At depths of a few thousand kilometers, the atmospheric gases of Jupiter and Saturn are so compressed by the weight of the overlying atmosphere that they liquefy. At depths of about 20,000 km in Jupiter’s atmosphere and 30,000 km in Saturn’s, the interior pressure climbs to 2 megabars and the temperature reaches 10,000 K. Under these conditions, hydrogen molecules are battered so violently that their electrons are stripped free, and the hydrogen becomes an electrical conductor like a liquid metal.