Heinlein is a crater in Promethei Terra

Promethei Terra

Promethei Terra is a large Martian region, centered at and covering 3300 km at its broadest extent. It lies to the east of the massive Hellas basin. Like much of the southern part of the planet it is a heavily cratered, highland region. Promethei Terra was named for a classic albedo feature...

, Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

. It is centered at 64.6 degrees south, 243.8 degrees west, and is 83 km in diameter. It is named after Robert A. Heinlein

Robert A. Heinlein

Robert Anson Heinlein was an American science fiction writer. Often called the "dean of science fiction writers", he was one of the most influential and controversial authors of the genre. He set a standard for science and engineering plausibility and helped to raise the genre's standards of...

, a famous author of science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

.

According to prevailing views and based on scientific analysis of available data, there may exist underground layers of ice at northern and southern latitudes greater than 30-40 degrees. Ice may have been detected at the north polar cap. There is then a chance that underground ice will be found in the vicinity of Heinlein, making it a possible site for human settlement. In winter, the south polar cap extends about 45 degrees in south latitude. Heinlein is then covered by this seasonal cap, which consists of frozen carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

, i.e., dry ice.