Glossary

Exoplanet

An exoplanet is a planet orbiting a star other than the Sun. More than 5,800 have been confirmed since the first around a Sun-like star in 1995, ranging from scorched gas giants to rocky worlds in their stars' habitable zones. Astronomers detect them mostly by the tiny dimming as a planet transits its star, or the star's slight wobble, and increasingly characterize their atmospheres, and even their surfaces, with the James Webb Space Telescope.

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Cosmology · Exoplanets · Direct Imaging

The Coldest World We Have Ever Photographed

Almost every planet we have imaged directly is a young, glowing furnace. Then JWST captured a mature, frigid super-Jupiter twelve light-years away, ne...

August 25, 202612 min read

Cosmology · Exoplanets · Astrobiology

The Planet That Almost Had a Sign of Life

In 2025, a team announced a gas in a distant world's air that, on Earth, is made almost only by living things. Then the scrutiny began, and it became ...

August 23, 202613 min read

Cosmology · Exoplanets · Magma Worlds

The World That Breathes Sulfur

Thirty-five light-years away, the super-Earth L 98-59 d has no solid ground. A permanent ocean of magma feeds a sky laced with sulfur, and it may be t...

July 14, 202613 min read

Cosmology · Exoplanets · Direct Imaging

The Planet That Webb Actually Photographed

Around a bright star in Cygnus, the James Webb Space Telescope blocked the glare of the star itself and captured the faint thermal glow of a world fif...

June 28, 202614 min read

Cosmology · Exoplanets · Planet Formation

Two Planets Caught in the Act of Being Born

Around a young Sun-like star called WISPIT 2, astronomers have directly imaged a gas giant glowing inside a dark gap in a multi-ringed disk, and then ...

June 21, 202614 min read

Cosmology · Exoplanets · Rogue Planets

The Planets That Drift Through the Dark

Untethered to any star, rogue worlds may outnumber the suns of the Milky Way. Here is how astronomers find the invisible, and why one of these frozen ...

June 17, 202614 min read