Site Glossary

The ideal curved trajectory of a projectile.

An astronomical distance equal to about 3.26 light-years.

the point in an orbit closest to the Sun.

A mathematical answer that fits the conditions of the situation.

efforts to detect and potentially prevent dangerous asteroid or comet impacts.

the total mass of a planet.

A glowing shell of gas expelled by a dying Sun-like star.

the distance from the centre of a planet to its surface.

an orbit that passes over or near Earth's poles.

the location or placement of an object or point in relation to a reference point or coordinate system.