The history of the Sun is hidden in the Moon  

A regular time capsule

A group of scientists wants to investigate the history of the Sun by studying…the Moon. The Sun, in addition to light and heat, sends to all the planets of the Solar System a continuous “rain” of charged particles and solar winds, every day for 4.5 billion years. On Earth, the ancient history of the Sun has been lost, since the incessant movement of tectonic plates has altered any effects of the Sun on our crust.

But the dead worlds keep their “records” intact and since the Moon is the closest such world to us, scientists think they should focus on it.

Any changes from lava flows or impacts from asteroids and comets, rather than being a hindrance, are a help, according to the new paper . Lava flows can block vast sites on the Moon’s surface from further interaction with the Sun. If we can dig deeper than these flows, we could have a snapshot of solar history before the lava flows.

Furthermore, collisions expose deeper layers of the crust to the surface, and we can see how long a sample has been exposed to solar radiation and use that to model the rate of cosmic ray production from the Sun over the past billion years. We can also look at the marks left by the high-energy particles as they hit the crust to get the same information.

Over time, lunar soil turns into breccia, a type of sedimentary rock. This process changes depending on the amount of solar radiation the soil receives. By comparing different samples at different depths and locations, we will be able to understand changes in the Sun’s brightness over time. Simply put, the Moon is a time capsule of the Sun’s history.