Extraterrestrial life

The first planet beyond our solar system was identified just 30 years ago. Since then, thousands have been found and characterized. As we look for more, exoplanet experts are also probing for signs of alien biospheres hundreds of light-years away. In this episode, co-host Janna Levin speaks with astrophysicist and astrobiologist Lisa Kaltenegger about how we’ll know we’re not alone in the cosmos.

The moons orbiting Jupiter and Saturn appear to have subsurface oceans — tantalizing targets in the search for life beyond Earth. But it’s not clear why these seas exist at all.

In some deep subterranean aquifers, cells have a chemical trick for making oxygen that could sustain whole underground ecosystems.

The marine geochemist Chris German brings decades of experience studying seafloor hydrothermal vents to NASA’s preparations for visits to other ocean worlds in our solar system.

A new radiation-based mechanism adds to the ways that amino acids could have been made in space and brought to the young Earth.

A new origins-based system for classifying minerals reveals the huge geochemical imprint that life has left on Earth. It could help us identify other worlds with life too.

Without a good definition of life, how do we look for it on alien planets? Steven Strogatz speaks with Robert Hazen, a mineralogist and astrobiologist, and Sheref Mansy, a chemist, to learn more.

The James Webb Space Telescope has the potential to rewrite the history of the cosmos and reshape humanity’s position within it. But first, a lot of things have to work just right.

After the ultra-powerful James Webb Space Telescope launches later this year, Laura Kreidberg will lead two efforts to check the weather on rocky planets orbiting other stars.