What is a object that orbits a larger object called?

Can the moon rotate once every 18 hours? What do the solar arrays do the hubble telescope? Why did early astronomers believe the geocentric model was true? What planet is 500 degrees celsius? Why would an astronaut weigh less on the moon than earth? What element is most abundant gas in emission nebulae? How does the sun affect the movement of air? When does sunlight shine equally in the southern and northern hemisphere? What does the moon look like during a last quarter moon? How old was Yuri Gagarine's when he left? In what year was The WELL launched? What is the dark ring on a microscope? Where above the earth are most stratus clouds made of water droplets? Which can be steered a balloon or a dirigible? The moon's gravity affects what? Does Niel Armstong have any kids? Why do scientists decided where one layer of the atmosphere ended and the next one began? Is 'soir' masculine or feminine in french? What damage does it do to the eye if you look directly at the sun? How many miliseconds is in a year?