Satellites orbit the earth at a speed of 28,000 kmph.
Satellites that are further away actually travel slower. The International Space Station has a Low Earth Orbit, about 400 kilometers (250 miles) above the earth's surface. Objects orbiting at that altitude travel about 28,000 kilometers per hour (17,500 miles per hour).
At the center of the sun, nuclear fusion converts hydrogen into helium, energy, and neutrinos. Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons).