NASA Mars: Mars habitable to Humans by 2035

Conceptual image of people working on Mars. 

Credit: NASA.

At the European Lunar Symposium 2014 held at the Natural History Museum earlier this month, NASA officials revealed that the Moon could be used as a practice ground for sending humans to Mars within 20 years.

Ellen Stofan

NASA's chief scientist Dr Ellen Stofan and deputy chief technologist Jim Adams told the assembled scientists that putting humans on Mars is NASA's 'primary mission'.

While there have been many robotic missions to Mars in search of water and signs of life, including Curiosity's current assignment, Dr Stofan believes it's now essential to send human scientists.

'To unambiguously settle the questions of whether there was life on Mars it will take scientists down on the surface,' Dr Stofan said.

However, she admitted there is still a long way to go to ready the technologies for such a mission.

With the exception of those who went to the Moon, the majority of people sent into space so far have been in 'low Earth orbit', relying on systems on Earth to keep them alive.

A journey to Mars would take months.

Bagging an asteroid
Before taking the plunge and attempting to send people to Mars, and the associated dangers of deep space, NASA plans to use the Moon as an intermediate proving ground, because it is close enough to return astronauts home within a couple of days.

Conceptual image of an astronaut retrieving a sample from a captured asteroid. 

Credit: NASA.

But rather than landing on the lunar surface, the plan is to pull an asteroid close enough to the Moon to allow astronauts to take samples from it.

The Asteroid Redirect Mission aims to find a small asteroid travelling between the Moon and Earth and to 'snag it, bag it and drag it' into orbit around the Moon where it can be reached by astronauts.

Hazardous journey
Robots would perform the capture portion, testing ion propulsion systems - the heavy-duty thrusters that would be needed to get humans and their equipment all the way to Mars.

The budget for seeking out near-Earth objects such as asteroids has already been doubled to find a suitable candidate for the mission.

The human phase would then test new suits designed to protect astronauts from health hazards such as bursts of solar wind. It would also train astronauts in protocols for working in deep space, far from home.

'We're working to reduce the risks so that people can arrive on Mars happy and healthy and ready to work.' Dr Stofan said.

Fly by
To the disappointment of many of the scientists in the audience, who want to see more lunar exploration, Dr Stofan and Adams said that NASA does not intend to use the Moon's surface as part of its journey to Mars.

They did acknowledge, however, the general importance of research on the surface, both for science and exploration, and said they will work with partners in other space agencies.

Research on the Moon could help work out how to gather resources from the surface of an alien world, such as how to extract water.

Beyond Mars
Adams finished the talk with tantalising inspiration. 'Where NASA is headed is to the Martian surface in the 2030s,' he said.

'It is my dream that once we've put boots on Mars and we've established that pioneering presence on the surface, we would have already been thinking about where to go next. I hope that you guys will be along for the ride.'

Mars Arsia Mons volcano: Previously wet and habitable

Arsia Mons, the third-largest volcano on Mars may have been home to a habitable environment in Mars's relatively recent past. 

The rippled terrain in the foreground shows where a glacier once clung to the foothills of the mountain. 

Brown University researchers show that eruptions occurred under that ice sheet, which would have created lakes of liquid water. Where there was water, there's the possibility of past life. 

(Colours indicate elevation.) 


Credit: NASA /Goddard Space Flight Center /Arizona State University /Brown University

Heat from a volcano erupting beneath an immense glacier would have created large lakes of liquid water on Mars in the relatively recent past, and where there's water, there is also the possibility of life.

A recent paper by Brown University researchers calculates how much water may have been present near the Arsia Mons volcano and how long it may have remained.

The slopes of a giant Martian volcano, once covered in glacial ice, may have been home to one of the most recent habitable environments yet found on the Red Planet, according to new research led by Brown University geologists.

Nearly twice as tall as Mount Everest, Arsia Mons is the third tallest volcano on Mars and one of the largest mountains in the solar system.

This new analysis of the landforms surrounding Arsia Mons shows that eruptions along the volcano's northwest flank happened at the same time that a glacier covered the region around 210 million years ago.

The heat from those eruptions would have melted massive amounts of ice to form englacial lakes, bodies of water that form within glaciers like liquid bubbles in a half-frozen ice cube.

The ice-covered lakes of Arsia Mons would have held hundreds of cubic kilometers of meltwater, according to calculations by Kat Scanlon, a graduate student at Brown who led the work, and where there's water, there's the possibility of a habitable environment.

Kat Scanlon

"This is interesting because it's a way to get a lot of liquid water very recently on Mars," Scanlon said.

While 210 million years ago might not sound terribly recent, the Arsia Mons site is much younger than the habitable environments turned up by Curiosity and other Mars rovers.


Those sites are all likely older than 2.5 billion years. The fact that the Arsia Mons site is relatively young makes it an interesting target for possible future exploration.

"If signs of past life are ever found at those older sites, then Arsia Mons would be the next place I would want to go," Scanlon said.

A paper describing Scanlon's work is published in the journal Icarus.

Scientists have speculated since the 1970s that the northwest flank of Arsia Mons may once have been covered by glacial ice.

Jim Head

That view got a big boost in 2003 when Brown geologist Jim Head and David Marchant at Boston University, showed that terrain around Arsia Mons looks strikingly similar to landforms left by receding glaciers in the Dry Valleys of Antarctica.

Parallel ridges toward the bottom of the mountain appear to be drop moraines, piles of rubble deposited at the edges of a receding glacier.

An assemblage of small hills in the region also appears to be debris left behind by slowly flowing glacial ice.

The glacier idea got another boost with recently developed climate models for Mars that take into account changes in the planet's axis tilt.

The models suggested that during periods of increased tilt, ice now found at the poles would have migrated toward the equator.

That would make Mars's giant mid-latitude mountains; Ascraeus Mons, Pavonis Mons and Arsia Mons, prime locations for glaciation around 210 million years ago.

More information: Paper: www.sciencedirect.com

Kepler-186f: First potentially habitable Earth-sized planet confirmed - water

The artist's concept depicts Kepler-186f, the first validated Earth-size planet orbiting a distant star in the habitable zone, a range of distances from a star where liquid water might pool on the surface of an orbiting planet.

The discovery of Kepler-186f confirms that Earth-size planets exist in the habitable zone of other stars and signals a significant step closer to finding a world similar to Earth.

The artistic concept of Kepler-186f is the result of scientists and artists collaborating to help imagine the appearance of these distant worlds. 

Credit: Danielle Futselaar.

The first Earth-sized exoplanet orbiting within the habitable zone of another star has been confirmed by observations with both the W. M. Keck Observatory and the Gemini Observatory.

The initial discovery, made by NASA's Kepler Space Telescope, is one of a handful of smaller planets found by Kepler and verified using large ground-based telescopes.

It also confirms that Earth-sized planets do exist in the habitable zone of other stars.

"What makes this finding particularly compelling is that this Earth-sized planet, one of five orbiting this star, which is cooler than the Sun, resides in a temperate region where water could exist in liquid form," says Elisa Quintana of the SETI Institute and NASA Ames Research Center who led the paper published in the current issue of the journal Science.

The region in which this planet orbits its star is called the habitable zone, as it is thought that life would most likely form on planets with liquid water.

Steve Howell, Kepler's Project Scientist and a co-author on the paper, adds that neither Kepler (nor any telescope) is currently able to directly spot an exoplanet of this size and proximity to its host star.

"However, what we can do is eliminate essentially all other possibilities so that the validity of these planets is really the only viable option."

With such a small host star, the team employed a technique that eliminated the possibility that either a background star or a stellar companion could be mimicking what Kepler detected.

To do this, the team obtained extremely high spatial resolution observations from the eight-meter Gemini North telescope on Mauna Kea in Hawai`i using a technique called speckle imaging, as well as adaptive optics (AO) observations from the ten-meter Keck II telescope, Gemini's neighbour on Mauna Kea.

Together, these data allowed the team to rule out sources close enough to the star's line-of-sight to confound the Kepler evidence, and conclude that Kepler's detected signal has to be from a small planet transiting its host star.

The diagram compares the planets of the inner solar system to Kepler-186, a five-planet system about 500 light-years from Earth in the constellation Cygnus. 

The five planets of Kepler-186 orbit a star classified as a M1 dwarf, measuring half the size and mass of the sun. 

The Kepler-186 system is home to Kepler-186f, the first validated Earth-size planet orbiting a distant star in the habitable zone—a range of distances from a star where liquid water might pool on the surface of an orbiting planet. 

The discovery of Kepler-186f confirms that Earth-size planets exist in the habitable zone of other stars and signals a significant step closer to finding a world similar to Earth. 

Kepler-186f is less than ten percent larger than Earth in size, but its mass and composition are not known. 

Kepler-186f orbits its star once every 130-days and receives one-third the heat energy that Earth does from the sun, placing it near the outer edge of the habitable zone. 

The inner four companion planets all measure less than fifty percent the size of Earth. Kepler-186b, Kepler-186c, Kepler-186d, and Kepler-186e, orbit every three, seven, 13, and 22 days, respectively, making them very hot and inhospitable for life as we know it. 

The Kepler space telescope, which simultaneously and continuously measured the brightness of more than 150,000 stars, is NASA's first mission capable of detecting Earth-size planets around stars like our sun. 

Kepler does not directly image the planets it detects. The space telescope infers their existence by the amount of starlight blocked when the orbiting planet passes in front of a distant star from the vantage point of the observer. 

The artistic concept of Kepler-186f is the result of scientists and artists collaborating to help imagine the appearance of these distant Credit: Credit: NASA Ames/SETI Institute/JPL-CalTech.

More information: "An Earth-Sized Planet in the Habitable Zone of a Cool Star," by E.V. Quintana et al. Science, 2014.

Alien moons could bake dry from young gas giants' hot glow

An Earthlike moon orbiting a gas giant host planet. 

Credit: NASA

When we think of where else life might exist in the universe, we tend to focus on planets but on a grander cosmic scale, moons could prove the more common life-friendly abode.

A single gas giant planet in the not-too-warm, not-too-cold habitable zone around its star, where Earth and Mars correspondingly reside, could host several livable moons.

At this early point in our hunt for exoplanets, most of the worlds we have found in the habitable zone are giants, not Earths.

It's possible that the first inhabited place we discover outside our Solar System will be a moon.

René Heller

It is this sort of consideration that inspires René Heller, a postdoctoral fellow in astronomy at McMaster University, in Ontario, Canada.

He studies how "exomoons" could form, what they might be like and how we might detect them with current or future astronomical instruments.

A major part of his work deals with gauging the habitability of exomoons, which is a bit trickier than planetary scenarios because they orbit another body besides their star.

Rory Barnes

A new paper by Heller and his colleague Rory Barnes, University of Washington and the NASA Virtual Planetary Laboratory examines how heat emanating from a freshly formed exoplanet, coupled with irradiation from the solar system's star, can roast the planet's moons.

Before the planet cools off sufficiently, its close-orbiting moons could lose all their water, leaving them bone-dry and barren.

"An exomoon's habitability is of course constrained by its location in the stellar habitable zone, but it also has a second heat source, its host planet, that has to be accounted for," said Heller, whose paper has been accepted for publication in the International Journal of Astrobiology.

"With regard to this second source, our study shows that at close range, the illumination from young and hot giant planets can render their moons uninhabitable."

Researchers believe moons could serve as suitable abodes for life just as well as planets.

Even moons far beyond the habitable zone, such as Jupiter's Europa and Saturn's Titan, offer tantalizing hints of potential habitability thanks to the subsurface ocean in the former and the intriguing organic chemistry of the latter.

Still, a moon around an exoplanet in the habitable zone stands as a far better bet for life than these frigid candidates.

Heller's findings suggest that we ought to exercise caution, however, before declaring that an Earth-sized, habitable-zone exomoon is a real-life Pandora, the lush moon of science fiction fame in "Avatar."

Before assuming an exomoon is habitable based on its host planet's locale, the moon's current and conjectured past orbital distances will need to be assessed.

"Earth-size exomoons that could soon be detected by our telescopes might have been desiccated shortly after formation and still be dry today," said Heller.

"In evaluating a moon's habitability, it is crucial to consider its history together with that of its host planet."

More Information: International Journal of Astrobiology / FirstView Article pp 1-9 Copyright©Cambridge University Press 2014 DOI:dx.doi.org/10.1017/S1473550413000463

NASA Curiosity Rover Finds New Evidence That Ancient Mars Was Habitable

The pale rock in the upper center of this image, about the size of a human forearm, includes a target called "Esperance," which was inspected by NASA's Mars Exploration Rover Opportunity.

This image is a composite of three exposures taken by Opportunity's panoramic camera during the 3,262nd Martian day, or sol, of the rover's work on Mars (March 28, 2013).

CREDIT: NASA/JPL-Caltech/Cornell/Arizona State Univ.

NASA's Mars rover Opportunity has made perhaps the biggest discovery of its nearly 10-year career, finding evidence that life may have been able to get a foothold on the Red Planet long ago.

The Opportunity rover spotted clay minerals in an ancient rock on the rim of Mars' Endeavour Crater, suggesting that benign, neutral-pH water once flowed through the area, scientists said.

"This is water you could drink," Opportunity principal investigator Steve Squyres of Cornell University told reporters today (June 7), explaining why the rock, dubbed "Esperance," stands out from other water-soaked stones the rover has studied.

"This is water that was probably much more favorable in its chemistry, in its pH, in its level of acidity, for things like prebiotic chemistry — the kind of chemistry that could lead to the origin of life," Squyres added.

Search for Life Suggests Alien Solar Systems More Habitable than Ours

Scattered around the Milky Way are stars that resemble our own sun—but a new study is finding that any planets orbiting those stars may very well be hotter and more dynamic than Earth.

That’s because the interiors of any terrestrial planets in these systems are likely warmer than Earth—up to 25 percent warmer, which would make them more geologically active and more likely to retain enough liquid water to support life, at least in its microbial form.

The preliminary finding comes from geologists and astronomers at Ohio State University who have teamed up to search for alien life in a new way.

They studied eight “solar twins” of our sun—stars that very closely match the sun in size, age, and overall composition—in order to measure the amounts of radioactive elements they contain.

Those stars came from a dataset recorded by the High Accuracy Radial Velocity Planet Searcher spectrometer at ESA's European Southern Observatory in Chile.

They searched the solar twins for elements such as thorium and uranium, which are essential to Earth’s plate tectonics because they warm our planet’s interior.

Plate tectonics helps maintain water on the surface of the Earth, so the existence of plate tectonics is sometimes taken as an indicator of a planet’s hospitality to life.

Of the eight solar twins they’ve studied so far, seven appear to contain much more thorium than our sun—which suggests that any planets orbiting those stars probably contain more thorium, too.

That, in turn, means that the interior of the planets are probably warmer than ours.

“If it turns out that these planets are warmer than we previously thought, then we can effectively increase the size of the habitable zone around these stars by pushing the habitable zone farther from the host star, and consider more of those planets hospitable to microbial life,” said Ohio State doctoral student Cayman Unterborn, who presented the results at the American Geophysical Union meeting in San Francisco this week.

“At this point, all we can say for sure is that there is some natural variation in the amount of radioactive elements inside stars like ours,” he added.

“With only nine samples including the sun, we can’t say much about the full extent of that variation throughout the galaxy. But from what we know about planet formation, we do know that the planets around those stars probably exhibit the same variation, which has implications for the possibility of life.”

His advisor, Wendy Panero, associate professor in the School of Earth Sciences at Ohio State, explained that radioactive elements such as thorium, uranium, and potassium are present within Earth’s mantle. These elements heat the planet from the inside, in a way that is completely separate from the heat emanating from Earth’s core.


Read more of this article at scienceblog.com

Hubble WFC3 Instrument discovers a true water world

Source: Hubblesite.org

Our solar system contains three types of planets: rocky, terrestrial worlds (Mercury, Venus, Earth, and Mars), gas giants (Jupiter and Saturn), and ice giants (Uranus and Neptune).

Planets orbiting distant stars come in an even wider variety, including lava worlds and “hot Jupiters.”

Observations by NASA’s Hubble Space Telescope have added a new type of planet to the mix. By analyzing the previously discovered world GJ1214b, astronomer Zachory Berta (Harvard-Smithsonian Center for Astrophysics) and colleagues proved that it is a waterworld enshrouded by a thick, steamy atmosphere.

“GJ1214b is like no planet we know of,” said Berta. “A huge fraction of its mass is made up of water.”

GJ1214b was discovered in 2009 by the ground-based MEarth (pronounced “mirth”) Project, which is led by CfA’s David Charbonneau.

This super-Earth is about 2.7 times Earth’s diameter and weighs almost 7 times as much.

It orbits a red-dwarf star every 38 hours at a distance of 1.3 million miles, giving it an estimated temperature of 450 ° Fahrenheit.

In 2010, CfA scientist Jacob Bean and colleagues reported that they had measured the atmosphere of GJ1214b, finding it likely that the atmosphere was composed mainly of water.

However, their observations could also be explained by the presence of a world-wide haze in GJ1214b’s atmosphere.

Berta and his co-authors used Hubble’s WFC3 instrument to study GJ1214b when it crossed in front of its host star. During such a transit, the star’s light is filtered through the planet’s atmosphere, giving clues to the mix of gases.

“We’re using Hubble to measure the infrared colour of sunset on this world,” explained Berta.

Hazes are more transparent to infrared light than to visible light, so the Hubble observations help tell the difference between a steamy and a hazy atmosphere.

They found the spectrum of GJ1214b to be featureless over a wide range of wavelengths, or colours. The atmospheric model most consistent with the Hubble data is a dense atmosphere of water vapour.

“The Hubble measurements really tip the balance in favour of a steamy atmosphere,” said Berta.

Since the planet’s mass and size are known, astronomers can calculate the density, which works out to about 2 grams per cubic centimeter.

Water has a density of 1 g/cm3, while Earth’s average density is 5.5 g/cm3. This suggests that GJ1214b has much more water than Earth, and much less rock.

As a result, the internal structure of GJ1214b would be very different than our world.

“The high temperatures and high pressures would form exotic materials like ‘hot ice’ or ‘superfluid water’ – substances that are completely alien to our everyday experience,” said Berta.

Theorists expect that GJ1214b formed farther out from its star, where water ice was plentiful, and migrated inward early in the system’s history.

In the process, it would have passed through the star’s habitable zone. How long it lingered there is unknown.

GJ1214b is located in the direction of the constellation Ophiuchus, and just 40 light-years from Earth.

Therefore, it’s a prime candidate for study by the next-generation James Webb Space Telescope (JWST).

A paper reporting these results has been accepted for publication in The Astrophysical Journal and is available online.

This release is being issued jointly with NASA

Habitable Planet in the 'Goldilocks Zone'

An artist rendering provided by Lynette Cook, National Science Foundation, shows a new planet. Astronomers have found a planet that is in the "Goldilocks zone" - just right for life.

Not too hot, not too cold. Not too far from its sun, not too close and it is near Earth - relatively speaking, at 120 trillion miles.

It also makes scientists think that these examples of habitable planets are far more common than they thought

Picture: AP Photo/Zina Deretsky, National Science Foundation

Meeting and Greeting the Nearest Aliens Will Take Centuries

Although our telescopes will likely become good enough to detect signs of life on exoplanets within the next 100 years, it would probably take many centuries before we could ever get a good look at the aliens.

"Unfortunately, we are perhaps as far away from seeing aliens with our own eyes as Epicurus was from seeing the first other worlds when, 23 centuries ago, he predicted the existence of these planets," said astrobiologist Jean Schneider at the Paris Observatory at Meudon. He and his colleagues discussed the difficulties of studying distant alien life in the journal Astrobiology.

Schneider and his colleagues say that in the next 15 to 25 years, there will likely be two generations of space missions able to analyze exoplanets in greater detail. The first generation will feature 1.5-to-2.5-meter-wide coronagraphs to block out the direct light from a star to help search for giant planets and nearby super-Earths.

The second generation will feature interferometers, coronagraphs and other equipment to better analyze the light reflected off these exoplanets. These missions could reveal what the planets might look like, and what they might have in their atmospheres or on their surfaces. At the same time, there will likely be coronagraphic cameras on extremely large ground-based telescopes.

After these projects, future missions could search for more potentially habitable planets either by peering at more distant stars more than 50 parsecs away or at rocky moons of giant planets seen in the habitable zones of nearby stars. The follow-up missions also could deeply investigate any exoplanets that display potential signs of life.

Such missions will require much larger arrays in space - for instance, taking a 100-pixel image of a planet twice the width of Earth some 16.3 light years away would require the elements making up a space telescope array to be more than 43 miles apart.

Such pictures of exoplanets could make out details such as rings, clouds, oceans, continents, and perhaps even hints of forests or savannahs. Long-term monitoring could reveal seasonal shifts, volcanic events, and changes in cloud cover. One might even detect the presence of moons by shadows they project on the planets.

More sensitive instruments could hunt for the wavelengths of infrared light associated with carbon dioxide, which could tell a lot about the atmosphere.

Beyond conventional signs of life as we know it, such as oxygen in atmospheres, another type of signal could be "technosignatures," features that cannot be explained simply by complex organic chemistry. Technosignatures could include laser light, chlorofluorocarbon gases, or even artificial constructions.

"Looking for aliens is philosophically important - it would tell us what is essential in the human condition," Schneider said.

However, if scientists actually detect signs of life, it will frustratingly take many centuries before humanity can realize the hope of seeing what these aliens might actually look like, Schneider and his colleagues explained.

"It is very disappointing," Schneider said.