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Scientists Debate Signatures of Alien Life Searching for signs of life on faraway planets, astrobiologists must decide which telltale biosignature gases to target. Photo illustration by Olena Shmahalo/Quanta Magazine February 2, 2016 Comments (5) Share this: facebooktwitterredditmail PDF Print Huddled in a coffee shop one drizzly Seattle morning six years ago, the astrobiologist Shawn Domagal-Goldman stared blankly at his laptop screen, paralyzed. He had been running a simulation of an evolving planet, when suddenly oxygen started accumulating in the virtual planet’s atmosphere. Up the concentration ticked, from 0 to 5 to 10 percent.“Is something wrong?” his wife asked.“Yeah.”The rise of...

Explanation: As January closes and in the coming days of February, early morning risers can spot the five naked-eye planets before dawn. Though some might claim to see six planets, in this seaside panoramic view all five celestial wanderers were found above the horizon along with a bright waning gibbous Moon on January 27. Nearly aligned along the plane of the ecliptic, but not along a line with the Sun, the five planets are spread well over 100 degrees across the sky. Just arriving on the predawn scene, fleeting Mercury stands above the southeastern horizon in the golden light of...

After a year-and-a-half long voyage aboard the International Space Station, a group of fungi collected from Antarctica has proven its ability to withstand harsh, Mars-like conditions. More than half of the cells remained intact over the course of the 18-month study, providing new insight for the possibility of life on Mars. These fungal samples, along with lichens from Spain and Austria, have allowed European researchers to assess the survivability and stability of microscopic lifeforms on the red planet. The tiny fungi taken from Antarctica are typically found in the cracks of rocks in this dry, hostile region. Scientists took samples...

Could a Mars colony become a nation? That question was posed by Michael Byers, who holds the Canada Research Chair in Global Politics and International Law at the University of British Columbia in a Washington Post article. Byers’ answer to his question was yes. A body of international law has evolved over time that recognizes the rights of people to self-determination.

Charles D. Walker (a former commercial astronaut), kicked up something of a fuss recently when he opined in the pages of the Arizona Daily Star that NASA should lead the way in space exploration and not leave everything to the private sector. The reasons he cites are risk and lack of a clear profit motive, particularly related to going to Mars. The commercial space sector should be encouraged to bring down the cost of space travel, particularly by operating a space taxi service to the International Space Station, in his view. But NASA must lead the way in exploration, particularly...

Explanation: What is that dark sand dune doing on Mars? NASA's robotic rover Curiosity has been studying it to find out, making this the first-ever up-close investigation of an active sane dune on another world. Named Namib Dune, the dark sand mound stands about 4 meters tall and, along with the other Bagnold Dunes, is located on the northwestern flank of Mount Sharp. The featured image was taken last month and horizontally compressed here for comprehensibility. Wind is causing the dune to advance about one meter a year across the light bedrock underneath, and wind-blown sand is visible on the...

There are several space stories we’re anticipating for 2016 but one story might appear — to some — to belong in the realm of science fiction: sometime in the coming year Elon Musk will likely reveal his plans for colonizing Mars. Early in 2015, Musk hinted that he would be publicly disclosing his strategies for the Mars Colonial Transport system sometime in late 2015, but then later said the announcement would come in 2016.

Skywatchers will have many opportunities in 2016 to see just how small we are in the universe. Four days into the new year, hundreds of meteors will dance across the night skies.... Come September, an outer ring of the sun's annular eclipse will be visible across Africa. In between, there will be spectacular shooting stars, super moons, and lunar eclipses to take in. ... From about Jan. 20 to Feb. 20, all five planets that are visible to the naked eye — Mercury, Venus, Mars, Jupiter and Saturn — will occupy the morning sky. This hasn't happened since 2005, according...

In 1993, French astronomer Jacques Laskar ran a series of calculations indicating that the gravity of the Moon is vital to stabilizing the tilt of our planet. Earth's obliquity, as this tilt is technically known as, has huge repercussions for climate. Laskar argued that should Earth's obliquity wander over hundreds of thousands of years, it would cause environmental chaos by creating a climate too variable for complex life to develop in relative peace. So his argument goes, we should feel remarkably lucky to have such a large moon on our doorstep, as no other terrestrial planet in our solar system...

Measure it any way you like, but this hasn't been that championship season of the "can do" spirit of America. Most of the presidential campaigners spend their allotted minutes criticizing what's wrong with the country, how others have made a mess of things and why voters should put them in charge of changing things. It's difficult to find the formula through the haze of confusion and fog of rhetoric. There's far more blowhard nastiness than creative eloquence. That's what politics is about, of course, but it gets tiresome in the holiday season when we're craving inspiration from our better angels,...

Most studies of potential Earth-smashers focus on objects in the asteroid belt roughly between Mars, Earth's outside neighbour, and Jupiter on its other flank, said the researchers. But they noted that the discovery in the last two decades of hundreds of giant comets dubbed centaurs, albeit with much larger orbits, requires expanding the list of potential hazards. These balls of ice and dust, typically 50-100 kilometres (31-62 miles) wide, have unstable, elliptical orbits that start way beyond Neptune, the most distant planet from the Sun. Their paths cross those of the giant planets Jupiter, Saturn, Uranus and Neptune, whose gravity...

space agency planned to launch a new Mars lander called InSight in March from Vandenberg Air Force Base in California. InSight, short for Interior Exploration using Seismic Investigations Geodesy and Heat Transport, was expected to arrive at Mars in September to take measurements of the red planet's interior and its atmosphere and to take color images. Instead, it's being sent back to its maker - Lockheed Martin - in Denver, Colorado. The faulty instrument is a very sensitive seismometer designed to measure movements in the Martian soil as small as the diameter of an atom, NASA said in a statement....

NASA is calling off its next mission to Mars because there isn't enough time to fix a leaky seal on a key science instrument. The InSight spacecraft was set for launch in March. The problem is with a protective pouch around the lander's seismometer, which was designed to measure ground movement on the red planet. NASA managers and French designers of the instrument said Tuesday they must now decide whether the pouch's vacuum seal needs to be repaired, redesigned or the mission scrapped. ...

In a finding that suggests "considerable water activity" on Mars, NASA says its Curiosity rover has found very high concentrations of silica on the red planet. The agency says it also found "a mineral named tridymite, rare on Earth and never seen before on Mars." The discoveries took place on Mount Sharp, where Curiosity drilled into a rock called "Buckskin" to find the tridymite, and where it used its "ChemCam" laser to measure high silica levels. The odd findings led researchers to take the rare step of ordering Curiosity to retrace its path to learn more. Explanations for the high...

The dark dunes, named the "Bagnold Dunes," skirt the northwestern flank of Mount Sharp and lie on the alien road of Curiosity's daring trek up the lower portion of the layered Martian mountain. Today, Dec 14, Curiosity is exploring a spectacular spot dubbed the "Namib Dune" shown in our new photo mosaic above. Ascending and diligently exploring the sedimentary lower layers of Mount Sharp, which towers 3.4 miles (5.5 kilometers) into the Martian sky, is the primary destination and goal of the rovers long term scientific expedition on the Red Planet. ... Before crossing the dune field, the team is...

Explanation: They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars. At that time, dark sand on the interior of Martian sand dunes became more and more visible as the spring Sun melted the lighter carbon dioxide ice. When occurring near the top of a dune, dark sand may cascade down the dune leaving dark surface streaks -- streaks that might appear at first...

Caltech and JPL scientists suggest the fingerprints of early photochemistry provide a solution to the long-standing mystery. Mars is blanketed by a thin, mostly carbon dioxide atmosphere—one that is far too thin to prevent large amounts of water on the surface of the planet from subliming or evaporating. But many researchers have suggested that the planet was once shrouded in an atmosphere many times thicker than Earth's. For decades that left the question, "Where did all the carbon go?" Now a team of scientists from Caltech and JPL thinks they have a possible answer. The researchers suggest that 3.8 billion...

Explanation: Planet Earth's horizon stretches across this recent Solar System group portrait, seen from the southern hemisphere's Las Campanas Observatory. Taken before dawn it traces the ecliptic with a line-up familiar to November's early morning risers. Toward the east are bright planets Venus, Mars, and Jupiter as well as Regulus, alpha star of the constellation Leo. Of course the planets are immersed in the faint glow of zodiacal light, visible from the dark site rising at an angle from the horizon. Sometimes known as the false dawn, it's no accident the zodiacal light and planets both lie along the ecliptic....

Phobos survived a giant impact early in its history, but damage from the crash left the moon weak, say Benjamin Black and Tushar Mittal, planetary scientists with University of California at Berkeley. Their study shows that in 20 million to 40 million years, Phobos will break apart, leaving a cloud of debris that will relatively quickly assembly into a ring around Mars. Initially, the ring will be as dense as Saturn's rings today, and it will last for up to 100 million years, the study shows.

Explanation: This moon is doomed. Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These martian moons may well be captured asteroids originating in the main asteroid belt between Mars and Jupiter or perhaps from even more distant reaches of the Solar System. The larger moon, Phobos, is indeed seen to be a cratered, asteroid-like object in this stunning color image from the robotic Mars Reconnaissance Orbiter, recorded at a resolution of about seven meters per pixel. But Phobos orbits...