Mercury's crust is thinner and more dense than conventionally believed, claims scientist

New calculations suggest Mercury has a much bigger core relative to its volume, according to University of Arizona scientist

Mercury's crust may be thinner than conventionally believed, according to a University of Arizona scientist , who made the claims following an analysis of the mathematical calculations.

Mercury is the nearest planet to the sun. Relatively small and rocky, it is difficult to collect data on the planet due to extremes of temperature. Indeed, Mercury's surface temperature can vary from -170 degrees centrigrade to almost 430 degrees because it has no atmosphere with which to retain heat.

These extremes of temperature make it difficult to extract data from using probes. Only one spacecraft has ever been able to orbit the planet and collect detailed data.

That mission ended in 2015, and the scientists who took part in it came to the conclusion that the planet's crust was around 35 kilometres (22 miles) thick.

However, a leading scientist from University of Arizona disagrees with this estimate. After using a new set of mathematical formulas, Michael Sori believes that Mercury's crust is actually just 26km (16 miles) thick.

Maybe it formed closer to a normal planet and maybe a lot of the crust and mantle got stripped away by giant impacts

In his study called "A Thin, Dense Crust for Mercury", published today, he argues that, while thinner than conventionally believed, the planet's crust is also more dense than aluminium.

To generate these findings, Sori analysed data taken from the Mercury Surface, Space Environment and Geochemistry Ranging (MESSENGER) spacecraft.

He then combined this information with a formula created by fellow planetary scientists, Isamu Matsuyama and Douglas Hemingway.

Sori's estimate provides further evidence that Mercury's crust was formed as a result of volcanic activity.

By studying the formation of the crust, it is believed that scientists can learn more about the planet's whole structure.

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

The scientist also believes that Mercury's core occupies 60 per cent of its volume. "Of the terrestrial planets, Mercury has the biggest core relative to its size," claimed Sori.

"Maybe it formed closer to a normal planet and maybe a lot of the crust and mantle got stripped away by giant impacts.

"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."

Previously, scientists believed that 11 per cent of Mercury's crusts contained rocks. But Sori said this statistic is likely to be nearer seven per cent, according to his calculations.

"The two bodies formed their crusts in very different ways, so it wasn't necessarily alarming that they didn't have the exact same percentage of rocks in their crust," he concluded.