Extreme Life Forms Might be Able to Survive on Eccentric Exoplanets

Exobiology - Exoplanet.

Sept. 11, 2012

Astronomers have discovered a veritable rogues' gallery of odd exoplanets -- from scorching hot worlds with molten surfaces to frigid ice balls.

And while the hunt continues for the elusive "blue dot" -- a planet with roughly the same characteristics as Earth -- new research reveals that life might actually be able to survive on some of the many exoplanetary oddballs that exist.

"When we're talking about a habitable planet, we're talking about a world where liquid water can exist," said Stephen Kane, a scientist with the NASA Exoplanet Science Institute at the California Institute of Technology in Pasadena. "A planet needs to be the right distance from its star -- not too hot and not too cold." Determined by the size and heat of the star, this temperature range is commonly referred to as the "habitable zone" around a star.

Kane and fellow Exoplanet Science Institute scientist Dawn Gelino have created a resource called the "Habitable Zone Gallery." It calculates the size and distance of the habitable zone for each exoplanetary system that has been discovered and shows which exoplanets orbit in this so-called "goldilocks" zone. The Habitable Zone Gallery can be found at http://www.hzgallery.org . The study describing the research appears in the Astrobiology journal and is available at http://arxiv.org/abs/1205.2429 .

But not all exoplanets have Earth-like orbits that remain at a fairly constant distance from their stars. One of the unexpected revelations of planet hunting has been that many planets travel in very oblong, eccentric orbits that vary greatly in distance from their stars.

"Planets like these may spend some, but not all of their time in the habitable zone," Kane said. "You might have a world that heats up for brief periods in between long, cold winters, or you might have brief spikes of very hot conditions."

Image above: A hypothetical planet is depicted here moving through the habitable zone and then further out into a long, cold winter. Image credit: NASA/JPL-Caltech.

Though planets like these would be very different from Earth, this might not preclude them from being able to support alien life. "Scientists have found microscopic life forms on Earth that can survive all kinds of extreme conditions," Kane said. "Some organisms can basically drop their metabolism to zero to survive very long-lasting, cold conditions. We know that others can withstand very extreme heat conditions if they have a protective layer of rock or water. There have even been studies performed on Earth-based spores, bacteria and lichens, which show they can survive in both harsh environments on Earth and the extreme conditions of space."

Kane and Gelino's research suggests that habitable zone around stars might be larger than once thought, and that planets that might be hostile to human life might be the perfect place for extremophiles, like lichens and bacteria, to survive. "Life evolved on Earth at a very early stage in the planet's development, under conditions much harsher than they are today," Kane said.

Kane explained that many life-harboring worlds might not be planets at all, but rather moons of larger, gas-giant planets like Jupiter in our own solar system. "There are lots of giant planets out there, and all of them may have moons, if they are like the giant planets in the solar system," Kane says. "A moon of a planet that is in or spends time in a habitable zone can be habitable itself."

As an example, Kane mentioned Titan, the largest moon of Saturn, which, despite its thick atmosphere, is far too distant from the sun and too cold for life as we know it to exist on its surface. "If you moved Titan closer in to the sun, it would have lots of water vapor and very favorable conditions for life."

Kane is quick to point out that there are limits to what scientists can presently determine about habitability on already-discovered exoplanets. "It's difficult to really know about a planet when you don't have any knowledge about its atmosphere," he said. For example, both Earth and Venus experience an atmospheric "greenhouse effect" -- but the runaway effect on Venus makes it the hottest place in the solar system. "Without analogues in our own solar system, it's difficult to know precisely what a habitable moon or eccentric planet orbit would look like."

Still, the research suggests that habitability might exist in many forms in the galaxy -- not just on planets that look like our own. Kane and Gelino are hard at work determining which already-discovered exoplanets might be candidates for extremophile life or habitable moons. "There are lots of eccentric and gas giant planet discoveries," Kane says. "We may find some surprises out there as we start to determine exactly what we consider habitable."

NASA's Exoplanet Science Institute at Caltech manages time allocation on the Keck Telescope for NASA. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages NASA's Exoplanet Exploration program office. Caltech manages JPL for NASA. More information about exoplanets and NASA's planet-finding program is at http://planetquest.jpl.nasa.gov .

Image, Text, Credits:  NASA / JPL-Caltech / Written by Josh Rodriguez.

Greetings, Orbiter.ch

NASA Orbiter Observations Point to 'Dry Ice' Snowfall on Mars

NASA - Mars Reconnaissance Orbiter (MRO) patch.

Sept. 11, 2012

NASA's Mars Reconnaissance Orbiter data have given scientists the clearest evidence yet of carbon-dioxide snowfalls on Mars. This reveals the only known example of carbon-dioxide snow falling anywhere in our solar system.

Frozen carbon dioxide, better known as "dry ice," requires temperatures of about minus 193 degrees Fahrenheit (minus 125 Celsius), which is much colder than needed for freezing water. Carbon-dioxide snow reminds scientists that although some parts of Mars may look quite Earth-like, the Red Planet is very different. The report is being published in the Journal of Geophysical Research.

Image above: Observations by NASA's Mars Reconnaissance Orbiter have detected carbon-dioxide snow clouds on Mars and evidence of carbon-dioxide snow falling to the surface. Image credit: NASA/JPL-Caltech.

"These are the first definitive detections of carbon-dioxide snow clouds," said the report's lead author, Paul Hayne of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We firmly establish the clouds are composed of carbon dioxide -- flakes of Martian air -- and they are thick enough to result in snowfall accumulation at the surface."

The snowfalls occurred from clouds around the Red Planet's south pole in winter. The presence of carbon-dioxide ice in Mars' seasonal and residual southern polar caps has been known for decades. Also, NASA's Phoenix Lander mission in 2008 observed falling water-ice snow on northern Mars.

Hayne and six co-authors analyzed data gained by looking at clouds straight overhead and sideways with the Mars Climate Sounder, one of six instruments on the Mars Reconnaissance Orbiter. This instrument records brightness in nine wavebands of visible and infrared light as a way to examine particles and gases in the Martian atmosphere. The analysis was conducted while Hayne was a post-doctoral fellow at the California Institute of Technology in Pasadena.

The data provide information about temperatures, particle sizes and their concentrations. The new analysis is based on data from observations in the south polar region during southern Mars winter in 2006-2007, identifying a tall carbon-dioxide cloud about 300 miles (500 kilometers) in diameter persisting over the pole and smaller, shorter-lived, lower-altitude carbon dioxide ice clouds at latitudes from 70 to 80 degrees south.

"One line of evidence for snow is that the carbon-dioxide ice particles in the clouds are large enough to fall to the ground during the lifespan of the clouds," co-author David Kass of JPL said. "Another comes from observations when the instrument is pointed toward the horizon, instead of down at the surface. The infrared spectra signature of the clouds viewed from this angle is clearly carbon-dioxide ice particles and they extend to the surface. By observing this way, the Mars Climate Sounder is able to distinguish the particles in the atmosphere from the dry ice on the surface."

Conceptual image depicting the Mars Reconnaissance Orbiter in an elliptical low-planet orbit around Mars. Image credit: NASA/JPL-Caltech.

Mars' south polar residual ice cap is the only place on the Red Planet where frozen carbon dioxide persists on the surface year-round. Just how the carbon dioxide from Mars' atmosphere gets deposited has been in question. It is unclear whether it occurs as snow or by freezing out at ground level as frost. These results show snowfall is especially vigorous on top of the residual cap.

"The finding of snowfall could mean that the type of deposition -- snow or frost -- is somehow linked to the year-to-year preservation of the residual cap," Hayne said.

JPL, a division of the California Institute of Technology in Pasadena, provided the Mars Climate Sounder instrument and manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate in Washington.

For more information about the Mars Reconnaissance Orbiter, visit: http://www.nasa.gov/mro and http://mars.jpl.nasa.gov/mro .

NASA / Dwayne Brown / JPL / Guy Webster.

Best regards, Orbiter.ch

Dawn has Departed the Giant Asteroid Vesta

NASA - Dawn Mission patch.

Sept. 11, 2012

 Dawn's Greatest Hits at Vesta

This video highlights Dawn's top accomplishments during its orbit around the giant asteroid Vesta. Video credit: NASA.

Mission controllers received confirmation today that NASA's Dawn spacecraft has escaped from the gentle gravitational grip of the giant asteroid Vesta. Dawn is now officially on its way to its second destination, the dwarf planet Ceres.

NASA Dawn spacecraft. Image credit: NASA/JPL-Caltech

Dawn departed from Vesta at about 11:26 p.m. PDT on Sept. 4 (2:26 a.m. EDT on Sept. 5). Communications from the spacecraft via NASA's Deep Space Network confirmed the departure and that the spacecraft is now traveling toward Ceres.

"As we respectfully say goodbye to Vesta and reflect on the amazing discoveries over the past year, we eagerly look forward to the next phase of our adventure at Ceres, where even more exciting discoveries await,” said Robert Mase, Dawn project manager, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

This image is from the last sequence of images NASA's Dawn spacecraft obtained of the giant asteroid Vesta, looking down at Vesta's north pole as it was departing. When Dawn arrived in July 2011, Vesta's northern region was in darkness. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Launched on Sept. 27, 2007, Dawn slipped into orbit around Vesta on July 15, 2011 PDT (July 16 EDT). Over the past year, Dawn has comprehensively mapped this previously uncharted world, revealing an exotic and diverse planetary building block. The findings are helping scientists unlock some of the secrets of how the solar system, including our own Earth, was formed.

A web video celebrating Dawn's "greatest hits" at Vesta is available at http://www.nasa.gov/multimedia/videogallery/index.html?media_id=151669301 . Two of Dawn's last looks at Vesta are also now available, revealing the creeping dawn over the north pole.

Image above: The shadowy outlines of the terrain in Vesta's northern region are visible in this image from NASA's Dawn spacecraft. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Dawn spiraled away from Vesta as gently as it arrived. It is expected to pull into its next port of call, Ceres, in early 2015.

Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. The California Institute of Technology in Pasadena manages JPL for NASA.

For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov

Dawn journal: http://blogs.jpl.nasa.gov/2012/09/dawn-vesta-split/

Images (mentioned), Video (mentioned), Text, Credit: NASA / JPL / Jia-Rui Cook.

Cheers, Orbiter.ch

NASA Mars Rover Curiosity's Arm Wields Camera Well

NASA - Mars Science Laboratory (MSL) patch.

Sept. 11, 2012

This view of the lower front and underbelly areas of NASA's Mars rover Curiosity combines nine images taken by the rover's Mars Hand Lens Imager (MAHLI) during the 34th Martian day, or sol, of Curiosity's work on Mars (Sept. 9, 2012). Image credit: ASA/JPL-Caltech/Malin Space Science Systems.

NASA's Mars rover Curiosity stepped through activities on Sept. 7, 8 and 9 designed to check and characterize precision movements by the rover's robotic arm and use of tools on the arm.

The activities confirmed good health and usefulness of Mars Hand Lens Imager, or MAHLI, and used that camera to check arm placement during several positioning activities.

Image above: NASA's Mars rover Curiosity carries five cylindrical blocks of organic check material for use in a control experiment if the rover's Sample Analysis at Mars (SAM) laboratory detects any organic compounds in samples of Martian soil or powdered rock. Image credit: NASA/JPL-Caltech/Malin Space Science Systems.

MAHLI took an image with its reclosable dust cover open for the first time on Mars, confirming sharp imaging capability that had been obscured by a thin film of dust on the cover during previous use of the camera. It took images of cameras at the top of Curiosity's mast, of the underbelly of the rover and of MAHLI's own calibration target, among other pointings.

"Wow, seeing these images after all the tremendous hard work that has gone into making them possible is a profoundly emotional moment," said MAHLI Principal Investigator Ken Edgett of Malin Space Science Systems, San Diego. "It is so exciting to see the camera returning beautiful, sharp images from Mars."

Image above: A sample of basaltic rock from a lava flow in New Mexico serves as a calibration target carried on the front of NASA's Mars rover Curiosity for the rover's Canadian-made Alpha Particle X-Ray Spectrometer (APXS) instrument. Image credit: NASA/JPL-Caltech/Malin Space Science Systems.

Selected MAHLI images, with captions, are available at: http://1.usa.gov/PecY9c . Raw versions of all MAHLI images are available along with raw images from the other cameras on Curiosity at: http://mars.jpl.nasa.gov/msl/multimedia/raw/ .

The camera's calibration target includes a 1909 Lincoln penny that Edgett purchased for this purpose. "We're seeing the penny in the foreground and, looking past it, a setting I'm sure the people who minted these coins never imagined," Edgett said.

The penny is a nod to geologists' tradition of placing a coin or other object of known scale as a size reference in close-up photographs of rocks, and it gives the public a familiar object for perceiving size easily when it will be viewed by MAHLI on Mars.

"The folks who drive the rover's arm and turret have taken a 220-pound arm through some very complex tai chi, to center a penny in an image that's only a few centimeters across," said MAHLI Deputy Principal Investigator Aileen Yingst of the Tucson-based Planetary Science Institute. "They make the impossible look easy."

 Mars Science Laboratory (MSL).  Image credit: NASA / JPL-Caltech

The arm characterization activities, including more imaging by MAHLI, will continue for a few days before Curiosity resumes driving toward a mid-term science destination area called Glenelg. In that area, the rover may use its scoop to collect a soil sample, and later its drill to collect a sample of powder from inside a rock.

Curiosity is five weeks into a two-year prime mission on Mars. It will use 10 science instruments to assess whether the selected study area ever has offered environmental conditions favorable for microbial life. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the mission for NASA's Science Mission Directorate in Washington.

More information about Curiosity is online at: http://www.nasa.gov/msl, http://www.jpl.nasa.gov/msl and http://mars.jpl.nasa.gov/msl .

Follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com

Images (mentioned), Text, Credits: NASA / JPL / Guy Webster.

Greetings, Orbiter.ch

ATLAS and CMS publish observations of a new particle in the search for the Higgs boson

CERN - European Organization for Nuclear Research logo.

11 September 2012

The ATLAS and CMS experiments at CERN today published observations of a new particle in the search for the Higgs boson in the journal Physics Letters B.

 CMS experiments detecting Higgs Boson

The papers: "Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC" and "Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC" are freely available online on ScienceDirect.

"These papers present the first observations of a new particle discovered by two big experiments at the Large Hadron Collider (LHC) in the search for the Standard Model Higgs boson which has spanned many decades and has involved many experiments," says CMS spokesperson Joe Incandela. "They are the most important papers to come from the LHC so far and the findings are key to the field of particle physics. We are very pleased to see them published in Physics Letters B, accessible to all who may want to read them."

An artist rendition of the Higgs boson emerging after a collision

"The discovery reported in these papers is a momentous step forward in fundamental knowledge," says ATLAS spokesperson Fabiola Gianotti. "It is the culmination of more than 20 years of effort of the worldwide high-energy physics community to build and operate instruments of unprecedented technology, complexity and performance: the LHC accelerator and related experiments."

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 20 Member States.

Read the papers:

"Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC": http://www.sciencedirect.com/science/article/pii/S037026931200857X

"Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC": http://www.sciencedirect.com/science/article/pii/S0370269312008581

Find out more:

Physics Letters B: http://www.journals.elsevier.com/physics-letters-b/

Large Hadron Collider: http://public.web.cern.ch/public/en/LHC/HowLHC-en.html

ScienceDirect: http://www.sciencedirect.com/

From the CERN Courier

"Discovery of a new boson – the ATLAS perspective": http://cerncourier.com/cws/article/cern/50564

"Inside story: the search in CMS for the Higgs boson": http://cerncourier.com/cws/article/cern/50566

Follow CERN on Twitter: http://twitter.com/cern/

Images, Text, Credit: CERN.

Greetings, Orbiter.ch

Zooming in on clumps in Saturn’s B-ring

NASA / ESA - Cassini-Huygens Mission patch.

10 September 2012

 Ring clumps and strands

Image above: Zooming in on clumps in Saturn’s B-ring (lower left), the image also spans the ringlets of the Cassini Division towards the A-ring in the top right. The view looks toward the sunlit side of the rings from about 31 degrees below the ring plane. The image scale is approximately 2 km per pixel.

Clumpy particles in Saturn’s B-ring provide stark contrast to the delicately ordered ringlets seen in the rest of this view presented by the Cassini spacecraft.

Saturn’s B-ring is the largest and brightest of the gas giant’s rings, the outer portion of which is seen in the left side of this image.

The ring’s outside edge is influenced by meddling moon Mimas, which orbits the planet once for every two circuits the icy ring particles complete.

These periodic gravity perturbations are thought to compress the ring particles into clumps, while maintaining the ring’s well-defined outer edge.

Beyond the B-ring lies the Huygens gap, the widest dark void visible in this image, punctuated only by the bright Huygens ringlet. The 4800 km-wide Cassini Division separates the B-ring from the outermost A-ring, but itself is marked out with faint, concentric strands of ring material.

From Earth, the Cassini Division appears as a thin black gap in Saturn’s rings, but close-up views from spacecraft expose the delicate structures in fine detail.

Cassini - Huygens wallpaper

This image was taken in visible light with the Cassini spacecraft narrow-angle camera on 10 July 2009 from a distance of 320 000 km from Saturn.

Cassini is a joint mission between ESA, NASA and ASI and has been in orbit around Saturn since 2004. It is now in its second extended mission phase, the Cassini Solstice Mission, which will continue until 2017. 

Related links:

At Saturn and Titan: http://www.esa.int/SPECIALS/Cassini-Huygens/index.html

Cassini in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=12

Images, Text, Credits: ESA / NASA / JPL / Space Science Institute.

Best regards, Orbiter.ch

ISRO's 100th mission: PSLV-C21 launched successfully

ISRO - Indian Space Research Organization logo.


Sept. 10, 2012

 PSLV-C21 Launch from Satish Dhawan Space Center (SDSC), Shriharikota, India

India successfully launched its 100th space mission with the indigenous PSLV-C21 rocket putting in orbit two foreign satellites (yesterday 09.09.2012).

In a copybook launch, witnessed by Prime Minister Manmohan Singh, ISRO's workhorse PSLV placed in orbit France's SPOT 6 satellite and Japanese spacecraft PROTIERES, some 18 minutes after a perfect lift off from the Satish Dhawan Space Centre.

PSLV-C21 Launch, 09.09.2012

The launch, scheduled for 9.51 AM, was delayed by two minutes at the end of the 51-hour countdown.

The Polar Satellite Launch Vehicle (PSLV), on its 22nd flight, soared into an overcast sky at 9.53 AM carrying the 720 kg French satellite, the heaviest satellite to be launched by India for a foreign client.

The mission was described as "a spectacular success" and a milestone by Singh, who keenly watched the entire launch sequence and applauded each stage separation culminating in the placing of the two satellites in orbit.

Launch Profile of the PSLV-C21

The launch was a landmark for Indian Space Research Organization (ISRO) which began its space odyssey on a humble note when it launched the indigenous 'Aryabhatta' on board a Russian rocket on April 19, 1975.

The launch has yet again demonstrated the versatility and robustness of PSLV with the rocket completing its 21st successful mission in a row since its first failed flight in September 1993.

No Indian satellite was on-board yesterday's flight which is the third wholly commercial launch undertaken by ISRO for foreign clients.

SPOT-6 satellite

SPOT-6 is the biggest commercial lift so far since India forayed into the money spinning commercial satellite launch services after 350 kg Agile of Italy put in orbit in 2007 by PSLV. Twelve other foreign commercial satellites launched by ISRO weighed below 300 kg.

For more information about Indian Space Research Organization (ISRO), visit: http://www.isro.org/

Images, Video, Text, Credits: ISRO / The Indian Express / Astrium.

Greetings, Orbiter.ch