Astrobiology Archives

January 13, 2024January 13, 2024 by Mark Thompson

Microbes Can Survive in Saltier Water than Previously Believed

Scientists exploring brine ponds in California. — The Oceans Across Space and Time research team collected brine from South Bay Salt Works during an initial field trip in 2019. (Image credit: Anne Dekas)

On Earth, it seems to be true that life will find a way; in the deepest ocean, the saltiest ocean or the highest mountain, live seems to find a way to get a foothold. One of the key ingredients for life seems to be the necessity for water. Until now, it was thought that there was a limit to the level of salinity within which life could thrive. A team of biologists have found bacterial life thrives in salty ponds where the water evaporates leaving high levels of salt. This only serves to expand the likely envrionments across the Universe that life could evolve.

December 31, 2023December 31, 2023 by Laurence Tognetti

TRAPPIST-1c Isn’t the Exo-Venus We Were Hoping For. But Don’t Blame the Star

A recent study accepted to The Astrophysical Journal uses computer models to investigate why the exoplanet, TRAPPIST-1c, could not possess a thick carbon dioxide (CO2) atmosphere despite it receiving the same amount of solar radiation from its parent star as the planet Venus receives from our Sun, with the latter having a very thick carbon dioxide atmosphere. This study comes after a June 2023 study published in Nature used data from NASA’s James Webb Space Telescope (JWST) to ascertain that TRAPPIST-1c does not possess a carbon dioxide atmosphere. Both studies come as the TRAPPIST-1 system, which is located approximately 41 light-years from Earth and orbits its star in just 2.4 days, has received a lot of attention from the scientific community in the last few years due to the number of confirmed exoplanets within the system and their potential for astrobiology purposes.

December 4, 2023December 4, 2023 by Matt Williams

Europa Clipper Could Help Discover if Jupiter's Moon is Habitable

Artist's concept of a Europa Clipper mission. Credit: NASA/JPL

Since 1979, when the Voyager probes flew past Jupiter and its system of moons, scientists have speculated about the possibility of life within Europa. Based on planetary modeling, Europa is believed to be differentiated between a rocky and metallic core, an icy crust and mantle, and a liquid-water ocean that could be 100 to 200 km (62 to 124 mi) deep. Scientists theorize that this ocean is maintained by tidal flexing, where interaction with Jupiter’s powerful gravitational field leads to geological activity in Europa’s core and hydrothermal vents at the core-mantle boundary.

Investigating the potential habitability of Europa is the main purpose of NASA’s Europa Clipper mission, which will launch on October 10th, 2024, and arrive around Jupiter in April 2030. However, this presents a challenge for astrobiologists since the habitability of Europa is dependent on many interrelated parameters that require collaborative investigation. In a recent paper, a team of NASA-led researchers reviewed the objectives of the Europa Clipper mission and anticipated what it could reveal regarding the moon’s interior, composition, and geology.

September 29, 2023September 29, 2023 by Laurence Tognetti

Since Aliens Obey the Laws of Physics, Can We Guess What They Look Like?

Since time immemorial, humans have gazed up at the stars and wondered if we’re alone in the universe. We have asked if there are other intelligent beings out there in the vastness of the cosmos, also known as extraterrestrial intelligence (ET). Yet, despite our best efforts, we have yet to confirm the existence of ET outside of the Earth. While the search continues, it’s fair to speculate if they might look “human” or humanoid in appearance, or if they could look like something else entirely. Here, we present a general examination and discussion with astrobiologists pertaining to what ET might look like and what environmental parameters (e.g., gravity, atmospheric makeup, stellar activity) might cause them to evolve differently than humans.

September 28, 2023September 28, 2023 by Matt Williams

If Earth is Average, We Should Find Extraterrestrial Life Within 60 Light-Years

Astronomers have detected thousands of planets, including dozens that are potentially habitable. To winnow them down, they need to understand their atmospheres and other factors. (NASA Illustration)

In 1960, while preparing for the first meeting on the Search for Extraterrestrial Intelligence (SETI), legendary astronomer and SETI pioneer Dr. Frank Drake unveiled his probabilistic equation for estimating the number of possible civilizations in our galaxy – aka. The Drake Equation. A key parameter in this equation was n_e, the number of planets in our galaxy capable of supporting life – aka. “habitable.” At the time, astronomers were not yet certain other stars had systems of planets. But thanks to missions like Kepler, 5523 exoplanets have been confirmed, and another 9,867 await confirmation!

Based on this data, astronomers have produced various estimates for the number of habitable planets in our galaxy – at least 100 billion, according to one estimate! In a recent study, Professor Piero Madau introduced a mathematical framework for calculating the population of habitable planets within 100 parsecs (326 light-years) of our Sun. Assuming Earth and the Solar System are representative of the norm, Madau calculated that this volume of space could contain as much as 11,000 Earth-sized terrestrial (aka. rocky) exoplanets that orbit within their stars’ habitable zones (HZs).

August 22, 2023August 22, 2023 by Matt Williams

The Most Compelling Places to Search for Life Will Look Like “Anomalies”

Will it be possible someday for astrobiologists to search for life "as we don't know it"? Credit: NASA/Jenny Mottar

In the past two and a half years, two next-generation telescopes have been sent to space: NASA’s James Webb Space Telescope (JWST) and the ESA’s Euclid Observatory. Before the decade is over, they will be joined by NASA’s Nancy Grace Roman Space Telescope (RST), Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx), and the ESA’s PLAnetary Transits and Oscillations of stars (PLATO) and ARIEL telescopes. These observatories will rely on advanced optics and instruments to aid in the search and characterization of exoplanets with the ultimate goal of finding habitable planets.

Along with still operational missions, these observatories will gather massive volumes of high-resolution spectroscopic data. Sorting through this data will require cutting-edge machine-learning techniques to look for indications of life and biological processes (aka. biosignatures). In a recent paper, a team of scientists from the Institute for Fundamental Theory at the University of Florida (UF-IFL) recommended that future surveys use machine learning to look for anomalies in the spectra, which could reveal unusual chemical signatures and unknown biosignatures.

July 28, 2023July 28, 2023 by Matt Williams

If Rogue Planets are Everywhere, How Could We Explore Them?

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Image Credit: ESO/M. Kornmesser/S. Guisard

At one time, astronomers believed that the planets formed in their current orbits, which remained stable over time. But more recent observations, theory, and calculations have shown that planetary systems are subject to shake-ups and change. Periodically, planets are kicked out of their star systems to become “rogue planets,” bodies that are no longer gravitationally bound to any star and are adrift in the interstellar medium (ISM). Some of these planets may be gas giants with tightly bound icy moons orbiting them, which they could bring with them into the ISM.

Like Jupiter, Saturn, Uranus, and Neptune, these satellites could have warm water interiors that might support life. Other research has indicated that rocky planets with plenty of water on their surfaces could also support life through a combination of geological activity and the decay of radionuclides. According to a recent paper by an international team of astronomers, there could be hundreds of rogue planets in our cosmic neighborhood. Based on their first-ever feasibility analysis, they also indicate that deep space missions could explore these unbound objects more easily than planets still bound to their stars.

July 28, 2023July 28, 2023 by Alan Boyle

How Will We the Find First Signs of Alien Life — and When?

When will we find evidence for life beyond Earth? And where will that evidence be found? University of Arizona astronomer Chris Impey, the author of a book called “Worlds Without End,” is betting that the first evidence will come to light within the next decade or so.

But don’t expect to see little green men or pointy-eared Vulcans. And don’t expect to get radio signals from a far-off planetary system, as depicted in the 1992 movie “Contact.”

Instead, Impey expects that NASA’s James Webb Space Telescope — or one of the giant Earth-based telescopes that’s gearing up for observations — will detect the spectroscopic signature of biological activity in the atmosphere of a planet that’s light-years away from us.

“Spectroscopic data is not as appealing to the general public,” Impey admits in the latest episode of the Fiction Science podcast. “People like pictures, and so spectroscopy never gets its fair due in the general talk about astronomy or science, because it’s slightly more esoteric. But it is the tool of choice here.”

https://radiopublic.com/fiction-science-GAxyzK

July 24, 2023July 24, 2023 by Matt Williams

This Mess of Boulders Was Deposited by an Ancient River on Mars

The Mastcam-Z imager on NASA's Perseverance rover captured a series of images on July 6 that were stitched together to show a field of boulders deposited in Jezero Crater by a fast-moving ancient river. Credit: NASA/JPL-Caltech/ASU/MSSS

Since the Viking 1 and 2 missions visited Mars in 1976, scientists have been confronted with mounting evidence that Mars once had flowing water on its surface. The images collected by the twin Viking landers and orbiters showed clear signs of ancient flow channels, alluvial deposits, and weathered rocks. Thanks to the dozens of additional orbiters, landers, and rovers sent that have been sent there since scientists have been getting a clearer picture of what Mars once looked like. At the end of this journey, they hope to find evidence (if there’s any to be found) that Mars once supported life and still does today.

The latest evidence of Mars’ warmer watery past comes to us courtesy of NASA’s Perseverance rover, which continues to explore the Jezero Crater and obtain samples for the first Mars sample-return mission. On Friday, June 23rd, the rover obtained its 20th sample, which was drilled from a rocky outcropping known as “Emerald Lake.” Named “Otis Peak,” this sample is part of an outcropping formed by mineral deposits transported by an ancient river and could contain invaluable geological information about the many places these minerals came from.

June 25, 2023June 25, 2023 by Laurence Tognetti

The Clouds of Venus Could Support Life

Image of Venus taken by NASA’s Pioneer-Venus Orbiter in 1979. (Credit: NASA)

A recent study published in Astrobiology examines the likelihood of the planet Venus being able to support life within the thick cloud layer that envelopes it. This study holds the potential to help us better understand how life could exist under the intense Venusian conditions, as discussions within the scientific community about whether life exists on the second planet from the Sun continue to burn hotter than Venus itself.