Explore The Strange Lake

The proto-planets were not only too small, but also far too hot, to keep hold of the volatile gases that were abundant in the nebula: hydrogen and helium. This is why terrestrial planets (Mercury, Venus, Earth and Mars) are composed of metals or silicate mantles. The atmospheres of these planets are either extremely thin or absent altogether. On the other hand, because the Jovian planets (Jupiter, Saturn, Uranus, Neptune) were distant from the conflagration, they were cool enough to accumulate these gases. These planets are primarily made up of hydrogen, helium, methane and ammonia, and are commonly labeled gas giants.