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.

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We Could Spread Life to the Milky Way With Comets. But Should We?

Gerald Rhemann captured this incredible image of Comet Leonard when a piece of the comet's tail was disconnected and carried away. Rhemann won Astronomy Photographer of the Year 2022 for the image. Image Credit: Gerald Rhemann

Here’s a thorny problem: What if life doesn’t always appear on planets that can support it? What if we find more and more exoplanets and determine that some of them are habitable? What if we also determine that life hasn’t appeared on them yet?

Could we send life-bringing comets to those planets and seed them with terrestrial life? And if we could do that, should we?

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Meteorites Bathed in Gamma Rays Produce More Amino Acids and Could Have Helped Life get Going on Earth

Carbonaceous chondrites like the Allende meteorite contain significant amounts of water and amino acids. Could they have delivered amino acids to early Earth and spurred on the development of life? Image Credit: By Shiny Things - originally posted to Flickr as AMNH - Meteorite, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=4196153

Our modern telescopes are more powerful than their predecessors, and our research is more focused than ever. We keep discovering new things about the Solar System and finding answers to long-standing questions. But one of the big questions we still don’t have an answer for is: ‘How did life on Earth begin?’

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Want to Colonize Space? Unleash the Power of Microbes

Researchers at Penn State University are developing a way to use microbes to turn human waste into food on long space voyages. Image: Yuri Gorby, Rensselaer Polytechnic Institute
Microbes play a critical role on Earth. Why not harness their power for space colonization? Image: Yuri Gorby, Rensselaer Polytechnic Institute

If space colonization is in our future, we’ll have to use the resources available there. But we won’t be able to bring our established industrial methods and processes from Earth into space. Transporting heavy mining machinery to the Moon, Mars, or anywhere else in space is not feasible. And each of those environments is wildly different from Earth. We’ll need novel approaches to solve all of the problems facing us, and the approaches will have to be sustainable.

Terrestrial microbes are the foundation of Earth’s biosphere, and they could play an outsized role in space colonization.

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Should We Build a Nature Reserve on Mars?

There are 8 billion of us now. The UN says when the population peaks around the year 2100, there’ll be 11 billion human souls. Our population growth is colliding with the natural world on a greater scale than ever, and we’re losing between 200 and 2,000 species each year, according to the World Wildlife Federation.

An Engineer from the UK says that one way to mitigate the damage from the clash between humanity and nature is to create more habitat. We could do that by building Terran ecosystem preserves on Mars.

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Earth’s First Known Mass Extinction Event Starved Life of Oxygen

The Blue Marble image of Earth from Apollo 17. Credit: NASA

650 million years ago, Earth was completely or almost completely frozen, according to the Snowball Earth Hypothesis. As the atmosphere changed and Earth warmed up, it heralded the beginning of the Ediacaran Period. The Ediacaran Period marks the first time multicellular life was widespread on the planet. It predates the more well-known Cambrian Period, when more complex life emerged, diversified, and flourished.

Life during the Ediacaran Period faced a mass extinction, and it was Earth’s first one.

What happened?

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Hydrothermal Vents Under the Arctic Ice are Perfect Places to Practice Exploring Europa

This illustration of Europa (foreground), Jupiter (right) and Io (middle) is an artist's concept showing possible oceanic volcanoes under its icy surface. Image Credit: NASA/JPL-Caltech

Someday on Europa, there’ll be a robotic explorer diving beneath its icy surface to find volcanoes. Yes, even though it’s an ice world, Europa shows signs of internal activity. Planetary scientists think volcanic features, similar to hydrothermal vents here on Earth, exist on Europa’s ocean floor. But, how to understand them?

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

Mars
A gibbous Mars. Credit: Mars Hope/NYUAD/Atlas 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.

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Early Life on Mars Might Have Wiped Out Life on Mars

Primitive simple life may have thrived on early Mars. Then it may have wiped itself out. Is it too late for a memorial? 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.

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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. 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.

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