Researchers Catch Comet Lovejoy Giving Away Alcohol

Comet Lovejoy lived up to its name by releasing large amounts of alcohol as well as a type of sugar into space, according to new observations by an international team. The discovery marks the first time ethyl alcohol, the same type in alcoholic beverages, has been observed in a comet. The finding adds to the evidence that comets could have been a source of the complex organic molecules necessary for the emergence of life.

Picture of the comet C/2014 Q2 (Lovejoy) on 12 February 2015 from 50km south of Paris.
Credits: Fabrice Noel

“We found that comet Lovejoy was releasing as much alcohol as in at least 500 bottles of wine every second during its peak activity,” said Nicolas Biver of the Paris Observatory, France, lead author of a paper on the discovery published Oct. 23 in Science Advances. The team found 21 different organic molecules in gas from the comet, including ethyl alcohol and glycolaldehyde, a simple sugar.
Comets are frozen remnants from the formation of our solar system. Scientists are interested in them because they are relatively pristine and therefore hold clues to how the solar system was made. Most orbit in frigid zones far from the sun. However, occasionally, a gravitational disturbance sends a comet closer to the sun, where it heats up and releases gases, allowing scientists to determine its composition.

Picture of the comet C/2014 Q2 (Lovejoy) on 22 February 2015
Credits: Fabrice Noel

Comet Lovejoy (formally cataloged as C/2014 Q2) was one of the brightest and most active comets since comet Hale-Bopp in 1997. Lovejoy passed closest to the sun on January 30, 2015, when it was releasing water at the rate of 20 tons per second. The team observed the atmosphere of the comet around this time when it was brightest and most active. They observed a microwave glow from the comet using the 30-meter (almost 100-foot) diameter radio telescope at Pico Veleta in the Sierra Nevada Mountains of Spain.

The IRAM 30-meter radio telescope
Credits: Nicolas Biver

Sunlight energizes molecules in the comet’s atmosphere, causing them to glow at specific microwave frequencies (if microwaves were visible, different frequencies would be perceived as different colors). Each kind of molecule glows at specific, signature frequencies, allowing the team to identify it with detectors on the telescope. The advanced equipment was capable of analyzing a wide range of frequencies simultaneously, allowing the team to determine the types and amounts of many different molecules in the comet despite a short observation period.
Some researchers think that comet impacts on ancient Earth delivered a supply of organic molecules that could have assisted the origin of life. Discovery of complex organic molecules in Lovejoy and other comets gives support to this hypothesis.
“The result definitely promotes the idea the comets carry very complex chemistry,” said Stefanie Milam of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, a co-author on the paper. “During the Late Heavy Bombardment about 3.8 billion years ago, when many comets and asteroids were blasting into Earth and we were getting our first oceans, life didn’t have to start with just simple molecules like water, carbon monoxide, and nitrogen. Instead, life had something that was much more sophisticated on a molecular level. We’re finding molecules with multiple carbon atoms. So now you can see where sugars start forming, as well as more complex organics such as amino acids — the building blocks of proteins — or nucleobases, the building blocks of DNA. These can start forming much easier than beginning with molecules with only two or three atoms.”
In July, the European Space Agency reported that the Philae lander from its Rosetta spacecraft in orbit around comet 67P/Churyumov­-Gerasimenko detected 16 organic compounds as it descended toward and then bounced across the comet’s surface. According to the agency, some of the compounds detected play key roles in the creation of amino acids, nucleobases, and sugars from simpler “building-block” molecules.
Astronomers think comets preserve material from the ancient cloud of gas and dust that formed the solar system. Exploding stars (supernovae) and the winds from red giant stars near the end of their lives produce vast clouds of gas and dust. Solar systems are born when shock waves from stellar winds and other nearby supernovae compress and concentrate a cloud of ejected stellar material until dense clumps of that cloud begin to collapse under their own gravity, forming a new generation of stars and planets.
These clouds contain countless dust grains. Carbon dioxide, water, and other gases form a layer of frost on the surface of these grains, just as frost forms on car windows during cold, humid nights. Radiation in space powers chemical reactions in this frost layer to produce complex organic molecules. The icy grains become incorporated into comets and asteroids, some of which impact young planets like ancient Earth, delivering the organic molecules contained within them.
“The next step is to see if the organic material being found in comets came from the primordial cloud that formed the solar system or if it was created later on, inside the protoplanetary disk that surrounded the young sun,” said Dominique Bockelée-Morvan from Paris Observatory, a co-author of the paper.
Milam was funded by a grant from the NASA Planetary Astronomy Program. The team included researchers from the Paris Observatory, CNRS (Centre National de la Recherche Scientifique, Paris), PSL Research University (Paris Sciences et Lettres, Paris), Bordeaux Observatory, France, IRAM (Institut de Radioastronomie Millimétrique, Grenoble, France) and Stockholm Observatory, Stockholm, Sweden, as well as from NASA. The 30-meter telescope used to make the team’s observations is operated by IRAM, a collaboration among France, Germany, and Spain. IRAM is supported by INSU (Institut National des Sciences de l’univers)/CNRS (France), MPG (Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.) (Germany), and IGN (Instituto Geográfico Nacional) (Spain).
Source: NASA

What’s Orbiting KIC 8462852 – Shattered Comet or Alien Megastructure?

Posted Yesterday

“Bizarre.” “Interesting.” “Giant transit”.  That were the reactions of Planet Hunters project volunteers when they got their first look at the light curve of the otherwise normal sun-like star KIC 8462852 nearly.

Something other than a transiting planet makes KIC 8462852 fluctuate wildly and unpredictably in brightness. Astronomers suspect a crumbled comet, but the cause remains a mystery. Credit: NASA

Of the more than 150,000 stars under constant observation during the four years of NASA’s primary Kepler Mission (2009-2013), this one stands alone for the inexplicable dips in its light. While almost certainly naturally-caused, some have suggested we consider other possibilities.

Kepler-11, a sun-like star orbited by six planets. At times, two or more planets pass in front of the star at once, as shown in this artist’s conception of a simultaneous transit of three planets observed by the Kepler spacecraft on Aug. 26, 2010. During each pass or transit, the star’s light fades in a periodic way. Credit: NASA/Tim Pyle

You’ll recall that the orbiting Kepler observatory continuously monitored stars in a fixed field of view focused on the constellations Lyra and Cygnus hoping to catch  periodic dips in their light caused by transiting planets. If a drop was seen, more transits were observed to confirm the detection of a new exoplanet.
And catch it did. Kepler found 1,013 confirmed exoplanets in 440 star systems as of January 2015 with 3,199 unconfirmed candidates. Measuring the amount of light the planet temporarily “robbed” from its host star allowed astronomers to determine its diameter, while the length of time between transits yielded its orbital period.

Graph showing the big dip in brightness of KIC 8462852 around 800 days (center) followed after 1500 days whole series of dips of varying magnitude up to 22%. The usual drop in light when an exoplanet transits its host star is a fraction of a percent. The star’s normal brightness has been set to “1.00” as a baseline. Credit: Boyajian et. all

Volunteers with the Planet Hunters project, one of many citizen science programs under the umbrella of Zooniverse, harness the power of the human eye to examine Kepler light curves (a graph of a star’s changing light intensity over time), looking for repeating patterns that might indicate orbiting planets. They were the first to meet up with the perplexing KIC 8462852.

A detailed look at a small part of the star’s light curve reveals an unknown, regular variation of its light every 20 days. Superimposed on that is the star’s 0.88 day rotation period. Credit: Boyajian et. al

This magnitude +11.7 star in Cygnus, hotter and half again as big as the Sun, showed dips all over the place. Around Day 800 during Kepler’s run, it faded by 15% then resumed a steady brightness until Days 1510-1570, when it underwent a whole series of dips including one that dimmed the star by 22%. That’s huge! Consider that an exo-Earth blocks only a fraction of a percent of a star’s light; even a Jupiter-sized world, the norm among extrasolar planets, soaks up about a percent.
Exoplanets also show regular, repeatable light curves as they enter, cross and then exit the faces of their host stars. KIC 8462852’s dips are wildly a-periodic.

Could a giant comet breakup and subsequent cascading breakups of those pieces be behind KIC 8462852’s erratic changes in brightness? Credit: NASA

Whatever’s causing the flickering can’t be a planet. With great care, the researchers ruled out many possibilities: instrumental errors, starspots (like sunspots but on other stars), dust rings seen around young, evolving stars (this is an older star) and pulsations that cover a star with light-sucking dust clouds.
What about a collision between two planets? That would generate lots of material along with huge clouds of dust that could easily choke off a star’s light in rapid and irregular fashion.
A great idea except that dust absorbs light from its host star, warms up and glows in infrared light. We should be able to see this “infrared excess” if it were there, but instead KIC 8462852 beams the expected amount of infrared for a star of its class and not a jot more. There’s also no evidence in data taken by NASA’s Wide-field Infrared Survey Explorer (WISE) several years previously that a dust-releasing collision happened around the star.

Our featured star shines at magnitude +11.7 in the constellation Cygnus the Swan (Northern Cross) high in the southern sky at nightfall this month. A 6-inch or larger telescope will easily show it. Use this map to get oriented and the map below to get there. Source: Stellarium

After examining the options, the researchers concluded the best fit might be a shattered comet that continued to fragment into a cascade of smaller comets. Pretty amazing scenario. There’s still dust to account for, but not as much as other scenarios would require.

Detailed map showing stars to around magnitude 12 with the Kepler star identified. It’s located only a short distance northeast of the open cluster NGC 6886 in Cygnus. North is up. Click to enlarge. Source: Chris Marriott’s SkyMap

Being fragile types, comets can crumble all by themselves especially when passing exceptionally near the Sun as sungrazing comets are wont to do in our own Solar System. Or a passing star could disturb the host star’s Oort comet cloud and unleash a barrage of comets into the inner stellar system. It so happens that a red dwarf star lies within about 1000 a.u. (1000 times Earth’s distance from the Sun) of KIC 8462852. No one knows yet whether the star orbits the Kepler star or happens to be passing by. Either way, it’s close enough to get involved in comet flinging.
So much for “natural” explanations. Tabetha Boyajian, a postdoc at Yale, who oversees the Planet Hunters and the lead author of the paper on KIC 8462852, asked Jason Wright, an assistant professor of astronomy at Penn State, what he thought of the light curves. “Crazy” came to mind as soon he set eyes on them, but the squiggles stirred a thought. Turns out Wright had been working on a paper about detecting transiting megastructures with Kepler.

There are Dyson rings and spheres and a Dyson swarm depicted here. Could this or a variation of it be what we’re seeing around KIC 8462852? Not likely, but a fun thought experiment. Credit: Wikipedia

In a recent blog, he writes: “The idea is that if advanced alien civilizations build planet-sized megastructures — solar panels, ring worlds, telescopes, beacons, whatever — Kepler might be able to distinguish them from planets.” Let’s assume our friendly aliens want to harness the energy of their home star. They might construct enormous solar panels by the millions and send them into orbit to beam starlight down to their planet’s surface. Physicist Freeman Dyson popularized the idea back in the 1960s. Remember the Dyson Sphere, a giant hypothetical structure built to encompass a star?
From our perspective, we might see the star flicker in irregular ways as the giant panels circled about it. To illustrate this point, Wright came up with a wonderful analogy:
“The analogy I have is watching the shadows on the blinds of people outside a window passing by. If one person is going around the block on a bicycle, their shadow will appear regularly in time and shape (like a regular transiting planet). But crowds of people ambling by — both directions, fast and slow, big and large — would not have any regularity about it at all.  The total light coming through the blinds might vary like — Tabby’s star.”

The Green Bank Telescope is the world’s largest, fully-steerable telescope. The GBT’s dish is 100-meters by 110-meters in size, covering 2.3 acres of space. Credit: NRAO/AUI/NSF

Even Wright admits that the “alien hypothesis” should be seen as a last resort. But to make sure no stone goes  unturned, Wright, Boyajian and several of the Planet Hunters put together a proposal to do a radio-SETI search with the Green Bank 100-meter telescope. In my opinion, this is science at its best. We have a difficult question to answer, so let’s use all the tools at our disposal to seek an answer.

KIC 8462852, photographed on Oct. 15, 2015. It’s an F3 V star (yellow-white dwarf) located about 1,480 light years from Earth. Credit: Gianluca Masi

In the end, it’s probably not an alien megastructure, just like the first pulsar signals weren’t sent by LGM-1 (Little Green Men). But whatever’s causing the dips, Boyajian wants astronomers to keep a close watch on KIC 8462852 to find out if and when its erratic light variations repeat. I love a mystery, but  answers are even better.
Source: Universe Today, written by Bob King

Earth's Gravitational Pull Cracks Open the Moon

by Charles Q. Choi, Live Science Contributor   |   October 13, 2015 11:54am ET

Lunar Reconnaissance Orbiter Camera images have revealed thousands of young, lobate thrust fault scarps on the moon. Image released Sept. 15, 2015. Credit: NASA/LRO/Arizona State University/Smithsonian Institution View full size image

Earth's gravitational pull is massaging the moon, opening up faults in the lunar crust, researchers say.
Just as the moon's gravitational pull causes seas and lakes to rise and fall as tides on Earth, the Earth exerts tidal forces on the moon. Scientists have known this for a while, but now they've found that Earth's pull actually opens up faults on the moon.
"We know the close relationship between the Earth and the moon goes back to their origins, but what a surprise [it was] to find the Earth is still helping to shape the moon," study lead author Thomas Watters, a planetary scientist at the Smithsonian Institution's National Air and Space Museum in Washington, D.C., told Space.com. [The Moon: 10 Surprising Lunar Facts]

The researchers analyzed data from NASA's Lunar Reconnaissance Orbiter (LRO), which launched in 2009. In 2010, the spacecraft helped scientists discover that the moon is shrinking: High-resolution LRO images revealed 14 lobe-shaped fault scarps, or cliffs, which likely formed as the hot interior of the moon cooled and contracted, forcing the solid crust to buckle.

The map shows the locations of over 3,200 lobate thrust fault scarps (red lines) on the Moon.
Credit: NASA/LRO/Arizona State University/Smithsonian Institution

View full size image

After more than six years in orbit and imaging nearly three-quarters of the moon's surface, LRO has detected more than 3,200 of these fault scarps. These cliffs are the most common tectonic feature on the moon, and are typically dozens of yards or meters high and less than about 6 miles (10 kilometers) long. Previous research had suggested they were less than 50 million years old, and are likely still actively forming today.
If the only influence on lunar fault scarp formation was the cooling of the moon's interior, the orientations of these cliffs should be random, because the forces of contraction would be equal in strength in all directions, researchers said.

Lunar Reconnaissance Orbiter Camera images (LROC) revealed thousands of lobate fault scarps on the moon, including this prominent one in the Vitello Cluster. Image released Sept. 15, 2015.
Credit: NASA/LRO/Arizona State University/Smithsonian Institution

View full size image

"It was a big surprise to find that the fault scarps don't have random orientations," Watters said.
Instead, "there is a pattern in the orientations of the thousands of faults, and it suggests something else is influencing their formation, something that's also acting on a global scale," Watters said in a statement. "That something is the Earth's gravitational pull."
Earth's tidal forces do not act equally across the surface of the entire moon. Instead, they act most strongly on the parts of the moon that are either closest to or farthest away from Earth. The result is that many scarps are lined up north to south at low and mid latitudes near the moon's equator and east to west at high latitudes near the moon's poles.
The effects of Earth's tidal forces are likely about 50 to 100 times smaller than those from the moon's contraction, Watters said. A model incorporating the effects of tidal and contractional forces on the moon's surface closely matched the fault scarps observed on the moon, he added.
"With LRO, we've been able to study the moon globally in detail not yet possible with any other body in the solar system beyond Earth, and the LRO data set enables us to tease out subtle but important processes that would otherwise remain hidden," John Keller, LRO project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a different statement.
If these lunar faults are still active, shallow "moonquakes" might occur along them. These rumbles should happen most often when Earth's tidal effects are greatest on the moon — when the moon is farthest away from the Earth in its orbit. A network of seismometers on the moon's surface could one day detect these quakes, Watters said.
Watters and his colleaguesdetailed their findings in the October issue of the journal Geology.

The Next Generation of Exploration: The NEOCam Mission

In February of 2014, NASA put out the call for submissions for the thirteenth mission of their Discovery Program. In keeping with the program’s goal of mounting low-cost, highly focused missions to explore the Solar System, the latest program is focused on missions that look beyond Mars to new research goals. On September 30th, 2015, five semifinalists were announced, which included proposals for sending probes back to Venus, to sending orbiters to study asteroids and Near-Earth Objects.

Near-Earth Asteroids (NEO) of large size can potentially orbit close to Earth, making them Potentially Hazardous Objects (PHO). Credit: ESA

Among the proposed NEO missions is the Near Earth Object Camera, or NEOCam. Consisting of a space-based infrared telescope designed to survey the Solar System for potentially hazardous asteroids, the NEOCam would be responsible for discovering and characterizing ten times more near-Earth objects than all NEOs that have discovered to date.
If deployed, NEOCam will begin discovering approximately one million asteroids in the Main Belt and thousands of comets in the course of its 4 year mission. However, the primary scientific goal of NEOCam is to discover and characterize over two-thirds of the asteroids that are larger that 140 meters, since it is possible some of these might pose a threat to Earth someday.

Artist’s concept of the NEOCam spacecraft, a proposed mission for NASA’s Discovery program that would search for potentially hazardous near-Earth asteroids. Credit: NASA/JPL-Caltech

The technical term is Potentially Hazardous Objects (PHO), and it applies to near-Earth asteroids/comets that have an orbit that will allow them to make close approaches to Earth. And measuring more than 140 meters in diameter, they are of sufficient size that they could cause significant regional damage if they struck Earth.
In fact, a study conducted in 2010 through the Imperial College of London and Purdue University found that an asteroid measuring 50-meters across with a density of 2.6 grams per cubic centimeter and a speed of 12.7 kps could generate 2.9 Megatons of airburst energy once it passed through our atmosphere. To put that in perspective, that’s the equivalent of about nine W87 thermonuclear warheads!
By comparison, the meteor that appeared over the small Russian community of Chelyabinsk in 2013 measured only 20 meters across. Nevertheless, the explosive airbust caused by it entering our atmosphere generated only 500 kilotons of energy,  creating a zone of destruction tens of kilometers wide and injuring 1,491 people. One can imagine without much effort how much worse it would have been had the explosion been six times as big!
What’s more, as of August 1st, 2015, NASA has listed a total of 1,605 potentially hazardous asteroids and 85 near-Earth comets. Among these, there are 154 PHAs believed to be larger than one kilometer in diameter. This represents a tenfold increase in discoveries since the end of the 1990s, which is due to several astronomical surveys being performed (as well as improvements in detection methods) over the past two and a half decades.

The NEOCam sensor (right) is the lynchpin for the proposed Near Earth Object Camera, or NEOCam, space mission (left). Credit: NASA/JPL-Caltech

As a result, monitoring and characterizing which of these objects is likely to pose a threat to Earth in the future has been a scientific priority in recent years. It is also why the U.S. Congress passed the “George E. Brown, Jr. Near-Earth Object Survey Act” in 2005. Also known as the “NASA Authorization Act of 2005”, this Act of Congress mandated that NASA identify 90% of all NEOs that could pose a threat to Earth.
If deployed, NEOCam will monitor NEOs from the Earth–Sun L1 Lagrange point, allowing it to look close to the Sun and see objects inside Earth’s orbit. To this, NEOCam will rely on a single scientific instrument: a 50 cm diameter telescope that operates at two heat-sensing infrared wavelengths, to detect the even the dark asteroids that are hardest to find.
By using two heat-sensitive infrared imaging channels, NEOCam can also make accurate measurements of NEO and gain valuable information about their sizes, composition, shapes, rotational states, and orbits. As Dr. Amy Mainzer, the Principal Investigator of the NEOCam mission,  explained:
“Everyone wants to know about asteroids hitting the Earth; NEOCam is designed to tackle this issue. We expect that NEOCam will discover about ten times more asteroids than are currently known, plus millions of asteroids in the main belt between Mars and Jupiter. By conducting a comprehensive asteroid survey, NEOCam will address three needs: planetary defense, understanding the origins and evolution of our solar system, and finding new destinations for future exploration.”

Dr. Mainzer is no stranger to infrared imaging for the sake of space exploration. In addition to being the Principal Investigator on this mission and a member of the Jet Propulsion Laboratory, she is also the Deputy Project Scientist for the Wide-field Infrared Survey Explorer (WISE) and the Principal Investigator for the NEOWISE project to study minor planets.

She has also appeared many times on the History Channel series The Universe, the documentary featurette “Stellar Cartography: On Earth”, and serves as the science consultant and host for the live-action PBS Kids seriesReady Jet Go!, which will be debuting in the winter of 2016. Under her direction, the NEOCam mission will also study the origin and ultimate fate of our solar system’s asteroids, and finding the most suitable NEO targets for future exploration by robots and humans.
Proposals for NEOCam have been submitted a total of three times to the NASA Discovery Program – in 2006, 2010, and 2015, respectively. In 2010, NEOCam was selected to receive technology development funding to design and test new detectors optimized for asteroid and comet detection and discovery. However, the mission was ultimately overruled in favor of the Mars InSight Lander, which is scheduled for launch in 2016.
As one of the semifinalists for Discovery Mission 13, the NEOCam mission has received $3 million for year-long studies to lay out detailed mission plans and reduce risks. In September of 2016, one or two finalist will be selected to receive the program’s budget of $450 million (minus the cost of a launch vehicle and mission operations), and will launch in 2020 at the earliest.
In related news, NASA has confirmed that the asteroid known as 86666 (2000 FL10) will be passing Earth tomorrow. No need to worry, though. At its closest approach, the asteroid will still be at a distance of 892,577 km (554,000 mi) from Earth. Still, every passing rock underlines the need for knowing more about NEOs and where they might be headed one day!
Source: Universe Today, written by Matt Williams

'The Martian' and Reality: How NASA Will Get Astronauts to Mars

by Mike Wall, Space.com Senior Writer   |   October 03, 2015 12:00am ET

NASA wants the world to know that putting boots on Mars is not just a sci-fi dream.
The space agency has been helping promote the new film "The Martian," which hits theaters across the United States today (Oct. 2), as a way to publicize its own plans to send astronauts to the Red Planet in the 2030s.
Setting up a crewed outpost on Mars is NASA's chief long-term goal in the realm of human spaceflight. Indeed, the space agency's operational robotic Mars craft — the Opportunity and Curiosity rovers, and the orbiters Mars Odyssey, Mars Reconnaissance Orbiter (MRO) and MAVEN (Mars Atmosphere and Volatile Evolution) — can be seen as scouts for the human pioneers to come, NASA officials say. [5 Manned Mission to Mars Ideas] 

"The evolution of a Martian starts with our science — starts with our ground-truth that we get from our rovers — and it builds up to human exploration," Jim Green, director of NASA's Planetary Science division, said Thursday (Oct. 1) at Kennedy Space Center in Florida, during an event focusing on "The Martian" and the space agency's Red Planet plans.

Save 10% on these Mars Essentials. Use code: MARS10.
Credit: Space.com Store

View full size image

Making it happen

In the film "The Martian" (2015), an astronaut played by Matt Damon has to improvise when his crew leaves him behind by accident. Check out our full infographic to see what we think it would take to survive on Mars.
Credit: By Karl Tate, Infographics Artist

View full size image

NASA is working on a number of different fronts to make a crewed Mars mission happen, Green said.
For example, the agency and its partners are currently conducting an unprecedented yearlong mission aboard the International Space Station (ISS). (Crewmembers generally stay aboard the orbiting lab for 5 to 6 months.)
Researchers are monitoring how NASA astronaut Scott Kelly and cosmonaut Mikhail Kornienko respond physiologically and psychologically to their extended time off Earth, in an effort to help prepare future pioneers for the long journey to Mars and back.
Furthermore, astronauts recently grew lettuce aboard the ISS — and ate it as well — as part of an experiment called "Veggie." The long-term goal of such projects is to make voyaging astronauts less dependent on Earth.
NASA is also developing a crew capsule called Orion and the Space Launch System (SLS) megarocket to help get astronauts to, and from, distant destinations such as Mars. Orion aced its first uncrewed test flight last December, and the SLS is scheduled to make its maiden voyage in 2018.
Technological development is ongoing in other key areas as well. For instance, reseachers are working to improve solar-electric propulsion systems, which use energy from the sun to strip electrons off gas molecules, then send these ions streaming out the back of a spacecraft to generate thrust.
"These are going to be huge ion engines that will allow us to haul tens of tons of material back and forth to Mars," Green said.
Much of this heavy gear — which will consist of human habitat modules and other infrastructure — must make it down to the Martian surface. That's a tall order, since the 1-ton Curiosity rover maxed out NASA's "sky crane" landing system. [How to Land on Mars: Martian Tech Explained (Infographic)]
So NASA is developing new tech, such as inflatable "decelerators" and an enormous supersonic parachute, to help get hefty payloads down safely and softly on the Red Planet. NASA has tested a prototype of this system twice during balloon-aided flights off Hawaii; the decelerator worked perfectly, but the parachute tore both times.

Robotic Red Planet explorers

The science work being done by Red Planet robots feeds into the crewed effort as well. For example, data and images gathered by MRO have allowed researchers to determine that the dark streaks that appear on steep Martian slopes during warm weather are caused by liquid water — a resource that future pioneers might be able to exploit.
"We're developing the science tools now — the continually orbiting and roving on Mars — to be able to get us the information to know what Mars is really like," Green said.
NASA's next Mars rover, which is scheduled to launch in 2020, will continue to build up the knowledge base, while also making concerted strides toward human exploration.
One of the Mars 2020 rover's instruments is a technology demonstration designed to generate oxygen from carbon dioxide in the Red Planet's atmosphere. Another instrument, a ground-penetrating radar, is capable of discovering subsurface aquifers of liquid water, if any exist in the landing zone, Green said.

The path to Mars

NASA is not planning to make the big leap directly from low Earth orbit, where the ISS circles, all the way to Mars. Rather, the agency first aims to test technologies and gain deep-space experience in the "proving ground" of Earth-moon space.
One proving-ground project is the Asteroid Redirect Mission, which involves plucking a boulder off a near-Earth asteroid with a robotic probe and towing the chunk of space rock to lunar orbit for future visitation by astronauts.
NASA plans to accomplish this — the robotic and crewed aspects (which will employ Orion and the SLS) — by 2025.
And the first crewed Mars mission may land not on the Red Planet but on one of its two tiny moons, Phobos and Deimos. Such a strategy would prove out the technologies required to get to Mars orbit, and also dilute the risks and costs of a crewed Red Planet campaign, advocates say.
So some of the steps along the path to Mars still need to be worked out. But the ultimate destination — the Martian surface — is not in doubt, NASA officials say.
"[Putting] boots on Mars is possibly the most exciting thing humans will ever do," NASA chief Charles Bolden said last month during an event at NASA Headquarters in Washington, D.C. that detailed NASA's crewed Mars plans.
"We have been engaged in getting to Mars — getting humans to Mars — for at least 40 years, beginning with the first precursors," he added. "I have no doubt that we can accomplish what we have set our minds to do."