Home! Earth, the 3d planet from the Sun, formed 4.5 bya and weighs 6.58 billion trillion tons. Earth is not a perfect sphere, but an oblate spheroid, “squashed” a little at the North and South poles. The equatorial diameter is about 7,926 miles, but the polar diameter is 7,899.86 miles. Earth’s spinning molten core produces the magnetosphere, a magnetic shield around the planet which largely protects the atmosphere from being blown away by solar winds.
Visit Mercury, the smallest and innermost planet in the Solar System. Its orbit around the Sun takes 87.97 days, the shortest of all the planets in the Solar System. Named after the Roman deity Mercury, the messenger of the gods, Mercury has 'mercurial' temperature swings from extreme heat to ex...