The planetsTheplanets Brandon DysonBrandonDyson Mercury whizzes around theMercurywhizzesaroundthe sun at 30 miles per second.sunat30milespersecond. The surface of mercury is veryThesurfaceofmercuryisvery similar to our moon.similartoourmoon. VenusVenus EarthEarth • II ff you weighed 70 poundsyouweighed70pounds (32(32 kg)kg) on the Earth, youontheEarth,you would weigh about 27wouldweighabout27 pounds [12 kg] on mars.pounds[12kg]onmars. • Mars excites scientistsMarsexcitesscientists