Antoniadi (Martian crater)

Antoniadi is a crater on Syrtis Major Planum in the Syrtis Major quadrangle, Mars, located at 21.5° north latitude and 299.2° west longitude. It is 394 km (245 mi) long and was named after Eugène Michael Antoniadi, a Greek astronomer (1870–1944) who spent most of his life in France.

There is evidence that Antoniadi Crater once contained rivers and lakes. The picture below shows an inverted channel in Antoniadi, as seen by HiRISE. Inverted channels formed from accumulated sediments that were cemented by minerals. These channels eroded into the surface, then the whole area was covered over with sediments. When the sediments were later eroded away, the place where the river channel existed remained because the hardened material were resistant to erosion.