Traces of ancient nitrogen could date our magnetic field. The Moon's soil preserves gases from the ancient Earth's atmosphere, say scientists who have studied results from the Apollo missions.
The discovery hints that our planet's magnetic field switched on about 3.9 billion years ago. This in turn points to when life began on Earth, as the magnetic field protects us from a hail of DNA-damaging particles from space.
The discovery hints that our planet's magnetic field switched on about 3.9 billion years ago. This in turn points to when life began on Earth, as the magnetic field protects us from a hail of DNA-damaging particles from space.
