Life Archives

October 27, 2022October 27, 2022 by Evan Gough

Earth’s Hardiest Bacteria Could Survive Hundreds of Millions of Years Just Under the Surface of Mars

A few years from now, a small capsule will enter Earth’s atmosphere and float to the surface under a parachute. The parachute will likely be radar-reflective so that it can be easily tracked. It may land in Australia’s outback, a popular spot for sample returns. Scientists will take it to a sterilized, secure lab and carefully open it. Inside, there’ll be rock samples from Mars collected by the Perseverance Rover.

If a new study is correct, scientists should look carefully for dormant life in those samples.

October 21, 2022October 21, 2022 by Evan Gough

Early Life on Mars Might Have Wiped Out Life on Mars

Even though Mars and Earth had similar early histories, including water, Mars still ended up with fewer minerals than Earth. Why? Image Credit: ESO/M. Kornmesser

Life might have wiped itself out on early Mars. That’s not as absurd as it sounds; that’s sort of what happened on Earth.

But life on Earth evolved and persisted, while on Mars, it didn’t.

October 21, 2022October 17, 2022 by Paul M. Sutter

Nitrous Oxide, aka “Laughing gas”, Could be an Indication of Life in an Exoplanet

Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Credits: NASA/JPL-Caltech — Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. It's a very active flare star. Credits: NASA/JPL-Caltech

A team of astronomers have proposed to hunt for signs of life by looking for the signature of nitrous oxide in alien atmospheres. It’s laughing gas, but it’s no joke.

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.

September 21, 2022September 21, 2022 by Carolyn Collins Petersen

Habitable Planets Will Most Likely be Cold, Dry “Pale Yellow Dots”

An artist's concept of K2-18b, a super-Earth exoplanet that could support life. But, not all habitable planets are pale blue dots. Some are dry and yellow. Courtesy STScI

Remember all the habitable planets we’ve seen in science fiction movies? There’s wintry Hoth, for example, and overwhelmingly hot Dune. The folks in Interstellar visited an ocean world and a desolate rocky world. For all their differences, these places were still what they call on Star Trek M-class habitable worlds. Sure they weren’t all like Earth, but that made them excitingly alien for the lifeforms they did support. In the real universe, it seems that alien worlds not quite like ours could be the norm. Earth could be the real alien world.

September 21, 2022September 21, 2022 by Brian Koberlein

It Appears That Enceladus is Even More Habitable Than we Thought

Phosphorus is likely abundant in the waters of Enceladus. Credit: Southwest Research Institute

The problem with looking for life on other worlds is that we only know of one planet with life. Earth has a wondrous variety of living creatures, but they all evolved on a single world, and their heritage stems from a single tree of life. So astrobiologists have to be both clever and careful when looking for habitable worlds, even when they narrow the possibilities to life similar to ours.

September 13, 2022September 13, 2022 by Seth Lockman

Alien Artifacts Could Be Hidden Across the Solar System. Here’s how we Could Search for Them.

Galileo Project members (from left: Carson Ezell, Ezra Kelderman, Abby White, Alex and Lily Delacroix) with the audio tower (left), radar spectrum tower (middle) and radar imaging tower (right) behind them on the roof of the Harvard College Observatory. Image credit: The Galileo Project

Do aliens exist? Almost certainly. The universe is vast and ancient, and our corner of it is not particularly special. If life emerged here, it probably did elsewhere. Keep in mind this is a super broad assumption. A single instance of fossilized archaebacteria-like organisms five superclusters away would be all it takes to say, “Yes, there are aliens!” …if we could find them somehow.

July 15, 2022July 15, 2022 by Evan Gough

These Ancient Microbes Give a Glimpse of What Extraterrestrial Life Might Look Like

Rhodopsins are ancient proteins evolved by some of Earth's first life forms. They turned sunlight into energy without photosynthesis. Image Credit: Sohail Wasif/University of California, Riverside.

Will we discover simple life somewhere? Maybe on Enceladus or Europa in our Solar System, or further away on an exoplanet? As we get more proficient at exploring our Solar System and studying exoplanets, the prospect of finding some simple life is moving out of the creative realm of science fiction and into concrete mission planning.

As the hopeful day of discovery draws nearer, it’s a good time to ask: what might this potential life look like?

June 28, 2022June 28, 2022 by Carolyn Collins Petersen

Curiosity Finds Life-Crucial Carbon in Mars Rocks

Curiosity at Mt. Sharp, Gale Crater, Mars. To the left of the rover are two drill holes into the rocks "Aberlady" and "Kilmarie." Curiosity found high concentrations of clay in both rocks. Image Credit: NASA/JPL-Caltech/MSSS

We are carbon-based life forms. That means the basis for the chemical compounds that forms our life is the element carbon. It’s crucial because it bonds with other elements such as hydrogen and oxygen to create the complex molecules that are part of life. So, when we look for evidence of life elsewhere in the solar system, we look for carbon. That includes Mars.

May 18, 2022May 18, 2022 by Evan Gough

Maybe We Don’t Hear From Aliens Because They Choose To Go Silent

Artist impression of an alien civilization. Image credit: CfA

How will humanity meet its end?

That’s only a depressing question if you think that humanity will go on forever. Alas, nothing lasts forever, and if something could last forever, it probably wouldn’t be our struggling primate species.

But we’ll likely be around for a while yet, pondering things as we do. One of the things we love to ponder is: why don’t we hear from any other alien civilizations?