U,V▪umbra- The dark, central part of a shadow. Observers of a total solar eclipse are in the umbra of the Moon.▪U.T. (Universal Time)- Universal Time is the time kept by astronomers to eliminate the confusion of time zones. Let’s say that a particular event is predicted to occur on one of the moons of Jupiter. What time do you give for this prediction? Every astronomer on Earth would want to use same same time on their clock. That is where universal time comes in. U.T. is the time in Greenwich England. It happens to be five hours ahead of Eastern Standard Time, Four hours ahead of Eastern Daylight Time. The current Universal Time will always be found in the upper right corner of the Carpe Caelum website.▪virga-precipitation that does not reach the surface of a planet due to evaporation in a hot atmosphere. The sulfuric acid rain of Venus does not manage to reach the ground.