Cosmic Log
Astronomers have identified thousands of stars that have planets, and that number could mushroom even faster when waves of next-generation telescopes come online. But where are the best places to look for life?
A newly released study focuses on the most plentiful category of stars in our Milky Way galaxy — M-dwarf stars, also known as red dwarfs — and delivers good news as well as bad news for astrobiologists.
Update for Nov. 28, 2023: NASA has postponed formal confirmation of the Dragonfly mission to Titan mission until mid-2024, and the launch readiness date is now estimated to be in 2028 rather than 2026.
Previously: NASA has chosen to commit up to $850 million to creating an interplanetary probe unlike any seen before: a rotor-equipped spacecraft that will fly through the smoggy atmosphere of Titan, Saturn’s biggest moon.
The Dragonfly mission will be managed by Johns Hopkins University’s Applied Physics Laboratory on NASA’s behalf, with its launch scheduled for 2026 on a rocket to be named later, and its landing due amid the dunes of Titan in 2034.
This won’t be the first landing on Titan: That happened back in 2005, when the Cassini spacecraft dropped off the Huygens lander to send back the first pictures from the moon’s cloud-obscured surface. Observations from Cassini and Huygens confirmed that chilly Titan held rivers and lakes of liquid methane and ethane, and that methane fell like rain on the icy terrain.
“Titan is the only other place in the solar system known to have an Earthlike cycle of liquids flowing across its surface,” Thomas Zurbuchen, NASA’s associate administrator for the Science Mission Directorate, said in a tweet. “Dragonfly will explore the processes that shape this extraordinary environment filled with organic compounds – the building blocks to life as we know it.”
Today’s announcement was the climax of a years-long process to choose the next mission for NASA’s New Horizons portfolio, which supports projects costing no more than $850 million. Past selections include the New Horizons mission to Pluto and the Kuiper Belt, the Juno mission to Jupiter. and the OSIRIS-REx mission to bring back a sample from asteroid Bennu.
BELLEVUE, Wash. — Underground lava tubes are great places to set up bases on the moon, or look for life on Mars — but they’ll be super-tricky to navigate. Which is why a NASA team is practicing with a cave rover in California.
Scientists are sharing their experiences from the Biologic and Resource Analog Investigations in Low Light Environments project, or BRAILLE, here at this week’s Astrobiology Science Conference.
The site of the experiment is California’s Lava Beds National Monument, which houses North America’s largest network of lava tubes. These are tunnel-like structures left behind by ancient volcanic flows of molten rock. They’re known to exist on the moon and Mars, and in some places there are even openings that make those lava tubes accessible from the surface.
The underground passageways provide shelter from the harsh radiation hitting the surface of the moon and Mars, which would be a big plus for would-be settlers. There’s even a chance that microbes could find a foothold in lava tubes on Mars, as they do on Earth.
BELLEVUE, Wash. — NASA says the record-setting belch of Martian methane that its Curiosity rover detected last week has faded away, leaving some big questions hanging in the air: Where did the gas come from, and what were its origins?
Much of the methane on Earth is produced biologically, from sources ranging from microbes to the digestive tracts of cows and humans. But methane can also be produced through geological, completely non-biological processes. For example, methane makes up about 5 percent of the atmosphere of the Saturnian moon Titan, which is so cold that methane and other hydrocarbons pool up in lakes and rivers.
Curiosity’s onboard chemistry lab — known as Sample Analysis at Mars, or SAM — has an instrument that can sense methane levels in the Red Planet’s atmosphere, and those levels usually amount to less than 1 part per billion by volume. But SAM has registered several curious methane spikes during its seven years of surface operations — including a rise to 6 parts per billion in 2013 that got NASA’s attention, and another detection that rose even higher during the following Martian year.
Last week, methane levels spiked to the highest levels ever detected by Curiosity: 21 parts per billion. That caused the SAM science team to change their plans for the weekend and make follow-up measurements.
Those measurements were sent back to the science team this morning, and they showed that methane levels were back to their usual level.
BELLEVUE, Wash. — NASA’s Curiosity rover has detected fresh whiffs of Martian methane, once again sparking speculation about a potential biological source — but researchers at the space agency say it’s too early to raise the alert for life on Mars.
Scientists who are gathering here for the annual Astrobiology Science Conference, or AbSciCon, acknowledge that depending on the context, methane could be an indicator of biological activity, as it is on Earth. But it could just as well be of purely geological origin.
“It’s not in itself a biosignature,” Abigail Allwood, a field geologist at NASA’s Jet Propulsion Laboratory, told GeekWire today during a media workshop.
The sea that lies beneath the icy surface of Enceladus, one of Saturn’s moons, could provide even more fuel for extraterrestrial organisms than previously thought.
That’s the upshot of a study to be presented at AbSciCon 2019, an astrobiology conference taking place next week in Bellevue, Wash. Hundreds of researchers will be sharing their findings about the prospects for life elsewhere in the solar system and the universe.
If you had to pick a place to set up shop amid the seven planets in the TRAPPIST-1 star system, 39 light-years from Earth, the fourth rock from that alien sun is the best place to start.
That Earth-sized world, known as TRAPPIST-1 e, came out on top in a recent round of exoplanetary climate modeling, detailed in a paper published Nov. 1 by the Astrophysical Journal.
Not that anyone’s planning on setting up shop there soon: Unless there’s a breakthrough that allows us to travel at a significant fraction of the speed of light, it would take hundreds of thousands of years to get to TRAPPIST-1. But the climate modeling methods developed for the TRAPPIST-1 system could help scientists decide which planets to target first with telescopes capable of analyzing alien atmospheres.
It’s been a quarter-century since Congress cut off NASA funding for the search for extraterrestrial intelligence, or SETI, but now the space agency is revisiting the topic under another name: technosignatures.
“I’m excited to announce that NASA is taking the 1st steps to explore ways to search for life advanced enough to create technosignatures: signs or signals, which if observed, would let us infer the existence of technological life elsewhere in the universe,” Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, said in a tweet today.
The search is the focus of a workshop taking place this week at the Lunar and Planetary Institute in Houston, with experts on the search for exoplanets, artificial radio signals and other potential pointers in attendance. House Science Committee Chairman Lamar Smith, R-Texas, is due to give a welcome message.
That’s a far cry from 1993, when a congressional effort spearheaded by Sen. Richard Bryan killed off NASA’s 10-year SETI program, which was known as the High Resolution Microwave Survey, or HRMS. “This hopefully will be the end of Martian hunting season at the taxpayer’s expense,” Bryan declared at the time.
Since then, much has changed.
Instead of cave dwellers gathered around a campfire, roasting mastodon meat, imagine an octopus tribe floating around a hydrothermal vent at the seafloor, boiling lobsters.
That’s the scenario sketched out by Dirk Schulze-Makuch, an astrobiologist at Germany’s Technical Institute Berlin who’s also an adjunct professor at Arizona State University and Washington State University.
In an essay published today on Smithsonian Air and Space magazine’s website, Schulze-Makuch notes that a fair number of potentially habitable planets could have surfaces completely covered by oceans. Could life arise on such planets? And if so, how technologically advanced could such species become?
Radar readings from the European Space Agency’s Mars Express orbiter point to the location of what appears to be a 12-mile-wide lake of liquid water, buried under about a mile of ice and dust in the Red Planet’s south polar region.
The find is consistent with what scientists have been saying for years about the prospects for subsurface water on Mars, and is likely to give a boost to the search for Red Planet life.
“There are all the ingredients for thinking that life can be there,” Enrico Flamini, project manager for the MARSIS radar instrument on Mars Express, said today during a Rome news conference to discuss the results. “However, MARSIS cannot say anything more.”
The analysis of the MARSIS readings were published today by the journal Science.