Posted on by Nancy Atkinson

The Moon as You’ve Never Seen It Before

Lunar Reconnaissance Orbiter Wide Angle Camera color shaded relief of the lunar farside (NASA/GSFC/DLR/Arizona State University).

[/caption]

You’re looking at a brand new view of the lunar farside, as never seen before. The team from the Lunar Reconnaissance Orbiter has released the first version of a topographic map of nearly the entire Moon, from data from the Wide Angle Camera (WAC) on the spacecraft.

“This amazing map shows you the ups and downs over nearly the entire Moon, at a scale of 100 meters across the surface, and 20 meters or better vertically,” said principal investigator Mark Robinson, writing on the LROC website. “Despite the diminutive size of the WAC (it fits in the palm of one’s hand), it images nearly the entire Moon every month.”

Every month? So why is this a “new” map since LRO has been in lunar orbit since mid-2009?

Robinson said that each month the Moon’s lighting changes, so the WAC methodically builds up a record of how different rocks reflect light under different conditions, and adds to the LROC library of stereo observations.

“The WAC really is the little camera that could!” Robinson said.

Left: LROC Wide Angle Camera attached to a test setup shortly before mounting on the spacecraft. Right: WAC being handed up to engineers for integration with LRO. Photos courtesy Mark Robinson, via the LROC website.

It is very similar to the MARCI camera (Mars Color Imager) on the Mars Reconnaissance Orbiter, another wide-angle, low-resolution camera specially built for orbital observations; both cameras were built by Malin Space Science Systems.

Topographic maps provide a detailed and accurate graphic representation of natural features on the ground, and Robinson this new map of the Moon will help both lunar scientists and future explorers on the Moon.

Combing data from the WAC along with the LRO Lunar Orbiter Laser Altimeter (LOLA), the scientists are able to provide a topographic map of nearly the entire Moon. Due to persistent shadows near the poles it is not possible to create a complete WAC stereo map at the very highest latitudes, but LOLA provides a very high resolution topographic model of the poles.

How is a digital topographic map created from stereo images? The WAC stereo images were compared one against another by pattern-matching a moving box of pixels until the best fit was found between two images with different viewing angles. The new topographic model was constructed from 69,000 WAC stereo models.

Robinson and his team are already looking towards improvements they can make with subsequent versions of their topographic maps.

“The current model incorporates the first year of stereo imaging, and there is another year of data that can be added to the solution,” he said. “These additional stereo images will not only improve the sharpness (resolution) of the model but also fill in very small gaps that exist in the current map. The LROC team has made small improvements to the camera distortion model, and the LOLA team has improved our knowledge of the spacecraft position over time. These next generation steps will further improve the accuracy of Version 2 of the LROC GLD100 topographic model of the Moon.”

You can see the “zoomable” full resolution versions of the new map for both the far and near side at this link.

Source: LROC website

Posted on by Jason Rhian

Want To Fly In Space? NASA Looking For More of the “Right Stuff”

NASA announced that it ws accepting applications for new astronauts. Photo Credit: Jeff Soulliere

[/caption]
NASA is looking for folks with the “right stuff.” The space agency is seeking qualified individuals for when the space agency once again travels into space – and beyond low-Earth-orbit. The announcement of NASA’s process for selecting its next class of astronauts was made at an event held at the Webb auditorium at NASA Headquarters located in Washington D.C. on Tuesday, Nov. 15.

At this event was NASA Administrator Charlie Bolden, Assistant Administrator for Human Capital Jeri Buchholz, Flight Crew Operations Director Janet Kavandi as well as five members of the 2009 astronaut class. They were Serena Aunon, Kjell Lindgren, Kathleen Rubins, Scott Tingle and Mark Vande Hei.

NASA is currently attempting to hand off providing access to low-Earth-orbit or LEO as it attempts to send astronauts beyond LEO for the first time in four decades. Photo Credit: jeff Soulliere

“For 50 years, American astronauts have led the exploration of our solar system,” Bolden said. “Today we are getting a glimpse of why that will remain true for the next half-century. Make no mistake about it, human space flight is alive and well at NASA.”
Bolden is a former shuttle astronaut himself, having flown into space four times.

The 2009 class of astronauts – was the first to graduate in a new era of space flight – one which would eventually see the retirement of NASA’s fleet of space shuttle orbiters. NASA is currently working to develop not only a new spacecraft – but a new launch vehicle as well. The Orion Multi-Purpose Crew Vehicle or Orion MPCV may one day ferry astronauts to points beyond LEO.

With NASA's fleet of shuttle orbiters on their separate ways to various museums across the country, NASA is currently lacking the capacity to launch astronauts on its own and is dependent on Russia's Soyuz spacecraft. Photo Credit: Jeff Soulliere

To get the Orion MPCV to orbit the space agency is developing the Space Launch System or SLS. This launch vehicle, resembling a cross between the space transportation system (STS) that comprised the shuttle – and the Saturn V moon rocket was recently unveiled by the space agency.

As far as access to LEO is concerned, NASA is working to hand those responsibilities over to commercial space firms such as SpaceX, Sierra Nevada Corporation and Boeing. These companies will also work to deliver crew and cargo to the orbiting International Space Station (ISS). If it all works out these new astronauts could well be among the first to return the U.S. to the Moon or be the first person to visit an asteroid or even Mars.

The astronaut's selected in this process could very well be the first astronauts to land on an asteroid - or even the planet Mars. Photo Credit: Jeff Soulliere

The Astronaut Candidate Program is open to any person that meets the agency’s qualifications. They can submit their applications online through the USAJobs.gov website. For those considering a career in the astronaut corps, here are some of the requirements:

• Bachelor’s Degree in either science, engineering or math
• Three years of relevant professional experience
• Experience in flying high-performance jet aircraft is considered a plus
• Educators that have taught grades kindergarten through the 12 are highly encouraged to apply

NASA will be accepting applications through January 27, 2012. The agency will bring in applicants to be interviewed and evaluated. NASA plans to make their final decision in 2013 – with training of these new astronauts starting that summer.

NASA has been working to see that the Orion Multi-Purpose Crew Vehicle or Orion MPCV is ready in time for deep space missions. Photo Credit: NASA.gov
Posted on by Nancy Atkinson

Venerable Voyager 2 Spacecraft Gets a Tune-up 14 billion Kilometers From Earth

Voyager 1
Artist's concept of NASA's Voyager spacecraft. Image credit: NASA/JPL-Caltech

[/caption]

Every mechanic loves to tinker with a machine to give it optimum operating efficiency. But this latest engineering feat involving the Voyager 2 spacecraft wins the prize for longest distance tune-up. Akin to servicing an old car to increase gas mileage, engineers at JPL sent commands across 14 billion kilometers (9 billion miles) out to Voyager 2, enabling it to switch to the backup set of thrusters that controls the roll of the spacecraft. This will reduce the amount of power that the 34-year-old probe needs to operate, giving it better “gas mileage” and — hopefully — the power to operate for at least another decade.

The move was a little risky, as these backup roll thrusters were previously unused. It meant trusting equipment which has been idle and out in the harsh environment of space for 32 years to work — and keep working for the remainder of the mission.

“The switchover is pretty permanent – the thrusters are not rated to be reused after being unheated,” said the @NASAVoyager2 Twitter feed.

Voyager 2 will save about 11.8 watts of electric power by turning off the heater that kept the hydrazine fuel to the primary thrusters warm.

Voyager 1 and 2 are each equipped with six sets, or pairs, of thrusters to control the pitch, yaw and roll motions of the spacecraft. With this latest command, both spacecraft are now using all three sets of their backup thrusters.

The primary roll thrusters now turned off fired more than 318,000 times. Voyager 1 changed to the backup for this same component after 353,000 pulses in 2004.

Projected levels of the Voyagers' RTG levels. Credit: @NASAVoyager2 Twitter Feed.

The rate of energy generated by Voyager 2’s Plutonium 238 nuclear power source continues to decline, and is now down to about 270 watts from the 470 watts being produced when the spacecraft launched in 1977. But now, by reducing its power requirements, engineers expect the spacecraft can continue to operate a bit longer.

Still, at the rate of decay, the Voyager spacecraft won’t have sufficient electric power to its instruments sometime by the mid-2020’s.

Using solar power for a spacecraft traveling beyond Jupiter is impractical, (which is why it is important that Congress pass a bill to restore funding for production of Plutonium 238).

Heliocentric distances for Pioneer, Voyager and New Horizons. Credit: NASAVoyager2 Twitter feed.

The Voyagers are on their way toward interstellar space, beyond our solar system, where no human spacecraft has been before. This latest tune-up will hopefully get Voyager 2 a little farther while she’s still able to communicate with Earth.

Posted on by Amy Shira Teitel

Historic Photos Commemorate First and Last Shuttle Crews

From left to right, they are: STS-135 pilot Doug Hurley, STS-1 pilot Robert Crippen, STS-1 commander John Young (a former Gemini and moonwalking Apollo astronaut), STS-135 commander Chris Ferguson, and STS-135 mission specialists Sandy Magnus and Rex Walheim.

[/caption]

In an historic photo shoot earlier this month, NASA commemorated the space shuttle’s retirement, personifying the thirty-year program with the first and last astronaut crews to fly the vehicle.

The shuttle program has certainly come a long way from STS-1 to STS-135. 

Young and Crippen. The STS-1 crew's official portrait, 1981. Image credit: NASA.

John Young and Robert Crippen launched on STS-1 in the shuttle Columbia on April 12, 1981, twenty years after Yuri Gagarin became the first man to orbit the Earth. It was a shakedown cruise, with the two astronauts spending only two days in orbit. They checked out the spacecraft’s systems, the vehicle’s overall flight worthiness, and made the first runway landing from orbit. The only payload the crew carried was a Development Flight Instrumentation (DFI) package. It contained sensors to measure and record Columbia’s performance in orbit and the stresses it felt during launch, ascent, orbital flight, descent and landing.

Thirty years and two months later, the crew of STS-135 had a much busier mission on their hands. Launched on July 8, 2011 in the Atlantis orbiter, the crew’s primary mission objective was to transfer thousands of pounds of supplies into the International Space Station and take thousands more pounds of unneeded cargo back down to Earth.

Atlantis stayed docked to the ISS for eight of its twelve days in orbit. The crew, along with the Expedition 28 crew that spent close to four months aboard the station, played a real life and oversized version of Tetris to get all the supplies squared away in the ISS’ multi-purpose module.

The crews of STS-135 and Expedition 28 pose with the flag flown in STS-1. Credit: NASA

With the cargo transfer complete, Atlantis undocked from the station on July 19. The crew spent the last two days of the final mission in orbit, deploying experiments and readying the spacecraft for landing. Atlantis touched down on the runway at the Kennedy Spaceflight Centre on July 21.

NASA’s complete image gallery, which includes images of the STS-135 post flight wrap up as well as pictures with the STS-1 crew, highlights the personal strain that runs through manned spaceflight. And it doesn’t stop there. During STS-135’s mission, commander Chris Ferguson presented the ISS’s crew the U.S. flag John Young and Robert Crippen carried into space on STS-1. The flag will remain on display on the station until the next crew that launches from the U.S. retrieves it. After returning to Earth, the flag will be launched again with the first crew to embark on a journey beyond Earth orbit.

The Crews of STS-1 and STS-135. John Young, STS-1 commander, Robert Crippen, STS-1 pilot, with the STS-135 crew of commander Chris Ferguson, pilot Doug Hurley and mission specialists Sandy Magnus and Rex Walheim. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool
Posted on by Jason Major

Europa’s Hidden Great Lakes May Harbor Life

Chaos terrain on Europa points to subsurface lakes, new research suggests. (NASA/JPL/Ted Stryk)

[/caption]

New research on Jupiter’s ice-covered moon Europa indicates the presence of a subsurface lake buried beneath frozen mounds of huge jumbled chunks of ice. While it has long been believed that Europa’s ice lies atop a deep underground ocean, these new findings support the possibility of large pockets of liquid water being much closer to the moon’s surface — as well as energy from the Sun — and ultimately boosting the possibility it could contain life.

During a press conference today, November 16 at 1 p.m. EST, researchers Britney Schmidt, Tori Hoeler, Louise Prockter and Tom Wagner presented new theories concerning the creation of “chaos terrain” on Europa.

Chaos terrain is exactly what it sounds like: irregularly-shaped landforms and surface textures on a world. In the case of Europa, the terrain is made of water ice that evidence shows has been loosened by the motion of liquid water beneath, expanded, and then has refrozen into hills and jagged mounds.

Topographic data shows the chaos terrain elevations above the surrounding surface. Reds and purples are the highest elevations. Credit: NASA

These mounds are visible in topographic data acquired by the Galileo spacecraft in 1998.

During the presentation a good analogy for the processes at work on Europa was made by Britney Schmidt, a postdoctoral fellow at the Institute for Geophysics, University of Texas at Austin and lead author of the paper. She demonstrated the formation of Europa’s “mosh pit of icebergs” using a drinking glass partially filled with ice cubes. When water was added to the glass, the ice cubes naturally rose up and shifted orientation. Should the water beneath them refreeze, as it would in the frigid environments found in the Jovian system, the ice cubes would be held fast in their new expanded, “chaotic” positions.

“Now we see evidence that it’s a thick ice shell that can mix vigorously, and new evidence for giant shallow lakes. That could make Europa and its ocean more habitable.”

– Britney Schmidt, lead author

Similar processes have also been seen occurring on Earth, both in Antarctica along the edges of ice shelves and in Greenland, where glaciers continually break apart and flow into the sea – often rolling over themselves and each other in the process.

Europa's "Great Lake." Scientists speculate many more exist throughout the shallow regions of the moon's icy shell. Image Credit: Britney Schmidt/Dead Pixel FX/Univ. of Texas at Austin.

The importance of these findings is that scientists finally have a model that demonstrates how Europa’s deep liquid ocean interacts with the ice near its surface in such a way as to allow for the transportation of energy and nutrients.

“This is the first time that anyone has come up with an end-to-end model that explains what we see on the surface,” said APL senior planetary scientist Louise Prockter.

With such strong evidence for this process, the likelihood that Europa could harbor environments friendly to life goes up dramatically.

“The potential for exchange of material between the surface and subsurface is a big key for astrobiology,” said Wes Patterson, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., and a co-author of the study. “Europa’s subsurface harbors much of what we believe is necessary for life but chemical nutrients found at the surface are likely vital for driving biology.”

Although the research favors the existence of these lakes, however, confirmation of such has not yet been found. That will require a future mission to Europa and the direct investigation of its icy surface – and what lies beneath.

Luckily a Europa mission was recently rated as one of the highest priority flagship missions by the National Research Council’s Planetary Science Decadal Survey and is currently being studied by NASA.

“If we’re ever to send a landed mission to Europa, these areas would be great places to study,” Prockter said.

Read more about this discovery in the Johns Hopkins University Applied Physics Laboratory press release, or in the NASA news release here. Also, watch the full conference recorded on Ustream below:

Posted on by David Warmflash

Phobos-Grunt’s Mysterious Thruster Activation: A Function of Safe Mode or Just Good Luck?

Phobos-Grunt Model. This is a full-scale mockup of Russia's Phobos-Grunt. The spacecraft was supposed to collect samples of soil on Mar's moon Phobos and return them to Earth for study. Credit: CNES

[/caption]

Editor’s note: Dr. David Warmflash, principal science lead for the US team from the LIFE experiment on board the Phobos-Grunt spacecraft, provides an update for Universe Today on the likelihood of saving the mission.

The Phobos-Grunt probe is still stuck in orbit around Earth. However, periodically the spacecraft experiences a mysterious slight boost in its orbit.  Following the first episode where this occurred, commentators speculated as to the cause.  The activation of the spacecraft’s thrusters – the small engines that are designed to steer the craft and make small adjustments  — was an obvious answer.

Is spacecraft trying to save itself?

The spacecraft is not responding to any communications, and engineers at the Russian Space Agency Roscosmos have decided that the craft had reverted to a safe mode after the engine of the Fregat rocket stage that was to propel her from a low to a higher orbit around Earth failed to ignite. While in safe mode, the craft had oriented herself to the Sun, using the thrusters to adjust her roll, pitch, and yaw. But to change the parameters of the orbit, she’d need to accelerate, so there was speculation that the needed thrust had come from leaks and venting of gases in a direction favorable to increased orbital stability.

After a second episode during which the altitude increased again, according to Ria Novosti editor-columnist of the journal “News of Cosmonautics” Igor Lisov has reported that a source in the space industry had explained that the probe “Corrects her orbit” every now and then.

Corrects her orbit? Does this mean that the probe knows where she is?

Probably not.

With information coming from Roscosmos being so scarce, reporting on the mission that began was launched on November 9, 2011 has depended on a few official statements from the agency, augmented by speculation from various space experts. Being in safe mode, Grunt simply is waiting for instructions –instructions that controllers are having difficulty delivering, because initial communication was not supposed to take place with the probe at such a low orbit.

If Grunt’s safe mode includes a program that fires thrusters every so often to keep the craft from entering the atmosphere in the event of a malfunction just after reaching low Earth orbit, no statements from Roscosmos have mentioned it, thus far. Whatever the reason, if it continues to occur, we can expect that the predicted date of atmospheric entry will be moved back again, just as it was moved from late December/early November to mid-January after the first orbital correction episode.

The Planetary Society’s Living Interplanetary Flight Experiment (LIFE) capsule, on board the Phobos-Grunt spacecraft. Credit:The Planetary Society

What might this mean for the mission? First of all, perhaps it could buy more time for controllers to establish communication –although Roscosmos has stated that December is the limit for correcting the problem, despite the fact that the probe will be in space at least until mid January. The second thing it could do would be to keep the Planetary Society’s LIFE experiment in space a little longer, which would have benefits only if the Grunt return capsule containing the LIFE biomodule separates from the rest of the craft and makes the reentry and landing that it was designed to do at the end of the flight. This possibility and the potential scientific value is discussed in my previous update, Might the LIFE Experiment be Recovered?

As for the question of why a craft that merely is supposed to find the Sun while in safe mode fires thrusters in a direction that improves the orbit, perhaps it is just good luck, or perhaps it really is part of the safe mode. Until Roscosmos provides more information of what may have caused this, the reason for the orbital correction remains a mystery.

Posted on by Ken Kremer

Dramatic Soyuz Docking Averts Potential Station Abandonment

View of ISS and Earth after successful docking of Soyuz TMA-22 on Nov 16 at 12:24 a.m. with crew of Russian cosmonauts Anton Shkaplerov and Anatoly Ivanishin and NASA astronaut Dan Burbank Credit: NASA TV

[/caption]

A Russian Soyuz capsule carrying the first crew of humans to fly to space in the post Space Shuttle Era has successfully docked at the International Space Station early this morning, Nov. 16 at 12:24 a.m. EST, averting the potential of having to at least temporarily abandon the massive Earth orbiting research complex.

After an 11 year stretch of continuous human occupation, the future residency of humans aboard the ISS swung in the balance in the wake of a Russian Soyuz rocket failure in August that temporarily grounded all Soyuz launches – manned and unmanned – until the root cause was determined and satisfactorily rectified with NASA’s consent.

The very survival of the ISS hinged on the successful launch of a trio of Russian and American space flyers just 2 days ago from the Baikonur Cosmodrome in Kazahkstan aboard the Soyuz TMA-22 capsule, which took place amidst an unprecedented blizzard and white out conditions with near zero visibility.

The three man crew of Russian rookie cosmonauts Anton Shkaplerov and Anatoly Ivanishin along with veteran NASA astronaut Dan Burbank arrived at the Poisk module of the orbiting outpost just in the nick of time – before the last three ISS crewmembers still aboard would have been forced to depart just 5 days from today leaving no humans aboard.

Soyuz TMA-22 approaches the International Space Station prior to docking at Poisk module on Nov 16 at 12:24 a.m. Credit: NASA TV

Luckily the Soyuz launch and automated rendezvous and linkup with the ISS flying some 400 km (248 miles) above the South Pacific proceeded flawlessly, announced Russian space officials at Mission Control in Moscow shortly after the successful docking. The event was carried live on NASA TV.

A full complement of 6 crew members was thus restored to the ISS, but the handover period will be exceedingly short because the Soyuz TMA-22 launch was postponed from September 22 due to the Soyuz rocket failure in August carrying the unmanned Progress cargo resupply vessel.

The new trio joins the current Expedition 29 residents comprising ISS Commander Mike Fossum (NASA) and Flight Engineers Satoshi Furukawa (Japan) and Sergei Volkov (Russia). But Fossum, Furukawa and Volkov will depart on Monday, Nov. 21, and thereby reduce the station crew population back down to three.

“The crew will have a very busy time during the short handover period,” said William Gerstenmaier, NASA Associate Administrator for the Human Exploration and Operation Directorate, who was present in Moscow.

“I want to thank our Russian colleagues for a tremendous job. It’s great to have six people back aboard the ISS,” Gerstenmaier said.

The newly arrived crew is expected to stay at the ISS for about five months and carry out a wide range of science experiments.

After closing the hooks and latches, removing the docking probe and conducting extensive pressure and leak checks, Shkaplerov, Ivanishin and Burbank opened the hatches and floated into the ISS to join their awaiting friends friends with a big round of bear hugs and greetings at about 2:39 a.m. EST today, Nov 16.

“Its great to see all six of you together up there,” radioed Gerstenmaier after the hatch opening.

“It’s was a great ride uphill and it will be a great stay up here,” Burbank replied.

The cosmonauts children exuberantly said “Hi , how are you. Kisses to you Daddy !” to their dads in space moments later !

Combined crews aboard the ISS after Nov 16 docking and hatch opening. NASA TV

The next three man Soyuz crew of US astronaut Don Pettit, Dutch astronaut André Kuipers, and Russian cosmonaut Oleg Kononenko, is set to arrive on December 23 and again restore the crew to a full complement of six.

Blastoff of Soyuz TMA-22 amidst swirling snowstorm at 11:14:03 p.m. Nov. 13 from Baikonur Cosmodrome, Kazakhstan. The three man crew comprised NASA astronaut Dan Burbank and Russian cosmonauts Anton Shkaplerov and Anatoly Ivanishin. Credit: NASA/Roscosmos

Read Ken’s continuing features about Russian Space Programs including Soyuz, Progress, Phobos-Grunt and Soyuz in South America starting here:
Soyuz Launches to Station amid Swirling Snowy Spectacular
Soyuz Poised for High Stakes November 13 Blastoff – Space Stations Fate Hinges on Success
Success ! Launch Video of Crucial Russian Rocket to ISS puts Human Flights back on Track
Russians Race against Time to Save Ambitious Phobos-Grunt Mars Probe from Earthly Demise
Russia’s Bold Sample Return Mission to Mars and Phobos Blasts Off
Video Duet – Soyuz Debut Blast off from the Amazon Jungle and Rockin’ Russian Rollout !
Historic 1st Launch of Legendary Soyuz from South America
Russian Soyuz Poised for 1st Blastoff from Europe’s New South American Spaceport

Nov 16: Ken Kremer lectures about Mars and Vesta exploration at Gloucester County College, NJ

Posted on by Tammy Plotner

Antique Stars Could Help Solve Mysteries Of Early Milky Way

The Milky Way is like NGC 4594 (pictured), a disc shaped spiral galaxy with around 200 billion stars. The three main features are the central bulge, the disk, and the halo. Credit: ESO
The Milky Way is like NGC 4594 (pictured), a disc shaped spiral galaxy with around 200 billion stars. The three main features are the central bulge, the disk, and the halo. Credit: ESO

[/caption]

Utilizing ESO’s giant telescopes located in Chile, researchers at the Niels Bohr Institute have been examining “antique” stars. Located at the outer reaches of the Milky Way, these superannuated stellar specimens are unusual in the fact that they contain an over-abundance of gold, platinum and uranium. How they became heavy metal stars has always been a puzzle, but now astronomers are tracing their origins back to our galaxy’s beginning.

It is theorized that soon after the Big Bang event, the Universe was filled with hydrogen, helium and… dark matter. When the trio began compressing upon themselves, the very first stars were born. At the core of these neophyte suns, heavy elements such as carbon, nitrogen and oxygen were then created. A few hundred million years later? Hey! All of the elements are now accounted for. It’s a tidy solution, but there’s just one problem. It would appear the very first stars only had about 1/1000th of the heavy-elements found in sun-like stars of the present.

How does it happen? Each time a massive star reaches the end of its lifetime, it will either create a planetary nebula – where layers of elements gradually peel away from the core – or it will go supernova – and blast the freshly created elements out in a violent explosion. In this scenario, the clouds of material once again coalesce… collapse again and form more new stars. It’s just this pattern which gives birth to stars that become more and more “elementally” concentrated. It’s an accepted conjecture – and that’s what makes discovering heavy metal stars in the early Universe a surprise. And even more surprising…

Right here in the Milky Way.

“In the outer parts of the Milky Way there are old ‘stellar fossils’ from our own galaxy’s childhood. These old stars lie in a halo above and below the galaxy’s flat disc. In a small percentage – approximately one to two percent of these primitive stars, you find abnormal quantities of the heaviest elements relative to iron and other ‘normal’ heavy elements”, explains Terese Hansen, who is an astrophysicist in the research group Astrophysics and Planetary Science at the Niels Bohr Institute at the University of Copenhagen.

The 17 observed stars are all located in the northern sky and could therefore be observed with the Nordic Optical Telescope, NOT on La Palma. NOT is 2.5 meter telescope that is well suited for just this kind of observations, where continuous precise observations of stellar motions over several years can reveal what stars belong to binary star systems.
But the study of these antique stars just didn’t happen overnight. By employing ESO’s large telescopes based in Chile, the team took several years to come to their conclusions. It was based on the findings of 17 “abnormal” stars which appeared to have elemental concentrations – and then another four years of study using the Nordic Optical Telescope on La Palma. Terese Hansen used her master’s thesis to analyse the observations.

“After slaving away on these very difficult observations for a few years I suddenly realised that three of the stars had clear orbital motions that we could define, while the rest didn’t budge out of place and this was an important clue to explaining what kind of mechanism must have created the elements in the stars”, explains Terese Hansen, who calculated the velocities along with researchers from the Niels Bohr Institute and Michigan State University, USA.

What exactly accounts for these types of concentrations? Hansen explains their are two popular theories. The first places the origin as a close binary star system where one goes supernova, inundating its companion with layers of heavier elements. The second is a massive star also goes supernova, but spews the elements out in dispersing streams, impregnating gas clouds which then formed into the halo stars.

The research group has analysed 17 stellar fossils from the Milky Way’s childhood. The stars are small light stars and they live longer than large massive stars. They do not burn hydrogen longer, but swell up into red giants that will later cool and become white dwarves. The image shows the most famous of the stars CS31082-001, which was the first star that uranium was found in.
“My observations of the motions of the stars showed that the great majority of the 17 heavy-element rich stars are in fact single. Only three (20 percent) belong to binary star systems – this is completely normal, 20 percent of all stars belong to binary star systems. So the theory of the gold-plated neighbouring star cannot be the general explanation. The reason why some of the old stars became abnormally rich in heavy elements must therefore be that exploding supernovae sent jets out into space. In the supernova explosion the heavy elements like gold, platinum and uranium are formed and when the jets hit the surrounding gas clouds, they will be enriched with the elements and form stars that are incredibly rich in heavy elements”, says Terese Hansen, who immediately after her groundbreaking results was offered a PhD grant by one of the leading European research groups in astrophysics at the University of Heidelberg.

May all heavy metal stars go gold!

Original Story Source: Niels Bohr Institute News Release. For Further Reading: The Binary Frequency of r-Process-element-enhanced Metal-poor Stars and Its Implications: Chemical Tagging in the Primitive Halo of the Milky Way.

Posted on by Tammy Plotner

Goldilocks And The Habitable Zone – The Increased Place In Space

Artist's impression of a planet orbiting red dwarf GJ1214.

[/caption]

It’s referred to as the “Goldilock’s Zone”, but this area in space isn’t meant for sleepy or hungry bears – it’s the relative area in which life can evolve and sustain. This habitable region has some fairly strict parameters, such as certain star types and rigid distance limits, but new research shows it could be considerably larger than estimated.

In a study done by Manoj Joshi and Robert Haberle, the team considered the relationship which occurs between the radiation for red dwarf stars and a possible planet’s reflective qualities. Known as albedo, this ability to “bounce back” light waves has a great deal to do with surface layers, such as ice and snow. Unlike our G-type Sun, the M-class red dwarf is much cooler and produces energy at longer wavelengths. This means a great deal of the radiation is absorbed – rather than reflected – turning the ice and snow into possible liquid water. And, as we know, water is considered to be a primary requirement for life.

“We knew that red dwarfs emit energy at a different wavelength, and we wanted to find out exactly what that might mean for the albedo of planets orbiting these stars.” explained Dr. Joshi from the National Centre for Atmospheric Science, who carried out the research in collaboration with Robert Haberle from the NASA Ames Research Centre.

What makes this theory even more charming is that M-class stars make up a very substantial portion of our galaxy’s total population – meaning there’s even more possible Goldilock’s Zones yet to be discovered. Considering the lifespan of a red dwarf star also increases the chances – as well as the distance a planet would need to be located for these properties to happen.

“M-stars comprise 80% of main-sequence stars, and so their planetary systems provide the best chance for finding habitable planets, i.e.: those with surface liquid water. We have modelled the broadband albedo or reflectivity of water ice and snow for simulated planetary surfaces orbiting two observed red dwarf stars (or M-stars) using spectrally resolved data of the Earth’s cryosphere.” explains Joshi. “In addition, planets with significant ice and snow cover will have significantly higher surface temperatures for a given stellar flux if the spectral variation of cryospheric albedo is considered, which in turn implies that the outer edge of the habitable zone around M-stars may be 10-30% further away from the parent star than previously thought.”

Have we discovered planets around red dwarf stars? The answer is yes. In order to calculate the effects of radiation and albedo, the team chose to use similar M-class stars, Gliese 436 and GJ 1214, and applied it to a simulated planet with an average surface temperature of 200 K. Why that particular temperature? In this circumstance, it’s the temperature at which one bar of carbon-dioxide condenses – a rough indicator of the outer edge of a habitable zone. It is theorized that anything registering below this temperature is too cold to harbor life.

What the team found was high albedo planets register a higher surface temperature when exposed to longer wavelength radiation. This means ice and snow covered planets could exist much further away from a red dwarf parent star – as much as one third more the distance.

“Previous studies haven’t included such detailed calculations of the different albedo effects of ice and snow.” explains Joshi. “But we were a little surprised how big the effect was.”

Original Story Source: Planet Earth OnLine. Further Reading: Suppression of the Water Ice and Snow Albedo Feedback on Planets Orbiting Red Dwarf Stars and the Subsequent Widening of the Habitable Zone.

Posted on by Nancy Atkinson

Live Webcast from American Museum of Natural History Today: Beyond Planet Earth

The American Museum of Natural History in New York will soon be opening up a new exhibition called “Beyond Planet Earth: The Future of Space Exploration,” and they are live-streaming a special public program at 12 Noon EST (17:00 UT), that includes NASA astronauts Mike Massimino and John Grunsfeld, crew members on mission STS-125 to repair the Hubble Space Telescope, and is hosted by Hayden Planetarium Director Neil deGrasse Tyson and Curator Michael Shara.

The discussion will focus on themes from Beyond Planet Earth, the STS-125 mission, and the temporary laser art installation From The Distant Past. For more information see the AMNH website, and watch a teaser video of “Beyond Planet Earth” below.

Continue reading “Live Webcast from American Museum of Natural History Today: Beyond Planet Earth”