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ATLANTIC SKIES Could humans live on Mars? – The Telegram

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As NASA’s Perserverance spacecraft speeds towards its February 2021 landing on Mars, many people are pondering the possibility of ordinary humans one day traveling to and living on the planet.

In the 1910s, Edgar Rice Burroughs’ masterfully written fictional books about Mars excited the public’s imagination with tales of humans traveling to the Red Planet and interacting with the native Martians. Hollywood’s 2015 movie, The Martian, teased the possibility of human survival (tenuous as it was) on Mars. Could humans really live, work and play on the surface of Mars, or will such an idea forever remain but a fantasy of literary fiction and cinematic CGI?

The problem of safely travelling to Mars aside, the first question that needs to be asked and answered is where would we live once we got to Mars? Due to the significant, constant solar radiation – not to mention periodic solar flares – that the surface of Mars is subject to due to its thin atmosphere (Earth’s atmosphere protects all life on its surface from the greater portion of the sun’s harmful radiation), we would have to live in some sort of underground structure.

Current estimates indicate at least five meters below the surface would provide the same protection level as our atmosphere. While the technology certainly exists to build such structures (NASA already has prototype Mars One shelters under construction), they would still have to be transported to Mars and constructed, perhaps by robotic construction crews, prior to any human settlers arriving.

OK, so we have a place to live once there, what other things are required? Foremost would be a supply of air to breathe – a properly-proportioned mixture of oxygen, nitrogen, and other trace gases to match that of Earth’s atmosphere. We would have to transport an adequate supply for the number of settlers on hand. That’s not a problem for a couple of astronauts carrying their own backpack supply, but certainly a more difficult task for a large number of settlers planning on emigrating there. It might be possible, over time, to grow enough oxygen-producing plants within specialized structures to generate the needed oxygen amount (to then be mixed with the other required gases); something, with enough space and time, that’s well within the realm of achievable, perhaps, once again, by robots pre-human arrival.

The next two requirements would, by necessity, be a high priority – food and water. At least initially, there would be no immediate means of obtaining water or growing crops, all water and food supplies would have to be transported to Mars, a significant and expensive logistics problem for those planning the trip, particularly if a large number. Terra-forming the Martian surface to generate a breathable atmosphere, a climate, and soil conducive to growing crops, and establishing an adequate water supply (from underground ice deposits) would probably take at least a few hundred years.

Could humans survive on Mars? Yes, at least a few could, for a short period of time, provided they took everything they needed for the time they planned to be there. Long-term settlement, however, would require a massive investment of time, money, technology, and effort; doable, yes, but would it be worth it? Perhaps. After all, the early explorers and settlers of our own planet faced many unknown challenges and life-threatening risks (though, perhaps, not to the same degree) when they set sail for distant lands, unsure of a safe arrival and what life would be like in the new world. In many ways, settling Mars would be a similar challenge, just on a much larger scale.

However, despite my own astronomy interests and science fiction-fueled dreams of traveling to distant planets, I think we humans would be far better off to invest all that time, money, technology, and effort into mitigating the significantly endangering environmental and social issues that are already confronting us. We live on a very unique (as far as we know), special and extremely beautiful island in the middle of a vast celestial ocean. It’s time we woke up to that fact and collectively worked to maintain and preserve that uniqueness, specialness and beauty, not only for ourselves, but also for the generations that follow.

Yes, the urge to and fascination of traveling midst the stars to other planets is exciting, and perhaps one day, in the distant future, humans will travel out there and settle other planets (including Mars), but if we don’t soon start to take care of the planet we live on, we’re not likely to survive as a species to ever step foot on any of those distant worlds.

This week’s sky

Mercury is too close to the sun, and, thus, not observable at present.

Jupiter (magnitude -2.54) is visible above the southern horizon around 8 p.m. It reaches its highest point (21 degrees) in the southern evening sky around 9:20 p.m., remaining visible until about 12:40 a.m., when it sinks below seven degrees above the southwest horizon.

Saturn (magnitude +0.35), as it has all summer, follows Jupiter into and across the early evening sky, becoming visible 18 degrees above the southeast horizon around 8:15 p.m. It remains visible until shortly before 10 p.m., when it disappears from view after dropping below 10 degrees above the southwest horizon shortly after 1 a.m.

Mars (magnitude -1.98 on Sept. 7, and -2.12 by Sept. 13) will continue to brighten this month and next, as it heads for its Oct. 13 opposition (when it will be at its brightest). The Red Planet is visible above the eastern horizon shortly after 10 p.m., reaching an altitude of 50 degrees above the southern horizon shortly before 4 a.m., and lingering in view until it’s lost in the dawn twilight around 6:25 a.m.

Venus (magnitude -4.3) rises in the east around 2:50 a.m., and reaches a height of 38 degrees (its highest point of the year) above the horizon before fading with the approaching dawn by about 6:25 a.m. On the morning of Sept. 13, look for the crescent moon directly above Venus in the pre-dawn sky.

Until next week, clear skies.

Events:

  • Sept. 7 – Venus at highest point in sky for 2020
  • Sept. 10 – Last quarter moon

Glenn K. Roberts lives in Stratford, P.E.I., and has been an avid amateur astronomer since he was a small child. He welcomes comments from readers at glennkroberts@gmail.com.

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Here are five cool facts about Thursday's Harvest Moon – The Weather Network

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2020’s Harvest Moon is nearly here, and this year, it’s a special one.

Look up in the sky on Thursday night, for one of the smallest Full Moons of 2020. Based on the timing, and a quirk of how we perceive the world around us, some extraordinary things are going on with this particular Full Moon.

WHAT IS A HARVEST MOON?

A Harvest Moon is the Full Moon that occurs closest to the Autumnal Equinox.

Depending on the year, it can happen anywhere from two weeks before or two weeks after the equinox.

In 2020, Full Moons fall on September 2 (20 days before the equinox) and October 1 (just 9 days after). So, the October 1 Full Moon takes the title of Harvest Moon this year.

NO SHARING IN 2020

Usually, this particular Full Moon of the year is known by more than one name. Depending on whether it takes place in September or October, the Harvest Moon typically shares time with the Corn Moon or the Hunter’s Moon.

2020 is different, though.

Credit: NASA’s Scientific Visualization Studio/Scott Sutherland

Since we have 13 Full Moons this year, with the upcoming Halloween Blue Moon, this is the first time since 1974 that the Harvest Moon gets a Full Moon all to itself.

MICROMOON

Thursday’s Harvest Moon will be a ‘micromoon’. The opposite of a supermoon, this is a Full Moon that occurs when it is within 90 per cent of its farthest distance from Earth for the month, or at least 405,000 km away.

This is the first of three micromoons this season. However, this isn’t the farthest Full Moon of 2020. That occurs on October 31.

2020-Mini-Full-Moons-Super-New-MoonsCredit: NASA’s Scientific Visualization Studio/Scott Sutherland

EAGER MOON

On average, the Moon rises about 50 minutes later each day. However, this timing varies based on the Moon’s distance from Earth and how far from the equator the observer is.

For example, for someone in Quito, Ecuador, the Moon rises around 40 minutes later when it is farthest from Earth, and 60 minutes later when it is closest. Someone in Winnipeg, MB, on those same nights, will see the Moon rising only 15 minutes later when it is farthest from Earth, and up to 85 minutes later when it is closest.

This Thursday’s micromoon Harvest Moon will be an “eager” one for those of us in Canada. It will rise only around 20 minutes or so later than it did on Wednesday (or even sooner for those farther north)!

THE MOON ILLUSION

Since Thursday’s Harvest Moon will be farther away than usual, it should appear slightly smaller to us here on Earth. Our brains may not register that fact to start, though, due to a little trick called The Moon Illusion.

We gauge the size and distance of something based on comparing that object to other things directly around it. The Moon technically doesn’t have anything directly around it, at least not that we can perceive with the naked eye. So, the brain tries to put it into perspective by comparing it to objects in the foreground – trees, buildings, etc. Fitting the Moon into that perspective, the brain perceives it as much larger than it actually is.

ugc calgary full moonThis Full Moon rose over Calgary, AB, on September 13, 2019. Credit: Siv Heang

You can try a couple of tricks of your own to cancel out this effect. Stretch your arm out and cover the Moon over with your thumb. Then uncover it. That will give you a better perspective. Looking at the Moon through a cellphone camera can help, too, and you can take a few pictures while you’re at it.

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On Mars, 4 supersalty lakes may be hiding under the south pole ice cap – Space.com

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Remnants of water once found on the surface of Mars may be hidden in a handful of small lakes below the Red Planet’s south pole, and more could exist, according to new research.

For decades, researchers have suspected that water lurks below the polar icecaps of Mars, just as it does here on Earth. In 2018, scientists detected evidence for such a reservoir on the Red Planet — signs of a lake about 12 miles (19 kilometers) across and hidden below about a mile (1.5 km) of ice at the south pole of Mars.

At the time, the researchers said that studying this underground pool of water could yield insights on the past and present chances for life on Mars. However, scientists had many more questions than answers about the origin, composition and longevity of this lake and its water.

Related: The search for life on Mars (a photo timeline)

In the new study, to learn more about this hidden water, researchers used the MARSIS radar sounder instrument on board the European Space Agency’s Mars Express spacecraft to scan a 155-by-185 mile (250-by-300 km) area surrounding the suspected underground lake. The scientists analyzed this radar data with techniques previously used to detect lakes under glaciers in Antarctica.

The scientists confirmed the liquid nature of the previously observed lake, narrowing down its dimensions to about 12 by 18 miles (20 by 30 km) in size. They cannot say how deep this lake extends, as the radio waves from MARSIS cannot penetrate salty water, study co-author Elena Pettinelli, a geophysicist at Roma Tre University in Rome, told Space.com.

Moreover, Pettinelli and her colleagues identified three other lakes on the order of 6 by 6 miles (10 by 10 km) in size. Strips of dry rock separate these smaller patches of water from the main lake, the scientists said.

The researchers suggested these lakes are extraordinarily salty. High brine content would keep their water liquid despite the extremely cold conditions at the base of the glaciers at Mars’ south pole, the scientists noted.

Potential underground lakes below the south pole of Mars are shown in blue.  (Image credit: Elena Pettinelli et al, Nature.)

Although Martian polar ice may be melting a little due to warm noontime temperatures, the scientists do not think it likely that such ongoing processes formed these lakes. Instead, the scientists think this saltwater may be the remnants of a larger body of water now lost from the surface, and may be millions or even billions of years old, Pettinelli said.

Scientists have considered the possibility that geothermal activity might have melted polar ice to form the underground lakes, but that explanation was plausible when there was only one such body of water. Forming several lakes this way might require a huge geothermal anomaly. “I don’t think it is physically possible, given what we know,” Pettinelli said.

Instead, these lakes may have formed due to a warmer global climate in the Martian past, Pettinelli said. “This is a complex system of water, not just a single pond,” she said. “It suggests that the conditions that created these lakes might have been more spread across the region, that there might be other systems like this around.”

All in all, if these lakes “are remnants of water that was once on the surface, it certainly may have been a good habitat to harbor life, extinct or living,” Pettinelli said. But the ideal mission to study such potential life would need to drill 0.9 miles (1.5 km) into the ice, which isn’t possible with available technology, she said. “Still, maybe one day a mission to the Martian poles may sample the surface there to see if we can find interesting information,” Pettinelli said.

In the future, the scientists would like to look for similar networks of lakes elsewhere at the south pole, and maybe at the north pole as well, Pettinelli said.

The scientists detailed their findings online today (Sept. 28) in the journal Nature Astronomy.

Follow Charles Q. Choi on Twitter @cqchoi. Follow us on Twitter @livescience and on Facebook.

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Water on Mars: discovery of three buried lakes intrigues scientists – Nature.com

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An image of Mars

Scientists have long thought that there could be water trapped beneath the surface of Mars.Credit: Steve Lee, Univ. Colorado/Jim Bell, Cornell Univ./Mike Wolff, SSI/NASA

Two years ago, planetary scientists reported the discovery of a large saltwater lake under the ice at Mars’s south pole, a finding that was met with excitement and some scepticism. Now, researchers say they’ve confirmed the presence of that lake — and found three more.

The discovery, reported on 28 September in Nature Astronomy1, was made using radar data from the European Space Agency’s (ESA) orbiting Mars Express spacecraft. It follows the detection of a single subsurface lake in the same region in 2018 — which, if confirmed, would be the first body of liquid water ever detected on the red planet and a possible habitat for life. But that finding was based on just 29 observations made from 2012 to 2015, and many researchers said they needed more evidence to support the claim. The latest study used a broader data set comprising 134 observations from between 2012 and 2019.

“We identified the same body of water, but we also found three other bodies of water around the main one,” says planetary scientist Elena Pettinelli at the University of Rome, who is one of the paper’s co-authors. “It’s a complex system.”

The team used a radar instrument on Mars Express called the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) to probe the planet’s southern polar region. MARSIS sends out radio waves that bounce off layers of material in the planet’s surface and subsurface. The way the signal is reflected back indicates the kind of material that is present at a particular location — rock, ice or water, for example. A similar method is used to identify subsurface glacial lakes on Earth. The team detected some areas of high reflectivity that they say indicate bodies of liquid water trapped under more than one kilometre of Martian ice.

The lakes are spread over about 75,000 square kilometres — an area roughly one-fifth the size of Germany. The largest, central lake measures 30 kilometres across, and is surrounded by three smaller lakes, each a few kilometres wide.

Salty lakes

On the surface of Mars, the low pressure that results from the planet’s lack of a substantial atmosphere makes liquid water impossible. But scientists have long thought that there could be water trapped under Mars’s surface, perhaps a remnant of when the planet once had seas and lakes billions of years ago. If such reservoirs exist, they could be potential habitats for Martian life. On Earth, life is able to survive in subglacial lakes in places such as Antarctica.

But the amount of salt present could pose problems. It’s thought that any underground lakes on Mars must have a reasonably high salt content for the water to remain liquid. Although this far beneath the surface there may be a small amount of heat from the interior of Mars, this alone would not be enough to melt the ice into water. “From a thermal point of view it has to be salty,” says Pettinelli.

Lakes with a salt content about five times that of seawater can support life, but as you approach 20 times that of seawater life is no longer present, says John Priscu, an environmental scientist at Montana State University.

“There’s not much active life in these briny pools in Antarctica,” says Priscu, whose group studies microbiology in icy environments. “They’re just pickled. And that might be the case [on Mars].”

Heated debate

The presence of the Martian lakes themselves is also still debated. After the 2018 discovery, researchers raised concerns such as the lack of an adequate heat source to turn the ice into water. And although the latest finding supports the 2018 observation and involves much more data, not everyone is yet convinced that the regions identified are liquid water.

“If the bright material really is liquid water, I think it’s more likely to represent some sort of slush or sludge,” says Mike Sori, a planetary geophysicist at from Purdue University, in West Lafayette, Indiana.

Jack Holt, a planetarty scientist at the University of Arizonasays that while he thinks the latest data are fine, he isn’t sure about the interpretation. “I do not think there are lakes,” says Holt, who is on the science team for the Mars Shallow Radar sounder (SHARAD) on NASA’s Mars Reconnaissance Orbiter (MRO). “There is not enough heat flow to support a brine here, even under the ice cap.”

A Chinese mission that is on its way to Mars might offer one way to check the claims. The Tianwen-1 mission will enter orbit in February 2021, and as well as deploying a rover onto the surface, the orbiter will carry a suite of scientific instruments. These include radar equipment that could be used to make similar observations. “Its capabilities are similar to MARSIS and SHARAD,” says David Flannery from the Queensland University of Technology.

For the time being, the prospect that these lakes are remnants of Mars’s wet past remains an exciting possibility. “There may have been a lot of water on Mars,” says Pettinelli. “And if there was water, there was the possibility of life.”

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