Mars Space Probe August 2019



The team's findings can also be applied to exoplanets, which are planets that circle stars beyond our own Sun. Some super-Earth exoplanets, which are rocky planets more massive than our own, have been proposed as "water worlds" covered with churning oceans. Could they have life? Perhaps. The potential would certainly be there. Dr. Vance and his team believe laboratory experiments and more sophisticated modeling of exotic oceans might help to find answers to these very profound questions. A billion years ago, our Moon was closer to Earth than it is now. As a result, it appeared to be a much larger object in the sky. During that ancient era, if human beings had been around to witness such a sight, it would have been possible to see the entire Moon--not merely the one near side face that we see now. A billion years ago, it took our Moon only twenty days to orbit our planet, and Earth's own day was considerably shorter--only eighteen hours long. Stupendous, almost unimaginably enormous tides, that were more than a kilometer in height, would ebb and flow every few hours. However, things changed, as the lunar orbit around our primordial planet grew ever wider and wider. Annually, Earth's Moon moves about 1.6 inches farther out into space. Currently, the lunar rate of rotation, as well as the time it takes to circle our planet, are the same. "We don't know how long the Dagwood-sandwich structure would exist. This structure represents a stable state, but various factors could mean the moon doesn't reach this stable state," Dr. Christophe Sotin said in a May 1, 2014 statement. Dr. Sotin is of the JPL.