What’s the News: NASA’s considering launching a boat from Earth, hurling it 746 million miles through space, and plopping it onto one of the minus-290 degrees Fahrenheit methane oceans of Titan. This mission to Saturn’s largest moon would the first of its kind to probe an alien ocean and—depending on the weather conditions—could be the first spacecraft to witness extraterrestrial rain. If the proposed mission beats out two other finalists, it could launch within the next five years. “Titan is an endpoint [in] exploring … the limits to life in our solar system,” project leader Ellen Stofan told New Scientist. “We’re going to be looking for patterns in abundances of compounds to look for evidence for more complex or interesting reactions.”
What’s the News: Astronomers have known for many years that Saturn’s moon Titan sports lakes of liquid methane. And in the past couple years, scientists have suggested that it also has an underground ocean composed of water and ammonia. Now, based on past observations by NASA’s Cassini spacecraft, astronomers are saying that Titan’s rotation indeed points to an underground sea—and where there’s water, there may also be life. “Our analysis strengthens the possibility that Titan has a subsurface ocean, but it does not prove it undoubtedly,” researcher Rose-Marie Baland told Astrobiology Magazine. “So there is still work to do.”
What’s the News: Some bacteria can live in extreme “hypergravity,” found a new study published in the Proceedings of the National Academy of Sciences, surviving and reproducing in forces 400,000 times greater than what’s felt on Earth. These findings fit with the idea that microbes carried on meteorites or other debris—a ride that would have subjected them to hypergravity-strength forces—may be the ancestors of life on Earth.
What’s the News: If you were to bring a glass of water to Mars, the liquid would instantly boil because the Red Planet’s carbon dioxide atmosphere is so thin: The vapor pressure of the water easily surpasses the weak atmospheric pressure, sending water molecules flying off quickly into the atmosphere. However, ancient shorelines and river-like features indicate that Mars had a watery past, leading researchers to wonder what happened to Mars’ once-thicker atmosphere. Now, data from the Mars Reconnaissance Orbiter has uncovered a massive deposit of solid CO2 at the south pole that could double the planet’s atmospheric pressure if it were released as gas. “If you double the amount of CO2 in the atmosphere, it’s quite possible that you could have liquid water,” planetary scientist Philip James of the Space Science Institute in Boulder told Scientific American. “People have suggested that this could happen, and now it looks like it could be possible.”
Young. Old. Scalding hot. Icy cold. Terrestrial midgets. Gas giants. As the cavalcade of planets spotted beyond our solar system continues to grow, we get to see worlds of all sorts—and we get to speculate on the staggering number of exoplanets that might inhabit just our own galaxy.
Today’s first piece of otherworldly news involves baby exoplanets. Astronomer Christian Thalmann says his team may have spotted planets in the process of forming around three different stars, the first time scientists have spotted the process in action.
An infant star forms from a collapsing cloud of dust and gas and gathers a dense, flat disk of material that rotates with the star like a record album. The material in the disk will eventually clump up into nascent planets. Theoretical models of planet formation predicted that those protoplanets should suck up more gas and dust with their gravity, clearing a wide gap in the otherwise solid disk. [Wired]
Peering at young stars like T Chamaeleontis (T Cha) LkCa15 and AB Auriga, Thalmann and colleagues saw those telltale gaps in the dusty rings (their study is forthcoming in the Astrophysical Journal Letters). The stars are much like our own sun, so these pictures of infant solar systems could resemble what our own looked like as a baby. But though the stars are nearby in cosmic terms—T Cha lies just 350 light years away—the gaps are faint enough that it’s difficult to tell for certain if newly forming planets, and not the influence of binary stars or other objects, are creating them.
If Thalmann’s team is right, catching the birth of new worlds would be a great scientific coup. Our galaxy, however, isn’t exactly hurting for planets.
You know the old routine in sci-fi: Aliens show up, people of Earth freak out. Whether we provoke aliens a la The Day the Earth Stood Still or they arrive foaming with blood lust like in Mars Attacks, storytellers’ general feeling is that the mass of humanity would not respond well to the real presence of extraterrestrial life. We need Will Smith and Tommy Lee Jones to keep ‘em separated from us.
In 2011—the year after we were supposed to make contact—are we humans still a backwater mob of talking apes who would crumble into pandemonium, or cosmic self-doubt, at the discovery of life beyond Earth? This week, a special issue of The Philosophical Transactions of the Royal Society addresses that question and more.
You’ve come a long way, baby
Albert Harrison, psychologist at the University of California, Davis, may live to regret saying nice things about humanity. But it’s nice to see somebody giving us a vote of confidence:
The Brookings Report warned in 1961 that the discovery of life beyond Earth could lead to social upheaval. But [Harrison] says “times have changed dramatically” since then. Even the discovery of intelligent aliens “may be far less startling for generations that have been brought up with word processors, electronic calculators, avatars and cell phones as compared with earlier generations used to typewriters, slide rules, pay phones and rag dolls,” Harrison writes in one of the papers. [MSNBC]
SETI (the Search for Extra-Terrestrial Intelligence) hasn’t been successful in its half-century hunt for alien civilizations, but it has ingrained into people the idea of looking for life beyond Earth. The continually increasing exoplanet count (one discovery was announced just today) is showing people just a small glimpse of the variety of worlds out there. Thus, Harrison says the people of Earth would respond to the discovery of alien life with “delight or indifference,” according to the Press Association.
The Kepler space telescope, launched nearly two years ago, has already proven its worth as an exoplanet hunter many times over. But the discoveries keep on coming. NASA just announced that Kepler has found its first rocky planet–and that the rocky world is only 1.4 times the size of Earth, making it the smallest exoplanet ever found.
Phil Plait explains that this nearly Earth-sized isn’t actually Earth-like and habitable:
[I]t orbits extremely close in to its star, circling over the star’s surface at a distance of roughly 3 million kilometers (1.8 million miles) — amazingly, it takes less than an Earth day to make one circuit. But being that close to a star comes at a price: the surface temperature of the planet must be several thousand degrees!
The planet, Kepler-10b, may not be habitable to life as we know it, but Plait is still plenty excited. Get the rest of the story on how the planet was found and what its discovery means over at Bad Astronomy.
80beats: Astronomers Predict a Bonanza of Earth-Sized Exoplanets
80beats: How Excited Should We Be About the New “Goldilocks” Exoplanet?
80beats: Astronomers Find a Bevy of Exoplanets; Won’t Discuss Most Interesting Ones
80beats: After a Flawless Launch, Kepler Telescope Gets Ready for Planet Hunting
DISCOVER: How Long Until We Find a Second Earth?
The Martian rovers and orbiters have sent so much data back to Earth in the last few years that discoveries about Mars’ wet and active past come left and right. Yesterday we covered the story that the stuck Spirit rover may have found evidence of recent water right under its tracks. And another study this week, out in Nature Geoscience, pinpoints a spot by a Mars volcano that could contain evidence of a watery system more than 3 billion years old—and perhaps even life, too.
The finding came after the Mars Reconnaissance Orbiter observed a mineral called hydrated silica sitting on the flank of the extinct Syrtis Major volcano.
The mineral is transported and then concentrated by hot water or steam, suggesting the deposits were laid down in what was once a hydrothermal environment. Groundwater may have been heated by magma from the erupting volcano and vented to the surface as steam, says John Mustard of Brown University in Rhode Island, a member of the team that identified the mineral. [New Scientist]
It’s just a lab experiment, but University of Arizona researcher Sarah Horst says that her team’s re-creation of the atmosphere on Saturn’s moon Titan showed that atmospheric reactions could produce some of life’s basic ingredients, and do it without the presence of liquid water.
Titan, which is larger than Mercury, boasts a thick atmosphere of mostly nitrogen with dashes of methane, carbon monoxide, and other trace ingredients (At -290 degrees Fahrenheit, Titan is a tad too frigid for liquid water). Horst brewed up an approximation of that mixture. She and her colleagues then blasted it with radio-frequency radiation, a lab stand-in for ultraviolet radiation from the sun.
NASA’s next rendezvous with the Red Planet got the go-ahead this week. The space agency approved development of MAVEN, the Mars Atmosphere and Volatile Evolution mission, which is scheduled to launch in November 2013.
In the last decade, missions like the Phoenix Lander, the Spirit and Opportunity rovers, and the Mars Express have reinforced the case that our neighbor was once watery, and far more hospitable to life than the planet we see today. The ancient evidence of liquid water suggests that the planet once had a dense atmosphere, which is now long gone. MAVEN’s mission is to investigate the interaction between Mars’s now-thin atmosphere and the solar wind, and to look for clues to how and when the sun stripped away the planet’s thick atmosphere.
Many researchers think that Mars’s loss of its magnetic field billions of years ago started the process.
“Mars can’t protect itself from the solar wind because it no longer has a shield, the planet’s global magnetic field is dead,” said [lead investigator Bruce] Jakosky, describing how the magnetic field disappeared and the atmosphere then exposed to the punishing solar wind. [AFP]
For more details about MAVEN, check out our coverage from 2008, when NASA first announced the mission. The team’s critical design review will come next July, which could be the true make-or-break time for the mission.
80beats: NASA Announces Plan to Study Martian Climate Mystery
80beats: Was Mars’ Moon Phobos Born From a Violent Collision?
80beats: Mars Rover Followed Mineral “Blueberries” to a Watery Discovery
80beats: Early Mars: Cold and Wet, But Potentially Still Full of Life