We May Have Jupiter To Thank For the Nitrogen In Earth's Atmosphere 46
An anonymous reader writes: Nitrogen makes up about 78% of the Earth's atmosphere. It's also the 4th most abundant element in the human body. But where did all the nitrogen on Earth come from? Scientists aren't sure, but they have a new theory. Back when the solar system was just a protoplanetary disk, the ice orbiting the early Sun included ammonia, which has a nitrogen atom and three hydrogen atoms. But there needed to be a way for the nitrogen to get to the developing Earth. That's where Jupiter comes in. During its theorized Grand Tack, where it plunged into the inner solar system and then retreated outward again, it created shock waves in the dust and ice cloud surrounding the sun. These shock waves caused gentle heating of the ammonia ice, which allowed it to melt and react with chromium-bearing metal to form a mineral called carlsbergite. New research (abstract) suggests this mineral was then present when the Earth's accretion happened, supplying much of the nitrogen we would eventually need for life.