MarsNews.com
March 27th, 2019

Rivers raged on Mars late into its history

via GIPHY

Long ago on Mars, water carved deep riverbeds into the planet’s surface—but we still don’t know what kind of weather fed them. Scientists aren’t sure, because their understanding of the Martian climate billions of years ago remains incomplete.

A new study by University of Chicago scientists catalogued these rivers to conclude that significant river runoff persisted on Mars later into its history than previously thought. According to the study, published March 27 in Science Advances, the runoff was intense—rivers on Mars were wider than those on Earth today—and occurred at hundreds of locations on the red planet.

But it’s a puzzle why ancient Mars had liquid water. Mars has an extremely thin atmosphere today, and early in the planet’s history, it was also only receiving a third of the sunlight of present-day Earth, which shouldn’t be enough heat to maintain liquid water. “Indeed, even on ancient Mars, when it was wet enough for rivers some of the time, the rest of the data looks like Mars was extremely cold and dry most of the time,” Kite said.

Seeking a better understanding of Martian precipitation, Kite and his colleagues analyzed photographs and elevation models for more than 200 ancient Martian riverbeds spanning over a billion years. These riverbeds are a rich source of clues about the water running through them and the climate that produced it. For example, the width and steepness of the riverbeds and the size of the gravel tell scientists about the force of the water flow, and the quantity of the gravel constrains the volume of water coming through.

Their analysis shows clear evidence for persistent, strong runoff that occurred well into the last stage of the wet climate, Kite said.

February 28th, 2019

First Evidence of Planet-Wide Groundwater System On Mars

Evolution of water-filled basins over time

Mars Express has revealed the first geological evidence of a system of ancient interconnected lakes that once lay deep beneath the Red Planet’s surface, five of which may contain minerals crucial to life.

Mars appears to be an arid world, but its surface shows compelling signs that large amounts of water once existed across the planet. We see features that would have needed water to form – branching flow channels and valleys, for example – and just last year Mars Express detected a pool of liquid water beneath the planet’s south pole.

A new study now reveals the extent of underground water on ancient Mars that was previously only predicted by models.

“Early Mars was a watery world, but as the planet’s climate changed this water retreated below the surface to form pools and ‘groundwater’,” says lead author Francesco Salese of Utrecht University, the Netherlands.

“We traced this water in our study, as its scale and role is a matter of debate, and we found the first geological evidence of a planet-wide groundwater system on Mars.”

February 15th, 2019

Archaeology On Mars – From The Fantastical To The Real

Rover and Pyramids on Mars GETTY

NASA’s Martian rover Opportunity breathed its last digital gasp this week. What was a busy scurrying robot picking over and investigating the Martian landscape is now a slowly decaying pile of metal and circuitry. That is to say, Opportunity has entered my world, the world of abandoned things that is archaeology.

Humans have been dreaming about Martian archaeology for well over a century now. When the Italian Astronomer Giovanni Schiaparelli described seeing canali on the surface of the red planet in 1877, many in the English-speaking world began to speculate that Schiaparelli was referring to artificially constructed canals. Percival Lowell became the largest champion of this interpretation. In his 1895 book “Mars,” Lowell claimed that the canals of Mars had been built by a desperate alien race seeking to salvage what water they could from the planet’s melting ice caps.

Yet all along this journey, the Martian landscape has become populated by actual human-made objects. Fourteen separate missions from four different space agencies have littered the surface of the Mars with not only landers and rovers, but heat shields, parachutes, and an untold number of broken bits. As an archaeologist, I love broken bits.

The things that people make and leave behind tell a different story then written history. A physical examination of landing sites on Mars would reveal critical details about why some landers arrived safely while others crashed to never be heard from again. Even the crashed landers tell a story of human triumph and ingenuity. One day, an astronaut will walk up to the original Viking 1 lander and marvel at the accomplishments of their ancestors. The material heritage we are currently scattering across the Martian surface will stand for centuries to come as a symbol of what we as human beings can do.

February 7th, 2019

Rosalind Franklin: Mars rover named after DNA pioneer

The Rosalind Franklin rover is due to launch to Mars next year

The UK-assembled rover that will be sent to Mars in 2020 will bear the name of DNA pioneer Rosalind Franklin.

The honour follows a public call for suggestions that drew nearly 36,000 responses from right across Europe.

Astronaut Tim Peake unveiled the name at the Airbus factory in Stevenage where the robot is being put together.

The six-wheeled vehicle will be equipped with instruments and a drill to search for evidence of past or present life on the Red Planet.

Giving the rover a name associated with a molecule fundamental to biology seems therefore to be wholly appropriate.

Rosalind Franklin played an integral role in the discovery of the structure of deoxyribonucleic acid.

It was her X-ray images that allowed James Watson and Francis Crick to decipher its double-helix shape.

Franklin’s early death from ovarian cancer in 1958, aged just 37, meant she never received the recognition given to her male peers.

The attachment to the European Space Agency (Esa) rover will now see her name travel beyond Earth.

“In the last year of Rosalind’s life, I remember visiting her in hospital on the day when she was excited by the news of the [Soviet Sputnik satellite] – the very beginning of space exploration,” Franklin’s sister, Jenifer Glynn, said on Thursday.

“She could never have imagined that over 60 years later there would be a rover sent to Mars bearing her name, but somehow that makes this project even more special.”

January 17th, 2019

Op/Ed: The Anthropocene Is Coming to Mars

Universities participating in NASA’s Mars Ice Challenge try to devise innovative ways to drill for water on the Red Planet. (NASA Langley Advanced Concepts Lab/Analytical Mechanics Associates)

Astrobiologist Alberto Fairén of Cornell University and the Center of Astrobiology in Madrid, Spain, asks a provocative question in a paper published recently in EOS: How will our exploration of Mars change the Red Planet?

The term Anthropocene has been widely used for the current period in Earth’s geological history, in which human actions have had enough impact on the planet that we see a clear distinction from the previous period, the Holocene. The geological signatures of that transition include a variety of features such as the extinction of many animal and plant species, an increase of carbon dioxide in the atmosphere (resulting in global warming), deposition of plastic in sediments, movements of soil from mining, and the construction of highways, dams, and residential areas.

The Anthropocene as a geological epoch is not formally recognized, but has been widely used to indicate a period where humans majorly affect planet Earth, beginning sometime in the mid-20th century. Fairén suggests that the same nomenclature should be used for Mars, starting with the first human mission slated for the mid-21st century. The thinking is that with the arrival of the first humans, we will inevitably leave topographic changes such as buildings and excavations, especially when utilizing natural resources on Mars as currently envisioned by NASA. To some extent we already have made changes, considering all our abandoned or crashed spacecraft on the planet and the tracks from our rovers. But once we see the first astronaut bootprints in the Martian sands, the impact will be so significant that, according to Fairén, we ought to speak no longer of the Late Amazonian period on Mars, but of the Mars Anthropocene. Earth and Mars will then have a shared geological epoch.

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.

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?

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.

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.

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.