Mars Has Features That Look Very Similar To Life Bearing Hot Springs On Earth

Rock formations near hot spring discharge channels at El Tatio, Chile, shown in this image, bear a striking resemblance to formations in the Gusev Crater on Mars. Image: Steven W. Ruff, Jack D. Farmer

A type of rock formation found on Mars may be some of the best evidence yet for life on that planet, according to a new study at Nature.com. The formations in question are in the Gusev Crater. When Spirit examined the spectra of the formations, scientists found that they closely match those of formations at El Tatio in Northern Chile.

The significance of that match? The El Tatio formations were produced by a combination of living and non-living processes.

The Gusev Crater geo-located on a map of Mars. Image: Wikimedia Labs
The Gusev Crater geo-located on a map of Mars. Image: Wikimedia Labs

The Gusev Crater is a large crater that formed 3 to 4 billion years ago. It’s an old crater lake bed, with sediments up to 3,000 feet thick. Gusev also has exposed rock formations which show evidence of layering. A system of water channels called Ma’adim Vallis flows into Gusev, which could account for the deep sediments.

When it comes to evidence for the existence of life on Mars, and on early Earth, researchers often focus on hydrothermal spring deposits. These deposits can capture and preserve the biosignatures of early life. You can’t find evidence of ancient life just anywhere because geologic processes erase it. This is why El Tatio has received so much attention.

It’s also why formations at Gusev have received attention. They appear to have a hydrothermal origin as well. Their relation to the rocks around them support their hydrothermal origin.

El Tatio in Chile is a hard-to-find combination of extremely high UV, low rainfall, high annual evaporation rate, and high elevation. This makes it an excellent analog for Mars.

The Mars-like conditions at El Tatio make it rather unique on Earth, and that uniqueness is reflected in the rock deposits and structures that it produces. The most unique ones may be the biomediated silica structures that resemble the structures in Gusev. This resemblance suggest that they have the same causes: hydrothermal vents and biofilms.

Silica structures at the Gusev Crater (left) closely resemble the silica structures at El Tatio (right.) Image: Steven W. Ruff, Jack D. Farmer
Silica structures at the Gusev Crater (left) closely resemble the silica structures at El Tatio (right.) Image: Steven W. Ruff, Jack D. Farmer

Biomediated Structures?

The rock structures at El Tatio are typically covered with very shallow water that supports bio-films and mats comprised of different diatoms and cyanobacteria. The size and shape of the structures varies, probably according to the variable depth, flow velocity, and flow direction of the water. The same variations are present at Gusev on Mars. This begs the question, “Could the structures at Gusev also have a biological cause?”

Microscopic images of structures at El Tatio. B, in the upper right, shows the biofilm community partly responsible for the formation of the structures. The surface biofilm community includes silica-encrusted microbial filaments and sheaths, and spindle-shaped diatoms (white arrows.) Image: Steven W. Ruff, Jack D. Farmer.
Microscopic images of structures at El Tatio. B, in the upper right, shows the biofilm community partly responsible for the formation of the structures. The surface biofilm community includes silica-encrusted microbial filaments and sheaths, and spindle-shaped diatoms (white arrows.) Image: Steven W. Ruff, Jack D. Farmer.

Luckily, we have a rover on Mars that can probe the Gusev formations more deeply. Spirit used its Miniature Thermal Emission Spectrometer (Mini-TES) to obtain spectra of the Gusev formations. These spectra confirmed the similarity to the terrestrial formations at El Tatio.

Spirit was helpful in other ways. The rover has one inoperable wheel, which drags across the Martian surface, disrupting and overturning rock structures. Spirit was intentionally driven across the Gusev formations, in order to overturn and expose fragments. Then, Spirit’s Microscopic Imager was trained on those fragments.

(A) shows the wheel marks left by Spirit. The darker ones on the right are from the inoperable wheel. (B) is a closeup of the box in (A). (C) shows some of the rover tracks and features in Gusev. (D) shows two whitish rocks, intentionally overturned by Spirit's busted wheel. Image: NASA/JPL/Spirit PanCam.
(A) shows the wheel marks left by Spirit. The darker ones on the right are from the inoperable wheel. (B) is a closeup of the box in (A). (C) shows some of the rover tracks and features in Gusev. (D) shows two whitish rocks, intentionally overturned by Spirit’s busted wheel. Image: NASA/JPL/Spirit PanCam.
MM scale close-up images of the Martian rocks, on the left, show many similarities with the El Tatio rocks, right. Images: Steven W. Ruff, Jack D. Farmer, NASA/JPL.
MM scale close-up images of the Martian rocks, on the left, show many similarities with the El Tatio rocks, right. Images: Steven W. Ruff, Jack D. Farmer, NASA/JPL.

Unfortunately, Spirit lacks the instrumentation to look deeply into the internal microscale features of the Martian rocks. If Spirit could do that, we would be much more certain that the Martian rocks were partly biogenic in origin. All of the surrounding factors suggest that they do, but that’s not enough to come to that conclusion.

This study presents more compelling evidence that there was indeed life on Mars at some point. But it’s not conclusive.

Colonizing the Inner Solar System

Colonizing The Inner Solar System
Colonizing The Inner Solar System


Science fiction has told us again and again, we belong out there, among the stars. But before we can build that vast galactic empire, we’ve got to learn how to just survive in space. Fortunately, we happen to live in a Solar System with many worlds, large and small that we can use to become a spacefaring civilization.

This is half of an epic two-part article that I’m doing with Isaac Arthur, who runs an amazing YouTube channel all about futurism, often about the exploration and colonization of space. Make sure you subscribe to his channel.

This article is about colonizing the inner Solar System, from tiny Mercury, the smallest planet, out to Mars, the focus of so much attention by Elon Musk and SpaceX.  In the other article, Isaac will talk about what it’ll take to colonize the outer Solar System, and harness its icy riches. You can read these articles in either order, just read them both.

At the time I’m writing this, humanity’s colonization efforts of the Solar System are purely on Earth. We’ve exploited every part of the planet, from the South Pole to the North, from huge continents to the smallest islands. There are few places we haven’t fully colonized yet, and we’ll get to that.

But when it comes to space, we’ve only taken the shortest, most tentative steps. There have been a few temporarily inhabited space stations, like Mir, Skylab and the Chinese Tiangong Stations.

Our first and only true colonization of space is the International Space Station, built in collaboration with NASA, ESA, the Russian Space Agency and other countries. It has been permanently inhabited since November 2nd, 2000.  Needless to say, we’ve got our work cut out for us.

NASA astronaut Tracy Caldwell Dyson, an Expedition 24 flight engineer in 2010, took a moment during her space station mission to enjoy an unmatched view of home through a window in the Cupola of the International Space Station, the brilliant blue and white part of Earth glowing against the blackness of space. Credits: NASA
NASA astronaut Tracy Caldwell Dyson, an Expedition 24 flight engineer in 2010, took a moment during her space station mission to enjoy an unmatched view of home through a window in the Cupola of the International Space Station, the brilliant blue and white part of Earth glowing against the blackness of space. Credits: NASA

Before we talk about the places and ways humans could colonize the rest of the Solar System, it’s important to talk about what it takes to get from place to place.

Just to get from the surface of Earth into orbit around our planet, you need to be going about 10 km/s sideways. This is orbit, and the only way we can do it today is with rockets. Once you’ve gotten into Low Earth Orbit, or LEO, you can use more propellant to get to other worlds.

If you want to travel to Mars, you’ll need an additional 3.6 km/s in velocity to escape Earth gravity and travel to the Red Planet. If you want to go to Mercury, you’ll need another 5.5 km/s.

And if you wanted to escape the Solar System entirely, you’d need another 8.8 km/s. We’re always going to want a bigger rocket.

The most efficient way to transfer from world to world is via the Hohmann Transfer. This is where you raise your orbit and drift out until you cross paths with your destination. Then you need to slow down, somehow, to go into orbit.

One of our primary goals of exploring and colonizing the Solar System will be to gather together the resources that will make future colonization and travel easier. We need water for drinking, and to split it apart for oxygen to breathe. We can also turn this water into rocket fuel. Unfortunately, in the inner Solar System, water is a tough resource to get and will be highly valued.

We need solid ground. To build our bases, to mine our resources, to grow our food, and to protect us from the dangers of space radiation. The more gravity we can get the better, since low gravity softens our bones, weakens our muscles, and harms us in ways we don’t fully understand.

Each world and place we colonize will have advantages and disadvantages. Let’s be honest, Earth is the best place in the Solar System, it’s got everything we could ever want and need. Everywhere else is going to be brutally difficult to colonize and make self-sustaining.

We do have one huge advantage, though. Earth is still here, we can return whenever we like. The discoveries made on our home planet will continue to be useful to humanity in space through communications, and even 3D printing. Once manufacturing is sophisticated enough, a discovery made on one world could be mass produced half a solar system away with the right raw ingredients.

We will learn how to make what we need, wherever we are, and how to transport it from place to place, just like we’ve always done.

Mercury, as imaged by the MESSENGER spacecraft, revealing parts of the never seen by human eyes. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Mercury, as imaged by the MESSENGER spacecraft, revealing parts of the never seen by human eyes. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Mercury is the closest planet from the Sun, and one of the most difficult places that we might attempt the colonize. Because it’s so close to the Sun, it receives an enormous amount of energy. During the day, temperatures can reach 427 C, but without an atmosphere to trap the heat, night time temperatures dip down to -173 C. There’s essentially no atmosphere, 38% the gravity of Earth, and a single solar day on Mercury lasts 176 Earth days.

Mercury does have some advantages, though. It has an average density almost as high as Earth, but because of its smaller size, it actually means it has a higher percentage of metal than Earth. Mercury will be incredibly rich in metals and minerals that future colonists will need across the Solar System.

With the lower gravity and no atmosphere, it’ll be far easier to get that material up into orbit and into transfer trajectories to other worlds.

But with the punishing conditions on the planet, how can we live there? Although the surface of Mercury is either scorching or freezing, NASA’s MESSENGER spacecraft turned up regions of the planet which are in eternal shadow near the poles. In fact, these areas seem to have water ice, which is amazing for anywhere this close to the Sun.

Images of Mercury's northern polar region, provided by MESSENGER. Credit: NASA/JPL
Images of Mercury’s northern polar region, provided by MESSENGER. Credit: NASA/JPL

You could imagine future habitats huddled into those craters, pulling in solar power from just over the crater rim, using the reservoirs of water ice for air, fuel and water.

High powered solar robots could scour the surface of Mercury, gathering rare metals and other minerals to be sent off world. Because it’s bathed in the solar winds, Mercury will have large deposits of Helium-3, useful for future fusion reactors.

Over time, more and more of the raw materials of Mercury will find their way to the resource hungry colonies spread across the Solar System.

It also appears there are lava tubes scattered across Mercury, hollows carved out by lava flows millions of years ago. With work, these could be turned into safe, underground habitats, protected from the radiation, high temperatures and hard vacuum on the surface.

With enough engineering ability, future colonists will be able to create habitats on the surface, wherever they like, using a mushroom-shaped heat shield to protect a colony built on stilts to keep it off the sun-baked surface.

Mercury is smaller than Mars, but is a good deal denser, so it has about the same gravity, 38% of Earth’s. Now that might turn out to be just fine, but if we need more, we have the option of using centrifugal force to increase it. Space Stations can generate artificial gravity by spinning, but you can combine normal gravity with spin-gravity to create a stronger field than either would have.

So our mushroom habitat’s stalk could have an interior spinning section with higher gravity for those living inside it. You get a big mirror over it, shielding you from solar radiation and heat, you have stilts holding it off the ground, like roots, that minimize heat transfer from the warmer areas of ground outside the shield, and if you need it you have got a spinning section inside the stalk. A mushroom habitat.

Venus as photographed by the Pioneer spacecraft in 1978. Some exoplanets may suffer the same fate as this scorched world. Credit: NASA/JPL/Caltech
Venus as photographed by the Pioneer spacecraft in 1978. Credit: NASA/JPL/Caltech

Venus is the second planet in the Solar System, and it’s the evil twin of Earth. Even though it has roughly the same size, mass and surface gravity of our planet, it’s way too close to the Sun. The thick atmosphere acts like a blanket, trapping the intense heat, pushing temperatures at the surface to 462 C.

Everywhere on the planet is 462 C, so there’s no place to go that’s cooler. The pure carbon dioxide atmosphere is 90 times thicker than Earth, which is equivalent to being a kilometer beneath the ocean on Earth.

In the beginning, colonizing the surface of Venus defies our ability. How do you survive and stay cool in a thick poisonous atmosphere, hot enough to melt lead? You get above it.

One of the most amazing qualities of Venus is that if you get into the high atmosphere, about 52.5 kilometers up, the air pressure and temperature are similar to Earth. Assuming you can get above the poisonous clouds of sulphuric acid, you could walk outside a floating colony in regular clothes, without a pressure suit. You’d need a source of breathable air, though.

Even better, breathable air is a lifting gas in the cloud tops of Venus. You could imagine a future colony, filled with breathable air, floating around Venus. Because the gravity on Venus is roughly the same as Earth, humans wouldn’t suffer any of the side effects of microgravity. In fact, it might be the only place in the entire Solar System other than Earth where we don’t need to account for low gravity.

Artist's concept of a Venus cloud city — a possible future outcome of the High Altitude Venus Operational Concept (HAVOC) plan. Credit: Advanced Concepts Lab at NASA Langley Research Center
Artist’s concept of a Venus cloud city — a possible future outcome of the High Altitude Venus Operational Concept (HAVOC) plan. Credit: Advanced Concepts Lab at NASA Langley Research Center

Now the day on Venus is incredibly long, 243 earth days, so if you stay over the same place the whole time it would be light for four months then dark for four months. Not ideal for solar power on a first glance, but Venus turns so slowly that even at the equator you could stay ahead of the sunset at a fast walk.

So if you have floating colonies it would take very little effort to stay constantly on the light side or dark side or near the twilight zone of the terminator. You are essentially living inside a blimp, so it may as well be mobile. And on the day side it would only take a few solar panels and some propellers to stay ahead. And since it is so close to the Sun, there’s plenty of solar power. What could you do with it?

The atmosphere itself would probably serve as a source of raw materials. Carbon is the basis for all life on Earth. We’ll need it for food and building materials in space. Floating factories could process the thick atmosphere of Venus, to extract carbon, oxygen, and other elements.

Heat resistant robots could be lowered down to the surface to gather minerals and then retrieved before they’re cooked to death.

Venus does have a high gravity, so launching rockets up into space back out of Venus’ gravity well will be expensive.

Over longer periods of time, future colonists might construct large solar shades to shield themselves from the scorching heat, and eventually, even start cooling the planet itself.

Earth as seen on July 6, 2015 from a distance of one million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. Credits: NASA
Earth as seen on July 6, 2015 from a distance of one million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. Credits: NASA

The next planet from the Sun is Earth, the best planet in the Solar System. One of the biggest advantages of our colonization efforts will be to get heavy industry off our planet and into space. Why pollute our atmosphere and rivers when there’s so much more space… in space.

Over time, more and more of the resource gathering will happen off world, with orbital power generation, asteroid mining, and zero gravity manufacturing. Earth’s huge gravity well means that it’s best to bring materials down to Earth, not carry them up to space.

However, the normal gravity, atmosphere and established industry of Earth will allow us to manufacture the lighter high tech goods that the rest of the Solar System will need for their own colonization efforts.

But we haven’t completely colonized Earth itself. Although we’ve spread across the land, we know very little about the deep ocean. Future colonies under the oceans will help us learn more about self-sufficient colonies, in extreme environments. The oceans on Earth will be similar to the oceans on Europa or Enceladus, and the lessons we learn here will teach us to live out there.

As we return to space, we’ll colonize the region around our planet. We’ll construct bigger orbital colonies in Low Earth Orbit, building on our lessons from the International Space Station.

One of the biggest steps we need to take, is understanding how to overcome the debilitating effects of microgravity: the softened bones, weakened muscles and more. We need to perfect techniques for generating artificial gravity where there is none.

A 1969 station concept. The station was to rotate on its central axis to produce artificial gravity. The majority of early space station concepts created artificial gravity one way or another in order to simulate a more natural or familiar environment for the health of the astronauts. Credit: NASA
A 1969 station concept. The station was to rotate on its central axis to produce artificial gravity. The majority of early space station concepts created artificial gravity one way or another in order to simulate a more natural or familiar environment for the health of the astronauts. Credit: NASA

The best technique we have is rotating spacecraft to generate artificial gravity. Just like we saw in 2001, and The Martian, by rotating all or a portion of a spacecraft, you can generated an outward centrifugal force that mimics the acceleration of gravity. The larger the radius of the space station, the more comfortable and natural the rotation feels.

Low Earth Orbit also keeps a space station within the Earth’s protective magnetosphere, limiting the amount of harmful radiation that future space colonists will experience.

Other orbits are useful too, including geostationary orbit, which is about 36,000 kilometers above the surface of the Earth. Here spacecraft orbit the Earth at exactly the same rate as the rotation of Earth, which means that stations appear in fixed positions above our planet, useful for communication.

Geostationary orbit is higher up in Earth’s gravity well, which means these stations will serve a low-velocity jumping off points to reach other places in the Solar System. They’re also outside the Earth’s atmospheric drag, and don’t require any orbital boosting to keep them in place.

By perfecting orbital colonies around Earth, we’ll develop technologies for surviving in deep space, anywhere in the Solar System. The same general technology will work anywhere, whether we’re in orbit around the Moon, or out past Pluto.

When the technology is advanced enough, we might learn to build space elevators to carry material and up down from Earth’s gravity well. We could also build launch loops, electromagnetic railguns that launch material into space. These launch systems would also be able to loft supplies into transfer trajectories from world to world throughout the Solar System.

Earth orbit, close to the homeworld gives us the perfect place to develop and perfect the technologies we need to become a true spacefaring civilization. Not only that, but we’ve got the Moon.

Sample collection on the surface of the Moon. Apollo 16 astronaut Charles M. Duke Jr. is shown collecting samples with the Lunar Roving Vehicle in the left background. Image: NASA
Sample collection on the surface of the Moon. Apollo 16 astronaut Charles M. Duke Jr. is shown collecting samples with the Lunar Roving Vehicle in the left background. Image: NASA

The Moon, of course, is the Earth’s only natural satellite, which orbits us at an average distance of about 400,000 kilometers. Almost ten times further than geostationary orbit.

The Moon takes a surprising amount of velocity to reach from Low Earth Orbit. It’s close, but expensive to reach, thrust speaking.

But that fact that it’s close makes the Moon an ideal place to colonize. It’s close to Earth, but it’s not Earth. It’s airless, bathed in harmful radiation and has very low gravity. It’s the place that humanity will learn to survive in the harsh environment of space.

But it still does have some resources we can exploit. The lunar regolith, the pulverized rocky surface of the Moon, can be used as concrete to make structures. Spacecraft have identified large deposits of water at the Moon’s poles, in its permanently shadowed craters. As with Mercury, these would make ideal locations for colonies.

Here, a surface exploration crew begins its investigation of a typical, small lava tunnel, to determine if it could serve as a natural shelter for the habitation modules of a Lunar Base. Credit: NASA's Johnson Space Center
Here, a surface exploration crew begins its investigation of a typical, small lava tunnel, to determine if it could serve as a natural shelter for the habitation modules of a Lunar Base. Credit: NASA’s Johnson Space Center

Our spacecraft have also captured images of openings to underground lava tubes on the surface of the Moon. Some of these could be gigantic, even kilometers high. You could fit massive cities inside some of these lava tubes, with room to spare.

Helium-3 from the Sun rains down on the surface of the Moon, deposited by the Sun’s solar wind, which could be mined from the surface and provide a source of fuel for lunar fusion reactors. This abundance of helium could be exported to other places in the Solar System.

The far side of the Moon is permanently shadowed from Earth-based radio signals, and would make an ideal location for a giant radio observatory. Telescopes of massive size could be built in the much lower lunar gravity.

We talked briefly about an Earth-based space elevator, but an elevator on the Moon makes even more sense. With the lower gravity, you can lift material off the surface and into lunar orbit using cables made of materials we can manufacture today, such as Zylon or Kevlar.

One of the greatest threats on the Moon is the dusty regolith itself. Without any kind of weathering on the surface, these dust particles are razor sharp, and they get into everything. Lunar colonists will need very strict protocols to keep the lunar dust out of their machinery, and especially out of their lungs and eyes, otherwise it could cause permanent damage.

Artist's impression of a Near-Earth Asteroid passing by Earth. Credit: ESA
Artist’s impression of a Near-Earth Asteroid passing by Earth. Credit: ESA

Although the vast majority of asteroids in the Solar System are located in the main asteroid belt, there are still many asteroids orbiting closer to Earth. These are known as the Near Earth Asteroids, and they’ve been the cause of many of Earth’s great extinction events.

These asteroids are dangerous to our planet, but they’re also an incredible resource, located close to our homeworld.

The amount of velocity it takes to get to some of these asteroids is very low, which means travel to and from these asteroids takes little energy. Their low gravity means that extracting resources from their surface won’t take a tremendous amount of energy.

And once the orbits of these asteroids are fully understood, future colonists will be able to change the orbits using thrusters. In fact, the same system they use to launch minerals off the surface would also push the asteroids into safer orbits.

These asteroids could be hollowed out, and set rotating to provide artificial gravity. Then they could be slowly moved into safe, useful orbits, to act as space stations, resupply points, and permanent colonies.

There are also gravitationally stable points at the Sun-Earth L4 and L5 Lagrange Points. These asteroid colonies could be parked there, giving us more locations to live in the Solar System.

Mosaic of the Valles Marineris hemisphere of Mars, similar to what one would see from orbital distance of 2500 km. Credit: NASA/JPL-Caltech
Mosaic of the Valles Marineris hemisphere of Mars, similar to what one would see from orbital distance of 2500 km. Credit: NASA/JPL-Caltech

The future of humanity will include the colonization of Mars, the fourth planet from the Sun. On the surface, Mars has a lot going for it. A day on Mars is only a little longer than a day on Earth. It receives sunlight, unfiltered through the thin Martian atmosphere. There are deposits of water ice at the poles, and under the surface across the planet.

Martian ice will be precious, harvested from the planet and used for breathable air, rocket fuel and water for the colonists to drink and grow their food. The Martian regolith can be used to grow food. It does have have toxic perchlorates in it, but that can just be washed out.

The lower gravity on Mars makes it another ideal place for a space elevator, ferrying goods up and down from the surface of the planet.

The area depicted is Noctis Labyrinthus in the Valles Marineris system of enormous canyons. The scene is just after sunrise, and on the canyon floor four miles below, early morning clouds can be seen. The frost on the surface will melt very quickly as the Sun climbs higher in the Martian sky. Credit: NASA
The area depicted is Noctis Labyrinthus in the Valles Marineris system of enormous canyons. The scene is just after sunrise, and on the canyon floor four miles below, early morning clouds can be seen. The frost on the surface will melt very quickly as the Sun climbs higher in the Martian sky. Credit: NASA

Unlike the Moon, Mars has a weathered surface. Although the planet’s red dust will get everywhere, it won’t be toxic and dangerous as it is on the Moon.

Like the Moon, Mars has lava tubes, and these could be used as pre-dug colony sites, where human Martians can live underground, protected from the hostile environment.

Mars has two big problems that must be overcome. First, the gravity on Mars is only a third that of Earth’s, and we don’t know the long term impact of this on the human body. It might be that humans just can’t mature properly in the womb in low gravity.

Researchers have proposed that Mars colonists might need to spend large parts of their day on rotating centrifuges, to simulate Earth gravity. Or maybe humans will only be allowed to spend a few years on the surface of Mars before they have to return to a high gravity environment.

The second big challenge is the radiation from the Sun and interstellar cosmic rays. Without a protective magnetosphere, Martian colonists will be vulnerable to a much higher dose of radiation. But then, this is the same challenge that colonists will face anywhere in the entire Solar System.

That radiation will cause an increased risk of cancer, and could cause mental health issues, with dementia-like symptoms. The best solution for dealing with radiation is to block it with rock, soil or water. And Martian colonists, like all Solar System colonists will need to spend much of their lives underground or in tunnels carved out of rock.

Two astronauts explore the rugged surface of Phobos. Mars, as it would appear to the human eye from Phobos, looms on the horizon. The mother ship, powered by solar energy, orbits Mars while two crew members inside remotely operate rovers on the Martian surface. The explorers have descended to the surface of Phobos in a small "excursion" vehicle, and they are navigating with the aid of a personal spacecraft, which fires a line into the soil to anchor the unit. The astronaut on the right is examining a large boulder; if the boulder weighed 1,000 pounds on Earth, it would weigh a mere pound in the nearly absent gravity field of Phobos. Credit: NASA/Pat Rawlings (SAIC)
Two astronauts explore the rugged surface of Phobos. Mars, as it would appear to the human eye from Phobos, looms on the horizon. The mother ship, powered by solar energy, orbits Mars while two crew members inside remotely operate rovers on the Martian surface. Credit: NASA/Pat Rawlings (SAIC)

In addition to Mars itself, the Red Planet has two small moons, Phobos and Deimos. These will serve as ideal places for small colonies. They’ll have the same low gravity as asteroid colonies, but they’ll be just above the gravity well of Mars. Ferries will travel to and from the Martian moons, delivering fresh supplies and sending Martian goods out to the rest of the Solar System.

We’re not certain yet, but there are good indicators these moons might have ice inside them, if so that is an excellent source of fuel and could make initial trips to Mars much easier by allowing us to send a first expedition to those moons, who then begin producing fuel to be used to land on Mars and to leave Mars and return home.

According to Elon Musk, if a Martian colony can reach a million inhabitants, it’ll be self-sufficient from Earth or any other world. At that point, we would have a true, Solar System civilization.

Now, continue on to the other half of this article, written by Isaac Arthur, where he talks about what it will take to colonize the outer Solar System. Where water ice is plentiful but solar power is feeble. Where travel times and energy require new technologies and techniques to survive and thrive.

Astronomy Cast Ep. 428: The Moons of Mars

The Moons of Mars


We begin a miniseries on Mars. How many episodes will we do? Who knows? But we start today with a discussion of the two Mars moons, Phobos and Deimos.

Visit the Astronomy Cast Page to subscribe to the audio podcast!

We usually record Astronomy Cast as a live Google+ Hangout on Air every Friday at 1:30 pm Pacific / 4:30 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.

Mars One Merges With Mobile Payment Company In Odd Restructuring

An artist's illustration of a Mars settlement. Image: Bryan Versteeg/MarsOne
An artist's illustration of an early Mars settlement. Credit: Bryan Versteeg/MarsOne

“Pssst. Hey you! Want to go to Mars? No, you won’t be able to come back, you’ll die there. No, we don’t have a ship. No, we don’t have any plans for life support, or for growing food to eat while you there. But we do have our own mobile payment app!”

So goes the sales pitch from Mars One, the oddball of the space exploration world.

In a move that can charitably be described as “puzzling”, Mars One is merging with Swiss mobile payment company InFin Innovative Finance AG. InFin is a small player in a mobile payment field dominated by huge entities like Google, Apple, and Samsung. So, other than ensuring that Mars One astronauts will be able to complete their online shopping without hassle, what is behind this merger?

Money.

In case you don’t know, Mars One is the Netherlands-based company proposing to send astronauts to Mars and set up a human colony there. There would be no returning to Earth, and the “lucky” people chosen by Mars One to be the first to go, would die there. Mars One has been roundly criticized by the aerospace community at large for its lack of detail and its lack of technical capability.

This latest move is unlikely to quell any of the criticism.

Artist's concept of a Martian astronaut standing outside the Mars One habitat. Credit: Bryan Versteeg/Mars One
Artist’s concept of a Martian astronaut standing outside the Mars One habitat. Credit: Bryan Versteeg/Mars One

Mars One has had no problem attracting a huge number of applicants to become astronauts and colonists. Over 200,000 people applied, and that number has been whittled down to 100. They’ve been able to attract applicants, and a lot of attention, but one thing they haven’t been able to attract is money.

Mars One say they need $6 billion to establish their colony on Mars, but they’ve only raised about $1 million so far, mostly from donations, astronaut application fees, and from t-shirt sales and other merchandise. Yes, t-shirts.

“Mars One is very pleased to have been acquired by InFin. This step provides the opportunity to raise capital through the listing on the Frankfurt Stock Exchange.” – Bas Lansdorp

Clearly, Mars One needs cash, and this merger gives Mars One access to capital. You see, InFin is traded on the Frankfurt Stock Exchange, and once the two entities have merged, Mars One will be publicly traded. It’s difficult to see how any institutional investors would ever go anywhere near Mars One stock, but it may be an investment for novelty-seekers, space enthusiasts, or true believers. Who knows?

In a press release, Mars One CEO and co-founder Bas Lansdorp said “This listing also supports our aim to attract international support to establish a permanent human settlement on Mars: our global followers will have the opportunity to be part of this adventure and to literally own a piece of this historic venture.”

A cynic might say that Mars One was just created by Lansdorp as a way to generate some cash from the interest surrounding human travel to Mars. This latest move just adds to the cynicism, since there’s no apparent synergy between a space travel company and a mobile payment company.

If the fact that they sell t-shirts to raise money for their Mars colony doesn’t make you question how capable and serious Mars One is, then this latest move surely will.

Or, maybe we’re being too hard on Mars One. It’s not like NASA or the ESA has ever inspired a line of clothing, or an opera.

Maybe Mars One is an innovator, and is thinking outside the box. Just because space exploration has always been done one way, doesn’t mean it can’t be done in another. Maybe in the final analysis, Mars One will be a successful endeavour, and will show others how unorthodox approaches can work. Only the future knows, and we’re still waiting for the future to tell us.

In the meantime, want to buy a t-shirt?

Curiosity Finds a Melted Space Metal Meteorite on the Surface of Mars

Image from Curiosity's Mast Camera (Mastcam), which captured a small rock believed to be a meteorite on Sol 153. Credit: NASA/JPL-Caltech/LANL/ASU

Since it landed on the surface of the Red Planet in 2012, the Curiosity rover has made some rather surprising finds. In the past, this has included evidence that liquid water once filled the Gale Crater, the presence of methane and organic molecules today, curious sedimentary formations, and even a strange ball-shaped rock.

And most recently, Curiosity’s Mast Camera (Mastcam) captured images of what appeared to be a ball of melted metal. Known as “Egg Rock” (due to its odd, ovoid appearance) this object has been identified as a small meteorites, most likely composed of nickel and iron.

Egg Rock was first noticed in an image that was snapped by Curiosity on Oct. 28th, 2016, (or Sol 153, the 153rd day of Curiosity’s mission). The rover then snapped a two-frame portrait of the meteorite (seen below) two days later (on Sol 155) and studied it using its ChemCam’s Remote Micro-Imager (RMI). This provided not only a close-up of the strange object, but also a chance for chemical analysis.

Close up of Egg Rock, showing the laser reflection from Curiosity's ChemCam.  Credit: NASA/JPL
Close up of “Egg Rock”, showing the laser reflections from Curiosity’s ChemCam instrument. Credit: NASA/JPL

The chemical analysis revealed that the rock was composed of metal, which explained its melted appearance. In essence, it is likely the rock became molten as it entered Mars’ atmosphere, leading to the metal softening and flowing. Once it reached the surface, it cooled to the point that this appearance became frozen on its face.

Such a find is quite exciting, if not entirely unexpected. In the past, Curiosity and other rovers has spotted the remains of other metallic meteorites. For instance, back in 2005, the Opportunity rover spotted a pitted, basketball-sized iron meteorite that was named “Heat Shield Rock“.

This was followed in 2009 by the discovery of “Block Island“, a large dark rock that measured 0.6 meters (2 feet) across and contained large traces of iron. And in 2014, Curiosity spotted the mostly-iron meteorite that came to be known as “Lebanon” which measured 2 meters (6.5 feet) wide – making it the largest meteorite to ever be found on Mars.

However, “Egg Rock” is somewhat unique, in that its appearance seems more “melted” than meteorites spotted in the past. And as George Dvorsky of Gizmodo indicated, other aspects of its appearance (such as the long hollows) could mean that it lost material, perhaps when it still molten (i.e. shortly after it reached the surface).

Iron Meteorite on Mars. Opportunity finds an iron meteorite on Mars, the first meteorite of any type ever identified on another planet. The pitted, basketball-size object is mostly made of iron and nickel. Opportunity used its panoramic camera to take the images used in this approximately true-color composite on the Sol 339 (Jan. 6, 2005). Credit: NASA/JPL/Cornell
Image of the iron meteorite fpund on Mars by the Opportunity rover on the Sol 339 (Jan. 6th, 2005). Credit: NASA/JPL/Cornell

And such finds are always interesting because they provide us with the opportunity to study chunks of the Solar System that might not survive the trip to Earth. Given its greater proximity to the Asteroid Belt, Mars is better situated to be periodically struck by objects that get kicked out of it by Jupiter’s gravity. In fact, it is theorized that this is how Mars got its moons, Phobos and Deimos.

In addition, meteorites are more likely to survive passing through Mars’ atmosphere, since it is only about 1% as dense as Earth’s. Last, but certainly not least, meteorites have been striking Earth and Mars for eons. But since Mars has had a dry, desiccated atmosphere for all of that time, meteorites that land on its surface are subject to less wind and water erosion.

As such, Martian meteorites are more likely to be intact and better preserved over the long haul. And studying them will give planetary scientists opportunities they may not enjoy here on Earth. Now if we could just transport some of these space rocks home for a more detailed analysis, we’d be in business! Perhaps that should be something for future missions to consider.

Further Reading: ASU – Red Planet Report

Best Photos Yet of the Mars Lander’s Demise

Credit: Schiaparelli lander protected by its heat shield as it enters the Martian atmosphere. Credit: ESA
A closeup of the dark, approximately circular crater about 7.9 feet (2.4 meters) in diameter marking the crash of the Schiaparelli test lander on Mars. The photo was taken on October 25 by NASA's Mars Reconnaissance Lander (MRO). Credit:
A closeup of the dark, approximately circular crater about 7.9 feet (2.4 meters) in diameter that marks the crash of the Schiaparelli test lander on Mars. The new, higher-resolution photo was taken on October 25 by NASA’s Mars Reconnaissance Lander (MRO). A hint of an upraised rim is visible along the crater’s lower left side. The tiny white specks may be pieces of the lander that broke away on impact. The odd dark curving line has yet to be explained.  Credit: NASA/JPL-Caltech

What’s the most powerful telescope for observing Mars? A telephoto lens on the HiRise camera on the Mars Reconnaissance Orbiter that can resolve features as small as 3 feet (1-meter) across. NASA used that camera to provide new details of the scene near the Martian equator where Europe’s Schiaparelli test lander crashed to the surface last week.

The Schiaparelli test lander was protected by its heat shield as it descended through the Martian atmosphere at high speed. Credit: ESA
The Schiaparelli test lander was protected by its heat shield as it descended through the Martian atmosphere at high speed. Credit: ESA

During an October 25 imaging run HiRise photographed three locations where hardware from the lander hit the ground all within about 0.9 mile (1.5 kilometers) of each other. The dark crater in the photo above is what you’d expect if a 660-pound object (lander) slammed into dry soil at more than 180 miles an hour (300 km/h). The crater’s about a foot and a half (half a meter) deep and haloed by dark rays of fresh Martian soil excavated by the impact.

But what about that long dark arc northeast of the crater?  Could it have been created by a piece of hardware jettisoned when Schiaparelli’s propellant tank exploded? The rays are curious too. The European Space Agency says that the lander fell almost vertically when the thrusters cut out, yet the asymmetrical nature of the streaks — much longer to the west than east — would seem to indicate an oblique impact. It’s possible, according to the agency, that the hydrazine propellant tanks in the module exploded preferentially in one direction upon impact, throwing debris from the planet’s surface in the direction of the blast, but more analysis is needed. Additional white pixels in the image could be lander pieces or just noise.

This Oct. 25, 2016, image shows the area where the European Space Agency's Schiaparelli test lander reached the surface of Mars, with magnified insets of three sites where components of the spacecraft hit the ground. It is the first view of the site from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter taken after the Oct. 19, 2016, landing event and our highest resolution of the scene to date. Annotations by the author. Click for a full-resolution image. Credit: NASA/JPL-Caltech
This Oct. 25, 2016, image shows the area where the European Space Agency’s Schiaparelli test lander reached the surface of Mars, with magnified insets of three sites where components of the spacecraft hit the ground. It is the first view of the site from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter taken after the Oct. 19, 2016, landing event and our highest resolution of the scene to date. Click for a full-resolution image. Credit: NASA/JPL-Caltech

In the wider shot, several other pieces of lander-related flotsam are visible. About 0.8 mile (1.4 km) eastward, you can see the tiny crater dug out when the heat shield smacked the ground. Several bright spots might be pieces of its shiny insulation. About 0.6 mile (0.9 kilometer) south of the lander impact site, two features side-by-side are thought to be the spacecraft’s parachute and the back shell.  NASA plans additional images to be taken from different angle to help better interpret what we see.

The last happy scene for the lander when it still dangled from its chute before dropping and slamming into the surface. Credit: ESA
Schiaparelli dangles from its parachute in this artist’s view. A software error caused the chute to deploy too soon. Credit: ESA

The test lander is part of the European Space Agency’s ExoMars 2016 mission, which placed the Trace Gas Orbiter into orbit around Mars on Oct. 19. The orbiter will investigate the atmosphere and surface of Mars in search of organic molecules and provide relay communications capability for landers and rovers on Mars. Science studies won’t begin until the spacecraft trims its orbit to a 248-mile-high circle through aerobraking, which is expected to take about 13 months.

Everything started out well with Schiaparelli, which successfully transmitted data back to Earth during its descent through the atmosphere, the reason we know that the heat shield separated and the parachute deployed as planned. Unfortunately, the chute and its protective back shell ejected ahead of time followed by a premature firing of the thrusters. And instead of burning for the planned 30 seconds, the rockets shut off after only 3. Why? Scientists believe a software error told the lander it was much closer to the ground than it really was, tripping the final landing sequence too early.

Landing on Mars has never been easy. We’ve done flybys, attempted to orbit the planet or land on its surface 44 times. 15 of those have been landing attempts, with 7 successes: Vikings 1 and 2, Mars Pathfinder, the Spirit and Opportunity rovers, the Phoenix Lander and Curiosity rover. We’ll be generous and call it 8 if you count the 1971 landing of Mars 3 by the then-Soviet Union. It reached the surface safely but shut down after just 20 seconds.

Mars can be harsh, but it forces us to get smart.

**** Want to learn more about Mars and how to track it across the sky? My new book, Night Sky with the Naked Eye, which will be published on Nov. 8, covers planets, satellites, the aurora and much more. You can pre-order it right now at these online stores. Just click an icon to go to the site of your choice – Amazon, Barnes & Noble or Indiebound. It’s currently available at the first two outlets for a very nice discount.

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How Will We Get to Mars? New Book and TV Series Provide the Details

What is it going to take to really get humans to Mars? A new television series and a companion book take a detailed and hard look at the future of Mars exploration. The six-part documentary series on the National Geographic Channel and the book by veteran, award-winning space journalist Leonard David are both titled, “Mars: Our Future on the Red Planet.”

The TV series debuts on November 14, 2016 and was produced by Academy Award-winning filmmaker Ron Howard (Apollo 13) and NASA scientist Brian Grazer. It combines interviews with some of the prominent ‘movers and shakers’ in the space community along with a scripted drama that portrays a human mission to Mars in the year 2033. Together, the show “tells the story of how we will one day call the Red Planet home through groundbreaking research and innovation.”

Watch the trailer:

Leonard David’s thoroughly researched book contains a wealth of information on the technological and sociological hurdles that need to be surmounted to make humans on Mars a reality, as well as revealing what work is currently being done on the road to the Red Planet. The books is large format, filled with stunning, full-color images throughout that provide a feast for the eye, including actual images from our spacecraft as well as illustrations of what future missions might entail.

While the book includes some portrayals of the television series’ drama of the crew of the Daedalus mission as they land on Mars and set up the first human base, the real drama comes from David’s interviews with real-life experts, the men and women who are fervently working towards the day an actual human mission goes to Mars.

I had the chance to talk with David about his new book, and asked what it was like to write a book in conjunction with a television series.

Author Leonard David speaking at the Mars Society meeting in Washington, DC. Image courtesy Leonard David.
Author Leonard David speaking at the Mars Society meeting in Washington, DC. Image courtesy Leonard David.

“It was a really interesting experience,” he said, “and we had a close-knit team that had telecons every week to try and synchronize the themes we were using. There were a few topics I wanted to make sure I was able to include, and there were several themes that the whole team wanted to make sure was included in both the book and the show.”

For example, the imagery in the book and the premise of the show reflect that a mission to Mars is likely going to be a global endeavor. “I wanted to make sure to emphasize this will not be just a US or NASA enterprise, and also that a lot of other countries are exploring Mars with spacecraft right now,” David said.

And so, the images in the book come from multi-national sources, and several are pictures I had never seen before, including the latest images from spacecraft, unique illustrations, and distinctive maps of potential human landing sites on Mars that are almost impossible to stop looking at.

Destination Mars: a detailed map of Mars from National Geographic. Credit: National Geographic.
Destination Mars: a detailed map of Mars from National Geographic. Credit: National Geographic.

David said that with the book, he didn’t want to take a stand on all the issues but combine as much information as possible to make it all available for people to think about.

He also said he wanted to portray the true realities of a human expedition to Mars.

“I wanted to make sure people understand that it’s not just throwing a bunch of tin cans on the surface of Mars and then jamming people in them,” he said. “There are so many other issues: sociological issues, there are cultural issues, and there are ethics issues particularly on the topic of possibly terraforming Mars. I just wanted to write a book that I haven’t already read, and I hit on themes that I don’t recall other books getting to.”

For example, David interviews Frank White, author of the seminal book “The Overview Effect,” and that title is now used as an evocative term to explain how seeing Earth from space has changed the human perspective and experience. But David asks White to consider what The Overview Effect will mean for human Martians.

“The Martians will soon develop their own culture and seem like true ‘aliens’ to Earthlings,” envisions White, leading ultimately to a “declaration of independence” from Earth by Mars.

Similarly, David’s discussions with Nick Kanas, professor emeritus in the department of psychiatry at the University of California, San Francisco, covers what Kanas calls “Earth out of view,” which means that since Earth is so far away, any future human Martians will have to solve their own problems. Therefore, any physical or mental issues that arise will have to be dealt with locally.

It could highlight a sense of isolation, being distant and away from everything, [Kanas adds]. “It’s a different sort of state. Whether that will produce depression, or psychosis, or extreme homesickness… I don’t know. We have a lot of questions that Mars is going to raise, and we don’t have the answers.”

And there are other realities that need to be considered.

“There will be death,” David said. “Mars is out to kill you to begin with, and there will be accidents and people will likely lose their life in some way. It’s going to call upon the pioneering spirit, and it will challenge us not only technologically, but psychologically and physiologically.”

David looks at the technology that will be required: the potential propulsion systems, how to ramp up current entry, descent and landing (EDL) systems for larger human-sized payloads, and the imperative of using what’s called In Situ Resource Utilization (ISRU).

Future missions to Mars and other locations in the Solar System may depend heavily on the skills of planetary geologists. Credit: NASA Ames Research Center
Future missions to Mars and other locations in the Solar System may depend heavily on the skills of planetary geologists. Credit: NASA Ames Research Center

“If we are going to try to avoid having these missions be just flags and footprints like the Apollo missions, it’s going to require living off the land on Mars,” David said.

Again, the experts David interviewed – called “The Heroes” in the book — provide an incredible depth of insight on all the issues facing a human mission to Mars. The Heroes include people such as historian John Logsdon, policy experts like Marcia Smith, entrepreneurs and innovators like Elon Musk, Mars engineers like JPL’s Rob Manning, planetary scientists such as NASA’s Chris McKay and Planetary Protection Officer Catherine Conley, then astronauts like Stanley Love who have already been on the front lines of long duration spaceflight and veteran Buzz Aldrin whose lifetime of experiences provide a unique perspective on human exploration. Reading the words of these experts was perhaps my favorite part of the book (besides those intriguing maps!)

With NASA and other space agencies now embracing Mars as the ultimate human destination, David said the time is now ripe for looking at all the issues that lie ahead on the path to Mars.

“This is a unique time,” he said. “I believe we are in a period that I call ‘now history.’ Never before in our history have we had the potential for the technology, communications and all the other things we need to go off the planet; we’ve never been here before. I think we have an opportunity to create this ‘now history,’ and what we do here and now is going to be a flagship for the future as far as our ability to not only go to Mars, but to go beyond to other planets as well.”

David said he hadn’t yet seen all the footage from the television series, but he was impressed with what he has watched so far. “Ron Howard is pretty good at this stuff, and so the quality is definitely there.” David also indicated there is a bit of a surprise ending to the show, so make sure to stay tuned.

Leonard David is a long-time contributor to Space.com and he writes a column for that site called Space Insider. He is also the coauthor of Buzz Aldrin’s book, “Mission to Mars.” You can find more articles by David at his website, Inside Outer Space.

More information on the book and how to purchase it can be found at the Nat Geo website, or at Amazon, and additional information on the television series can be found here.

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Schiaparelli is Gone. Smashed on the surface of Mars

Mars Reconnaissance Orbiter view of Schiaparelli landing site before and after the lander arrived. The images have a resolution of 6 meters per pixel and shows two new features on the surface when compared to an image from the same camera taken in May this year. The black dot appears to be the lander impact site and the smaller white dot below the paw-shaped cluster of craters, the parachute. Credit: NASA
Mars Reconnaissance Orbiter view of Schiaparelli landing site before and after the lander arrived. The images have a resolution of 6 meters per pixel and shows two new features on the surface when compared to an image from the same camera taken in May this year. The black dot appears to be the lander impact site and the smaller white dot below the paw-shaped cluster of craters, the parachute. Credit: NASA
Mars Reconnaissance Orbiter view of Schiaparelli landing site before and after the lander arrived. The images have a resolution of 6 meters per pixel and shows two new features on the surface when compared to an image from the same camera taken in May this year. The black dot appears to be the lander impact site and the smaller white dot below the paw-shaped cluster of craters, the parachute. Credit: NASA

Instead of a controlled descent to the surface using its thrusters, ESA’s Schiaparelli lander hit the ground hard and may very well have exploded on impact.  NASA’s Mars Reconnaissance Orbiter then-and-now photos of the landing site have identified new markings on the surface of the Red Planet that are believed connected to the ill-fated lander.

Schiaparelli entered the martian atmosphere at 10:42 a.m. EDT (14:42 GMT) on October 19 and began a 6-minute descent to the surface, but contact was lost shortly before expected touchdown seconds after the parachute and back cover were discarded. One day later, the Mars Reconnaissance Orbiter took photos of the expected touchdown site as part of a planned imaging run.

The landing site is shown within the Schiaparelli landing ellipse (top) along with before and after images below. Copyright Main image: NASA/JPL-Caltech/MSSS, Arizona State University; inserts: NASA/JPL-Caltech/MSSS
The landing site is shown within the Schiaparelli landing ellipse (top) along with before and after images below. Copyright Main image: NASA/JPL-Caltech/MSSS, Arizona State University; inserts: NASA/JPL-Caltech/MSSS

One of the features is bright and can be associated with the 39-foot-wide (12-meter) diameter parachute used in the second stage of Schiaparelli’s descent. The parachute and the associated back shield were released from Schiaparelli prior to the final phase, during which its nine thrusters should have slowed it to a standstill just above the surface.

The other new feature is a fuzzy dark patch or crater roughly 50 x 130 feet (15 x 40 meters) across and about 0.6 miles (1 km) north of the parachute. It’s believed to be the impact crater created by the Schiaparelli module following a much longer free fall than planned after the thrusters were switched off prematurely.

Artist's concept of Schiaparelli deploying its parachute. The parachute may also have played a role in the crash. It may have deployed too soon, causing the thrusters to fire up too soon and run out of fuel. Or the thrusters may have simply cut out after firing. Credit: ESA
Artist’s concept of Schiaparelli deploying its parachute. The parachute may also have played a role in the crash. It may have deployed too soon, causing the thrusters to fire too soon. The thrusters may also have simply cut out too soon after firing. Credit: ESA

Mission control estimates that Schiaparelli dropped from between 1.2 and 2.5 miles (2 and 4 km) altitude, striking the Martian surface at more than 186 miles an hour (300 km/h). The dark spot is either disturbed surface material or it could also be due to the lander exploding on impact, since its thruster propellant tanks were likely still full. ESA cautions that these findings are still preliminary.

Something went wrong with Schiaparelli's one or more sets of thrusters during the descent. Credit: ESA
Something went wrong with Schiaparelli’s one or more sets of thrusters during the descent, causing the lander to crash on the surface at high speed. Credit: ESA

Since the module’s descent trajectory was observed from three different locations, the teams are confident that they will be able to reconstruct the chain of events with great accuracy. Exactly what happened to cause the thrusters to shut down prematurely isn’t yet known.

Mars’ Moon Deimos

The Moons of Mars
Image of the Martian Moon of Deimos, as imaged by the Mars Reconnaissance Orbiter. Credit: HiRISE/MRO/LPL (U. Arizona)/NASA

Mars and Earth have several things in common. Like Earth, Mars is a terrestrial planet (i.e. composed of silicate rock and minerals). It also has polar ice caps, a tilted axis, and evidence of liquid water on its surface. On top of that, Mars and Earth are the only terrestrial planets in the Solar System to have natural satellites.

In fact, Mars has two satellites, which are appropriately named Phobos and Deimos (named after the Greek gods of horror and terror, respectively). Of the two, Deimos is the smaller moon and orbits at a greater distance from the planet. And like Deimos, it has the characteristics of an asteroid, which is a strong indication of where it may have come from.

Discovery and Naming:

Deimos was discovered in 1877 by American astronomer Asaph Hall, who was deliberately searching for Martian moons at the United States Naval Observatory (USNO). Its name was suggested shortly thereafter by Henry Madan, the Science Master of Eton College, and was derived from Homer’s The Iliad.

Phobos and Deimos, photographed here by the Mars Reconnaissance Orbiter, are tiny, irregularly-shaped moons that are probably strays from the main asteroid belt. Credit: NASA - See more at: http://astrobob.areavoices.com/2013/07/05/rovers-capture-loony-moons-and-blue-sunsets-on-mars/#sthash.eMDpTVPT.dpuf
Phobos and Deimos, photographed by the Mars Reconnaissance Orbiter. Credit: NASA/JPL

Size, Mass and Orbit:

Deimos has a mean radius of between 6 and 6.38 km (3.73 – 3.96 mi). However, the moon is not a round body, and measures roughly 15 × 12.2 × 11 km (9.32 x 7.58 x 6.835 mi), making it 0.56 times the size of Phobos. At 1.4762 × 1015 kg, or 1.4762 trillion metric tons, Deimos is 1/49,735,808 times as massive as the Moon. As a result, Deimos’ surface gravity is very weak, just 0.003 m/s – or 0.000306 g. 

Deimos’ orbit is nearly circular, ranging from 23455.5 km at periapsis (closest) to 23470.9 km at apoapsis (farthest) – which works out to an average distance (semi-major axis) of 23,463.2 km. With an average orbital speed of 1.3513 km/s, it takes 30 hours, 18 minutes and 43.2 seconds to complete a single orbit (or 1.263 days).

Composition and Surface Features:

Deimos, like Phobos, is similar in composition to carbonaceous chondrite and silicate/carbon-rich (C- and D-type) asteroids. Though the surface is cratered, it is considerably smoother than Phobos’ surface, which is due to its craters being filled with regolith.

Only two geological features on Deimos have been given names – the craters of Voltaire and Swift. These features take their names from the famous 17th/18th century French and English writers who speculated about the existence of two Martian moons before they were even discovered.

HiRISE captured these enhanced-color images of Deimos, the smaller of the two moons of Mars, on 21 February 2009. Credit: NASA/JPL
Image of Deimos captured by HiRISE, showing the craters of Voltaire and Swift in the upper left corner. Credit: NASA/JPL/University of Arizona

Origin:

The origin of Mars’ moons remains unknown, but some hypotheses exist. The most widely-accepted theory states that, based on their similarity to C- or D-type asteroids, they are objects that were kicked out of the Asteroid Belt by Jupiter’s gravity. They were then captured by Mars’ and fell into their current orbits due to atmospheric drag or tidal forces.

However, this theory remains controversial since Mars’ current atmosphere is too thin. As such, it is highly unlikely that it would have been able to cause enough drag to slow either moon down enough for them to have achieved their current orbits. A modified version of this hypothesis is that Phobos and Deimos were once a binary asteroid, which was then captured and separated by tidal forces.

Other popular hypotheses include that they were formed by accretion in their current orbits, or that Mars was once surrounded by many large asteroids which were ejected into orbit it after a collision with a planetesimal – like the one that formed Earth’s Moon. Over time, these would have fallen back to the surface until only Phobos and Deimos remained.

Exploration:

Overall, Deimos history of exploration is tied to that of Mars and Phobos. While no landings have been made on its surface, several have been proposed in the past. The first of these were made as part of  the Soviet Phobos (Fobos) program, which involved two probes – Fobos 1 and 2 – that were launched in July of 1988.

If the first proved successful in landing on Phobos, the second would been diverted to make a landing on Deimos. However, the first probe was lost en route to Mars while the second managed to returned some data and images of Phobos surface before contact was lost.

In 1997-1998, NASA selected the proposed Aladdin mission as a finalist for its Discovery Program. The plan was to visit both Phobos and Deimos with sample return missions involving an orbiter and lander. After reaching the surface, the landers would collect samples and then launch them back to the orbiters (which would return them to Earth). However, the mission was passed over in favor of the MESSENGER probe, which was sent to study Mercury.

Other missions have been proposed with are still under study. These include the “Hall” concept proposed in 2008, which calls for a probe that relies on solar-electric propulsion (SEP) to reach Mars and return with samples to Earth. Another was the Gulliver mission, a concept proposed in 2010 which would attempt to retrieve 1 kg (2.2 lbs) of material from Deimos’ surface.

The planners behind the OSIRIS-REx mission have also proposed mounting a second mission that would return samples from Phobos and Deimos. And at the 2014 Lunar and Planetary Science Conference, a proposal was made for a low-cost mission based on the Lunar Atmosphere Dust and Environment Explorer. It is named the Phobos and Deimos & Mars Environment (PADME) mission, and would involve an orbiter being sent to Mars by 2021.

Deimos has been photographed from the surface of Mars by both the Opportunity and Curiosity rovers. And someday, actual astronauts may be able to look up at it from the Martian surface. From their point of view, Deimos would appear like a star to the unaided eye. At its brightest, it might look like Venus does from here on Earth.

For those watching over an extended period of time, Deimos would pass directly in front of the Sun quite regularly. It’s too small to cause a total eclipse, it would look like a black dot moving across the face of the Sun.

We have written many interesting articles about Mars’ moons here at Universe Today. Here’s How Many Moons Does Mars Have?, Phobos and Deimos – the Moons of Mars Explained, Phobos and Deimos Together at Last!, Moon Dance: Curiosity Rover Captures Movie of Phobos and Deimos Together and Opportunity sees Phobos and Deimos.

For more information, be sure to check out this Solar Views article on Deimos.

Astronomy Cast also has some relevant episodes on the subject – Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Sources: