Question

Asteroids that come within the orbit of the Earth at their perihelions (closest approach to the Sun) are known as ___________ asteroids.

Aten
Apollo
Trojan
Amors

Answer 1

Any object, such as an asteroid or comet, orbiting the Sun with a perihelion, q < 1.3 AU, well inside the orbit of Mars, is defined as an NEO. Aphelia, Q, of NEOs generally lie within a sphere of radius 5.2 AU, defined by Jupiter's orbit.