from the cradle-of-life dept.
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)
Plasma physicist and nuclear weapons specialist John Brandenburg has an out-of-left-field theory about two gigantic hydrogen bomb-type nuclear explosions that supposedly took place on Mars within last hundred million years. He points to overabundance of radioisotope Xenon 129 that results from fission of heavy nuclei as evidence. Xenon 129 is a signature of nuclear explosions and exists in Earth's atmosphere because of the atmospheric nuclear testing and plutonium production that had gone on in the twentieth century. It is also made in supernova explosions as a result of intense neutron bombardment and is therefore embedded in asteroids and meteoroids within the Solar System. John Brandenburg claims that the only way the amount of Xenon 129 that is inferred from 1976 Viking Mars mission data and verified by mass spectrometer on Curiosity rover could have been produced in the distant past is by the way of nuclear explosions. No meteor showers could explain this because meteors contain both Xenon 129 and 132 in equal quantities and the amount of Xenon 129 contained within them is tiny and gets released only at very high temperatures. Mars has 2.5 times more Xenon 129 than Earth's atmosphere prior to 1937 (no nuclear production) and the meteorites. He points to two sites on the Red Planet where the hypothetical explosions took place: in the Northern plains in Mare Acidalium at approximately 50N, 30W, near Cydonia Mensa and in Utopia Planum at approximately 50N 120W near Galaxias Chaos.
He was a recent guest on The Space Show, where he reiterated his theory. It's a long podcast and nukes on Mars talk starts at 47 minutes into the show.
He also gave a presentation to a packed auditorium at the American Institute of Aeronautics and Astronautics (AIAA) 2016 about a different theory of his:
Mars in one Month: The GEM theory of Energy and Momentum Exchange With Spacetime and Forces Observed in the Eaglework Q-V Thruster
Wacky, but interesting, no?
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)