A skull of one of our distant ancestors, Ardipithecus ramidus. Male chest-beating may not be the only option for how species socialize.

The Science of Aliens, Part I: Would They Be Friendly, or Threatening?

Any advanced alien species would have a social structure, but would also likely have predatory roots.

Phosphorus is found in everything from matches to fertilizer—and may be critical to starting the spark of life and keeping it going.

The Fuss Over Phosphorus

A critical element takes center stage in the discussion of how life began, and where it might exist.

Layered sediments like these in Jezero Crater may be good places for Perseverance to search for evidence of life. Should we wish the rover luck?

We May Never Find Life on Mars—And That Could Be a Good Thing

Perseverance, the Fermi Paradox, and the Great Filter.

The Earth’s magnetic field does more than just cause auroral light shows. Could it play a role in extinctions, too?

Could Doomsday Come From a Reversal of the Magnetic Poles?

Lessons from the Laschamps Excursion 42,000 years ago

The Centauri system: Alpha Centauri A is the bright star to the left, Alpha Centauri B is the bright star to the right, and Proxima Centauri is circled in red.

This Intriguing Signal From Alpha Centauri May (or May Not) Be a Planet

Could the star system closest to us host a habitable super-Earth?

“Who are you calling a bird-brain?”

Crows Are Even Smarter Than We Thought

Could they help us understand intelligent life on other worlds?

Laguna La Brava in the Atacama desert of Chile.

Arsenic and (Very) Old Life

This normally toxic substance might have been useful in the oxygen-deprived environment of early Earth.

AI gets more capable every day.  Are we prepared?

Artificial Intelligence: Cure for What Ails Us, or Looming Threat to the World?

From biological machines to superintelligence.

The Parkes Telescope in Australia heard something odd in 2019. Unfortunately, the signal, if it was one, has not been repeated.

The First Sign of Intelligent Life Beyond Earth?

Examining this and other intriguing questions at the start of 2021.

With Chang'e-5 having just returned samples from the moon, China's next extraterrestrial landing (by Tianwen 1, shown in an artist's conception) will be on Mars in February 2021.

Astrobiology’s Biggest Stories of 2020

A lot has been achieved, even in an awful year.

Earth's early magma ocean gave our planet its first atmosphere.

Early Earth Was No Inviting Blue Planet—It Was More Like Venus

New insights on how, and when, terrestrial planets become habitable.

Early settlers on Mars will need a way to make their own rocket fuel.

How Salt Water Could Fuel a Mars Mission

A new invention might speed up human exploration of the Red Planet.

Looks like Mars, but it's not.  A layer of the clay mineral smectite was found beneath the surface in the Yungay region of the hyperarid Atacama desert (pictured here).

A New Place to Look for Life on Mars

…or at least evidence of past biology.

Conditions on early Earth may not have been so different from conditions on K2-141b today.

The Most Hellish Planet Yet

In a place where it rains rocks, we can exclude life for sure, right?

Trilobites were among the casualties of the great mass extinction at the end of the Permian era.

An Environmental Horror Story

The Permian mass extinction, 252 million years ago, has lessons for today.

The European Mars Express spacecraft captured this image of icy Korolev crater on Mars in 2018.

When Asteroid Impacts Are a Good Thing

Craters could create habitable conditions on many planets and moons.

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Two Dozen Exoplanets that Might be More Habitable than Earth

Do we need to change our search parameters when looking for extraterrestrial life?

The Ultimi Scopuli region on Mars, as seen (in black-and-white and enhanced color) by the HiRISE camera on NASA's Mars Reconnaissance Orbiter.

More Lakes Found Under the Martian Ice

But would such cold places be habitable?

Artist's concept of a lightning strike on Venus.

The Likelihood of Life on Venus Just Increased Dramatically

A sample-return mission to our planetary neighbor should now be considered.

Sand grains or microbes?  In this case, it's a cluster of E. coli bacteria. But it can be hard to tell, so we'll need discerning new instruments.

A New Tool to Detect Alien Biochemistry

Life detection on Mars and the icy moons of the outer Solar System looks more and more feasible.

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