Radar examples

Solar System

Arecibo Legacy: New Data on Near-Earth Asteroids

The largest set of radar data for near-Earth asteroids will help us understand their origins and protect Earth from future impacts.

Theia Impact

Solar System

Where Did Earth’s Trojans Go? Ask the Moon

Why doesn't Earth have Trojan asteroids of its own? Large impacts in the early years of the solar system may be to blame.

a telescope on a deck oberlooking water with the sun setting behind a mountain

Stargazer's Corner: Adventures Under the Night Sky

Amateur Astronomers Team Up to Measure Distance to a Close-passing Asteroid

A small group of amateurs teamed up to measure the parallax, and thus the distance, to a near-Earth asteroid as it passed by our planet.

Asteroid makes close approach

Celestial News & Events

Watch an Asteroid Race Across the Sky

The kilometer-wide, potentially hazardous asteroid 1994 PC1 will fly past Earth on January 18th. Good news on two counts: It won't hit us, and it's bright enough to see in a 4-inch telescope.

Near-Earth asteroid

Solar System

How Often Do Chicxulub-level Asteroids Hit Earth?

Asteroids of different sizes crashing on Earth originated from different parts of the main asteroid belt, researchers say; the finding has implications for how often such collisions happen.

Near-Earth asteroid passing Earth

Solar System

Karma Asteroid Family Might Be Sending Members Near Earth

New simulations have identified the Karma family of asteroids in the main belt as a potential source of near-Earth asteroids.

2020 XL5 orbit

Solar System

Second Earth Trojan Asteroid Discovered

A recently discovered asteroid appears to be an Earth Trojan, orbiting a gravitationally stable area with only one other known occupant.