The  humble slime mold, physarum polycephalum.

The Astrobiology of Alien Worlds

A comprehensive review of life as we know it—and may not know it.

The surface of Venus (shown here in an artist's conception, with erupting volcanoes) is too hot for life. But what about the clouds above?

Microbes in the Clouds of Venus

New insights on life in an unlikely place

The Mars 2020 mission departing Earth, courtesy of an Atlas V rocket.

Mars Exploration Takes a Major Leap

Sample return and life detection are on the near horizon.

700 million years ago, "Snowball Earth" was in a deep freeze. Thanks a lot, asteroids.

Asteroids May Have Pummeled Earth 800 Million Years Ago—And That Was Not All Bad

Impact craters on the Moon suggest our planet was hit by 40 to 50 trillion tons of material.

Planets close to small red dwarf stars are frequently tidally locked, so that their day (the time it takes to rotate once on their axis) is as long as their year (the time it takes to orbit the star).

Planets Close to Their Host Stars May Be Habitable, but There’s a Catch

A dusty atmosphere will increase the chances of life existing, but also make it harder to find.

Catalog item P023: The asteroid 433 Eros, as seen by NASA's NEAR spacecraft in 2000.

This New Catalog of the Universe Contains, to the Best of Our Knowledge, One of Everything

If you want to find technologically advanced life, investigate the anomalies.

The Pyrenean violet is one of Nature's strange “resurrection plants.”

Meet the Real Resurrection Plant, <i>Ramonda myconi</i>

This extreme survivor lives for 250 years and can withstand dehydration and freezing.

Captain Kirk, meet the Horta.  Horta, meet Captain Kirk.

Silicon-Based Life, That Staple of Science Fiction, May Not Be Likely After All

Silicon could still be important for the beginning and end of organic life, however.

Right size, right distance, right kind of star.  The search for an Earth 2.0 is heating up.

We’re Very Close to Finding a Solar System like Our Own

A newly discovered exoplanet is in a 378-day orbit around a G dwarf star like our own Sun.

With so many worlds out there, the question is: How many are home to advanced life?

Statistics Say Intelligent Life in the Universe May Be Rare

But simpler life is probably common.

The first hard-shelled animals, like the trilobite at center, needed a lot of oxygen to move around and make a living.

Long-lasting Oxygen in Earth’s Early Atmosphere May Have Jump-Started the Evolution to Animal Life

It’s the stuff that higher organisms need.

The smaller white stars in this Hubble Space Telescope image of the central region of our galaxy are of the same type as the Sun. But our local star may be unusual in its ability to foster life.

How Common is Life, and Are We Unique?

Two recent papers prompt a revisiting of the Fermi Paradox.

Salt nodules (whitish rocks in the foreground) are the last outpost of life in the hyperarid core of the Atacama Desert (see hammer for scale).

Viruses Thrive Even in one of Earth’s Toughest Deserts

To prosper here, their microbe hosts live in the rocks and draw water from the atmosphere.

Stromatolites today in Shark Bay, Australia—living fossils of the first microbial communities on early Earth.

The Case for Past Life on Mars Gets Stronger

But how much evidence is needed until we can say there’s proof?

Biological? Post-biological? Something in between? What is humanity's future?

Reaching the Singularity May be Humanity’s Greatest and Last Accomplishment

Should we be searching for post-biological aliens?

Electron microscope image of SARS-CoV-2, the virus that causes COVID-19, isolated from a patient in the United States.

There Are More Viruses on Earth Than There Are Stars in the Universe

And yes, they’re alive.

The European Space Agency’s Exomars rover, named Rosalind Franklin for the scientist who helped discern the structure of DNA, is due to land on Mars next year.

A New Way to Test for Life on Mars

The presence of sulfur-rich organic compounds may help in the search for Martian biology.

Betelgeuse (as seen here by the ALMA telescope) is going to blow sometime. It's just a question of when.

The Threat From Stellar Explosions

Betelgeuse is harmless, but other stars going supernova could spell death for Earth.

Four billion years ago, things were a little different around here.

What Was it Really Like on Early Earth?

New studies point to the conditions under which life originated on our planet.

Artist's conception of a hydrocarbon lake on Titan.

On Saturn’s Moon Titan, Living Cells May Be Very Different From Ours

Yet another good reason to visit this exotic world.

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