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posted by martyb on Wednesday March 21 2018, @01:21PM   Printer-friendly
from the Neptune's-rejects dept.

Mars' oceans formed early, possibly aided by massive volcanic eruptions

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million years earlier and were not as deep as once thought.

[...] The new model proposes that the oceans formed before or at the same time as Mars' largest volcanic feature, Tharsis, instead of after Tharsis formed 3.7 billion years ago. Because Tharsis was smaller at that time, it did not distort the planet as much as it did later, in particular the plains that cover most of the northern hemisphere and are the presumed ancient seabed. The absence of crustal deformation from Tharsis means the seas would have been shallower, holding about half the water of earlier estimates.

"The assumption was that Tharsis formed quickly and early, rather than gradually, and that the oceans came later," Manga said. "We're saying that the oceans predate and accompany the lava outpourings that made Tharsis."

It's likely, he added, that Tharsis spewed gases into the atmosphere that created a global warming or greenhouse effect that allowed liquid water to exist on the planet, and also that volcanic eruptions created channels that allowed underground water to reach the surface and fill the northern plains.

Timing of oceans on Mars from shoreline deformation (DOI: 10.1038/nature26144) (DX)

Related: Evidence of Giant Tsunami on Mars Suggests an Early Ocean
Evidence of Sea Floor Hydrothermal Deposits Found on Mars
Ceres May Have Had a Global Surface Ocean in the Past


Original Submission

Related Stories

Evidence of Giant Tsunami on Mars Suggests an Early Ocean 2 comments

A team of researchers with members from France, Italy and the U.S. has found what they believe is evidence of a giant tsunami occurring on Mars approximately 3 billion years ago due to an asteroid plunging into an ocean. In their paper published in the Journal of Geophysical Research, the group outlines the evidence and why they believe a tsunami is the most likely factor that led to the creation of some unique planetary formations.

Scientists have been investigating the possibility of oceans on Mars for several years, but have so far been unable to prove they existed. Also, other researchers have found evidence for tsunamis on Mars but have not been able to find an associated oceanic impact crater to go along with it. In this new effort, the researchers believe they have found both.

Prior research uncovered what has been described as thumbprint-looking terrain on the surface of Mars, which some researchers have ascribed to mud moving downhill from volcanoes or being pushed by glaciers. But they might have been created by a very large tsunami, the researchers suggest, and they have found a crater that they believe might have been the cause of it. Lomonosov crater, they suggest, situated in the northern plains, could very well be the scar that was left as a reminder of an asteroid striking in a northern ocean, generating waves hundreds of feet high, eventually spilling onto land and leaving enormous deposits behind. If such an asteroid did strike the ocean, the team continues, after diving through the water, it would have created a crater on the ocean floor. That crater would have been a void that would be suddenly filled with water from all sides, smashing together, creating a secondary tsunami following behind the first. As the first tsunami was receding over land, the second tsunami would have struck, and it was those two acting together that the researchers believe caused the characteristic thumbprint ridges to come about. They have used numerical modeling of wave propagation to back up their claims.

Today's Marscape is the result of the tsunami hitting Fukushima's sister plant.

More information: Francois Costard et al. Modeling tsunami propagation and the emplacement of thumbprint terrain in an early Mars ocean, Journal of Geophysical Research: Planets (2017). DOI: 10.1002/2016JE005230


Original Submission

Evidence of Sea Floor Hydrothermal Deposits Found on Mars 5 comments

https://www.jpl.nasa.gov/news/news.php?feature=6966

The discovery of evidence for ancient sea-floor hydrothermal deposits on Mars identifies an area on the planet that may offer clues about the origin of life on Earth.

A recent international report examines observations by NASA's Mars Reconnaissance Orbiter (MRO) of massive deposits in a basin on southern Mars. The authors interpret the data as evidence that these deposits were formed by heated water from a volcanically active part of the planet's crust entering the bottom of a large sea long ago.

"Even if we never find evidence that there's been life on Mars, this site can tell us about the type of environment where life may have begun on Earth," said Paul Niles of NASA's Johnson Space Center, Houston. "Volcanic activity combined with standing water provided conditions that were likely similar to conditions that existed on Earth at about the same time -- when early life was evolving here."

Mars today has neither standing water nor volcanic activity. Researchers estimate an age of about 3.7 billion years for the Martian deposits attributed to seafloor hydrothermal activity. Undersea hydrothermal conditions on Earth at about that same time are a strong candidate for where and when life on Earth began. Earth still has such conditions, where many forms of life thrive on chemical energy extracted from rocks, without sunlight. But due to Earth's active crust, our planet holds little direct geological evidence preserved from the time when life began. The possibility of undersea hydrothermal activity inside icy moons such as Europa at Jupiter and Enceladus at Saturn feeds interest in them as destinations in the quest to find extraterrestrial life

Did they find any Xenon-129?

Also at BGR.

Ancient hydrothermal seafloor deposits in Eridania basin on Mars (open, DOI: 10.1038/ncomms15978) (DX)


Original Submission

Ceres May Have Had a Global Surface Ocean in the Past 14 comments

Dawn Finds Possible Ancient Ocean Remnants at Ceres

Minerals containing water are widespread on Ceres, suggesting the dwarf planet may have had a global ocean in the past. What became of that ocean? Could Ceres still have liquid today? Two new studies from NASA's Dawn mission shed light on these questions.

The Dawn team found that Ceres' crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and that this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres' rigid surface crust, which could be the signature of residual liquid left over from the ocean, too.

"More and more, we are learning that Ceres is a complex, dynamic world that may have hosted a lot of liquid water in the past, and may still have some underground," said Julie Castillo-Rogez, Dawn project scientist and co-author of the studies, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

Ceres.

Constraints on Ceres' internal structure and evolution from its shape and gravity measured by the Dawn spacecraft (open, DOI: 10.1002/2017JE005302) (DX)

The interior structure of Ceres as revealed by surface topography (DOI: 10.1016/j.epsl.2017.07.053) (DX)

Previously: Dawn Spies Magnesium Sulphate and Possible Geological Activity on Ceres
Ceres's Cryovolcanoes Viscously Relax Into Nothingness
Organic Molecules Found on Ceres
Early Asteroids May Have Been Made of Mud Rather Than Rock
Dawn Mission Extended at Ceres


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  • (Score: -1, Troll) by Anonymous Coward on Wednesday March 21 2018, @01:26PM (2 children)

    by Anonymous Coward on Wednesday March 21 2018, @01:26PM (#656081)

    Mars belongs to Elong Musky. Pledge fealty to your Lord Musk and receive the musky seed of Elon.

  • (Score: 2) by jimtheowl on Wednesday March 21 2018, @04:59PM

    by jimtheowl (5929) on Wednesday March 21 2018, @04:59PM (#656197)
    I thought that this was a terrible article, abusing coin term such as "Global Warming" and making broad obvious statements such as "“Volcanoes may be important in creating the conditions for Mars to be wet” as if written by someone that had just got acquainted with the topic and thought that they were new.

    The paper seems more interesting, but you really have to dig to find bits and pieces without a paid subscription.

    Based on this, I am definitively not getting one for Nature.
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