And you can now easily modify a webcam to take decent planetary images that can then be stacked and processed with software freely available on the web.

…And check out this video animation also by Christian Fröschlin that shows the rotation (!) of Mars:

Mars as seen from Ottawa, Canada, taken using an IPhone 4S through a NexStar 8SE telescope on April 4th, 2014. Awesome! Credit-Andrew Symes @FailedProtostar

Shahrin Ahmad made an excellent video from Malaysia that demonstrates just what raw captured images of Mars look like before processing:

Note that the large dark triangular region is Syrtis Major.

Mars annotated, a stack of 1128 frames shot at 666x. Credit-Mike Weasner/Cassiopeia Observatory.

The northern polar cap is currently tipped towards us, as it’s northern hemisphere summertime on Mars. Many images reflect this prominent feature, as well as the orographic clouds skirting the Hellas basin that have been the hallmark of the Mars opposition of 2014. These are also apparent visually at the eyepiece. It’s worth staying up a bit towards local midnight to observe and image Mars, as it transits at its maximum elevation — and is above the murk of the sky low to the horizon — right around this time.

Mars captured through a Celestron C6 SCT telescope on April 5th, 2014. Credit: Joel Tonyan.

Mars: a study of color contrasts on the eve of opposition. Credit-Laura Austin @LAismylady

And Mars observing season doesn’t end this week. Mars makes its closest passage to the Earth for 2014 next Monday on April 14th at 0.618 Astronomical Units (A.U.s) distant. Mars will occupy the evening sky for the remainder of 2014 before finally reaching solar conjunction on June 14th, 2015. Mars will still be greater than a respectable 10″ in apparent size until June 24th and will continue to offer observers a fine view at the eyepiece.

Mars as seen from Rhode Island on the night of opposition. Credit-Cherie @KelieAna

And don’t forget, that waxing gibbous Moon is now homing in on Mars and will only sit a few degrees away from the Red Planet and Spica on the night of the April 14th/15th, 2014 during a fine total lunar eclipse. And no, a “red” planet + a “blood red” eclipsed Moon does not equal doomsday… but it’ll make a great photo op!

Mars imaged using a 150 mm scope. Credit-Sergei Golyshev under a Creative Commons Share-Alike 2.0 Generic License.

… and finally, Mars and the bright blue-white star Spica offered us a fine morning view as the storm front passed over Astroguyz HQ here in Florida this AM:

Author — Mars, Spica, and our partly cloudy terrestrial atmosphere. Photo by author.

Want something more? Have you ever seen Mars… in the daytime? Currently shining at magnitude -1.5, its just possible if you known exactly where to look for it low to the east about 10 minutes or so before local sunset. In fact, near opposition is the only time you can carry this unusual feat of visual athletics out. The best chance in 2014 is on the evening of April 13th and 14th, when the waxing gibbous Moon lies nearby:

Looking east on the evening of April 13th, just before sunset. Credit: Starry Night education software.

Good luck, and thanks to everyone who imaged Mars this season!

April 9, 2014December 23, 2015 by Elizabeth Howell

Mercury Had Quite The Explosive Past, Spacecraft Analysis Shows

The different colors in this MESSENGER image of Mercury indicate the chemical, mineralogical, and physical differences between the rocks that make up the planet’s surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

Mercury — a planet once thought to have no volcanism at all — likely had a very active past, a new analysis of images from NASA’s MESSENGER spacecraft shows. After looking at 51 vents across Mercury, the team concluded that they show different amounts of erosion — hinting that the explosions happened at different times in the planet’s history.

“If [the explosions] happened over a brief period and then stopped, you’d expect all the vents to be degraded by approximately the same amount,” stated Goudge, a graduate geology student at Brown University who led the research.

“We don’t see that; we see different degradation states. So the eruptions appear to have been taking place over an appreciable period of Mercury’s history.”

Information came from orbital data collected from MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) since 2011, which provided more consistent data than the previous flybys, the researchers added. To better figure out the age of these vents, they examined those that are located in impact craters; any vents there before the impact occurred would have been wiped out.

Two pyroclastic vents in Mercury's Kipler crater in optical (top) and false-color views from NASA's MESSENGER spacecraft. Pyroclastic material is in brown-red in the bottom image. The vents were likely too fragile to survive the impact of the crater, scientists said, showing that they likely arose after the impact occurred. Credit: Brown University/NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington — Two pyroclastic vents in Mercury’s Kipler crater in optical (top) and false-color views from NASA’s MESSENGER spacecraft. Pyroclastic material is in brown-red in the bottom image. The vents were likely too fragile to survive the impact of the crater, scientists said, showing that they likely arose after the impact occurred. Credit: Brown University/NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

The vents show up along with deposits of pyroclastic ash, which are leftovers of volcanic explosions. This shows that like Earth, the interior of Mercury has volatiles or compounds that have low boiling points. (Earth examples of these are water and carbon dioxide.)

By looking at the pattern of erosion in the craters, Goudge found that there are pyroclastic deposits in craters that are between 1 and 3.5 billion years old. By comparison, Mercury and the rest of the solar system formed about 4.5 billion years ago, and the finding shows the pyroclastic activity happened well after then.

“These ages tell us that Mercury didn’t degas all of its volatiles very early,” Goudge added. “It kept some of its volatiles around to more recent geological times.”

You can read more about the study in the Journal of Geophysical Research.

Source: Brown University

April 9, 2014December 23, 2015 by Elizabeth Howell

NASA’s Operation IceBridge In Search Of Ice Change In Arctic

The NASA P-3B's shadow on sea ice off of southeast Greenland during an IceBridge survey on Apr. 9, 2013. Flying at a low altitude allows IceBridge researchers to gather detailed data. Credit: NASA / Jim Yungel

How much is the polar ice melting, and how are the sheets being affected by climate change? These are some of the questions that NASA’s Operation IceBridge seeks to answer. You can see a quick overview of the mission in the video above.

“IceBridge, a six-year NASA mission, is the largest airborne survey of Earth’s polar ice ever flown,” NASA stated in the YouTube description accompanying the video.

“It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. These flights will provide a yearly, multi-instrument look at the behavior of the rapidly changing features of the Greenland and Antarctic ice,” the agency added.

The aerial survey is intended to supplement information from NASA’s Ice Cloud and Land Elevation Satellite (ICESat), which has been orbiting Earth since 2003, and the forthcoming ICESat-2 that is expected to launch in early 2016.

The surveys started in 2009 and are expected to wrap up in 2016. This year’s field season runs from about March to May. For more information on IceBridge, check out this 2013 Universe Today article by Ken Kremer.

April 9, 2014December 23, 2015 by Shannon Hall

Why Universe Today Writes on Climate Change

n this rare image taken on July 19, 2013, the wide-angle camera on NASA's Cassini spacecraft has captured Saturn's rings and Earth in the same frame. Image Credit: NASA/JPL-Caltech/Space Science Institute

Online science reporting is difficult. Never mind the incredible amount of work each story requires from interviewing scientists to meticulously choosing the words you will use to describe a tough subject. That’s the fun part. It’s just after you hit the blue publish button, when the story goes live, that things get rough. Your readers will tear you apart. They will comment on any misplaced commas, a number with one too many significant figures, and an added space in between sentences. They will criticize and not compliment.

Now I’m not saying this isn’t welcome. By all means if I have misspoken, do let me know. I need to be on top of my game 100% of the time and readers’ comments help make that happen. They can improve an article tremendously, allowing readers to carry on the conversation and provide a richer context. Thought-provoking commenters always bring a smile to my face.

But then there’s online environmental reporting. From day one, reader comments made me realize that I needed to develop a thicker skin. I won’t go into the nasty details here, but in my most recent article, readers asked why Universe Today — an astronomy and space news site — would report on the science and even the politics regarding climate change. Well dear readers, I have heard you, and here is the answer to your question.

Universe Today is a dedicated space and astronomy news site. And I am proud to be a part of the team bringing readers up-to-date with the ongoings in our local universe. But that definition covers a wide variety of subjects, some might even say an infinite number of subjects.

On any given day authors from our team might write about subjects from planets within our solar system to distant galaxies. We want to better understand these celestial objects by focusing on their origin, evolution and fate. And in doing so we will discuss research that utilizes physics or chemistry, biology or astronomy. We might even write about politics, especially if NASA’s budget is involved.

I argue that writing about the Earth falls into the above category. After all, we do live on a planet that circles the Sun. And unlike Venus, where thick skies of carbon dioxide and even clouds of sulfuric acid make the surface incredibly difficult to see, we can directly study our surface, even run our fingers through the sand.

Intensive geologic surveys of the Earth below your feet help astronomers to understand the geology of other environments, including our nearest neighbor Venus and distant moons. We now know Enceladus has an ocean because of its combination of two compensating mass anomalies — an effect we see here on Earth. Perhaps one day this research will even help us understand geologic features on distant exoplanets.

Any study, which helps us better understand our home planet, whether it looks at plate tectonics or the sobering effects of global warming, exists under the encompassing umbrella of astronomy.

Now for my second, philosophical, argument. On the darkest of nights, thousands of stars compose the celestial sphere above us. The universe is boundless. It is infinite. We stand on but one out of 100 billion (if not more) planets in the Milky Way galaxy alone, which in turn, is but one out of 100 billion galaxies in the observable universe. We live in complete isolation. It’s both humbling and awe-inspiring.

Carl Sagan was the first to coin the phrase “pale blue dot” and in his words:

“Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”

Sagan argues that we have the moral duty to protect our home planet. This sense of obligation stems from the humble lessons gained from astronomy. So if Universe Today is not the appropriate platform to write about climate change I’m not sure what is.

All comments welcome.