what is the composition of the planets? Are they originally the same but happen to change due to radiation from the sun over the life of the solar system?? and one more question are all the terrestrial (inner) planets are exactly the same size??? thanks!
2007-02-20 12:32:09 · 2 answers · asked by ceec 4 in Science & Mathematics ➔ Astronomy & Space
The inner terrestrial planets (Mercury, Venus, Earth and Mars) are, of course, mostly made of rock. That is why they are called terrestrial planets - terrestrial means made of earth. The effects of the sun's radiation caused Mercury to have no atmosphere, Venus to be covered in sulfuric acid clouds, Earth to have liquid water and Mars to have little atmosphere or water. They were never the same size.
The outer planets (Jupiter, Saturn, Uranus and Neptune) are all gas giants which are mostly made of hydrogen and helium with some methane in Uranus' and Neptune's clouds. That's because they were all large enough and far enough from the sun to hold onto there gases. Pluto, though no longer a planet but a dwarf planet, is composed of mainly ices and rocks.
To get all the facts on the planets click on the following: http://www.solarviews.com/eng/ then click on the planet you want information about.
2007-02-20 13:56:09 · answer #1 · answered by Twizard113 5 · 1⤊ 0⤋
It varies hugely, as does their size. Enter their names into the Google or Wikipedia websites; get recent Astronomy books from the library.
2007-02-20 21:20:59 · answer #2 · answered by CLICKHEREx 5 · 1⤊ 0⤋