Astrophysics and Cosmology

an object that orbits another object.

A model that represents objects using proportional sizes or distances.

radius of the event horizon for a simple non-rotating black hole.

A way of writing very large or very small numbers using powers of ten.

half the longest diameter of an elliptical orbit.

a feature of classical black-hole solutions where the theory ceases to provide a complete physical description.

The Sun and all the objects that orbit it.

human-made objects or fragments remaining in orbit that no longer serve a useful purpose.

investigation of space using robotic or crewed technology.

an uncrewed spacecraft designed to investigate space or astronomical objects.