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These Are The 4 Most Promising Worlds For Alien Life in Our Solar System

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The Earth’s biosphere contains all the known ingredients necessary for life as we know it. Broadly speaking these are: liquid water, at least one source of energy, and an inventory of biologically useful elements and molecules.

 

But the recent discovery of possibly biogenic phosphine in the clouds of Venus reminds us that at least some of these ingredients exist elsewhere in the Solar System too. So where are the other most promising locations for extra-terrestrial life?

Mars

Mars is one of the most Earth-like worlds in the Solar System. It has a 24.5-hour day, polar ice caps that expand and contract with the seasons, and a large array of surface features that were sculpted by water during the planet’s history.

The detection of a lake beneath the southern polar ice cap and methane in the Martian atmosphere (which varies with the seasons and even the time of day) make Mars a very interesting candidate for life.

Methane is significant as it can be produced by biological processes. But the actual source for the methane on Mars is not yet known.

It is possible that life may have gained a foothold, given the evidence that the planet once had a much more benign environment. Today, Mars has a very thin, dry atmosphere comprised almost entirely of carbon dioxide.

This offers scant protection from solar and cosmic radiation. If Mars has managed to retain some reserves of water beneath its surface, it is not impossible that life may still exist.

 

Europa

Europa was discovered by Galileo Galilei in 1610, along with Jupiter’s three other larger moons. It is slightly smaller than Earth’s moon and orbits the gas giant at a distance of some 670,000km once every 3.5 days.

Europa is constantly squeezed and stretched by the competing gravitational fields of Jupiter and the other Galilean moons, a process known as tidal flexing.

The moon is believed to be a geologically active world, like the Earth, because the strong tidal flexing heats its rocky, metallic interior and keeps it partially molten.

The surface of Europa is a vast expanse of water ice. Many scientists think that beneath the frozen surface is a layer of liquid water – a global ocean – which is prevented from freezing by the heat from flexing and which may be over 100 km deep.

Evidence for this ocean includes geysers erupting through cracks in the surface ice, a weak magnetic field and chaotic terrain on the surface, which could have been deformed by ocean currents swirling beneath. This icy shield insulates the subsurface ocean from the extreme cold and vacuum of space, as well as Jupiter’s ferocious radiation belts.

At the bottom of this ocean world it is conceivable that we might find hydrothermal vents and ocean floor volcanoes. On Earth, such features often support very rich and diverse ecosystems.

 

Enceladus

Like Europa, Enceladus is an ice-covered moon with a subsurface ocean of liquid water. Enceladus orbits Saturn and first came to the attention of scientists as a potentially habitable world following the surprise discovery of enormous geysers near the moon’s south pole.

These jets of water escape from large cracks on the surface and, given Enceladus’ weak gravitational field, spray out into space. They are clear evidence of an underground store of liquid water.

Not only was water detected in these geysers but also an array of organic molecules and, crucially, tiny grains of rocky silicate particles that can only be present if the sub-surface ocean water was in physical contact with the rocky ocean floor at a temperature of at least 90 ˚C.

This is very strong evidence for the existence of hydrothermal vents on the ocean floor, providing the chemistry needed for life and localised sources of energy.

 

Titan

Titan is the largest moon of Saturn and the only moon in the Solar System with a substantial atmosphere. It contains a thick orange haze of complex organic molecules and a methane weather system in place of water – complete with seasonal rains, dry periods and surface sand dunes created by wind.

PIA14602 modest(NASA)

The atmosphere consists mostly of nitrogen, an important chemical element used in the construction of proteins in all known forms of life. Radar observations have detected the presence of rivers and lakes of liquid methane and ethane and possibly the presence of cryovolcanoes – volcano-like features that erupt liquid water rather than lava.

This suggests that Titan, like Europa and Enceladus, has a sub-surface reserve of liquid water.

At such an enormous distance from the Sun, the surface temperatures on Titan are a frigid -180 ˚C – way too cold for liquid water. However, the bountiful chemicals available on Titan has raised speculation that lifeforms – potentially with fundamentally different chemistry to terrestrial organisms – could exist there. The Conversation

Gareth Dorrian, Post Doctoral Research Fellow in Space Science, University of Birmingham.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 





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These Are The 4 Most Promising Worlds For Alien Life in Our Solar System

in Science News by


The Earth’s biosphere contains all the known ingredients necessary for life as we know it. Broadly speaking these are: liquid water, at least one source of energy, and an inventory of biologically useful elements and molecules.

 

But the recent discovery of possibly biogenic phosphine in the clouds of Venus reminds us that at least some of these ingredients exist elsewhere in the Solar System too. So where are the other most promising locations for extra-terrestrial life?

Mars

Mars is one of the most Earth-like worlds in the Solar System. It has a 24.5-hour day, polar ice caps that expand and contract with the seasons, and a large array of surface features that were sculpted by water during the planet’s history.

The detection of a lake beneath the southern polar ice cap and methane in the Martian atmosphere (which varies with the seasons and even the time of day) make Mars a very interesting candidate for life.

Methane is significant as it can be produced by biological processes. But the actual source for the methane on Mars is not yet known.

It is possible that life may have gained a foothold, given the evidence that the planet once had a much more benign environment. Today, Mars has a very thin, dry atmosphere comprised almost entirely of carbon dioxide.

This offers scant protection from solar and cosmic radiation. If Mars has managed to retain some reserves of water beneath its surface, it is not impossible that life may still exist.

 

Europa

Europa was discovered by Galileo Galilei in 1610, along with Jupiter’s three other larger moons. It is slightly smaller than Earth’s moon and orbits the gas giant at a distance of some 670,000km once every 3.5 days.

Europa is constantly squeezed and stretched by the competing gravitational fields of Jupiter and the other Galilean moons, a process known as tidal flexing.

The moon is believed to be a geologically active world, like the Earth, because the strong tidal flexing heats its rocky, metallic interior and keeps it partially molten.

The surface of Europa is a vast expanse of water ice. Many scientists think that beneath the frozen surface is a layer of liquid water – a global ocean – which is prevented from freezing by the heat from flexing and which may be over 100 km deep.

Evidence for this ocean includes geysers erupting through cracks in the surface ice, a weak magnetic field and chaotic terrain on the surface, which could have been deformed by ocean currents swirling beneath. This icy shield insulates the subsurface ocean from the extreme cold and vacuum of space, as well as Jupiter’s ferocious radiation belts.

At the bottom of this ocean world it is conceivable that we might find hydrothermal vents and ocean floor volcanoes. On Earth, such features often support very rich and diverse ecosystems.

 

Enceladus

Like Europa, Enceladus is an ice-covered moon with a subsurface ocean of liquid water. Enceladus orbits Saturn and first came to the attention of scientists as a potentially habitable world following the surprise discovery of enormous geysers near the moon’s south pole.

These jets of water escape from large cracks on the surface and, given Enceladus’ weak gravitational field, spray out into space. They are clear evidence of an underground store of liquid water.

Not only was water detected in these geysers but also an array of organic molecules and, crucially, tiny grains of rocky silicate particles that can only be present if the sub-surface ocean water was in physical contact with the rocky ocean floor at a temperature of at least 90 ˚C.

This is very strong evidence for the existence of hydrothermal vents on the ocean floor, providing the chemistry needed for life and localised sources of energy.

 

Titan

Titan is the largest moon of Saturn and the only moon in the Solar System with a substantial atmosphere. It contains a thick orange haze of complex organic molecules and a methane weather system in place of water – complete with seasonal rains, dry periods and surface sand dunes created by wind.

PIA14602 modest(NASA)

The atmosphere consists mostly of nitrogen, an important chemical element used in the construction of proteins in all known forms of life. Radar observations have detected the presence of rivers and lakes of liquid methane and ethane and possibly the presence of cryovolcanoes – volcano-like features that erupt liquid water rather than lava.

This suggests that Titan, like Europa and Enceladus, has a sub-surface reserve of liquid water.

At such an enormous distance from the Sun, the surface temperatures on Titan are a frigid -180 ˚C – way too cold for liquid water. However, the bountiful chemicals available on Titan has raised speculation that lifeforms – potentially with fundamentally different chemistry to terrestrial organisms – could exist there. The Conversation

Gareth Dorrian, Post Doctoral Research Fellow in Space Science, University of Birmingham.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 





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Something Strange Happens on Mars During a Solar Eclipse

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The moons of Mars are not quite like our Earth’s Moon. Phobos, the larger of the two, is much closer to its planet; compared to the Moon’s 27-day orbit, Phobos swings around Mars in line with the planet’s equator thrice every Martian day (sol).

 

Solar eclipses, therefore, are much more frequent than those here on Earth. Phobos passes in front of – but never entirely covers – the Sun for an annular or partial eclipse somewhere on Mars most sols. Because Phobos is moving so fast, it never transits for more than 30 seconds.

But, even during this brief time, the Mars InSight lander has recorded something peculiar happening.

To the surprise of Mars scientists, during Phobos eclipses, the lander’s seismometer – the instrument that records ground motions to monitor possible quake activity – tilts, just an infinitesimal little bit, towards one side.

Researchers at ETH Zurich’s Institute of Geophysics were actually studying data from Mars InSight to see if some of the effects of eclipses here on Earth also occur on Mars.

Specifically: “When Earth experiences a solar eclipse, instruments can detect a decline in temperature and rapid gusts of wind, as the atmosphere cools in one particular place and air rushes away from that spot,” explained seismologist Simon Stähler of ETH Zurich.

InSight is equipped with temperature and wind sensors – but these recorded no change in the atmosphere during Phobos transits. Atmospheric turbulence, atmospheric temperature, and barometric pressure remained pretty much consistent with a normal sol.

 

The solar cells did, however, register the transits. Actually, it would be very curious if they didn’t, since Phobos can block as much as 40 percent of the Sun’s light – so it was reassuring that something went according to plan.

“When Phobos is in front of the Sun, less sunlight reaches the solar cells, and these in turn produce less electricity,” Stähler said. “The decline in light exposure caused by Phobos’s shadow can be measured.”

But that was the extent of the “expected”. Because both the magnetometer and the seismometer chimed in with odd readings – the seismometer with its unexpected tilt.

Actually, the oddity with the magnetometer – used to monitor the magnetic field on the Martian surface – was pretty easy to figure out. Two components showed a decrease very similar to the decrease in the current from the solar array. So the scientists deduced that the decreased current was likely the cause.

“But we didn’t expect this seismometer reading; it’s an unusual signal,” Stähler said. “Imagine a 5-​franc coin; now, push two silver atoms under one edge. That’s the incline we’re talking about: 10^-8.”

 

It doesn’t seem to be a false positive; the signal is recorded for three transits, faint but real. The team expected that it might be a seismic response to the moon’s tidal – that is, gravitational – pull as it passed overhead.

However, when they compared it to other readings of seismic activity from Mars, the signal bore no similarity to previous seismic activity.

Another possibility is that the tether connecting the seismometer to the lander contracted. However, this would have produced a tilt in the opposite direction to what was observed.

And a change in atmospheric temperature could have introduced a density change that nudged the seismometer, but, as we have already discussed, no such change was detected.

But there was one more signal. An infrared radiometer recorded a slight drop in surface temperature during the longest transit, followed by a period of about a minute and a half while the ground warmed back up to its pre-transit temperature.

This, the team believes, is the most likely cause of the strange reading.

“During an eclipse, the ground cools,” said seismologist Martin van Driel of ETH Zurich. “It deforms unevenly, which tilts the instrument.”

 

A similar effect was observed in 1997, at the Black Forest Observatory in Germany.

A technician forgot to turn off the light when leaving the seismometer vault, resulting in elevated noise in long-period data as the warmth from the bulb expanded the granite on which the seismometer rested.

A series of experiments with artificial heat sources ensued, demonstrating that seismometers react almost instantaneously to heat changes in the seismic pillar.

The team repeated their own version of this experiment, and found that they were able to obtain a signal consistent with the tilting of InSight’s seismometer.

This information could be used to better understand Phobos and Mars, the researchers said.

For one, InSight’s location is very accurately mapped. Knowing when a Phobos eclipse begins and ends at that location could help scientists more accurately constrain its orbit.

And that, in turn, could help us understand what’s in store for Phobos’ future.

The moon’s orbit is decaying at a rate of 1.8 centimetres per year, slowing as it goes; eventually, scientists predict, it will grow so close to Mars that tidal forces will tear Phobos apart, turning it into a ring of debris circling Mars.

If the slowdown can be characterised, that can tell us how elastic and warm the planet’s interior is – or how inelastic and cool. And that, in turn, can shed some light on Mars’ formation history.

The research has been published in Geophysical Research Letters.

 



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NASA Rover Glimpses a Ghostly Martian Dust Devil Whirling Across The Red Planet

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Mars may have only a thin atmosphere compared to other Solar System planets, but boy does it make the most of it. Water ice can rise high in the sky to form thin clouds. Wild winds can whip up into uncontrolled dust storms that shroud the entire planet, or create dust towers that extend almost into space.

 

So it should come as no surprise that NASA’s Mars Curiosity rover, beavering away in the Gale Crater, sometimes lays its electronic eyes on Martian weather phenomena – and now, it’s spotted a dust devil spinning across the rocky crater floor.

Seeing weather phenomena on Mars that we also see on Earth isn’t just interesting, though – it can also tell us a lot about seasonal atmospheric changes on the Red Planet.

It’s coming into Martian summer in the planet’s southern hemisphere, where the Gale Crater can be found, and the atmosphere in the region is heating up. Just as uneven heating of the atmosphere on Earth generates atmospheric movement, so too is the Martian atmosphere affected.

“Stronger surface heating tends to produce stronger convection and convective vortices, which consist of fast winds whipping around low pressure cores,” writes atmospheric scientist Claire Newman of Aeolis Research on the Mars Exploration blog.

“If those vortices are strong enough, they can raise dust from the surface and become visible as ‘dust devils’ that we can image with our cameras.”

 

Dust devils are pretty well understood, and they come about the same way on both Earth and Mars. They form best in relatively flat, dry terrain, when the air at the surface level is warmer than the air above it.

This hot surface air rises through the cooler, denser air, creating an updraft. This causes the cooler air to sink. If a horizontal wind then blows through this vertical circulation, a dust devil whips into action.

They’re extremely common on Mars, but we only know this because, as they move across the ground, they sweep up the dust in their path, leaving tracks behind them. Actually seeing them in action on the Red Planet is quite rare, since our observational capabilities are limited, and dust devils themselves are relatively short-lived.

The dust devil above, seen in the top centre of the image, was captured by Curiosity’s Navcam on Sol 2847, and covers a span of about 5 minutes, Newman says. Even though it seems ghostly, the fact that we can see it means it was pretty powerful.

“We often have to process these images, by enhancing what’s changed between them, before dust devils clearly show up,” she writes. “But this dust devil was so impressive that – if you look closely! – you can just see it moving to the right, at the border between the darker and lighter slopes, even in the raw images.”

Studying these movies can reveal a lot about dust devils on Mars – where they form, for instance, how they evolve, how long they last, the type of dust they pick up, and how they vary from location to location.

They can also reveal wind speed and duration, which, in combination with meteorological readings, can help scientists learn more about Martian weather, and how dust devils fit into it.

Curiosity is the only operational rover on Mars at the moment (InSight is a stationary lander), so whatever surface information can be gleaned on Martial dust devils is very limited. Mars also has operational orbiters, though, which cover a lot more ground.

These have caught the occasional dust devil in action from space, as well as the many, many tracks they have left behind after they fade away.

 



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Ancient Mars Had Planet-Wide Rainstorms So Intense They Breached Its Lakes

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Billions of years ago, rain once fell on the Martian plain, and not always softly. 

New research on the Red Planet’s now-empty lakes suggests a huge amount of liquid water must have spilled from the skies roughly 3.5 to 4 billion years ago, enough to sculpt river-like channels and breach several lake basins.

 

“This is extremely important because 3.5 to 4 billion years ago Mars was covered with water. It had lots of rain or snowmelt to fill those channels and lakes,” says planetary scientist Gaia Stucky de Quay from the University of Texas.

Modelling what Mars’ climate looked like all those years ago is incredibly difficult, but studies on the geomorphology and chemistry of the planet certainly suggest it was once home to an abundance of water, fed by both rainfall and snowmelt.

Scientists aren’t sure how long these downpours lasted or whether the weather was torrential, a drizzle or a mix, but marks on the surface of Mars suggest there were once heavy enough showers to leave a lasting impression.

“Now it’s completely dry,” says Stucky de Quay. 

“We’re trying to understand how much water was there and where did it all go.” 

Using satellite images and topography, researchers examined 96 lake basins on Mars that are thought to have formed all those billions of years ago. Some of the basins had ruptured from overflowing water, known as open basins, while others remain intact, known as closed basins. 

 

By measuring these lakes and their watersheds, the team was able to show how much rainfall and snowmelt would have been needed to fill the intact basins without breaching them, while simultaneously overflowing the open basins. 

In cases where a closed and open basin were fed by the same river, researchers could predict both the maximum and minimum rainfall that might have fallen in a single event.

In just one rainstorm, which could have lasted for days or even thousands of years, researchers estimate precipitation on Mars fell somewhere between 4 and 159 meters (13 and 520 feet).

While the effects can be seen planet-wide, not all areas were impacted equally. Some open-basin lakes were in regions that would be considered ‘semi arid’ on Earth, so they probably received less water than more humid parts.

“We again stress that our constraints are based on a threshold – not cumulative – event (i.e., lake overflow) that must have occurred during a single, quasi-continuous runoff episode, which may have recurred multiple times,” the authors write.

“Indeed, the inlet valleys’ large erosional volumes require cumulative water volumes that generally exceed lake basin volumes, thus suggesting repeated runoff episodes… “

 

In other words, the deeper channels being driven to the lakes were probably chiselled out over several downpours, which would probably have flooded the lakes on several occasions. 

Recently, however, some scientists have suggested these valleys were not carved simply by water, and by overestimating the impact of rainfall, we might be miscalculating the rainfall itself.

Nevertheless, the authors think these new insights into precipitation and aridity could help improve and test our climate models for the Red Planet, but they admit their findings are just a piece in the bigger puzzle.

Understanding the climate evolution of Mars will be key to assessing its potential for harbouring life, and that’s why the Mars 2020 Perseverance rover is making its way to a lake bed right now. 

The study was published in Geology.

 



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These Orbs Look Like Candy, But They’re Actually Different Flavours of Phobos

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NASA’s Mars Odyssey probe has been orbiting the Red Planet for almost 19 years now, making it the longest continually active spacecraft in orbit around a planet other than Earth.

 

That incredible tour of duty means it’s witnessed lots of strange things we can’t easily see from our terrestrial vantage point, and this stunning, colourful composite of the Martian moon Phobos is a great example of the alien sights Mars Odyssey gets to glimpse up close.

These six rather delicious-looking circular shapes may resemble some kind of fruit-flavoured candy, but they’re actually different glimpses of Phobos – with the colour variations representing different temperatures, as detected by Mars Odyssey’s infrared camera, the Thermal Emission Imaging System (THEMIS).

010 phobos temperature 1Temperature variations on the Martian moon Phobos. (NASA/JPL-Caltech/ASU/NAU)

THEMIS – which shares Greek mythology ties with both Phobos and its lunar sibling, Deimos – here reveals Phobos at its coldest in blue, when the Martian moon was fully shadowed by the Red Planet during a lunar eclipse.

By contrast, the bright red centres (seen top-right and bottom-left), show the thermal signature of Phobos under full sunlight, where the lunar surface directly facing the Sun heats up to a maximum temperature of around 27 degrees Celsius (81 degrees Fahrenheit).

“[It’s] a kind of temperature bullseye – warmest in the middle and gradually cooler moving out,” Odyssey project scientist Jeffrey Plaut explained in 2019.

 

“Each Phobos observation is done from a slightly different angle or time of day, providing a new kind of data.”

Ongoing analysis of Phobos and its surface features stands to reveal whether the tiny moon (with a radius of only about 11 kilometres, or 7 miles) is an asteroid that got pulled into the gravitational lure of Mars, or perhaps a lost chunk of the planet itself – a fragment that got chipped off by a surface impact in the Red Planet’s mysterious past.

Lots of questions remain, and Mars Odyssey’s ever-watchful eyes could be our best hope of securing the answers. We don’t have forever, though: Phobos, perhaps aptly named after the god of fear, may have already booked in its date with destiny.

 



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NASA’s Rover Is Taking a Tree-Like Device That Converts CO2 Into Oxygen to Mars

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NASA’s Perseverance Mars rover launched from Cape Canaveral, Florida, on 30 July, carrying a host of cutting-edge technology including high-definition video equipment and the first interplanetary helicopter.

 

Many of the tools are designed as experimental steps toward human exploration of the red planet. Crucially, Perseverance is equipped with a device called the Mars Oxygen In-Situ Resource Utilization Experiment, or MOXIE: an attempt to produce oxygen on a planet where it makes up less than 0.2 percent of the atmosphere.

Oxygen is a cumbersome payload on space missions. It takes up a lot of room, and it’s very unlikely that astronauts could bring enough of it to Mars for humans to breathe there, let alone to fuel spaceships for the long journey home.

That’s the problem MOXIE is looking to solve. The car-battery-sized robot is a roughly 1 percent scale model of the device scientists hope to one day send to Mars, perhaps in the 2030s.

Like a tree, MOXIE works by taking in carbon dioxide, though it’s designed specifically for the thin Martian atmosphere. It then electrochemically splits the molecules into oxygen and carbon monoxide, and combines the oxygen molecules into O2.

It analyses the O2 for purity, shooting for about 99.6 percent O2. Then it releases both the breathable oxygen and the carbon monoxide back into the planet’s atmosphere. Future scaled-up devices, however, would store the oxygen produced in tanks for eventual use by humans and rockets.

54ad8d226bb3f7a01aba7179A breakdown of the components inside the MOXIE oxygen generator. (NASA/Wikimedia Commons)

The toxicity of the carbon monoxide produced isn’t a worry, according to Michael Hecht, a principal investigator for MOXIE. The gas reenters the Martian atmosphere but won’t alter it very much.

“If you release the carbon monoxide into the Mars atmosphere, eventually it will combine with a very small amount of residual oxygen that’s there and turn back into carbon dioxide,” Hecht previously told Business Insider.

 

For that reason, the carbon monoxide also wouldn’t hinder a potential biosphere on Mars – a closed, engineered environment where Earthly life could thrive.

Because MOXIE is a small proof-of-concept experiment, it won’t produce much oxygen – if all goes well, it should be producing about 10 grams per hour, which is roughly the amount of oxygen in 1.2 cubic feet of Earth air. For context, humans need about 19 cubic feet of air per day.

MOXIE will test its capabilities by producing oxygen in one-hour increments intermittently throughout the duration of Perseverance’s mission, according to NASA. The device should start working soon after the rover lands on 18 February 2021.

This article was originally published by Business Insider.

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For The First Time, We Can See Patterns of an Eerie Glow in The Martian Atmosphere

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When the Sun sets in a blaze of blue and night falls over the dusty plains of Mars, something weird and wonderful occurs. High up above the surface, the atmosphere begins to glow with an ultraviolet light, sometimes pulsing, as nitrogen and oxygen combine into nitric oxide.

 

This invisible glow, first revealed by the Mars Orbiter mission in 2005, has now been characterised in detail – and its surprising behaviour is revealing how the Martian atmosphere circulates and changes over the course of the year.

Thin and tenuous as it may be, the atmosphere of Mars is surprisingly complex. Wild winds drive monster storms that can engulf the entire planet. There are seasonal fluctuations in its composition, as well as fluctuations that don’t fit any known processes.

Nightglow, by comparison, isn’t quite as mysterious. In fact, the same phenomenon – nightglow driven by the combination of nitrogen and oxygen, albeit in near-infrared wavelengths – has been observed on Venus, too. 

What it can tell us, however, is how Mars’s atmosphere circulates and changes seasonally, in order to help better predict the Red Planet’s crazy weather.

“If we’re going to send people to Mars,” said atmospheric scientist Zachariah Milby of the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics, “we better understand what’s going on in the atmosphere.”

process(LASP)

The glow occurs when currents high in the Martian atmosphere fall in altitude as temperatures plummet. This altitude is where nitrogen and oxygen atoms (which have been split from CO2, O2, and N2 by sunlight during the day) combine into nitric oxide, emitting small bursts of ultraviolet light; in aggregate, it’s detectable as a nightglow.

The new observations come from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) orbiter, which has been studying Mars in great detail since 2014.

 

Five times a day, MAVEN took detailed images of Mars using its Imaging Ultraviolet Spectrograph; with these observations, scientists could track the movements of the ultraviolet glow for the first time.

To the team’s great surprise, the atmosphere pulses three times a night – but only during spring and autumn. During these times, the glow appears around the planet’s middle, growing stronger around the equinoxes.

At other times of the year, the glow is brightest over the polar region in which winter reigns, strongest around the solstice. There, it forms unexpected configurations – waves and spirals.

“The ultraviolet glow comes mostly from an altitude of about 70 kilometres (44 miles), with the brightest spot about 1,000 kilometres (621 miles) across, and is as bright in the ultraviolet as Earth’s northern lights,” Milby said.

“Unfortunately, the composition of Mars’ atmosphere means that these bright spots emit no light at visible wavelengths that would allow them to be seen by future Mars astronauts. Too bad: the bright patches would intensify overhead every night after sunset, and drift across the sky at 300 kilometres per hour (186 mph).”

And there was another surprise – a persistent bright spot at approximately 0 latitude and 0 longitude, that has yet to be explained. It could be due to the terrain below, or something else that has yet to be discovered.

glow compThe equatorial (left) and polar (right) glow. (LASP)

The pulsations in particular reveal a link to waves in the Martian atmosphere. These circle the planet, and their number and speed show that the waves in the middle atmosphere are linked to the daily pattern of solar heating, as well as the shape of the terrain below.

The pulsating spots show a link between the middle atmospheric layer and those above and below – and this relationship is yet another aspect to be explored in future research.

 

There are still a number of questions to be answered, but the research is a step in the right direction in understanding the complex behaviour of the atmosphere of Mars.

“The behaviour of the Martian atmosphere is every bit as complicated and insightful as that of Earth’s atmosphere,” said lead author and planetary scientist Nick Schneider of CU Boulder.

“We use supercomputers to predict weather on Earth so that you can plan for your vacation or growing crops. The same computer models can be spun up for Mars and all the other planets.”

The research has been published in the Journal of Geophysical Research – Space Physics.

 



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SpaceX Breakthrough as Mars ‘Starship’ Prototype Rocket Aces Successful Test Flight

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SpaceX on Tuesday successfully completed a flight of less than a minute of the largest prototype ever tested of the future rocket Starship, which the company hopes to use one day to colonize Mars.

 

“Mars is looking real,” SpaceX founder Elon Musk tweeted in response to a fan.

The current Starship prototype is fairly crude: it’s a large metallic cylinder, built in a few weeks by SpaceX teams on the Texas coast, in Boca Chica – but it’s still smaller than the actual rocket will be.

Several previous prototypes exploded during ground tests, during a learning process of trial and error.

In images shared Tuesday by several space specialists, including the space news website NASASpaceFlight.com, the latest prototype – dubbed SN5 – reached an undetermined altitude before descending to land in a cloud of dust, demonstrating good trajectory control.

“And when the smoke cleared, she stood there majestically, after the 150 meter flight!” tweeted NASA’s top scientist, Thomas Zurbuchen.

The so-called “hop test” was planned to reach a 150-meter (492-foot) altitude, but SpaceX has not confirmed any details about the test flight.

In 2019, an earlier prototype – the smaller Starhopper – flew to 150 meters in altitude and returned to land.

010 spacex starship 2(SpaceX)

The Starship envisioned by Musk will be 120 meters tall and will be able to land vertically on Mars.

“We are going to the Moon, we are going to have a base on the Moon, we are going to send people to Mars and make life multi-planetary,” Musk said Sunday, after welcoming two NASA astronauts back from the International Space Station.

The astronauts had traveled in the Dragon capsule developed by SpaceX.

© Agence France-Presse

 





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The Majestic Valleys of Mars May Not Have Been Carved by Rivers After All

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The question of whether ancient life could have existed on Mars centres on the water that once flowed there, but new research published Monday suggests that many of the Red Planet’s valleys were gouged by icy glaciers not rivers. 

 

The study in Nature Geoscience, which comes amid a flurry of new Mars missions trying to discover if the now-barren planet ever hosted life, casts doubt on a dominant theory that the planet once had a warm, wet climate with abundant liquid water that sculpted the landscape. 

Researchers from Canada and the United States examined more than 10,000 Martian valleys and compared them to channels on Earth that were carved under glaciers.

“For the last 40 years, since Mars’s valleys were first discovered, the assumption was that rivers once flowed on Mars, eroding and originating all of these valleys,” said lead author Anna Grau Galofre in a statement released by the University of British Columbia.

But these formations come in a huge variety “suggesting that many processes were at play to carve them,” she added. 

Researchers found similarities between some Martian valleys and the subglacial channels of Devon Island, in the Canadian Arctic, which has been nicknamed “Mars on Earth” for its barren, freezing conditions and hosted NASA space training missions.

Mars and Antartic superimposed cover 3(Cal-Tech CTX mosaic and MAXAR/Esri)

Above: Collage showing Mars’s Maumee valleys (top half) superimposed with channels on Devon Island in Nunavut (bottom half). The shape of the channels, as well as the overall network, appears almost identical.

The study authors said their findings suggest that some Martian valleys could have been formed some 3.8 billion years ago by meltwater beneath ice sheets, which they said would align with climate modelling predicting that the planet would have been much cooler in its ancient past. 

 

“The findings demonstrate that only a fraction of valley networks match patterns typical of surface water erosion, which is in marked contrast to the conventional view,” said co-author Mark Jellinek

Nature Geoscience noted that understanding climate conditions “in the first billion years of Mars’ history is important in determining whether the planet was ever habitable”.

The study authors said that icy temperatures could in fact have better supported ancient life. 

“A sheet of ice would lend more protection and stability of underlying water, as well as providing shelter from solar radiation in the absence of a magnetic field – something Mars once had, but which disappeared billions of years ago,” the University of British Columbia statement said.

The research comes after NASA launched its latest Mars rover, Perseverance, to look for signs of ancient microbial life on the Red Planet.

If all goes to plan, Perseverance will reach Mars on 18 February 2021 and collect rock samples that could provide invaluable clues about whether there was ever past life on Mars.

However, the retrieval and analysis is not expected before the 2030s.

China has also launched its first Mars rover, which should arrive by May 2021.

© Agence France-Presse

 



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