The thin dense crust of Mercury
Using data gathered by the MESSENGER spacecraft while it was in orbit around Mercury, scientists now estimate that the planet’s crust is thinner than previously believed, 16 miles thick rather than 22 miles.
The crust is also as dense as aluminum. It is also the thinnest crust, relative to the planet’s core, of any rocky planet in the solar system.
Mercury’s core is believed to occupy 60 percent of the planet’s entire volume. For comparison, Earth’s core takes up roughly 15 percent of its volume. Why is Mercury’s core so large?
“Maybe it formed closer to a normal planet and maybe a lot of the crust and mantle got stripped away by giant impacts,” Sori said. “Another idea is that maybe, when you’re forming so close to the sun, the solar winds blow away a lot of the rock and you get a large core size very early on. There’s not an answer that everyone agrees to yet.”
There appears to be a great deal of uncertainty to these conclusions, and I would not be surprised if these conclusions change with the arrival of more data.
Using data gathered by the MESSENGER spacecraft while it was in orbit around Mercury, scientists now estimate that the planet’s crust is thinner than previously believed, 16 miles thick rather than 22 miles.
The crust is also as dense as aluminum. It is also the thinnest crust, relative to the planet’s core, of any rocky planet in the solar system.
Mercury’s core is believed to occupy 60 percent of the planet’s entire volume. For comparison, Earth’s core takes up roughly 15 percent of its volume. Why is Mercury’s core so large?
“Maybe it formed closer to a normal planet and maybe a lot of the crust and mantle got stripped away by giant impacts,” Sori said. “Another idea is that maybe, when you’re forming so close to the sun, the solar winds blow away a lot of the rock and you get a large core size very early on. There’s not an answer that everyone agrees to yet.”
There appears to be a great deal of uncertainty to these conclusions, and I would not be surprised if these conclusions change with the arrival of more data.