Astrobiology Archives

July 28, 2023July 28, 2023 by Alan Boyle

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

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)

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.

May 7, 2023May 7, 2023 by Laurence Tognetti

A Lack of Alien Signals Actually Tells Us a Lot

In a recent study published in The Astronomical Journal, a researcher from the École Polytechnique Fédérale de Lausanne (EPFL) discusses the potential reasons why we haven’t received technoemission, also called technosignatures, from an extraterrestrial intelligence during the 60 years that SETI has been searching, along with recommending additional methods as to how we can continue to search for such emissions.

March 28, 2023April 1, 2023 by Laurence Tognetti

Europa’s Ice Rotates at a Different Speed From its Interior. Now We May Know Why

Image of Europa taken by NASA's Juno spacecraft on Sept 29, 2022. (Credit: NASA/JPL-Caltech/Southwest Research Institute/Malin Space Science Systems)

Jupiter’s moon, Europa, contains a large ocean of salty water beneath its icy shell, some of which makes it to the surface from time to time, and this vast ocean could host life, as well. Europa was most recently observed by NASA’s Juno spacecraft, but current examinations of the moon’s internal ocean are limited to computer models and simulations produced here on Earth, as no mission is actively exploring this tiny moon orbiting Jupiter. Other than the internal water occasionally breaching the icy shell and making it to the surface, what other effects could the internal ocean have on the icy shell that encloses it?

March 28, 2023March 28, 2023 by Matt Williams

Moons Orbiting Rogue Planets Could be Habitable

An artist's conception of a potentially-habitable exomoon. It seems reasonable that exoplanets have exomoons, and now we're going to look for them. Credit: NASA

When looking for signs of life beyond the Solar System, astrobiologists are confined to looking for life as we understand it. For the most part, that means looking for rocky planets that orbit within their star’s circumsolar habitable zone (HZ), the distance at which liquid water can exist on its surface. In the coming years, next-generation telescopes and instruments will allow astronomers to characterize exoplanet atmospheres like never before. When that happens, they will look for the chemical signatures we associate with life, like nitrogen, oxygen, carbon dioxide, methane, and ammonia.

However, astrobiologists have theorized that life could exist in the outer Solar System beneath the surfaces of icy moons like Europa, Callisto, Titan, and other “Ocean Worlds.” Because of this, there is no shortage of astrobiologists who think that the search for extraterrestrial life should include exomoons, including those that orbit free-floating planets (FFPs). In a recent study, researchers led by the Max Planck Institute for Extraterrestrial Physics (MPE) determined the necessary properties that allow moons orbiting FFPs to retain enough liquid water to support life.

March 20, 2023March 20, 2023 by Laurence Tognetti

The Favorite Solar System Moons of Planetary Geologists; An In-Depth Discussion

The Galilean moons of Jupiter: Io, Europa, Ganymede, and Callisto. (Credit: NASA/JPL-Caltech)

The moons of our Solar System have garnered quite a lot of attention in the last few years, especially pertaining to astrobiology and the search for life beyond Earth. From the Galilean moons of Jupiter to the geysers of Enceladus to the methane lakes on Titan, these small worlds continue to humble us with both their awe and mystery. But do the very same scientists who study these mysterious and intriguing worlds have their own favorite moons? As it turns out, seven such planetary geologists were kind enough to share their favorite Solar System moons with Universe Today!

February 27, 2023February 27, 2023 by Laurence Tognetti

Our Best Instruments Couldn’t Find Life on Mars

Jezero Crater (Left; Credit: NASA/JPL-Caltech) and Red Stone Jurassic fossil delta of the Atacama Desert in northwestern Chile (Right; Credit: Dr. Armando Azua-Bustos)

The planet Mars is arguably the most extensively studied planetary body in the entire Solar System, which began with telescopic observations by Galileo Galilei in 1609, with such telescopic observations later being taken to the extreme by Percival Lowell in the late 19^th century when he reported seeing what he believed were artificial canals made by an advanced intelligent race of Martians. But it wasn’t until the first close up image of Mars taken by NASA’s Mariner 4 in 1965 that we saw the Red Planet for what it really was: a cold and dead world with no water and no signs of life, whatsoever.

February 25, 2023February 25, 2023 by Laurence Tognetti

Europa Could be Covered in Salty Ice

Jupiter's second Galilean moon, Europa. Its smooth surface has fewer craters than other moons, but they help us understand its icy shell. (Credit: NASA/JPL/Galileo spacecraft) — The Hubble spotted evidence of geysers coming from Jupiter's moon Europa, but nobody's been able to find them again. (Credit: NASA/JPL/Galileo spacecraft)

Jupiter’s second Galilean moon, Europa, is one of the most fascinating planetary objects in our Solar System with its massive subsurface ocean that’s hypothesized to contain almost three times the volume of water as the entire Earth, which opens the possibility for life to potentially exist on this small moon. But while Europa’s interior ocean could potentially be habitable for life, its unique surface features equally draw intrigue from scientists, specifically the large red streaks that crisscross its cracked surface.

January 28, 2023January 29, 2023 by Laurence Tognetti

A Martian Meteorite Contains Organic Compounds. The Raw Ingredients for Life?

Martian meteorite Tissint. (Image Credit: Dr. Ludovic Ferriere (study co-author); Natural History Museum Vienna)

In a recent study published in Sciences Advances, an international team of scientists led by the Technical University of Munich examined the Martian meteorite Tissint, which fell near the village of Tissint, Morocco, on July 18, 2011, with pieces of the meteorite found as far as approximately 50 kilometers (30 miles) from the village. What makes Tissint intriguing is the presence of a “huge organic diversity”, as noted in the study, which could help scientists better understand if life ever existed on Mars, and even the geologic history of Earth, as well.