Planetary Science

“Twilight rays” are but one of several viewing treats for the liminal time between day and night

Samples from the far side of the moon gathered by China’s Chang’e 6 mission record eons of tumultuous lunar history

The nearby star Vega, featured in the 1997 movie Contact, appears to have a smooth disk devoid of giant planets for reasons we can’t explain

Finding a perfect sphere is actually pretty difficult

The Martian new year arrives with the Red Planet’s vernal equinox. Explaining why requires a deep dive into celestial mechanics and Earth’s calendrical history

At dusk and dawn, the sky dances with three phases of in-between light

A gigantic space rock that slammed into Earth more than three billion years ago grievously wounded the biosphere—and then helped it heal

We have been adding “leap seconds” to time kept by our atomic clocks, but soon we may have to subtract one. Are the tiny adjustments worth the bother?

For the first time, we are sending a spacecraft to explore an alien ocean world—a moon that might host life today

Hera will arrive in 2026 at Dimorphos, an asteroid deliberately struck by NASA’s DART spacecraft

Claims of worlds orbiting Barnard’s star have been made before. But an advanced instrument could provide the breakthrough that finally confirms the star hosts a planetary system

Sooner or later a doomsday asteroid will wipe out most life on Earth—unless, that is, we prevent threatening space rocks from hitting us in the first place