Genesis

In 2001, NASA launched its Genesis probe to capture and bring to Earth particles of the solar wind. Genesis crashed in Utah in 2004, but enough of the pristine material survived to support two separate scientific studies.

Both studies suggest Earth was not formed from the original disk of gas and dust that orbited the Sun, as has been assumed. Differences in the abundances of isotopes of nitrogen and oxygen in the Earth and the solar wind suggest there was an intermediate step that changed the composition of the planetary disk before Earth formed.

Scientists have theories about what may have happened, but further work will be needed to work out exactly what caused the change.