MarsNews.com
March 24th, 2016

NASA gravity map offers closest ever look at Mars

By tracking the gravitational pull on spacecraft over Mars, NASA has created one of the most detailed maps yet of the Red Planet’s surface, and what lies beneath.

“Gravity maps allow us to see inside a planet, just as a doctor uses an X-ray to see inside a patient,” Antonio Genova of the Massachusetts Institute of Technology (MIT) said in a statement.
“The new gravity map will be helpful for future Mars exploration, because better knowledge of the planet’s gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars.”
As well as providing insight for future missions, the gravity map also offers explanations for developments in the planet’s past.

March 10th, 2016

Close comet flyby threw Mars’ magnetic field into chaos

The close encounter between comet Siding Spring and Mars flooded the planet with an invisible tide of charged particles from the comet’s coma. The dense inner coma reached the surface of the planet, or nearly so. The comet’s powerful magnetic field temporarily merged with, and overwhelmed, the planet’s weak field, as shown in this artist’s depiction. Illustration credits: NASA/Goddard.

Just weeks before the historic encounter of comet C/2013 A1 (Siding Spring) with Mars in October 2014, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft entered orbit around the Red Planet. To protect sensitive equipment aboard MAVEN from possible harm, some instruments were turned off during the flyby; the same was done for other Mars orbiters. But a few instruments, including MAVEN’s magnetometer, remained on, conducting observations from a front-row seat during the comet’s remarkably close flyby.
The one-of-a-kind opportunity gave scientists an intimate view of the havoc that the comet’s passing wreaked on the magnetic environment, or magnetosphere, around Mars. The effect was temporary but profound.

“Comet Siding Spring plunged the magnetic field around Mars into chaos,” said Jared Espley, a MAVEN science team member at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We think the encounter blew away part of Mars’ upper atmosphere, much like a strong solar storm would.”

November 27th, 2015

The Amazingly Creepy Way Mars Will Kill One of Its Moons

It was a rough month for Phobos, as astronomers decreed—yet again—that Mars is ripping its lumpy moon apart. But apparently, Phobos’ loss is the Red Planet’s gain. After the satellite is torn to pieces, its fragments will fan out into a disk and 20 million years from now, Mars will become a ringed planet.

That’s the conclusion of a UC Berkeley-led study published this week in Nature Geoscience, which takes Phobos’ violent demise to an unexpectedly beautiful conclusion. But this little moon’s fate is more than just a cosmic curiosity. Rather, the researchers argue that Phobos could be a window into the origin of ring systems throughout the Solar System and beyond.

November 5th, 2015

NASA Mission Reveals Speed of Solar Wind Stripping Martian Atmosphere

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission has identified the process that appears to have played a key role in the transition of the Martian climate from an early, warm and wet environment that might have supported surface life to the cold, arid planet Mars is today.

MAVEN data have enabled researchers to determine the rate at which the Martian atmosphere currently is losing gas to space via stripping by the solar wind. The findings reveal that the erosion of Mars’ atmosphere increases significantly during solar storms. The scientific results from the mission appear in the Nov. 5 issues of the journals Science and Geophysical Research Letters.

“Mars appears to have had a thick atmosphere warm enough to support liquid water which is a key ingredient and medium for life as we currently know it,” said John Grunsfeld, astronaut and associate administrator for the NASA Science Mission Directorate in Washington. “Understanding what happened to the Mars atmosphere will inform our knowledge of the dynamics and evolution of any planetary atmosphere. Learning what can cause changes to a planet’s environment from one that could host microbes at the surface to one that doesn’t is important to know, and is a key question that is being addressed in NASA’s journey to Mars.”

October 27th, 2015

SwRI scientists predict that rocky planets formed from ‘pebbles’

Using a new process in planetary formation modeling, where planets grow from tiny bodies called “pebbles,” Southwest Research Institute scientists can explain why Mars is so much smaller than Earth. This same process also explains the rapid formation of the gas giants Jupiter and Saturn, as reported earlier this year.

“This numerical simulation actually reproduces the structure of the inner solar system, with Earth, Venus, and a smaller Mars,” said Hal Levison, an Institute scientist at the SwRI Planetary Science Directorate. He is the first author of a new paper published in theProceedings of the National Academy of Sciences of the United States (PNAS) Early Edition.

The fact that Mars has only 10 percent of the mass of the Earth has been a long-standing puzzle for solar system theorists. In the standard model of planet formation, similarly sized objects accumulate and assimilate through a process called accretion; rocks incorporated other rocks, creating mountains; then mountains merged to form city-size objects, and so on. While typical accretion models generate good analogs to Earth and Venus, they predict that Mars should be of similar-size, or even larger than Earth. Additionally, these models also overestimate the overall mass of the asteroid belt.

October 15th, 2015

Did Mars once have rivers? Pebbles say yes.

Researchers have used the shape of rounded Martian pebbles to extrapolate how far they must have traveled down an ancient riverbed on the Red Planet. The analysis suggests they moved approximately 30 miles (50 kilometers), indicating that Mars once had an extensive river system.

The shape of some Martian pebbles suggests these rocks once rolled dozens of miles down a river, hinting that ancient Martian waterways were stable and not merely ephemeral streams, researchers say.

NASA’s Mars rover Curiosity discovered the small, round stones near its landing site in Gale Crater on the Red Planet in 2013. Researchers previously determined that these stones resemble those found in rivers on Earth, which become round as they slide, roll and hop down riverbeds and scrape other rocks.

Now, a new study suggests the Martian rocks rolled in the river for quite a while — a finding that should help scientists reconstruct what ancient Mars was like and shed light on the Red Planet’s past potential to support life, study team members said.

October 8th, 2015

NASA’s Curiosity Rover Team Confirms Ancient Lakes on Mars

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Strata at Base of Mount Sharp

A new study from the team behind NASA’s Mars Science Laboratory/Curiosity has confirmed that Mars was once, billions of years ago, capable of storing water in lakes over an extended period of time.

Using data from the Curiosity rover, the team has determined that, long ago, water helped deposit sediment into Gale Crater, where the rover landed more than three years ago. The sediment deposited as layers that formed the foundation for Mount Sharp, the mountain found in the middle of the crater today.

“Observations from the rover suggest that a series of long-lived streams and lakes existed at some point between about 3.8 to 3.3 billion years ago, delivering sediment that slowly built up the lower layers of Mount Sharp,” said Ashwin Vasavada, Mars Science Laboratory project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, and co-author of the new Science article to be published Friday, Oct. 9.

September 28th, 2015

NASA Confirms Evidence That Liquid Water Flows on Today’s Mars NASA

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New findings from NASA’s Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars. Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.
“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

September 28th, 2015

LIVE NOW: Major Mars mystery revealed! NASA

September 14th, 2015

Terraced Craters: Windows Into Mars’ Icy Past NASA

It was a “crazy-looking crater” on the face of Mars that caught Ali Bramson’s eye. But it was a simple calculation that explained the crater’s strange shape.

Combining data gleaned from two powerful instruments aboard NASA’s Mars Reconnaissance Orbiter, or MRO, Bramson and her colleagues determined why the crater is terraced — not bowl shaped, like most craters of this size.

“Craters should be bowl shaped, but this one had terraces in the wall,” says Bramson, a graduate student in the University of Arizona’s Lunar and Planetary Laboratory, or LPL.

Terraces can form when there are layers of different materials in the planet’s subsurface, such as dirt, ice or rock.

“When the crater is forming, the shock wave from an object hitting a planet’s surface propagates differently depending on what substrates are beneath the area of impact,” Bramson says. “If you have a weaker material in one layer, the shock wave can push out that material more easily, and the result is terracing at the interface between the weaker and stronger materials.”