'Day temperature of 2,000°C': James Webb finds Neptune-like planet, so hot it’s evaporating before our eyes

Produced by: Mohsin Shaikh

Hellish Neptune

LTT 9779 b orbits so close to its star that its dayside reaches a blistering 2,000°C, making it one of the most extreme exoplanets ever observed. Could any atmosphere survive such infernal heat?

Cloud Divide

Strange clouds of silicate minerals coat one side of LTT 9779 b’s dayside—while the other is bare. Astronomers suspect fierce winds sculpt this bizarre asymmetry in the planet’s atmosphere.

Tidal Prison

Locked in place, one hemisphere of LTT 9779 b is in eternal daylight while the other remains in perpetual darkness. This strange celestial dance creates dramatic temperature contrasts.

Fiery Whirlwind

Powerful eastward winds whip around LTT 9779 b, redistributing its extreme heat. But with temperatures hotter than molten lava, can anything truly balance this planet’s chaotic weather?

Steamy Signal

Water vapor has been detected in the atmosphere of this ultra-hot Neptune. But in such an extreme environment, does this mean hope for habitability—or a clue to total atmospheric loss?

Webb’s Triumph

Thanks to the James Webb Space Telescope, astronomers mapped the heat, clouds, and chemistry of this scorching exoplanet, offering the most detailed look yet at an ultra-hot Neptune.

Scorching Orbit

LTT 9779 b races around its star in less than a day—so close that its atmosphere is being stripped away. Yet somehow, it still clings to its clouds. What’s keeping them from vanishing?

Molten Mirror

The western side of LTT 9779 b’s dayside is so reflective it bounces back significant stellar radiation, while the eastern side absorbs it. Could this odd reflectivity be the key to survival?

Extreme Atmosphere

LTT 9779 b defies expectations, holding onto its atmosphere despite brutal conditions. This discovery challenges our understanding of how planets survive in the most hostile environments.