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December 6th, 2018

Meteorites from Mars Suffer a Velocity Boost Due to Material Pileup

A cartoon on the generation of Martian meteorites. – Tokyo Institute of Technology

One hundred and ninety-eight meteorites from Mars have been discovered on Earth as of Sep., 2017. Hypervelocity impacts on Mars have been a widely accepted mechanism that launches Martian rocks into the space. Petrographic analyses of the Martian meteorites have shown that they suffer relatively low peak pressure ranging from 30 to 50 GPa during impact ejection events. In contrast, shock physics tells us that a stronger shock compression higher than 50 GPa is required to accelerate materials up to the escape velocity of Mars (5 km/s). This contradiction between petrology and shock physics was the outstanding problem regarding the Martian meteorites’ launch.

he new discovery of late-stage acceleration has a wide range of implications not only for the Martian meteorites’ launch, but also for material exchange amongst planetary bodies (See Figure 1). Since microbes may survive the relatively weak shock compression, the late-stage acceleration could provide us with new insight into (Litho-)Panspermia. The researchers are planning to do a series of hypervelocity impact experiments to validate the numerically discovered new mechanism using a two-stage light gas gun installed at the Planetary Exploration Research Center, Chiba Institute of Technology, Japan.

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Posted by tourdemars to: Life on Mars, Meteorites

November 29th, 2018

Opinion: Mars Beckons

Niv Bavarsky

The science and technology behind NASA’s latest space explorer to land on Mars are so awe-inducing that it’s hardly surprising when scientists commenting on the triumph drop their usual jargon to speak like excited schoolchildren.

“It’s nice and dirty; I like that,” was how Bruce Banerdt, the principal investigator behind the InSight mission, reacted when, shortly after setting down Monday on the flat and featureless Martian plain known as the Elysium Planitia, the lander beamed back an image speckled with red dust. “This image is actually a really good argument for why you put a dust cover on a camera. Good choice, right?”

Unlike the [rovers], InSight — Interior Exploration using Seismic Investigations, Geodesy and Heat Transport — is meant to stay in one spot and deploy instruments to measure marsquakes (yes, on Earth they’re “earthquakes”) in order to learn about what’s going on in the innards of the planet. One gizmo will take Mars’s temperature by hammering itself 16 feet below the surface. Deploying the instruments alone is expected to take two months, and the entire mission is meant to last a Martian year, roughly two Earth years.

What for? A random sampling of comments from the public suggests not everyone is convinced that digging on Mars is money well spent. But the basic answer is that whether it’s practical or not, humans will continue to explore the heavens so long as the moon, Mars and the myriad celestial bodies beyond fire our imagination and curiosity. What happened in the earliest days of the universe? How were Earth and its fellow planets formed? And the question of questions: Is there life out there?

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Posted by tourdemars to: Future Missions, General News, Humans To Mars, InSight, Life on Mars, Mars 2020, Mars Exploration Rovers, Mars Science Laboratory, Planetology

October 26th, 2018

Electricity in Martian dust storms helps to form perchlorates

A Martian dust devil winding its way along the Amazonis Planitia region of northern Mars in March 2012. (Photo: NASA’s Mars Reconnaissance Orbiter)

The zip of electricity in Martian dust storms helps to form the huge amounts of perchlorate found in the planet’s soils, according to new research from Washington University in St. Louis.

It’s not lightning but another form of electrostatic discharge that packs the key punch in the planet-wide distribution of the reactive chemical, said Alian Wang, research professor in the Department of Earth and Planetary Sciences in Arts & Sciences.

“We found a new mechanism that can be stimulated by a type of atmospheric event that’s unique to Mars and that occurs frequently, lasts a very long time and covers large areas of the planet — that is, dust storms and dust devils,” Wang said. “It explains the unique, high concentration of an important chemical in Martian soils and that is highly significant in the search for life on Mars.”

The new work is an experimental study that simulates Martian conditions in a laboratory chamber on Earth.

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Posted by tourdemars to: Life on Mars, Phoenix Lander, Planetology

October 23rd, 2018

Mars could have enough molecular oxygen to support life, and scientists figured out where to find it

Mars as seen by NASA’s Hubble Space Telescope on July 18, near its closest approach to Earth since 2003. (NASA / ESA / STScI)

Modern-day Mars may be more hospitable to oxygen-breathing life than previously thought.

A new study suggests that salty water at or near the surface of the red planet could contain enough dissolved O2 to support oxygen-breathing microbes, and even more complex organisms such as sponges.

“Nobody thought of Mars as a place where aerobic respiration would work because there is so little oxygen in the atmosphere,” said Vlada Stamenković, an Earth and planetary scientist at the Jet Propulsion Laboratory who led the work. “What we’re saying is it is possible that this planet that is so different from Earth could have given aerobic life a chance.”

As part of the report, Stamenković and his coauthors also identified which regions of Mars are most likely to contain brines with the greatest amounts of dissolved oxygen. This could help NASA and other space agencies plan where to send landers on future missions, they said.

The work was published Monday in Nature Geoscience.

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Posted by tourdemars to: Life on Mars, Mars Express, Planetology

September 24th, 2018

Ancient Mars Had Right Conditions For Underground Life, New Research Suggests

New research shows that ancient Mars likely had ample chemical energy to support the kinds of underground microbial colonies that exist on Earth. Credit: NASA

A new study shows evidence that ancient Mars probably had an ample supply of chemical energy for microbes to thrive underground.

“We showed, based on basic physics and chemistry calculations, that the ancient Martian subsurface likely had enough dissolved hydrogen to power a global subsurface biosphere,” said Jesse Tarnas, a graduate student at Brown University and lead author of a study published in Earth and Planetary Science Letters. “Conditions in this habitable zone would have been similar to places on Earth where underground life exists.”

Earth is home to what are known as subsurface lithotrophic microbial ecosystems — SliMEs for short. Lacking energy from sunlight, these subterranean microbes often get their energy by peeling electrons off of molecules in their surrounding environments. Dissolved molecular hydrogen is a great electron donor and is known to fuel SLiMEs on Earth.

This new study shows that radiolysis, a process through which radiation breaks water molecules into their constituent hydrogen and oxygen parts, would have created plenty of hydrogen in the ancient Martian subsurface. The researchers estimate that hydrogen concentrations in the crust around 4 billion years ago would have been in the range of concentrations that sustain plentiful microbes on Earth today.

The findings don’t mean that life definitely existed on ancient Mars, but they do suggest that if life did indeed get started, the Martian subsurface had the key ingredients to support it for hundreds of millions of years. The work also has implications for future Mars exploration, suggesting that areas where the ancient subsurface is exposed might be good places to look for evidence of past life.

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Posted by tourdemars to: Life on Mars

July 25th, 2018

Mars Express Detects Liquid Water Hidden Under Planet’s South Pole

The European Space Agency (ESA)

Radar data collected by ESA’s Mars Express point to a pond of liquid water buried under layers of ice and dust in the south polar region of Mars.

Evidence for the Red Planet’s watery past is prevalent across its surface in the form of vast dried-out river valley networks and gigantic outflow channels clearly imaged by orbiting spacecraft. Orbiters, together with landers and rovers exploring the martian surface, also discovered minerals that can only form in the presence of liquid water.

But the climate has changed significantly over the course of the planet’s 4.6 billion year history and liquid water cannot exist on the surface today, so scientists are looking underground. Early results from the 15-year old Mars Express spacecraft already found that water-ice exists at the planet’s poles and is also buried in layers interspersed with dust.

The presence of liquid water at the base of the polar ice caps has long been suspected; after all, from studies on Earth, it is well known that the melting point of water decreases under the pressure of an overlying glacier. Moreover, the presence of salts on Mars could further reduce the melting point of water and keep the water liquid even at below-freezing temperatures.

But until now evidence from the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, MARSIS, the first radar sounder ever to orbit another planet, remained inconclusive.

It has taken the persistence of scientists working with this subsurface-probing instrument to develop new techniques in order to collect as much high-resolution data as possible to confirm their exciting conclusion.

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Posted by tourdemars to: Life on Mars, Mars Express, Planetology

June 18th, 2018

Pushing the limit: could cyanobacteria terraform Mars?

Cyanobacteria could be used to render the atmospheres of other planets suitable for human life.
Credit: DETLEV VAN RAVENSWAAY/GETTY IMAGES

The bacteria that 3.5 billion years ago were largely responsible for the creation of a breathable atmosphere on Earth could be press-ganged into terraforming other planets, research suggests.

A team of biologists and chemists from Australia, the UK, France and Italy has been investigating the ability of cyanobacteria – also known as blue-green algae – to photosynthesise in low-light conditions.

Cyanobacteria are some of the most ancient organisms around, and were responsible, though photosynthesis, for converting the Earth’s early atmosphere of methane, ammonia and other gases into the composition it sustains today.

The photochemistry used by the microbes is pretty much the same as that used by the legion of multicellular plants that subsequently evolved. The process involves the use of red light. Most plants are green because chlorophyll is bad at absorbing energy from that part of the visible light spectrum, and thus reflects it.

Light itself, however, is a critical component for photosynthesis, which is why plants (and suitably equipped bacteria) fail to grow in very dark environments. Just how dark such environments need to be before the process becomes impossible was the focus of the new research.

The team of scientists, which included Elmars Krausz from the Australian National University in Canberra, tested the ability of a cyanobacterial species called Chroococcidiopsis thermalis to photosynthesise in low light.

Previously it had been widely thought that the necessary photochemistry shut down at a light wavelength of 700 nanometres – a point known as the “red limit”.

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Posted by tourdemars to: Humans To Mars, Life on Mars, Technology, Terraforming

June 7th, 2018

Curiosity Rover Finds 3.5-Billion-Year-Old Organic Compounds and Strange Methane on Mars

A potential explanation for the seasonal Martian methane.
Illustration: NASA/JPL-Caltech

No, NASA hasn’t discovered life on Mars yet—but a new result makes it seem like maybe, at some point in the planet’s history, the conditions were ripe for some extraterrestrial beings. Maybe.

The scientists behind experiments conducted by the Curiosity rover are today reporting two results that make the Red Planet’s story even more interesting. One group found carbon-containing organic matter in 3.5-billion-year-old rock. Another noticed the methane levels around Curiosity varied by the season. Combined, these results present tantalizing hints of a potentially habitable Martian past.

From everything we can tell of the chemistry and the minerals deposited in the Gale crater where Curiosity is stationed, “we think it was a habitable environment,” Jennifer Eigenbrode from the NASA Goddard Space Flight Center told Gizmodo. “It had the ability to support life—but doesn’t mean life were there.”

As for the methane, Curiosity’s Tunable Laser Spectrometer measured the methane levels in its surrounding atmosphere over five years. The levels averaged at 0.41 parts per billion by volume, but ranged from 0.24 to 0.65 depending on the season. Here on Earth, we associate methane with life, but it’s a mystery what could be causing it on Mars. Perhaps it’s some geologic process. “It probably indicates more active water in the subsurface than we understood,” scientist Kirsten Siebach, Martian geologist at Rice University not involved with the studies, told Gizmodo.

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Posted by tourdemars to: Life on Mars, Mars Science Laboratory, Planetology

April 12th, 2018

Inside The Cleanroom Where NASA’s New Mars Lander Waits to Launch

A few rule for the cleanroom where NASA’s new InSight Mars lander waits for launch. One, if you must sneeze, sneeze away from the spacecraft. Two, if you drop anything, let one of NASA’s escorts pick it up for you. Three, do not under any circumstances cross the black-and-yellow-striped tape and touch the spacecraft.

Oh also—an engineer tells a dozen media in a conference room at Vandenberg Air Force Base—do not lick the spacecraft. There’s always that one rebel, I suppose.

The reasons to behave ourselves are many, and they are serious. For one, InSight costs nearly a billion dollars, and although it’s engineered to survive the punishing journey to Mars, it’s not engineered to be licked. And two, this conference room is loaded with planetary protection specialists, whose oh-no-big-deal job is to make sure Earthling microbes don’t end up colonizing Mars. And not just for the solar system’s sake—NASA is obligated by international treaty to keep other planets clean. In just a month, it’ll fire InSight to the Red Planet, where the lander will drill to unravel the geological mysteries of our solar system’s rocky bodies.

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Posted by tourdemars to: InSight, Life on Mars

November 13th, 2017

Life Can Survive on Mars Far, Far Longer Than We Thought Universe Today

Mars is not exactly a friendly place for life as we know it. While temperatures at the equator can reach as high as a balmy 35 °C (95 °F) in the summer at midday, the average temperature on the surface is -63 °C (-82 °F), and can reach as low as -143 °C (-226 °F) during winter in the polar regions. Its atmospheric pressure is about one-half of one percent of Earth’s, and the surface is exposed to a considerable amount of radiation.

Until now, no one was certain if microorganisms could survive in this extreme environment. But thanks to a new study by a team of researchers from the Lomonosov Moscow State University (LMSU), we may now be able to place constraints on what kinds of conditions microorganisms can withstand. This study could therefore have significant implications in the hunt for life elsewhere in the Solar System, and maybe even beyond!

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Posted by jburk to: Life on Mars