Site Glossary

The magnitude of gravitational acceleration, approximately 9.8 m/s² near Earth’s surface.

A way of comparing apparent weight or acceleration effects with normal gravitational conditions.

A stage of interphase involving cell growth and normal activity.

The stage during which the cell prepares for division.

The time taken for the Solar System to orbit once around the centre of the Milky Way.

A massive collection of stars, gas, dust, planets, and dark matter held together by gravity.

A group of galaxies bound together by gravity.

a graph showing orbital speed at different distances from a galaxy's centre.

An organ that stores and releases bile.

A reproductive (sex) cell such as a sperm or egg.