Life Archives

May 6, 2022May 5, 2022 by Paul M. Sutter

Scientists Create Molecules that can Follow Darwinian Evolution

photo of a turtle swimming underwater — Photo by Belle Co on Pexels.com

A team of researchers at the University of Tokyo have discovered a set of RNA molecules that are capable of replication and diversification. This potentially allows the molecules to undergo Darwinian evolution, pointing the way to a possible first step to life on Earth. As lead author Assistant Professor Ryo Mizuuchi said, “The results could be a clue to solving the ultimate question that human beings have been asking for thousands of years — what are the origins of life?”

May 4, 2022May 4, 2022 by Evan Gough

Hydrogen Gas Can Seep Through Rock Providing Food to Bacteria. Another Place to Look for Life On Other Worlds.

An artist’s interpretation of liquid water on the surface of the Europa pooling beneath chaos terrain. Credit: : NASA/JPL-Caltech

Spin Google Earth around until you’re looking down at the nation of Oman. Ancient rock in that country is the backdrop for a new study with consequences for our search for life. Water reacts with this rock to produce hydrogen, which could be an energy source for bacteria. Could this happen on other worlds?

April 27, 2022April 27, 2022 by Matt Williams

All Five of Life's Informational Components can Form in Space

On Earth, all life comes down to the polymeric molecules known as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). These two building blocks contain all of the instructions for every living organism and its many operations. In turn, these are made up of five informational components (nucleobases), which are composed of organic molecules (purines and pyrimidines). For decades, scientists have been scouring meteorite samples for these building blocks.

To date, these efforts have resulted in the detection of three of the five nucleobases within meteorites. However, a recent analysis led by researchers from Hokkaido University, Japan (with support from NASA) has revealed the remaining two nucleobases that have eluded scientists until now. This discovery could help resolve the ongoing debate about whether life on Earth emerged on its own or was assisted by organic compounds deposited by meteorites (aka. panspermia).

March 31, 2022March 31, 2022 by Evan Gough

Europa Could be Pulling Oxygen Down Below the Ice to Feed Life

Jupiter’s moon Europa is a prime candidate in the search for life. The frozen moon has a subsurface ocean, and evidence indicates it’s warm, salty, and rich in life-enabling chemistry.

New research shows that the moon is pulling oxygen down below its icy shell, where it could be feeding simple 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 10, 2022March 10, 2022 by Evan Gough

Even More Complex Organic Molecules Have Been Found in a Protoplanetary Disc. Was Life Inevitable?

This artist's concept a protoplanetary disk around a young star. Researchers at the Leiden Observatory found the large organic molecule dimethyl ether in a protoplanetary disk for the first time. Credit: NASA/JPL-Caltech

Will we ever understand life’s origins? Will we ever be able to put our finger on the exact moment and circumstances that lead to living matter? Will we ever pinpoint the spark? Who knows.

But what we can do is find out how widespread the conditions for life are and how widespread the molecular constituents for life are.

February 23, 2022February 23, 2022 by Evan Gough

Does the Entire Planet Have a Mind of its Own?

In a self-described "thought experiment," University of Rochester astrophysicist Adam Frank and colleagues David Grinspoon at the Planetary Science Institute and Sara Walker at Arizona State University use scientific theory and broader questions about how life alters a planet, to posit four stages to describe Earth's past and possible future. Image Credit: (University of Rochester illustration / Michael Osadciw)

What is humanity? Do our minds set us apart from the rest of nature and from the rest of Earth? Or does Earth have a collective mind of its own, and we’re simply part of that mind? On the literal face of it, that last question might sound ridiculous.

But a new thought experiment explores it more deeply, and while there’s no firm conclusion about humanity and a planetary mind, just thinking about it invites minds to reconsider their relationship with nature.

Overcoming our challenges requires a better understanding of ourselves and nature, and the same is true for any other civilizations that make it past the Great Filter.

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.

February 16, 2022February 16, 2022 by Evan Gough

One of Life’s Building Blocks can Form in Space

A new kind of chemical reaction can explain how peptides can form on the icy layers of cosmic dust grains. Those peptides could have been transported to the early Earth by meteorites, asteroids or comets. Image Credit: © S. Krasnokutski / MPIA Graphics Department

Peptides are one of the smallest biomolecules and are one of life’s critical building blocks. New research shows that they could form on the surfaces of icy grains in space. This discovery lends credence to the idea that meteoroids, asteroids, or comets could have given life on Earth a kick start by crashing into the planet and delivering biological building blocks.

February 8, 2022February 8, 2022 by Evan Gough

Massive Rocky Planets Probably Don’t Have big Moons

The Earth straddling the limb of the Moon, as seen from above Compton crater on the lunar farside, taken by the Lunar Reconnaissance Orbiter spacecraft. Credit: NASA/GSFC/Arizona State University.

The Moon has orbited Earth since the Solar System’s early days. Anyone who’s ever spent time at the ocean can’t fail to notice the Moon’s effect. The Moon drives the tides even in the world’s most remote inlets and bays. And tides may be vital to life’s emergence.

But if Earth were more massive, the Moon may never have become what it is now. Instead, it would be much smaller. Tides would be much weaker, and life may not have emerged the way it did.