Posted on by Jason Major

African Lake Has a Twin on Titan

Titan's Ontario Lacus is found to bear a striking resemblance to Namibia's Etosha Pan. (NASA/JPL/ESA)

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A large lake on Saturn’s cloud-covered Titan seems very similar to the Etosha Pan, a salt-encrusted dry lakebed in northern Namibia that periodically fills with water. As it turns out, Titan’s “great lake” may also be temporary.

Ontario Lacus, so named because of its similarity both in shape and size to Lake Ontario here on Earth, was first discovered near the south pole of Titan by the Cassini spacecraft in 2009. Its smooth, dark appearance in radar images indicated a uniform and reflective surface, implying a large — although likely shallow — body of liquid.

Of course, on Titan the liquid isn’t water — it’s methane, which is the main ingredient of the hydrologic cycle found on the giant moon. That far from the Sun the temperatures at Titan’s poles fall to a frigid -300ºF (-185ºC), much too cold for water to exist as a liquid and so, on this world, methane has taken its place.

A research team led by Thomas Cornet of the Université de Nantes, France has taken a closer look at Cassini’s radar data of Ontario Lacus and found evidence of channels carved into the southern portion. According to the team, this likely indicates that the lakebed surface is exposed.

Cassini image of Ontario Lacus. (NASA/JPL/SSI)

“We conclude that the solid floor of Ontario Lacus is most probably exposed in those areas,” said Cornet.

In addition, sediment layers surrounding the lake suggest that the liquid level has varied.

All in all, this reveals a striking resemblance between Ontario Lacus and Namibia’s Etosha Pan — an “ephemeral lake” that is dry for much of the year, occasionally filling with a shallow layer of water which evaporates, leaving salty rings of sediment.

The inherent otherworldly nature of Etosha Pan is further underlined — and perhaps foreshadowed! — by its use as a backdrop in the 1968 sci-fi film 2001: A Space Odyssey.

Although Ontario Lacus was initially thought to be permanently filled with liquid hydrocarbons, the team’s findings draw a strong correlation with this well-known Earthly environment, suggesting a much more temporary nature and showing the value of comparative research.

Satellite image of Etosha Pan, acquired on April 28, 2012. (Chelys/EOSnap)

“These results emphasise the importance of comparative planetology in modern planetary sciences,” said Nicolas Altobelli, Cassini project scientist for ESA.”Finding familiar geological features on alien worlds like Titan allows us to test the theories explaining their formation.”

Read the press release from ESA here.

Image credits: Cassini radar image JPL/NASA. Envisat radar image ESA. Composite image: LPGNantes.

Posted on by Nancy Atkinson

Cosmic Rays: They Aren’t What We Thought They Were

IceCube team poses for a picture in front of deployment tower after the completion of the IceCube Neutrino Detector in December of 2010. Photo by: Chad Carpenter/NSF

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The origin of cosmic rays has been one of the most enduring mysteries in physics, and it looks like it’s going to stay that way for a while longer. One of the leading candidates for where cosmic rays come from is gamma ray bursts, and physicists were hoping a huge Antarctic detector called the IceCube Neutrino Observatory would confirm that theory. But observations of over 300 GRB’s turned up no evidence of cosmic rays. In short, cosmic rays aren’t what we thought they were.

But, just like Thomas Edison who said that “every wrong attempt discarded is another step forward,” physicists view this latest finding as progress.

“Although we have not discovered where cosmic rays come from, we have taken a major step towards ruling out one of the leading predictions,” said IceCube principal investigator and University of Wisconsin–Madison physics professor Francis Halzen.

Cosmic rays are electrically charged particles, such as protons, that strike Earth from all directions, with energies up to one hundred million times higher than those created in man-made accelerators. The intense conditions needed to generate such energetic particles have focused physicists’ interest on two potential sources: the massive black holes at the centers of active galaxies and gamma ray bursts (GRBs), flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies.

IceCube is using neutrinos, which are believed to accompany cosmic ray production, to explore these two theories. In a paper published in the April 19 issue of the journal Nature, IceCube scientists describe a search for neutrinos emitted from 300 gamma ray bursts observed, most recently in coincidence with the SWIFT and Fermi satellites, between May 2008 and April 2010. Surprisingly, they found none – a result that contradicts 15 years of predictions and challenges one of the two leading theories for the origin of the highest energy cosmic rays.

Aurora seen behind the IceCube Lab. Photo by: Sven Lidstrom/NSF

The detector searches for high-energy (teraelectronvolt; 1012-electronvolt) neutrinos, and in their paper the team said they found an upper limit on the flux of energetic neutrinos associated with GRBs that is at least a factor of 3.7 below the predictions. This implies that either GRBs are not the only sources of cosmic rays with energies greater than 1018More info on IceCube.

Paper in Nature.

Source: IceCube/University of Wisconsin

Posted on by Nancy Atkinson

NASA Wants Your Help in Finding Asteroids

Simulated asteroid image - topography overlaid on radar imagery of 1999 RQ36. Credit: NASA/GSFC/UA

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If you are an amateur astronomer who likes a challenge, NASA has a new project and is looking for a little help from their amateur astronomers friends. Called called “Target Asteroids!” the project is part of the upcoming OSIRIS-REx mission to improve basic scientific understanding of Near Earth Objects. NASA is hoping amateur astronomers can help in the mission by discovering new asteroids and studying their characteristics to help better characterize the population of NEOs. NASA says amateur contributions will affect current and future space missions to asteroids.

Amateur astronomers can help determine the position, motion, rotation and changes in the intensity of light asteroids emit. Professional astronomers will use this information to refine theoretical models of asteroids, improving their understanding about asteroids similar to the one OSIRIS-Rex will encounter.

OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security – Regolith Explorer) is scheduled to launch 2016 and will be a sample return mission from an asteroid, 1999 RQ36. When it meets up with the asteroid in 2019, it will map the asteroid’s global properties, measure non-gravitational forces and provide observations that can be compared with data obtained by telescope observations from Earth. In 2023, OSIRIS-REx will return back to Earth at least 2.11 ounces (60 grams) of surface material from the asteroid.

Target Asteroids! data will be useful for comparisons with actual mission data. The project team plans to expand participants in 2014 to students and teachers.

“Although few amateur astronomers have the capability to observe 1999 RQ36 itself, they do have the capability to observe other targets,” said Jason Dworkin, OSIRIS-REx project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md.

Previous observations indicate 1999 RQ36 is made of primitive materials. OSIRIS-REx will supply a wealth of information about the asteroid’s composition and structure. Data also will provide new insights into the nature of the early solar system and its evolution, orbits of NEOs and their impact risks, and the building blocks that led to life on Earth.

Amateur astronomers long have provided NEO tracking observations in support of NASA’s NEO Observation Program. A better understanding of NEOs is a critically important precursor in the selection and targeting of future asteroid missions.

“For well over 10 years, amateurs have been important contributors in the refinement of orbits for newly discovered near-Earth objects,” said Edward Beshore, deputy principal investigator for the OSIRIS-REx mission at the University of Arizona in Tucson.

Visit the Target Asteroids! webpage.

Posted on by Ken Kremer

Demating Discovery for Smithsonian Welcome

Demating of Discovery from Shuttle Carrier Aircraft at Dulles Airport. Credit: NASA

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Following Discovery’s triumphant final flight from her Florida Spaceport home and victory lap tour above the skies of Washington D.C. – piggybacked atop a 747 Jumbo Jet – she landed at her permanent new home at the Smithsonian’s Virginia annex on April 17 and the dynamic duo taxied off the Dulles Airport runway to a temporary parking spot off to the side.

Tonight, Discovery is being demated from the Shuttle Carrier Aircraft, designated NASA 905.

Discovery awaits Demating after landing at Dulles Airport on April 17, 2012 and as numerous aircraft fly by for landing descent. Discovery sits atop modified Boeing 747 carrier jet. Hoisting cranes at left.
Credit: Ken Kremer

As Discovery awaited demating off to the side of a Dulles runway, numerous jets have descended right past – with some lucky passengers catching a birds eye glimpse of that remarkable sight of Discovery sitting atop a 747 jet.

A pair of rented monstrous cranes at front and back will hoist Discovery – weighing around 166,000 pounds – off the jets rear and three unbolted attach points. The 747 will then be backed out, Discovery’s landing gear and wheels will be extended and the cranes will gently lower NASA’s most experienced shuttle orbiter to the ground in a delicate and rarely performed ballet.

Demating cranes, Discovery and NASA 905 Jumbo Jet at Dulles Airport on April 17, 2012.
Credit: Ken Kremer

A small crew of the few remaining shuttle workers has meticulously prepared the Dulles airport site over the past few weeks, drilled stabilizing holes into the tarmac and assembled the Demag cranes which stem from a company in New Jersey and were specially flown in from a Canadian worksite.

NASA’s fleet leading orbiter will then be towed a short distance to her permanent new home at the Smithsonian National Air and Space Museum’s Steven F. Udvar-Hazy Center in Chantilly, Virginia.

The public is invited to attend the Smithsonian’s “Welcome Discovery Day Celebration” on Thursday, April 19 to witness the final leg of Discovery’s trip, being towed inside. The museum doors open at 8 a.m. sharp.

Those who attend the Smithsonian’s April 19 festivities will be treated to a once in a lifetime view of a shuttle shuffle and two space shuttles – Discovery and Enterprise -poised nose to nose for about 4 hours.

Space Shuttle Enterprise is being towed out of the Udvar-Hazy Center to make way for parking Discovery in her new home at the exact same spot now occupied by the prototype orbiter Enterprise since 2003.

Over the weekend, Enterprise will be hoisted atop the modified 747 and fly to her new home in New York City on April 23 – weather permitting.

Enterprise will land at JFK Airport and eventually be transported by barge to the Intrepid Sea, Air, and Space Museum in Manhattan.

See you at the Smithsonian and send Ken your Discovery photos to post at Universe Today.

Posted on by Jason Major

How Big Was Monday’s CME?

Solar flares pose a major hazard to electronics and infrastructure in Low Earth Orbit, but they may have played a role in kick-starting life on Earth. Credit: NASA/SDO/J. Major

April 16's M-class solar flare erupted with a CME that could dwarf the Earth, shown here to scale. (NASA/SDO/J. Major)

This big! The M1.7-class flare that erupted from active region 1461 on Monday, April 16 let loose an enormous coronal mass ejection many, many times the size of Earth, making this particular writer very happy that our planet was safely tucked out of aim at the time… and 93 million miles away.

The image above was obtained by NASA’s Solar Dynamics Observatory’s AIA 304 imaging instrument on Monday during the height of the event. I rotated the disk of the Sun 90 degrees to get a landscape look over the eastern limb, cropped it down and then added an Earth image to scale — just to show how fantastically huge our home star really is.

(Read “Watch it Rain on the Sun”)

Some minor editing was done to increase contrast and heighten detail in the eruption.

The CME was not directed our way, but it was aimed at NASA’s STEREO-B spacecraft, which will encounter the ejected material full-on.

Read more about this event in a previous Universe Today post here, and check out hi-def videos of the CME from SDO here.

Image credit: NASA/SDO and the AIA science team. Edited by Jason Major.

Posted on by Nancy Atkinson

Watch it Rain on the Sun

The big solar flare and coronal mass ejection earlier this week created an unusual event on the Sun: it rained. Not water drops of course, but coronal rain. After the eruption, blobs of plasma fell back to the surface of the Sun, sometimes making ‘splashes’ where they hit. Coronal rain is plasma gas that condenses in the corona and then descends back to the surface. It has long been a mystery and its motion has perplexed solar physicists. For some reason, coronal rain falls much slower than is expected for plasma falling due to the huge gravitational pull of the Sun. Many times, rather than falling straight down — as it would if gravity was the only force pulling on it — the plasma rain follows invisible magnetic field lines, which can be detected by instruments on board watchful spacecraft.

This video was produced from data from the Solar Optical Telescope on NASA/JAXA’s Hinode spacecraft of the big M1/7 class flare that erupted on April 16 from Active Region 1461. Scientists say thanks to spacecraft like Hinode and the Solar Dynamic Observatory, this phenomenon can be studied in much more detail so that they can better understand this unusual event.

Posted on by Jason Major

Grab a seat for the Celestial Lights show!

Ole's cameras capture shimmering sheets of aurora over the Arctic. (© Ole C. Salomonsen)


Painstakingly assembled from over 150,000 digital photos taken over the course of eight months, this stunning time-lapse video of aurora-filled Arctic skies is the latest creation by photo/video artist Ole C. Salomonsen. Take a moment, turn up the sound, sit back and enjoy the show!

This is Ole’s second video project. The footage was shot on location in parts of Norway, Finland and Sweden from September 2011 to April 2012, and shows the glorious effects that the Sun’s increasing activity has had on our planet’s upper atmosphere.

Ole writes on his Vimeo page:

The video is a merge of two parts; the first part contains some more wild and aggressive auroras, as well as a few Milky Way sequences, hence either auroras are moving fast because they are or they are fast due to motion of the Milky Way / stars. Still, some of the straight-up shots are very close to real-time speed — although auroras mostly are slower, she can also be FAST!

The second part has some more slow and majestic auroras, where I have focused more on composition and foreground. The music should give you a clear indication of where you are.

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The music was provided by Norwegian composer Kai-Anders Ryan.

Ole’s “hectic” aurora season is coming to a close now that the Sun is rising above the horizon in the Arctic Circle, and he figured that it was a good time to release the video. It will also be available on 4K Digital Cinema on request.

“Hope you like the video, and that you by watching it are able to understand my fascination and awe for this beautiful celestial phenomenon,” says Ole.

You can follow Ole’s work on Facebook at facebook.com/arcticlightphoto, and check out his website here.

Video © Ole C. Salomonsen. Music by Kai-Anders Ryan.

Posted on by Nancy Atkinson

Get Great Astronomy Apps and Support Astronomers Without Borders

Screenshot for Android, telescope control for SkySafari3. Courtesy AWB

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Celebrate the last two weeks of Global Astronomy Month and get a great price on the very popular SkySafari 3 apps for Apple and Android mobile devices and Mac OS X. Not only will you get an app that has been called a ‘game-changer’ for astronomy software, but during a special promotion, 30% of proceeds from all SkySafari sales will be donated to Astronomers Without Borders to support their wonderful programs.

All three versions of SkySafari 3 — Basic, Plus and Pro – are now at significant discounts, and if you’ve been considering purchasing SkySafari, now is the time, especially since you can support the great work of Astronomers Without Borders at the same time.

SkySafari 3 – $1.99 (regularly $2.99). 120,000 stars and 220 star clusters, nebulae, and galaxies. Solar system’s major planets and moons using NASA spacecraft imagery, 20 asteroids and comets.

SkySafari 3 Plus – $11.99 (regularly $14.99). Wired or wireless telescope control with accessories sold separately. 2.5 million stars, 31,000 deep sky objects (with entire NGC/IC catalog), over 4,000 asteroids, comets, and satellites.

SkySafari 3 Pro – $39.99 (regularly $59.99). Wired or wireless telescope control with accessories sold separately. 15 million stars (most of any astronomy app), 740,000 galaxies to 18th magnitude, over 550,000 solar system objects including every known comet and asteroid.

If you don’t need the SkySafari app, please consider donating to AWB.

Mike Simmons, who leads AWB, told Universe Today that this astronomy outreach organization really could use financial help.

“We do probably a half-million dollars in programs each year based on the hard work of passionate amateur astronomers and educators around the world,” he said, all on way less than $25,000 a year.

“This can’t be sustained, of course, and our programs — and everyone’s expectations of us — continue to grow,” Simmons wrote. “This is really, really important to us. 2012 presents many opportunities and we’re working on them. But we need to convert some of the passion we have in abundance to income to keep it going. If we can’t do it this year then I’m not sure we can do it in the future.”

Another way to help AWB is to purchase special eclipse glasses for the upcoming eclipse and the Venus transit – for which AWB has big plans for helping people around the world observe this very infrequent event.

Also, there is the a program allowing people to buy a quality small refractor and have a second one donated to a club or school in a developing country.

For more information, check out Astronomers Without Borders and the SkySafari 3 app sale, the eclipse glasses and the BOGO for a small refractor telescope for you and a needy school.

Thanks in advance for your support of a great organization!

Posted on by Nancy Atkinson

JUICE to Jupiter Could Be ESA’s Next Major Science Mission

Artist concept of JUICE, a Jupiter moons orbiter mission. Credit: ESA

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The Science Programme Committee of the European Space Agency has recommended that the next major space mission for ESA be an orbiter mission to the Jupiter system named JUICE, the JUpiter ICy moons Explorer. This mission would launch in about 2020 and explore potentially habitable moon around the gas giant, Callisto, Europa, and Ganymede.

This recommendation is not the final decision, but puts JUICE as a front-runner for when representatives of all 19 ESA member states meet to discuss the various mission candidates on May 2, 2012

Other missions being considered are ATHENA , the Advanced Telescope for High-ENergy Astrophysics (originally called IXO) – which would be the biggest X-ray telescope ever built — even though smaller in scope than the original IXO) and study the extremes of the Universe: from black holes to large-scale structure ; and NGO, the New Gravitational wave Observatory, a smaller version of LISA, a space-borne gravitational wave detector which would place a three satellites in orbit.

“This is a big blow to space based astrophysics,” wrote European science blogger Steinn Sigurdsson, who added that rumors are floating around that the NGO science team may be disbanded immediately, even though the new report issued by the Science Programme Committee is just a recommendation.

Planetary Society blogger Emily Lakdawalla also commented on the selection — if it is accepted — “represents a big win for planetary science and a big loss for space-based astrophysics in Europe. Which is, one can’t help but notice, opposite to what the currently-proposed NASA budget represents.”

Whatever mission is chosen for the next flagship science mission, ESA knows it will likely have to do it on their own.

In March 2011, NASA informed ESA that that it was highly unlikely that they could become a major partner in an “L” (large) mission for the 2020 timeframe.

“Given the resulting impossibility to continue with the mission concepts defined in the Assessment Phase, the Executive terminated the relative activities for EJSM-Laplace, IXO, and LISA, and informed the members of the three Science Study Teams of the termination of their mandate,” the new report says. “To preserve as much as possible the investment of the scientific community and of the Member States in the study activities of the L mission candidates, the Executive implemented a recovery action in the form of a fast-track re-formulation activity. The aim has been to ascertain if and which of the science goals of the L mission candidates could be implemented in the context of a programmatically feasible European-led, or potentially European-only mission.”

With NASA no longer in the mix, ESA knew they would have to descope their proposed missions, and with costs needing to be at least 20% less than originally planned. “Needless to say, missions within these constraints must be significantly less complex than the original L mission concepts selected in 2007,” the report says.

ESA’s science goals for the front-runner JUICE mission is to visit the Jupiter system concentrating on the characterization of three possible ocean-bearing worlds, Ganymede, Europa and Callisto as planetary objects and potential habitats and on the exploration of the Jupiter system considered as an archetype for gas giants in the solar system and elsewhere. The focus of JUICE is to characterize the conditions that may have led to the emergence of habitable environments among the Jupiter’s icy satellites.

Sources: Dynamics of Cats, Planetary Society blog,

Posted on by Jason Major

The Case of the Missing Dark Matter

Artist's impression of dark matter surrounding the Milky Way. (ESO/L. Calçada)

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A survey of the galactic region around our solar system by the European Southern Observatory (ESO) has turned up a surprising lack of dark matter, making its alleged existence even more of a mystery.

The 2.2m MPG-ESO telescope, used in the survey. (ESO/H.H.Heyer)

Dark matter is an invisible substance that is suspected to exist in large quantity around galaxies, lending mass but emitting no radiation. The only evidence for it comes from its gravitational effect on the material around it… up to now, dark matter itself has not been directly detected. Regardless, it has been estimated to make up 80% of all the mass in the Universe.

A team of astronomers at ESO’s La Silla Observatory in Chile has mapped the region around over 400 stars near the Sun, some of which were over 13,000 light-years distant. What they found was a quantity of material that coincided with what was observable: stars, gas, and dust… but no dark matter.

“The amount of mass that we derive matches very well with what we see — stars, dust and gas — in the region around the Sun,” said team leader Christian Moni Bidin of the Universidad de Concepción in Chile. “But this leaves no room for the extra material — dark matter — that we were expecting. Our calculations show that it should have shown up very clearly in our measurements. But it was just not there!”

Based on the team’s results, the dark matter halos thought to envelop galaxies would have to have “unusual” shapes — making their actual existence highly improbable.

Still, something is causing matter and radiation in the Universe to behave in a way that belies its visible mass. If it’s not dark matter, then what is it?

“Despite the new results, the Milky Way certainly rotates much faster than the visible matter alone can account for,” Bidin said. “So, if dark matter is not present where we expected it, a new solution for the missing mass problem must be found.

“Our results contradict the currently accepted models. The mystery of dark matter has just became even more mysterious.”

Read the release on the ESO site here.