Definition: Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
Input: A dark albedo feature about across has been named Olbers in honour of Vesta's discoverer, but it does not appear in elevation maps as a fresh crater would, and its nature is presently unknown, perhaps an old basaltic surface.

There is a large crater named Vesta that was discovered by Olbers.  There is a dark crater on this asteroid named after Olbers, that is likely made of basalt.