There appears to be stronger evidence of a possible ocean on ancient Mars. A recent study indicates that the meteor that created the 75-mile Lomonosov crater may have produced a "mega-tsunami" that left its mark on the planet. Its rim is the same height as the estimated depth of the ocean and resembles marine craters on Earth. Also, a hole in the southern lip of the crater could have been the result of the ocean roaring back from that direction. Earlier evidence had hinted the ocean's shores were shaped by at least one impact in the same general area as the Lomonosov crater -- this latest study, however, has narrowed things down to a specific impact site.