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 26, 2023July 26, 2023 by Matt Williams

Olympus Could Have Been a Giant Volcanic Island in an Ancient Martian Ocean

Olympus Mons, captured by the ESA's Mars Express mission from orbit. Credit: ESA/DLR/FUBerlin/AndreaLuck

Olympus Mons, located at the northwest edge of the Tharsis Montes region on Mars, was appropriately named. Based on readings obtained by the Mars Orbiter Laser Altimeter (MOLA), an instrument aboard NASA’s Mars Global Surveyor (MGS), this mountain is the tallest in the Solar System, standing 21.9 km (13.6 mi) tall – about two and a half times the height of Mount Everest (8.85 km; 5.5 mi). According to current estimates, this extinct shield volcano formed during Mars’ Hesperian Period (ca. 3.7 to 3 billion years ago), which was characterized by widespread volcanic activity and catastrophic flooding.

This coincides with a period when Mars had a denser atmosphere, a warmer environment, and flowing water on its surface. This included a global ocean that spanned much of the northern hemisphere, known today as the Northern Lowlands, encompassing Olympus Mons. According to a recent study led by researchers from the Centre National de Recherches Scientifique (CNRS), features found on the slopes of Olympus Mons indicate that it could have been a massive volcanic island where volcanic eruptions flowed into the ocean, similar to ones found on Earth.

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.

July 7, 2023July 7, 2023 by Matt Williams

Venus has Clouds of Concentrated Sulfuric Acid, but Life Could Still Survive

Image from NASA's Mariner 10 spacecraft in February 1974 as it traveled away from Venus. (Credit: NASA/JPL-Caltech)

The surface of Venus is like a scene from Dante’s Inferno – “Abandon all hope, ye who enter here!” and so forth. The temperature is hot enough to melt lead, the air pressure is almost one hundred times that of Earth’s at sea level, and there are clouds of sulfuric acid rain to boot! But roughly 48 to 60 km (30 to 37.3 mi) above the surface, the temperatures are much cooler, and the air pressure is roughly equal to Earth’s at sea level. As such, scientists have speculated that life could exist above the cloud deck (possibly in the form of microbes) as it does on Earth.

Unfortunately, these clouds are not composed of water but of concentrated sulfuric acid, making the likelihood that life could survive among them doubtful. However, a new study led by scientists from the Massachusetts Institute of Technology (MIT) reveals that the basic building blocks of life (nucleic acid bases) are stable in concentrated sulfuric acid. These findings indicate that Venus’ atmosphere could support the complex chemistry needed for life to survive, which could have profound implications in the search for habitable planets and extraterrestrial life.

June 21, 2023June 21, 2023 by Matt Williams

Bringing the Gift of Hope to Ukrainian Kids through Astronomy

Earthlings Hub is bringing education and counseling services to orphans and refugees in Ukraine, Credit: Earthlings Hub

The war in Ukraine has taken a terrible toll, and the damage extends far from the shifting battle lines. In addition to the many soldiers and civilians who’ve died, over 2.5 million children have been displaced within the country. The war has also exacerbated the problems of orphaned children, who are especially vulnerable in urban areas where the fighting has been most intense. Ensuring these children and their families can get adequate food and medical care is always challenging. Ensuring they have access to education and counseling services so their lives are not severely interrupted is even more so.

But there’s also the need for inspiration and hope for the future, which becomes all the more important in times of war and displacement. This is the purpose of Earthlings Hub, a non-profit organization dedicated to bringing astronomy and science education to refugee and orphan children in Ukraine. Founded in 2022 by members of the Blue Marble Space Institute of Science (BMSIS), Earthlings Hub is made up of scientists, teachers, and psychologists working to provide students with access to scientific research, equipment, and an inquiry-based educational program that goes beyond the standard school curriculum.

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 14, 2023March 14, 2023 by Andy Tomaswick

Finding Life in the Solar System Means Crunching a Lot of Data. The Perfect Job for Machine Learning

There are plenty of places for life to hide. Even on our blue planet, where we know there is abundant life, it is sometimes difficult to predict all the different environments it might crop up in. Exploring worlds other than our own for life would make it exponentially more difficult to detect it because, realistically, we don’t really know what we’re looking for. But life will probably present itself with some sort of pattern. And there is one new technology that is exceptional at detecting patterns: machine learning. Researchers at the SETI Institute have started working on a machine-learning-based AI system that will do just that.

January 24, 2023January 24, 2023 by Nancy Atkinson

JWST Sees Frozen Water, Ammonia, Methane and Other Ices in a Protostellar Nebula

A large, dark cloud is contained within the frame. In its top half it is textured like smoke and has wispy gaps, while at the bottom and at the sides it fades gradually out of view. On the left are several orange stars: three each with six large spikes, and one behind the cloud which colours it pale blue and orange. Many tiny stars are visible, and the background is black. — This image by the James Webb Space Telescope’s Near-InfraRed Camera (NIRCam) features the central region of the Chameleon I dark molecular cloud, which resides 630 light years away. Credit: NASA, ESA, CSA, and M. Zamani (ESA/Webb); Science: M. K. McClure (Leiden Observatory), F. Sun (Steward Observatory), Z. Smith (Open University), and the Ice Age ERS Team.

Want to build a habitable planet? Then you’ll need various and sundry ingredients such as carbon, hydrogen oxygen, nitrogen and sulfur. The James Webb Space Telescope has found the building blocks for these key ingredients in the colds depths of a distant protostellar nebula called the Chameleon I molecular cloud. Scientists say the discovery of these proto-ingredients allows astronomers to examine the simple icy molecules that one day will be incorporated into future exoplanets.

January 9, 2023January 9, 2023 by Matt Williams

How Could We Detect Life Inside Enceladus?

Scientists recently determined that a certain strain of Earth bacteria could thrive under conditions found on Enceladus. Credit: NASA/JPL/Space Science Institute

For astrobiologists, the scientists dedicated to the search for life beyond Earth, the moons of Saturn are a virtual treasure trove of possibilities. Enceladus is especially compelling because of the active plumes of water emanating from its southern polar region. Not only are these vents thought to be connected directly to an ocean beneath the moon’s icy surface, but the Cassini mission detected traces of organic molecules and other chemicals associated with biological processes. Like Europa, Ganymede, and other “Ocean Worlds,” astrobiologists think this could indicate hydrothermal activity at the core-mantle boundary.

Both NASA and the ESA are hoping to send missions to Enceladus that could study its plumes in more detail. These include the Enceladus Orbitlander recommended in the Planetary Science and Astrobiology Decadal Survey 2023-2032 and the ESA’s Enceladus Moonraker, which could depart Earth in the next decade, taking advantage of a favorable alignment between the planets. In anticipation of what these missions could find, an international team of researchers used data from the Cassini mission to establish how samples of plume material could constrain how much biomass Enceladus has within it.

October 27, 2022October 27, 2022 by Matt Williams

Here are Four Ways JWST Could Detect Alien Life

Artist conception of the James Webb Space Telescope. Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez

Less than a year after it went to space, the James Webb Space Telescope (JWST) has already demonstrated its worth many times over. The images it has acquired of distant galaxies, nebulae, exoplanet atmospheres, and deep fields are the most detailed and sensitive ever taken. And yet, one of the most exciting aspects of its mission is just getting started: the search for evidence of life beyond Earth. This will consist of Webb using its powerful infrared instruments to look for chemical signatures associated with life and biological processes (aka. biosignatures).

The chemical signatures vary, each representing a different pathway toward the potential discovery of life. According to The Conversation’s Joanna Barstow, a planetary scientist and an Ernest Rutherford Fellow at The Open University specializing in the study of exoplanet atmospheres, there are four ways that Webb could do this. These include looking for chemicals that lifeforms depend on, chemical byproducts produced by living organisms, chemicals essential to maintaining a stable climate, and chemicals that shouldn’t coexist.