Erebus is a crater lying situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars, this extraterrestrial geological feature was visited by the Opportunity rover on the way to the much larger crater Victoria.

This crater features two other minor named outcrops on the edges of this topographical depression.

Erebus is located roughly 2,500 metres (8,200 ft) south of the much smaller crater Vostok, which was previously visited by Opportunity.

The etched terrain is characterized by heavily eroded rocks that form polygonal structures separated by ridges and valleys.

However, it is very old and eroded, and is barely visible from the ground; it appears merely as a number of flat rocky outcrops encircling a region of dunes.