Posted on by Jenny Winder

Euclid and the Geometry of the Dark Universe

Artist’s impression of Euclid Credit: ESA/C. Carreau

Euclid, an exciting new mission to map the geometry, distribution and evolution of dark energy and dark matter has just been formally adopted by ESA as part of their Cosmic Vision 2015-2025 progamme. Named after Euclid of Alexandria, the “Father of Geometry”, it will accurately measure the accelerated expansion of the Universe, bringing together one of the largest collaborations of astronomers, engineers and scientists in an attempt to answer one of the most important questions in cosmology: why is the expansion of the Universe accelerating, instead of slowing down due to the gravitational attraction of all the matter it contains?

In 2007 the Hubble Space Telescope produced a 3D map of dark matter that covered just over 2 square degrees of sky, while in March this year the Baryon Oscillation Spectroscopic Survey (BOSS) measured the precise distance to just over a quarter of a million galaxies. Working in the visible and near-infrared wavelengths, Euclid will precisely measure around two billion galaxies and galaxy clusters in 3 dimensions in a wide extragalactic survey covering 15,000 square degrees (over a third of the sky) plus a deep survey out to redshifts of ~2, covering an area of 40 square degrees, the 3-D galaxy maps produced will trace dark energy’s influence over 10 billion years of cosmic history, covering the period when dark energy accelerated the expansion of the Universe.

The mission was selected last October but now that it has been formally adopted by ESA, invitations to tender will be released, with Astrium and Thales Alenia Space, Europe’s two main space companies expected to bid. Hoping to launch in 2020, Euclid will involve contributions from 11 European space agencies as well as NASA while nearly 1,000 scientists from 100 institutes form the Euclid Consortium building the instruments and participating in the scientific harvest of the mission. It is expected to cost around 800m euros ($1,000m £640m) to build, equip, launch and operate over its nominal 6 year mission lifetime, where it will orbit the second Sun-Earth Lagrange point (L2 in the image below) It will have a mass of around 2100 kg, and measure about 4.5 metres tall by 3.1 metres. It will carry a 1.2 m Korsch telescope, a near infrared camera/spectrometer and one of the largest optical digital cameras ever flown in space.

Sun Earth Lagrange Points Credit: Xander89 via Wikimedia Commons

Dark matter represents 20% of the universe and dark energy 76%. Euclid will use two techniques to map the dark matter and measure dark energy. Weak gravitational lensing measures the distortions of light from distant galaxies due to the mass of dark matter, this requires extremely high image quality to suppress or calibrate-out image distortions in order to measure the true distortions by gravity. Euclid’s camera will produce images 100 times larger than those produced by Hubble, minimizing the need to stitch images together. Baryonic acoustic oscillations, wiggle patterns, imprinted in the clustering of galaxies, will provide a standard ruler to measure dark energy and the expansion in the Universe. This involves the determination of the redshifts of galaxies to better than 0.1%. It is also hoped that later in the mission, supernovas may be used as markers to measure the expansion rate of the Universe.

Find out more about Euclid and other Cosmic Vision missions at ESA Science

Lead image caption: Artist’s-impression-of-Euclid-Credit-ESA-C.-Carreau

Second image caption: Sun Earth Lagrange Points Credit: Xander89 via Wikimedia Commons

Posted on by Nancy Atkinson

Newest X-Ray Observatory Will Hunt for Black Holes and More

An artist's concept of NuSTAR in space. Image credit: NASA/JPL-Caltech/Orbital Sciences

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The next launch of a NASA space mission is the Nuclear Spectroscopic Telescope Array, or NuSTAR. It study wide range of objects in space, from massive black holes to our own Sun, and will be the first space telescope to create focused images of cosmic X-rays with the highest energies.

“We will see the hottest, densest and most energetic objects with a fundamentally new, high-energy X-ray telescope that can obtain much deeper and crisper images than before,” said Fiona Harrison, the NuSTAR principal investigator, who has been working on this project for 20 years.

Meanwhile, NASA has cancelled another X-ray telescope, the Gravity and Extreme Magnetism Small Explorer (GEMS) X-ray telescope, an astrophysics mission that was going to launch in 2014 to observe the space near neutron stars and black holes. GEMS failed meet a the qualifications of a confirmation review and was heading to go over budget.

“The decision was made to non-confirm GEMS,” said Paul Hertz, director of NASA’s Astrophysic Division, at a meeting of the National Research Council’s Committee on Astronomy and Astrophysics. “The rationale was that the pre-confirmation cost and schedule growth was too large.” The project was going well over the initial cost of $105 million and was facing a delay in launch.

But NuSTAR is scheduled to launch on June 13 from the Kwajalein Atoll in the Pacific Ocean near the equator. The X-ray space telescope will initially take off on a L-1011 “Stargazer” aircraft, and then launch in midair into orbit on a Pegasus XL rocket from Orbital Sciences.

The mission has been awaiting launch since March, when NASA delayed its liftoff pending a review of the rocket.

NuSTAR will work with other telescopes in space now, including NASA’s Chandra X-ray Observatory, which observes lower-energy X-rays. Together, they will provide a more complete picture of the most energetic and exotic objects in space, such as black holes, dead stars and jets traveling near the speed of light.

This new observatory looks with X-rays similar to the X-rays used in hospitals and airports, but the telescope will have more than 10 times the resolution and more than 100 times the sensitivity of previous telescopes.

“NuSTAR uses several innovations for its unprecedented imaging capability and was made possible by many partners,” said Yunjin Kim, the project manager for the mission at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We’re all really excited to see the fruition of our work begin its mission in space.”

NuSTAR has an innovative design using a nested shell of mirrors to provide better focus. It also has state-of-the-art detectors and a large 33-foot (10-meter) mast, which connects the detectors to the nested mirrors, providing the long distance required to focus the X-rays. This mast is folded up into a canister small enough to fit atop the Pegasus launch vehicle. It will unfurl about seven days after launch. About 23 days later, science operations will begin.
The mission will focus on studying the formation of black holes and investigate how exploding stars forge the elements that make up planets and people, along with study the Sun’s atmosphere.

Sources: JPL Space News (GEMS)

Posted on by Nancy Atkinson

Features on Mars Erased From Existence

Proof that Mars is an ever-changing world: a view from the Mars Reconnaissance Orbiter in 2010 showed tracks from a rolling boulder; in an image of the same region 1 Mars year later the tracks have dissapeared. Credit: NASA/JPL/University of Arizona

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More proof that Mars is an ever-changing world: In 2010, the Mars Reconnaissance Orbiter’s HiRISE camera spotted evidence that a boulder had rolled down an incline in a crater. The boulder left a visible track in the Martian regolith big enough to be spotted by MRO. But just one Martian year later, the tracks are gone, erased from existence.

“This is most likely due to the fine bright dust that is transported in the atmosphere falling down and re-covering the dark markings,” wrote Ross A. Beyer on the HiRISE site.

Beyer said the boulder tracks are much darker because as the boulders roll “they set off miniature dust avalanches. The bright, fine dust slides away, leaving a darker, larger grained dust underneath.”

How do boulders start moving on Mars? The boulders were disturbed in some way, breaking them loose from the crater edge, and there are two different possibilities. One, is that a meteorite impact or other tremor shook the boulder loose. Another possibility, as in the case of avalanches MRO has seen on Mars, the spring thawing of frozen carbon dioxide which forms during the Martian winter can cause rocks and debris to break loose from a cliff or incline.

Mars is certainly not the dead world we once thought it was, and the power of HiRISE keeps revealing a changing, unpredicatable landscape.

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 Nancy Atkinson

Asteroid Lutetia Flyby Animation

All asteroids and comets visited by spacecraft as of November 2010 Credits: Montage by Emily Lakdawalla. Ida, Dactyl, Braille, Annefrank, Gaspra, Borrelly: NASA / JPL / Ted Stryk. Steins: ESA / OSIRIS team. Eros: NASA / JHUAPL. Itokawa: ISAS / JAXA / Emily Lakdawalla. Mathilde: NASA / JHUAPL / Ted Stryk. Lutetia: ESA / OSIRIS team / Emily Lakdawalla. Halley: Russian Academy of Sciences / Ted Stryk. Tempel 1, Hartley 2: NASA / JPL / UMD. Wild 2: NASA / JPL.

In today’s Weekly Space Hangout, Emily Lakdawalla from the Planetary Society mentioned an animation of recently released images from the Rosetta mission’s flyby of asteroid Lutetia. It was put together and processed by Ian Regan, and Emily suggested you play this on a hand-held device (like a smart phone) in a dark room and move it around like you yourself are maneuvering the flyby! Try it — it is a very cool effect!

And while you’re at it, you also need to check out Emily’s montage poster of asteroids and comets, below:


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Check out more pretty images of Lutetia by Emily at the Planetary Blog.

Posted on by Nancy Atkinson

Will Russia Rescue ExoMars?

The ExoMars program. Credit: ESA

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After NASA was forced to back out the joint ExoMars mission with the European Space Agency due to budget constraints, ESA went looking for help with the planned multi-vehicle Mars mission. Now, reportedly the Head of Roscosmos Vladimir Popovkin met with Director General of the ESA, Jean-Jacques Dordain last week, and the two signed a memorandum of understanding to work together to make ExoMars a reality.

“The sides consider this project feasible and promising,” Popovkin’s spokeswoman Anna Vedishcheva was quoted in Ria Novosti. “The sides are to sign the deal by year-end.”

Russia’s participation in the project was also approved by the space council of the Russian Academy of Sciences.

The ExoMars program was slated to send an orbiter to Mars in 2016 and a rover in 2018, but after NASA pulled out of its part of the bargain — of providing several science instruments and an Atlas launch vehicle – ESA knew they could not do the entire mission on their own. Last fall, when it was becoming apparent that NASA’s ability to participate was in jeopardy, Dordain extended an invitation to Russia, and in turn Roscosmos officials hinted they might be interested in joining, offering to provide the use of their Proton rockets for the launches. The two space agencies then had preliminary talks at the Ariane 5 launch at Kourou, French Guiana in March, 2012.

Russian space agency chief Vladimir Popovkin said that Russia’s financing of ExoMars could be partially covered by insurance payments of 1.2 billion rubles (about $40.7 million) for the lost Phobos-Grunt sample return mission that would have gone to the Martian moon Phobos.

Artist concept of the ExoMars/Trace Gas Orbiter mission. Credit: NASA

The details of the new ExoMars partnership are yet to be worked out, but the ESA/NASA partnership would have sent the Trace Gas Orbiter to the Red Planet in 2016 to search for atmospheric methane — a potential signature for microbial life – as well as an advanced astrobiology rover to drill into the surface in 2018, with the hopes of determining if life ever evolved on Mars.

Unsurprisingly, the potential deal with Russia comes as a huge relief to European space scientists who have spent years working on ExoMars. Journalist Paul Sutherland quoted UK scientist John Zarnecki of the Open University, as saying, “It looks like the cavalry has come riding over the horizon to save us, but this time they are dressed in Russian uniforms. There will be a lot scientists in universities and research institutes throughout Europe who will be very relieved to hear this news. Otherwise it seemed that several years work preparing instruments for this mission was going to go down the drain.”

Sources: Sen.com, Ria Novosti

Posted on by Nancy Atkinson

Take a Ride on a Rocket Sled To Test Supersonic Decelerators

Low Density Supersonic Decelerator prototype. Credit: NASA

Landing large payloads on Mars — large enough to bring humans to the Red Planet’s surface — is still beyond our capability. “There’s too much atmosphere on Mars to land heavy vehicles like we do on the moon, using propulsive technology completely,” said Rob Manning, Chief Engineer for the Mars Exploration Directorate, in an article we wrote a few years ago about the problems of landing on Mars “and there’s too little atmosphere to land like we do on Earth. Mars atmosphere provides an ugly, grey zone.”

The best hope on the horizon for making the human missions to Mars possible are supersonic decelerators that are now being developed. This new technology will hopefully be able to slow larger, heavier landers from the supersonic speeds of atmospheric entry to subsonic ground-approach speeds. NASA’s Low Density Supersonic Decelerator (LDSD) program is testing out some of these new devices and recently performed a trial run on a rocket sled test to replicate the forces a supersonic spacecraft would experience prior to landing. The sled tests will see how inflatable and parachute decelerators work to slow spacecraft prior to landing and allow NASA to increase landed payload masses, as well as improve landing accuracy and increase the altitude of safe landing-sites.

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Three devices are being developed: two different sizes of supersonic inflatable aerodynamic decelerators and super-huge parachutes. The supersonic inflatable decelerators are very large, durable, balloon-like pressure vessels that inflate around the entry vehicle and slow it from Mach 3.5 or greater to Mach 2. These decelerators are being developed in 6-meter-diameter and 9-meter-diameters.

The large parachute is 30 meters in diameter, and it will further slow the entry vehicle from Mach 2 to subsonic speeds. All three devices will be the largest of their kind ever flown at speeds several times greater than the speed of sound.

Together, these new drag devices can increase payload delivery to the surface of Mars from our current capability of 1.5 metric tons to 2 to 3 metric tons, depending on which inflatable decelerator is used in combination with the parachute. They will increase available landing altitudes by 2-3 kilometers, increasing the accessible surface area we can explore. They also will improve landing accuracy from a margin of 10 kilometers to just 3 kilometers. All these factors will increase the capabilities and robustness of robotic and human explorers on Mars.

NASA is now testing these devices on rocket sleds and later will conduct tests high in Earth’s stratosphere, simulating entry into Mars’ thin atmosphere. The first supersonic flight tests are set for 2013 and 2014.

Find out more about the LDSD program here.

Posted on by Nancy Atkinson

Did Water or Lava Carve the Outflow Channels on Mars?

Outflow channel in the Tharsis region on Mars. Credit: NASA/JPL/University of Arizona

Large features on Mars called outflow channels have been a point of contention among planetary scientists. “Most Mars scientists accept that outflow channels were carved by water, but alternate hypotheses persist, especially that lava carved the outflow channels,” said Alfred McEwen Principal Investigator of the HiRISE camera on the Mars Reconnaissance Orbiter. McEwen said that water is still the preferred mechanism and he doubts that all the channels could have been created by lava flows.

But in what could be seen as a type of compromise, he offered a new theory for the outflow channels, based on observations by HiRISE: the channels were originally carved by huge water flows on ancient Mars and later were partially filled in by lava.

“This sequence of events provides a better explanation,” McEwen said.

Large outflow channels can be 10 km or more in width and may be hundreds of kilometers long. From orbital images, they appear to be huge, dry river beds, carved by very large volumes of running water.

While these features are too large to have been caused by flooding from rainfall, other explanations have been offered. One model involves large amounts of water frozen as permafrost in the soil and when a major source of local heating occurred, such as volcanic activity, there was melting and catastrophic flooding.

However, other explanations don’t involve water at all, but suggest flowing lava created these channels.

Speaking at the 2012 Lunar and Planetary Science Conference last week, McEwen mentioned specifically one proponent of the lava hypothesis, David Leverington from Texas Tech University, who proposed last year that slippery, low-viscosity lavas created the channels. Leverington says the lava hypothesis offers a simpler explanation that fits well within a wider geological framework of Mars and compares well with similar channel-like features on the Moon and Venus.

“He makes some good points,” McEwen said, “and argues for a form of Occam’s Razor. But we have been searching extensively with HiRISE and finding things that satisfy Leverington’s challenges.”

McEwen said the abundant evidence of water carving the channels is too hard to dismiss. Several examples of outflow channels show deposits from water-based flooding that lava flow can’t explain; additionally, there is ample evidence of bedrock erosion by water on Mars.

McEwen also said crater dating areas of several outflow channels show that the channels themselves are older than the lava flow.

Part of Athabasca Valles, draped in lava. Credit: NASA/JPL/University of Arizona

“In the Athabasca Valles channels, MRO data showed that lava completely filled the channels and even overflow in places,” he said. “The lava can actually make channels look young.”

Uzboi Valles offers the best counterexample to Leverington’s hypothesis, McEwen said. “No lava fills in this highlands channel, and the channel preserves local layered alluvial deposits and shorelines. So that means we cannot explain all outflows channels from lava erosion.”

McEwen and his team suggest that large floods may have occurred in the Hesperian to early Amazonian, ending about 1 to 1.5 billion years ago, carving the channels. Then, later came the lava flows that formed Mars’ broad plains and sand dunes that we now see – which also filled in some of the outflow channels.

Bedrock Exposures in Uzboi Vallis. Credit: NASA/JPL/University of Arizona

But McEwen said the debate about these channels is good science. “Did water create these channels? That is a good question,” he said. “We shouldn’t just assume the answer is yes. But we propose water must have carved at least some of the channels, and that water outflow is the main mechanism. If you disagree with anything I’ve said, go to the HiRISE website’s “HiWish” page to suggest areas for further imaging of these features. I’ve been disappointed how few members of the science community have used this tool,” he said.

Further reading:

McEwen and team’s LPSC abstract (pdf)
Leverington’s paper in Geomorphology (pdf)

Posted on by Nancy Atkinson

Huge ‘Tornado’ on the Sun

Spectacular rotation of material from solar prominences and the coronal cavities on September 25, 2011. Credit: NASA/Dr. Xing Li, Dr. Huw Morgan and Mr. Drew Leonard.

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The Solar Dynamics Observatory captured images and video of a spectacular rotation of material from the Sun in a solar prominence. The whirling, dancing prominence created a massive tornado-like feature on the Sun, five times bigger than the Earth. “This is perhaps the first time that such a huge solar tornado is filmed by an imager,” said Dr. Xing Li of Aberystwyth University, presenting his team’s work at the National Astronomy Meeting this week in the UK. “The superb spatial and temporal resolution of SDO allows us to observe the solar atmosphere in great detail.”

The solar tornado was discovered using the Atmospheric Imaging Assembly (AIA) telescope on board SDO. On September 25, 2011, the AIA saw superheated gases as hot as 50,000 – 2,000,000 Kelvin sucked from the origin of a solar prominence, and spiral up into the high atmosphere. It traveled about 200,000 kilometers (124,000 miles) along the Sun for a period of at least three hours.

The hot gases in the tornadoes have speeds as high as 300,000 km per hour (186,000 mph) as opposed to terrestrial tornadoes, which can reach 150 km/h (90 mph).

Li and his team said that these tornadoes often occur at the root of huge coronal mass ejections. The solar tornadoes drag winding magnetic field and electric currents into the high atmosphere. It is possible that the magnetic field and currents play a key role in driving the coronal mass ejections.

A smaller solar tornado was captured in February of 2012:

The team’s work has been submitted for publication in the Astrophysical Journal. See more of the images and animations here.