|
| A 300 megapixel photo of our Sun compiling over 150,000 individual images. (Andrew McCarthy) |
If you want to learn about the history of the Sun, then look no further than
the Moon.
That's the recommendation of a team of scientists who hope to harness future
Artemis lunar missions to help understand the life history of our home star.
The Sun has always influenced all the bodies in the Solar System. Not only
do we receive heat and light from the Sun, but also a constant rain of
high-energy particles and solar wind.
And this isn't just happening today, but has happened every single day for
the
past 4.5 billion years.
On planets like Earth, however, we've lost the ancient history of the Sun's
influence on us. The weathering from wind, the erosion from water, and the
constant cycles of plate tectonics take any alterations that the Sun might
have made on our crust and either blown it away or buried it deep within our
mantle.
But dead worlds are much better record keepers, according to a
new white paper recently appearing on the preprint journal arXiv.
And since the Moon is the nearest dead world to us, and the target of the
Artemis series of missions, we should go looking there.
Admittedly, there has been some surface activity on the Moon since its
initial formation, like lava flows and impacts from asteroids and comets.
But that activity is actually a help rather than a hindrance, according to
the white paper.
Lava flows can seal off large sections of the surface of the Moon from
further interaction with the Sun. If we are able to dig down beneath the
flows and into the deeper regolith of the Moon, we would have a snapshot in
solar history from before the lava flowed.
And while impacts do tend to mix things up, they also expose deeper layers
of the surface, giving us easy access to them.
The researchers outlined a few key quantities that we can measure from lunar
samples and how they connect to the activity of the Sun.
For example, we can look at how long a sample has been exposed to cosmic
rays and use that to model the rate of cosmic ray production from the Sun
for the past few billion years.
We can also look at tracks left by high-energy particles as they burrow into
the crust to get at that same information.
Over time lunar soil slowly transforms into breccia, and this process
changes with the amount of solar radiation. By comparing different samples
at different depths and locations we can understand the change in the Sun's
brightness over time.
According to the white paper, there's no more accessible location in the
Solar System to peer into the Sun's ancient history.
Simply put, the Moon is a solar time capsule.
This article was originally published by Universe Today. Read the
original article.