biosignatures Archives

October 11, 2022October 11, 2022 by Matt Williams

NASA has Built a Collection of Instruments That Will Search for Life Inside Europa and Enceladus

Counterclockwise from top: California’s Mono Lake was the site of a field test for JPL’s Ocean Worlds Life Surveyor. A suite of eight instruments designed to detect life in liquid samples from icy moons, OWLS can autonomously track lifelike movement in water flowing past its microscopes. Credit: NASA/JPL-Caltech

One of the most exciting aspects of space exploration today is how the field of astrobiology – the search for life in our Universe – has become so prominent. In the coming years, many robotic and even crewed missions will be bound for Mars that will aid in the ongoing search for life there. Beyond Mars, missions are planned for the outer Solar System that will explore satellites and bodies with icy exteriors and interior oceans – otherwise known as “Ocean Worlds.” These include the Jovian satellites Europa and Ganymede and Saturn’s moons Titan and Enceladus.

Similar to how missions to Mars have analyzed soil and rock samples for evidence of past life, the proposed missions will analyze liquid samples for the chemical signatures that we associate with life and biological processes (aka. “biosignatures”). To aid in this search, scientists at NASA’s Jet Propulsion Laboratory have designed the Ocean Worlds Life Surveyor (OWLS), a suite of eight scientific instruments designed to sniff out biosignatures. In the coming decades, this suite could be used by robotic probes bound for “Ocean Worlds” all across the Solar System to search for signs of life.

March 31, 2022March 31, 2022 by Evan Gough

It’s Not Conclusive, But Methane is Probably the Best Sign of Life on Exoplanets

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle) — This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

When the James Webb Space Telescope aims at exoplanet atmospheres, it’ll use spectroscopy to identify chemical elements. One of the things it’s looking for is methane, a chemical compound that can indicate the presence of life.

Methane is a compelling biosignature. Finding a large amount of methane in an exoplanet’s atmosphere might be our most reliable indication that life’s at work there. There are abiotic sources of methane, but for the most part, methane comes from life.

But to understand methane as a potential biosignature, we need to understand it in a planetary context. A new research letter aims to do that.

March 23, 2022March 23, 2022 by Evan Gough

Next Generation Telescopes Could Search for Intelligent Civilizations Directly

An artist's illustration of the LUVOIR-A telescope concept. There are two conceptual designs for LUVOIR, one with an 8 meter mirror and one with a 15 meter mirror. Image Credit: NASA

We’re still in the early days of searching for life elsewhere. The Perseverance rover is on its way to a paleo-delta on Mars to look for fossilized signs of ancient bacterial life. SETI’s been watching the sky with radio dishes, listening for signals from distant worlds. Our telescopes are beginning to scan the atmospheres of distant exoplanets for biosignatures.

Soon we’ll take another step forward in the search when new, powerful telescopes begin to search not just for life but for other civilizations.

March 19, 2022March 19, 2022 by Matt Williams

Machine Learning Will be one of the Best Ways to Identify Habitable Exoplanets

The field of extrasolar planet studies is undergoing a seismic shift. To date, 4,940 exoplanets have been confirmed in 3,711 planetary systems, with another 8,709 candidates awaiting confirmation. With so many planets available for study and improvements in telescope sensitivity and data analysis, the focus is transitioning from discovery to characterization. Instead of simply looking for more planets, astrobiologists will examine “potentially-habitable” worlds for potential “biosignatures.”

This refers to the chemical signatures associated with life and biological processes, one of the most important of which is water. As the only known solvent that life (as we know it) cannot exist, water is considered the divining rod for finding life. In a recent study, astrophysicists Dang Pham and Lisa Kaltenegger explain how future surveys (when combined with machine learning) could discern the presence of water, snow, and clouds on distant exoplanets.

February 21, 2022February 21, 2022 by Matt Williams

NASA and HeroX are Crowdsourcing the Search for Life on Mars

This low-angle self-portrait of NASA's Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target called "Buckskin." The MAHLI camera on Curiosity's robotic arm took multiple images on Aug. 5, 2015, that were stitched together into this selfie. Credits: NASA/JPL-Caltech/MSSS

For almost sixty years, robotic missions have been exploring the surface of Mars in search of potential evidence of life. More robotic missions will join in this search in the next fifteen years, the first sample return from Mars (courtesy of the Perseverance rover) will arrive here at Earth, and crewed missions will be sent there. Like their predecessors, these missions will rely on mass spectrometry to analyze samples of the Martian sands to look for potential signs of past life.

Given how much data we can expect from these missions, NASA is looking for new methods to analyze geological samples. To this end, NASA has partnered with the global crowdsourcing platform HeroX and the data-science company DrivenData to launch the Mars Spectrometry: Detect Evidence for Past Life challenge. With a prize purse of $30,000, this Challenge seeks innovative methods that rely on machine learning to automatically analyze Martian geological samples for potential signs of past life.

November 22, 2021November 22, 2021 by Evan Gough

Is That a Fossil on Mars? Non-Biological Deposits can Mimic Organic Structures

NASA's Perseverance rover, which is searching signs of ancient life on Mars. Some of the rocks in this image are volcanic in origin. (credit: NASA/JPL-Caltech/MSSS)

There’s nothing easy about searching for evidence of life on Mars. Not only do we somehow have to land a rover there, which is extraordinarily difficult. But the rover needs the right instruments, and it has to search in the right location. Right now, the Perseverance lander has checked those boxes as it pursues its mission in Jezero Crater.

But there’s another problem: there are structures that look like fossils but aren’t. Many natural chemical processes produce structures that mimic biological ones. How can we tell them apart? How can we prepare for these false positives?

August 25, 2021August 25, 2021 by Andy Tomaswick

The Best Evidence for Life on Mars Might be Found on its Moons

The search for Martian life has been ongoing for decades. Various landers and rovers have searched for biosignatures or other hints that life existed either currently or in the past on the Red Planet. But so far, results have been inconclusive. That might be about to change, though, with a slew of missions planned to collect even more samples for testing. Mars itself isn’t the only place they are looking, though. Some scientists think the best place to find evidence of life is one of Mars’ moons.

July 22, 2021July 22, 2021 by Matt Williams

Micrometeorites Churn up the Surface of Europa. If you Want to Find Life, You’ll Need to dig Down a Meter or So

An artist's rendering of Europa and Jupiter based on images sent by visiting spacecraft. Credit: NASA/JPL-Caltech

In the coming decade, NASA and the ESA will be sending two dedicated missions that will explore Jupiter’s moon Europa. These missions are known as the Europa Clipper and the JUpiter ICy moons Explorer (JUICE) missions, which will fulfill a dream that has been decades in the making – searching for possible evidence of life inside Europa. Since the 1970s, astronomers have theorized that this satellite contains a warm-water ocean that could support life.

The case for life in Europa has only been bolstered thanks to multiple flybys and observation campaigns that have been mounted since. According to new research led by the University of Hawaii at Manoa, the best way to look for potential signs of life (aka. biosignatures) would be to analyze small impact craters on Europa’s surface. These patches of exposed subsurface ice could point the way towards life that might exist deeper in the moon’s interior.

June 6, 2021June 14, 2021 by Matt Williams

New Technique to Search for Life, Whether or not it’s Similar to Earth Life

Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada

In 1960, the first survey dedicated to the Search for Extraterrestrial Intelligence (SETI) was mounted at the Green Bank Observatory in West Virginia. This was Project Ozma, which was the brainchild of famed astronomer and SETI pioneer Frank Drake (for whom the Drake Equation is named). Since then, the collective efforts to find evidence of life beyond Earth have coalesced to create a new field of study known as astrobiology.

The search for extraterrestrial life has been the subject of renewed interest thanks to the thousands of exoplanets that have been discovered in recent years. Unfortunately, our efforts are still heavily constrained by our limited frame of reference. However, a new tool developed by a team of researchers from the University of Glasgow and Arizona State University (ASU) could point the way towards life in all of its forms!

May 28, 2021May 28, 2021 by Andy Tomaswick

Researchers Develop a new Framework for Searching for Biosignatures

Planning ahead is something astronomy and space exploration excels at. Decadal surveys and years of engineering effort for missions give the field a much longer time horizon than many others. In the near future, scientists know there will be plenty of opportunities to search for biosignatures everywhere from nearby ocean worlds (i.e. Titan) to far away potentially habitable exoplanets. But it’s not clear what those biosignatures would look like. After all, currently there is only Earth’s biosphere to study, and it would be unfortunate to miss hints of another just because it didn’t look like those found on Earth. Now a team led by researchers at the Santa Fe Institute (SFI) have come up with a framework that could help scientists look for biosignatures that might be completely different from those found on Earth.