Uranus and Neptune

Uranus (left) and Neptune (right)

The giant planets of the outer Solar System are now referred to as the Ice Giants.  They are both blue in color and have dense and deep atmospheres similar to Jupiter and Saturn.  The temperatures are very low and wind activity is very strong, with the highest wind speeds ever recorded occurring on Neptune.   As with the other gas planets, life is unlikely to be able to live in the atmosphere or at depth in the crushing pressures and unfavorable high temperatures towards the core.   A recent idea has been postulated that organic molecules - hydrocarbons -  do form in the atmospheres of these planets, but their high mass causes them to settle towards the core.  As they do so, the hydrogen molecules are removed from the carbon and this is progressively crushed to diamond as it sinks, effectively creating diamond rain.  It finally settles out to a diamond core.
 © All images NASA

© 1999 Satellite Events Enterprises Inc.