Scientists say that the moon provided protection for our infant planet billions of years ago.
- The moon may still control the Earth's tides. But billions of years ago when the Earth was a newly formed planet, the moon may have also been somewhat of an early Earth guardian. Four billion years ago, the sun was in its infancy and was much more active than it is today with extremely powerful solar flares reaching their tendrils out towards the planets of our solar system. These flares and the resulting solar winds probably could have cooked all the atmosphere out of the Earth, but they didn't.
And scientists now believe that the moon and the magnetic field it used to have could be why. The moon was once closer to Earth, a lot closer, only around 80,000 miles versus today's 238,900. And at that distance, the Earth and the moon's magnetic fields would have been connected, which could have shielded the Earth, at least somewhat, from those dangerous solar winds. But maybe even more interestingly, the researchers discovered that at that distance the moon and Earth could have exchanged atmosphere, possibly solving the puzzle as to why astronauts found nitrogen in lunar soil.