Life Archives

June 15, 2023June 15, 2023 by Evan Gough

Did Life Need Plate Tectonics to Emerge?

New research indicates that mobile plate tectonics—thought to be necessary for the creation of a habitable planet—was not occurring on Earth 3.9 billion years ago. Image Credit: University of Rochester illustration / Michael Osadciw

It’s widely accepted that Earth’s plate tectonics are a key factor in life’s emergence. Plate tectonics allows heat to move from the mantle to the crust and plays a critical role in cycling nutrients. They’re also a key part of the carbon cycle that moderates Earth’s temperature.

But new research suggests that there was no plate tectonic activity when life appeared sometime around 3.9 billion years ago. Does this have implications for our search for habitable worlds?

May 30, 2023May 30, 2023 by Evan Gough

A New Place to Search for Habitable Planets: “The Soot Line.”

Artist impression of a young planet-forming disk illustrating the respective locations of the soot and water-ice lines. Planets born interior to the soot line will be silicate-rich. Planets born interior to the water-ice line, but exterior to the soot line will be silicate and soot-rich (“Sooty Worlds”). Planets born exterior to the water-ice line will be water worlds. Image credit: Ari Gea/SayoStudio.

The habitable zone is the region around a star where planets can maintain liquid water on their surface. It’s axiomatic that planets with liquid water are the best places to look for life, and astronomers focus their search on that zone. As far as we can tell, no water equals no life.

But new research suggests another delineation in solar systems that could influence habitability: The Soot Line.

May 18, 2023May 12, 2023 by Paul M. Sutter

Fatty Acids Might Exist in Space

A team of physicists have discovered that the environment of a molecular cloud in interstellar space can support the existence of fatty acids, a key component of life on Earth.

May 11, 2023May 11, 2023 by Evan Gough

Advanced Life Should Have Already Peaked Billions of Years Ago

The Drake Equation, a mathematical formula for the probability of finding life or advanced civilizations in the universe. Credit: University of Rochester

Did humanity miss the party? Are SETI, the Drake Equation, and the Fermi Paradox all just artifacts of our ignorance about Advanced Life in the Universe? And if we are wrong, how would we know?

A new study focusing on black holes and their powerful effect on star formation suggests that we, as advanced life, might be relics from a bygone age in the Universe.

May 4, 2023May 4, 2023 by Evan Gough

Solar Flares Could Have Helped Life Get Started on Earth

Solar flares pose a major hazard to electronics and infrastructure in Low Earth Orbit, but they may have played a role in kick-starting life on Earth. Credit: NASA/SDO/J. Major

Stars emit powerful flares that can be deadly for any burgeoning life on nearby planets. Images from spacecraft that monitor the Sun show these flares in glorious, horrifying detail. But the flares from the Sun are mere nuisances compared to some stars. Some stars produce catastrophic superflares, which can be tens of thousands of times more energetic than the Sun’s. That much energy can sterilize a planet’s surface.

But new research shows that a certain amount of flaring activity on the Sun could’ve been beneficial. It could’ve kick-started life on Earth.

March 22, 2023March 22, 2023 by Carolyn Collins Petersen

Did Supernovae Help Push Life to Become More Diverse?

Distant past supernovae could be linked by cosmic ray particles to climate change on Earth and changes in biodiversity. Courtesy: Henrik Svensmark, DTU Space.

Life on Earth has been around for a long time—at least 3.8 billion years. During that time, it evolved significantly. Why has biodiversity here changed so much? A new study proposes a startling idea. Some major diversity changes are linked to supernovae—the explosions of massive stars. If true, it shows that cosmic processes and astrophysical events can influence the evolution of life on our planet.

March 21, 2023March 21, 2023 by Carolyn Collins Petersen

JWST Sees Organic Molecules Swirling Around a Newborn Star

A newborn star in the Lupus 1 Molecular cloud is showing complex organic molecules that could be life precursors. The Webb space telescope is studying this cloud to find these chemicals. Courtesy Gabriel Rodrigues Santos. From https://science.nasa.gov/barnard-228-dark-wolf-nebula-lupus — A newborn star in the Lupus 1 Molecular cloud is showing that complex organic molecules exist it its birth cloud. They could be life precursors. The Webb space telescope is studying this cloud to find these chemicals. Courtesy Gabriel Rodrigues Santos. From https://science.nasa.gov/barnard-228-dark-wolf-nebula-lupus

One of the most interesting questions we can ask is, “How did life form?”. To answer it, scientists go back to look at the basic chemical building blocks of life. Those are water, carbon-based organic molecules, silicates, and others. The James Webb Space Telescope offered a peek at the gases, ice particles, and dust surrounding a newborn star and found organic molecules exist there.

February 28, 2023March 1, 2023 by Matt Williams

Do Red Dwarfs Provide Enough Sunlight for Plants to Grow?

This artist’s impression shows the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image between the planet and Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface. Credit: ESO/M. Kornmesser

To date, 5,250 extrasolar planets have been confirmed in 3,921 systems, with another 9,208 candidates awaiting confirmation. Of these, 195 planets have been identified as “terrestrial” (or “Earth-like“), meaning that they are similar in size, mass, and composition to Earth. Interestingly, many of these planets have been found orbiting within the circumsolar habitable zones (aka. “Goldilocks zone”) of M-type red dwarf stars. Examples include the closest exoplanet to the Solar System (Proxima b) and the seven-planet system of TRAPPIST-1.

These discoveries have further fueled the debate of whether or not these planets could be “potentially-habitable,” with arguments emphasizing everything from tidal locking, flare activity, the presence of water, too much water (i.e., “water worlds“), and more. In a new study from the University of Padua, a team of astrobiologists simulated how photosynthetic organisms (cyanobacteria) would fare on a planet orbiting a red dwarf. Their results experimentally demonstrated that oxygen photosynthesis could occur under red suns, which is good news for those looking for life beyond Earth!

February 9, 2023February 9, 2023 by Evan Gough

The Raw Materials for Life Form Early on in Stellar Nurseries

This is a two-panel mosaic of part of the Taurus Giant Molecular Cloud, the nearest active star-forming region to Earth. The darkest regions are where stars are being born. Inside these vast clouds, complex chemicals are also forming. Image Credit: Adam Block /Steward Observatory/University of Arizona

Life doesn’t appear from nothing. Its origins are wrapped up in the same long, arduous process that creates the elements, then stars, then planets. Then, if everything lines up just right, after billions of years, a simple, single-celled organism can appear, maybe in a puddle of water on a hospitable planet somewhere.

It takes time for the building blocks of stars and planets to assemble in space, and the building blocks of life are along for the ride. But there are significant gaps in our understanding of how all that works. A new study is filling in one of those gaps.

January 17, 2023January 17, 2023 by Evan Gough

Worlds Bustling With Plantlife Should Shine in a Detectable Wavelength of Infrared

Artist's rendering of a super-Earth-type exoplanet, TOI 1452 b. Credit: Benoit Gougeon, Université de Montréal.

Future historians might look back on this time and call it the ‘exoplanet age.’ We’ve found over 5,000 exoplanets, and we’ll keep finding more. Next, we’ll move beyond just finding them, and we’ll turn our efforts to finding biosignatures, the special chemical fingerprints that living processes imprint on exoplanet atmospheres.

But there’s more to biosignatures than atmospheric chemistry. On a planet with lots of plant life, light can be a biosignature, too.