An Earth-sized planet found in the habitable zone of a nearby star

Until about a decade ago, only two habitable zone planets of any size were known to astronomers: Earth and Mars.

Universal History Archive / Getty Images

A few months ago a group of NASA exoplanet astronomers, who are in the business of discovering planets around other stars, called me into a secret meeting to tell me about a planet that had captured their interest.

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Could invisible aliens really exist among us? An astrobiologist explains

The intelligent life we are searching for doesn't have to be humanoid.

Francis DEMANGE/Gamma-Rapho via Getty Images

Life is pretty easy to recognise. It moves, it grows, it eats, it excretes, it reproduces.

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What can old stars teach us about the birth of our galaxy?

These needles in the vast galactic haystack take more effort to find, but they help piece together our origins.

  • With billions of stars in our galaxy, why should astronomers seek out the oldest ones?
  • Age-dating stars is a complicated process, so astronomers use chemical compositions, telescopes, and prisms to determine the age of these ancient stars.
  • Some telescopes used for this purpose are in extremely remote places, where you can observe the bright band of the Milky Way with the naked eye.
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Mars 2020 will hunt for 'microfossils', signs of ancient alien life

The Jerezo crater — where Mars 2020 is set to land — could be a good place to find signs of past life on Mars.

NASA
  • The Jerezo crater is likely home to hydrated silica, a material which on Earth is especially good at preserving signs of life.
  • Mars 2020 is set to land on the planet crater in February 2021. NASA's Curiosity rover is currently the only rover operating on Mars.
  • The discovery of past life on Mars would be revolutionary, at least in science and philosophy.
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Scientists create precursor to life in thermal vent experiment

Scientists speculate that if life were to have spontaneously developed on Earth, the first thing there would need to be are vesicles.

  • The findings also suggest that life may have formed in the deep oceans of other celestial bodies in our solar system as well.
  • These are a lot like cell membranes, only they don't contain any of the complicated machinery that real, living cells do.
    • Researchers recently demonstrated that these vesicles form frequently in environments similar to the hydrothermal vents of early Earth.
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