The European Space Agency announced Thursday that it has taken high-definition pictures of an ancient river nearly 1,000 miles long on Mars.
According to the report, the "striking" river also has "numerous tributaries" and is believed to be more than 4 miles wide and nearly 1,000 feet deep at some points. The agency believes that the river was carved by water between 1.8 and 3.5 billion years ago and went dry due to evaporation.
The agency has named the river Reull Vallis. The photos were taken with the ESA's Mars Express satellite last year.