(MENAFN – The Conversation) In 2018 a team of Italian scientists announced to the world that there was a lake on Mars . Using satellite radar data, the team detected a very bright area approximately 20 kilometres across located about 1.5 kilometres deep under the ice and dust of the south polar cap.
After analysis, they concluded that the bright area was a subglacial lake filled with liquid water. The discovery raised some fundamental questions.
Was this the only lake hidden beneath the ice on Mars? How could liquid water exist in the extreme cold of the Martian south polar region, where the average surface temperatures are lower than -100 °C?
After acquiring additional satellite data, my colleagues and I have discovered three more distinct ‘lakes’ near the one found in 2018 and confirmed that all four bodies contain liquid water.
Read more: Mars: mounting evidence for subglacial lakes, but could they really host life?
How can we see lakes under the ice on Mars?
The radar sounder MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) is one of eight instruments on board the European Space Agency orbiter Mars Express. This scientific spacecraft has been circling the red planet since December 2003.
The orbiting radar directs radio ‘chirps’ toward the planetary surface. These signals are partly reflected back by the surface, and partly penetrate deeper, where they may be absorbed, scattered, or reflected back to the radar. Liquid water reflects radar signals better than many other materials, so the surface of a body of liquid water shines brightly in a radar image.
Radar sounders are used on Earth to detect subglacial lakes in Antarctica, Greenland and Canada. Here, a technique called radio-echo sounding (RES) is commonly used to analyse the signals.
There are some obvious differences between how radar sounding is used on Earth and on Mars. For a start, MARSIS operates from altitudes between 250 km and 900 km above the surface, it has a 40-metre long antenna, and it operates at much lower frequencies (1.8-5 MHz) than Earth-based radar sounders.
These differences meant we had to do some work to adapt standard radio-echo sounding techniques for use with signals from MARSIS. However, we were able to analyse data from 134 MARSIS tracks acquired between 2010 and 2019 over an area 250 km wide and 300 km long near the south pole of Mars.
In this area, we identified three distinct bright patches around the lake already ‘seen’ in 2018. We then used an unconventional probabilistic method to confirm that the bright patches really do represent bodies of liquid water.
We also obtained a much clearer picture of the shape and extent of the lake discovered in 2018. It is still the largest of the bodies of water, measuring 20 km across on its shortest axis and 30 km on its longest.
How could liquid water exist beneath the Martian ice?
The surface temperatures in our study area are around -110 °C on average. The temperatures at the base of the ice cap may be slightly warmer, but still way below the freezing point of pure water.
So how can bodies of liquid water exist here, let alone persist for periods of time long enough for us to detect them?
After the first lake was found in 2018, other groups had suggested the area might be warmed from below by magma within the planet crust. However, there is to date no evidence this is the case, so we think extremely high salt levels in the water are a more likely explanation.
Read more: What on Earth could live in a salt water lake on Mars? An expert explains
Perchlorate salts, which contain chlorine, oxygen, and another element, such as magnesium or calcium, are everywhere in the Martian soil. These salts absorb moisture from the atmosphere and turn to liquid (this process is termed ‘deliquescence’), producing hypersaline aqueous solutions (brines), which crystallise at temperatures far below the freezing point of pure water. Furthermore, laboratory experiments have shown that solutions formed by deliquescence can stay liquid for long periods even after temperatures drop below their own freezing points.
We therefore suggested in our paper that the waters in the south polar subglacial lakes are ‘salty’. This is particularly fascinating, because it has been shown that brines like these can hold enough dissolved oxygen to support microbial life.
Could conditions be right for life beneath the ice?
Our discoveries raise new questions. Is the chemistry of the water in the south polar subglacial lakes suitable for life? How does this modify our definitions of habitable environments? Was there ever life on Mars?
To address these questions new experiments and new missions must be planned. In the meantime, we are gearing up to continue acquiring MARSIS data to collect as much evidence as possible from the Martian subsurface.
Each new piece of evidence brings us one step closer to answering some of the most fundamental scientific questions about Mars, the solar system and the universe.
Read more: Mars: mounting evidence for subglacial lakes, but could they really host life?
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Why NASA's moonshot, Boeing, Bezos and Musk have a lot riding on U.S. election – Reuters Canada
WASHINGTON/SEATTLE (Reuters) – U.S. President Donald Trump’s differences with rival presidential candidate Joe Biden extend far beyond planet earth.
President Trump’s plans to win the race in space call for a 2024 moon mission, and ending direct U.S. financial support for the International Space Station in 2025 – turning over control of the decades-old orbital laboratory to private space companies.
Biden, on the other hand, would likely call for a delayed moonshot and propose a funding extension for the International Space Station if he wins the White House, according to people familiar with the fledging Biden space agenda.
Pushing back the moon mission could cast more doubt on the long-term fate of Boeing Co’s Space Launch System (SLS) rocket, just as Elon Musk’s SpaceX and Jeff Bezos’ Blue Origin scramble to bring rival rockets to market as soon as next year.
Extending support for the space station for a decade would also be a major boost for Boeing, whose $225 million annual ISS operations contract is set to expire in 2024 and is at the depths of a financial crisis caused by the COVID-19 pandemic and the 737 MAX grounding after fatal crashes.
Boeing and SpaceX are already supplying spacecraft to ferry astronauts to the ISS under a program begun under the Obama administration and supported by both Trump and Biden.
Though slowing the moonshot would push back contracts for moon landers and related equipment the companies aim to win, the emerging Biden space agenda appears broadly set to promote competition between traditional defense contractors like Boeing and “new space” rivals like SpaceX who promise lower-cost and reusable rocket systems and space vehicles.
For the commercial space industry, “consistency is key,” said Mike French, a vice president at the Aerospace Industries Association trade group who earlier served as NASA chief of staff under Obama.
“If you shake the etch-a-sketch now, you will (be) risking a series of potentially historic accomplishments and the strong and sustained bipartisan support NASA has seen across its portfolio,” French told Reuters.
Roughly 20 former senior NASA officials and scientists have assembled as a volunteer subgroup under the Biden campaign’s science committee to informally help draw up ideas for a space platform.
Many held jobs in the Obama administration and are jockeying for influential roles on the transition team or in a Biden administration.
Reuters spoke to three of those people, as well as over a dozen lobbyists, industry executives, and former NASA officials who have held their own discussions with Biden’s campaign.
Members of the subgroup also want to boost NASA funding for Earth science and support partnerships with other nations. They stressed that Biden’s space agenda, and the staff assignments to lead it, were in a formative stage as his campaign prioritizes more pressing issues, like the coronavirus pandemic and joblessness.
A Biden campaign spokesman pointed to earlier remarks from Biden. In August, after SpaceX launched and returned the first astronauts from U.S. soil on a trip to the ISS in nearly a decade, Biden said he looked forward to “leading a bold space program that will continue to send astronaut heroes to expand our exploration and scientific frontiers.”
Representatives for Blue Origin and Boeing declined to comment. SpaceX and the Trump campaign did not respond to requests for comment.
FIGHT OVER BOEING ROCKET
But the Biden space group is divided on what to do about Boeing’s SLS, several sources said.
The super heavy-lift rocket has been beset by development delays and cost overruns, but supports tens of thousands of jobs in Alabama and California and is seen by backers as central to NASA’s exploration plans and the only path to Trump’s 2024 timeline for the Artemis mission.
Critics say the rocket’s ageing technology and launch costs of $1 billion or more per mission should prompt a formal White House or Congressional review of the program, particularly if SpaceX and Blue Origin are able to offer new rockets at lower cost.
It costs as little as $90 million to fly Musk’s massive but still less-powerful Falcon Heavy, and some $350 million per launch for United Launch Alliance’s legacy Delta IV Heavy.
Whether a Biden space policy would be more friendly to SLS or to newer commercial alternatives from “new space” players will be heavily influenced by his choice for NASA administrator, a role the campaign wants to be filled by a woman, two people said.
NASA views SLS as its only human-rated ride to the moon in the near term, said Doug Loverro, the former NASA head of human spaceflight.
“But is that the long-term direction to continue to pursue?” Loverro asked.
Reporting by Joey Roulette in Washington, D.C. and Eric M Johnson in Seattle; Editing by Greg Mitchell and Edward Tobin
Asteroid samples successfully sealed in capsule to return to Earth, NASA says – Barrie 360 – Barrie 360
William Harwood – CBS News
An estimated two pounds or more of rock and soil collected from the asteroid Bennu by NASA’s OSIRIS-REx spacecraft have been successfully sealed up in a protective re-entry capsule for return to Earth in 2023, project managers said Thursday.
While detailed hands-on analysis cannot begin until the samples are returned, scientists have already gained insights into the flaky nature of Bennu’s soil, or regolith, by watching how it behaved when the rocks and soil were collected on October 20.
And that is already feeding into discussions about how to possibly one day divert a threatening asteroid from a collision with Earth.
“The OSIRIS-REx mission has collected a phenomenal data set about asteroid Bennu, which is a potentially hazardous asteroid with approximately (a) 1-in-2,700 chance of impacting the Earth late in the 22nd century,” said Dante Lauretta, the mission’s principal investigator.
“The biggest uncertainties on the mission where the response of the regolith to the TAGSAM (sample collector) pressing down onto the surface. And I know already different groups within NASA and other agencies have been able to use our data set for scenarios of the kind that you’re describing.”
Said Lori Glaze, director of planetary science at NASA Headquarters: “I think this information is going to be incredibly important as we think about how to mitigate future potential impacts from these potentially hazardous objects.”
But the primary goal of the OSIRIS-REx mission was to collect a minimum of 60 grams — 1.1 ounces — of rock and soil from Bennu, and the spacecraft appears to have far exceeded that modest requirement.
During a dramatic touch-and-go impact October 20, the spacecraft slowly descended to the surface of Bennu, pressing its TAGSAM collector down onto the soil as compressed nitrogen gas was released, stirring up a blizzard of rocks and fine-grained particles.
The collector was designed so the gas would drive small particles into internal chambers, capturing them for return to Earth. In fact, the TAGSAM captured so much material a flap intended to seal the material inside the collector was jammed open by a rock fragment, allowing small fragments to escape.
As a result, mission managers opted to stow the collector well ahead of schedule, foregoing plans to “weigh” the collected samples by slowly spinning the spacecraft and carefully analyzing its motion compared to earlier measurements when the sample collector was empty.
But with soil and small rock fragments working their way out of the collector, time was of the essence. Earlier this week, flight controllers carried out a 36-hour procedure to reposition OSIRIS-REx’s robot arm so the TAGSAM collector on the far end could be stowed and sealed inside a protective capsule.
If all goes well, OSIRIS-REx will begin the two-year trip back to Earth next spring. The sample capsule will be released in September 2023 for a parachute descent to Utah where recovery crews will be waiting to rush the material to a lab at the Johnson Space Center for initial analysis.
Because mission managers decided not to attempt weighing the collected samples, they do not know for sure how much material was captured. But based on the amount visible to OSIRIS-REx’s cameras, Lauretta said he is confident at last two pounds or rock and soil were scooped up as the TAGSAM pressed into and blow Bennu’s surface.
“There was very little resistance to the spacecraft’s downward motion from the asteroid regolith,” he said. “And so we were continuing to penetrate and burrow underneath the subsurface of the asteroid while the TAGSAM gas was being injected into the regolith.
“Current assessments are that we penetrated a minimum of 24 centimeters (9.4 inches) … and possibly as deep as over 48 centimeters (18.9 inches) with TAGSAM gas firing and collecting and driving material into the collection chamber during that entire time. So we are highly confident … the TAGSAM was was full to capacity.”
Even though a few “tens of grams” of material managed to float free of the sample collector before it could be stowed, Lauretta said he believes “we still have hundreds of grams of material in the sample collector head, probably over a kilogram easily.”
“But of course, we have to wait till 2023 to open up the TAGSAM and be sure.”
banner image via NASA/Goddard/University of Arizona/Lockheed Martin
What you need to know about the rare Halloween full moon – Global News
This will be the first time a full moon has fallen on Halloween since 1974 and it won’t happen again until 2039, but there are a few other reasons why this October full moon will be extra spooky.
“You could call it a Boo-Blue-Super Mini-Hunter Full Moon,” said Rick Stankiewicz, publicity director for the Peterborough Astronomical Association.
Here is why Stankiewicz might say that:
- Boo: Full moon falls on Halloween
- Blue: Second full moon in the month.
- Super Mini: Furthest from Earth and appearing as the smallest full moon of 2020. The apogee — that is, when the moon’s orbit takes it furthest from Earth — technically occurs on Oct. 30, when the Moon will be 406,394 km away.
- Hunter Moon: The full moon that follows the Harvest Moon (Oct. 1, 2020), which is always the first Full Moon closest to the Fall Equinox. The Hunter Full Moon will usually be in October or November.
Stankiewicz said the blue moon part of the name is a bit deceiving. “It won’t look blue,” he said. “At moonrise, 6:24 p.m., it might look yellowish or orange if we are lucky.”
A rare blue moon will light up the sky on Halloween
He said the best time to see the Moon is shortly after moonrise, low in the eastern sky. That’s because it will be closer to the horizon. “The Moon will look a little bigger then,” he said. “The odds of having a hint of colour is always better when it is near the horizon because of the atmosphere it has to shine through.”
If you miss the view this time around, you’ll have to wait until 2039 to see it again.
“It is not the rarest celestial event because it does repeat itself every 19 years,” Stankiewicz said. “But let’s face it, there are lots of ‘stars aligning’ for all these moon-types to be coming together on a Halloween night.”
© 2020 Global News, a division of Corus Entertainment Inc.
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