Mars’ enigmatic south pole — the one with the water ice surface deposits that seem to swirl like cappuccino froth — likely has a subsurface composed of smectite clays rather than liquid water lakes, researchers now say.
Since 2018, data from the European Space Agency’s (ESA) Mars Express orbiter had indicated what researchers initially thought might be liquid water lakes as much as three miles under the Martian south pole. Specifically, they were intrigued by bright reflectance spectra detected by the orbiter’s MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument.
But an international team of Mars polar climate researchers used MARSIS’ ground-penetrating radar and a diagnostic technique known as dielectric permittivity to measure this substructure’s ability to store electric energy. Isaac B. Smith, a planetary scientist at Canada’s York University, and co-authors of a paper just published in the journal Geophysical Research Letters used the radar’s reflection strength to estimate the permittivity difference between the ice and the base of the polar cap. This enabled the team to make comparisons that led to the conclusions that smectite clay best fit their lab models.
The beauty of this result is it answers all questions related to the “lakes” idea without raising new ones, Smith, the paper’s lead author, told me. We actually see the clays there, and they can explain the radar observations, so at this point it feels like an open-and-shut case, he says.
As for smectites?
They are a class of clay that covers about half of the Martian surface, particularly in Mars’ southern hemisphere, reports York University. Formed when basalt (the volcanic rock that comprises most of Mars’ surface) breaks down chemically in the presence of liquid water, when frozen to cryogenic temperatures these clays can make the kind of bright radar reflection the team reports.
The south polar cap sits on the very old southern highlands, while the northern ice cap sits on the northern low plains, which are relatively new in comparison, Daniel Lalich, a research associate at the Cornell Center for Astrophysics and Planetary Science and a co-author on the paper, told me.
In contrast, Smith says Mars’ north polar cap is much younger than the south, and it sits on top of large piles of sand. The south polar cap sits on ancient terrain that exhibits clear evidence of water activity in the past, but more than three billion years ago, he says.
But given what the researchers know about the conditions on Mars, any ice in the subsurface wouldn’t be warm enough to melt and form lakes. However, the discovery of this clay beneath the surface does indicate that this south pole area did have liquid water at some point in Mars’ history.
Smectites, cover a large portion of Mars’ surface, mostly in the southern hemisphere, says Smith. Therefore, it’s not at all surprising to find clays at the south pole. Clays form in the presence of water, he says, so we now have a better idea of the distribution of liquid water in the past, and that helps us understand Mars’ evolution through time.
What does this result mean for the total water budget on Mars?
The majority of the water on the planet is locked up in the polar ice caps, with the next biggest reservoirs being mid latitude glaciers and icy mantling deposits, says Lalich. In terms of Mars astrobiology, this means we’re still searching for any currently habitable environments, he says.
“I’m sad to say that there is no known liquid water on Mars at the moment, it’s all frozen,” said Smith.
Although the team was disappointed that the radar measurements didn’t actually indicate liquid lakes deep beneath the surface of the Martian south pole, they take satisfaction that they think they’ve solved at least one of Mars’ mysteries.
“We know so little about the base of the polar cap, it just seemed like this would have to be some big complex problem,” said Lalich. “Then it turns out the whole thing can be explained by this relatively common type of clay. That was a pretty nice surprise.”
Elon Musk trolls Biden with Trump line over perceived Inspiration4 snub – CNET
Elon Musk, SpaceX founder and leading orbital travel agent, was feeling a bit slighted by the world’s most powerful man after President Joe Biden failed to acknowledge the company’sthat sent four civilians on a three-day trip in orbit of our planet.
The flight was bankrolled by billionaire Jared Isaacman, who commanded the mission aboard a Crew Dragon capsule, alongside geologist Sian Proctor, data engineer Chris Sembroski and St. Jude Children’s Research Hospital employee Hayley Arceneaux. The quartetoff the coast of Florida on Saturday.
The mission served as a fundraiser for St. Jude, with over $60 million raised from the public so far. Isaacman also pledged $100 million and Musk added $50 million.
When a Twitter user asked why the president hadn’t acknowledged Inspiration4, Musk hopped into the replies.
“He’s still sleeping,” the CEO wrote, in an apparent reference to Donald Trump’s favorite nickname for his former adversary, “sleepy” Joe Biden.
It seems fair to point out, as a number of other Twitter users have, that the president may have a few other things on his plate at the moment, like continuing to manage the response to a global pandemic, climate crisis and various national security threats.
For what it’s worth, NASA administrator Bill Nelson, a Biden appointee, did offer his congratulations to the crew multiple times.
The White House did not immediately respond to a request for comment.
Inspiration4 is the latest in a string ofthis year. Richard Branson flew to the edge of space on the first fully crewed flight of his Virgin Galactic spaceplane in July. Nine days later, Amazon and Blue Origin founder Jeff Bezos cruised a bit higher with three other passengers on his New Shepard spacecraft.
Unlike those flights, which lasted under 15 minutes each, the Inspiration4 mission was a much more complex venture that saw the four passengers performing scientific research during the multiple day flight as they orbited Earth over 40 times.
15 photos of last night's stunning 'Harvest Moon' over Victoria (PHOTOS) – Victoria Buzz
Last night, a full Harvest Moon peaked over Vancouver Island.
Each year, the full moons in September and October fight for the title of “Harvest Moon”, with the full Moon that occurs nearest to the equinox winning the title.
If October’s full Moon occurs closer to the equinox than September’s, the September full moon is then referred to as the Corn Moon.
Since last night’s full moon peaked only two days before the fall equinox, it won the title of “Harvest Moon”.
The moon rose in the southeast and reached peak illumination just after sunset.
Thankfully, the weather was on our side for perfect viewing of the sky last night.
For those who may have missed it last night here are 15 photos of last night’s full Harvest Moon over Victoria:
NASA reorganizes to prepare for future missions to the Moon and Mars – Yahoo Movies Canada
As it moves towards returning to the Moon ideally sometime in 2024, NASA Administrator Bill Nelson is creating two new mission directorates. With the move, the agency is separating its existing Human Exploration and Operations Mission Directorate into the Exploration Systems Development Mission Directorate (ESDMD) and Space Operations Mission Directorate. NASA said it’s making the change in response to the increasing number of missions it’s conducting in low-Earth orbit, in addition to the plans it has for exploring deep space in the future.
It also announced who’s leading those units. Jim Free, a NASA veteran who has been with the space agency on and off since 1990, is the new associate administrator of ESDMD, while Kathy Lueders is taking on the equivalent position at the Space Operations Mission Directorate. Before becoming the first-ever woman to oversee human spaceflight at NASA, Lueders managed the Commercial Crew Program. As for what the two units will do, ESDMD will oversee the development of programs critical to Project Artemis and eventually manned spaceflight to Mars. Meanwhile, its counterpart will focus on launch operations, including those involving the International Space Station, with an eye towards Moon missions later.
According to NASA, the reorganization is ultimately about looking forward to the next 20 years. The new structure will allow one unit to focus on human spaceflight while the other builds future space systems. In that way, the agency says there will be a constant cycle of development and operations to help it move forward with its space exploration goals.
“This reorganization positions NASA and the United States for success as we venture farther out into the cosmos than ever before, all while supporting the continued commercialization of space and research on the International Space Station,” Nelson said. “This also will allow the United States to maintain its leadership in space for decades to come.”
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