
Earth formed from inner-Solar-System material, study finds
A new analysis of ten isotope systems in meteorites shows Earth's building blocks came exclusively from the inner Solar System, with outer-Solar-System material contributing less than 2% of Earth's mass and possibly none at all. Jupiter's gravity likely formed a barrier that prevented material exchange between the inner and outer Solar System, implying Earth, Mars, and Vesta share a similar inner-Solar-System composition. The findings raise questions about how Earth's oceans formed if water-rich material did not come from farther out, and whether this pattern applies to Mercury and Venus as well.
