Near-Earth asteroids (NEAs)

Definition

Near-Earth asteroids (NEAs) are asteroids whose orbits bring them into close proximity with Earth. They are of interest due to their potential for impact and as targets for scientific study and resource utilization.

5 Must Know Facts For Your Next Test

1. NEAs are classified based on their orbital characteristics, including Aten, Amor, and Apollo groups.
2. The most famous NEA is 99942 Apophis, which will make a notably close approach to Earth in 2029.
3. NASA's Near-Earth Object Program is dedicated to tracking and characterizing NEAs to assess potential impact threats.
4. Some NEAs are considered potentially hazardous objects (PHOs) due to their size and close approaches to Earth.
5. Missions such as OSIRIS-REx have been launched to study NEAs up close and even return samples to Earth.

Review Questions

• What defines a near-Earth asteroid (NEA)?
• Name the three main groups of NEAs based on their orbital characteristics.
• Why are near-Earth asteroids significant in planetary defense?

Related terms

Asteroid Belt: A region of space located between the orbits of Mars and Jupiter where most asteroids in the solar system are found.

Potentially Hazardous Object (PHO): An asteroid or comet with an orbit that brings it dangerously close to Earth and is large enough to cause significant regional damage if it were to impact.

OSIRIS-REx: A NASA mission aimed at studying the near-Earth asteroid Bennu and returning a sample from its surface for analysis on Earth.