In 2006, the International Astronomical Union decided that Pluto was not a planet in the Earth's solar system. Pluto was named a dwarf planet after a discovery of a similar-sized object deeper in the Kuiper belt, which w... More »

www.reference.com Science Astronomy Planets

Jupiter is the largest planet in the solar system. It is approximately 1,120 percent larger than planet Earth and has an estimated radius of 43,441 miles. More »

www.reference.com Science Astronomy Planets

Using a formula that astrophysicist Greg Laughlin had created, the planets have been given values in terms of currency. The Earth is valued at five quadrillion dollars, as of February 2011, making it the most expensive a... More »

www.reference.com Science Astronomy

The smallest planet in the solar system, according to the International Astronomical Union's classification, is Mercury, with a radius of approximately 1,516 miles, which is 38 percent the size of Earth. The next smalles... More »

www.reference.com Science Astronomy Planets

In 2006, the International Astronomical Union redefined the criteria for what qualifies as a planet, causing Pluto to lose its designation as such. As of 2014, Pluto is considered one of five dwarf planets, with the othe... More »

In 2006, the International Astronomical Union changed Pluto's classification from a planet to a dwarf planet because the planet has not cleared its orbit of other objects. When a planet clears its orbit, all other object... More »

Mercury is the smallest planet in our solar system; Jupiter is the largest.Pluto was once considered to be the smallest planet, but since Pluto is no longer thought to be a planet, Mercury now takes the title. More »