Fascinating new images have led researchers to conclude the planet Mercury is shrinking, now measuring up to 8.6 miles smaller in diameter than it was nearly four billion years ago.
According to a report released Sunday, the planet is shrinking because it is cooling.
A NASA spacecraft has shown the first complete images of the single rocky plate that encloses Mercury and whic is contracting and warping the surface into puckered ridges and cliffs.
Shrinking: Scientists say cooling has caused Mercury to shrink almost 9 miles in diameter
'It is Mercury's version of a mountain belt,' Paul Byrne, a planetary geologist at the Carnegie Institution in Washington D.C. told National Geographic. 'It would be a very dramatic landscape.'
While all planets loose heat to varying degrees, the chilling has had an unusual effect on Mercury's surface, pocked with craters and cut by ridges more than double the length of Florida.
While we can observe changes to the terrain the 800 degree Fahrenheit heat makes ever setting foot on the planet impossible.
Instead scientists watch the changes with the MESSENGER spacecraft, which has orbited the planet since 2011.
'We see the landscape literally crumpling up,' William McKinnon, professor in the Department of Earth and Planetary Sciences at St. Louis' Washington University told reporters. 'Massive slabs of rock are sliding over one another.'
Familiar surface: The planet's craggy surface is similar to that of our own moon
McKinnon added that were we able to put seismometers on the surface we could likely hear ongoing earthquakes affecting the surface.
New data gives a fuller picture of the planet's history from bombardment by asteroids to changing temperatures.
'We have the big picture now,' Byrne said.
Mars and Earth's moon have cliffs and ridges similar to Mercury's surface but with a major difference.
'Mercury is anomalous because it seems to have shrunk much more in size than the moon or Mars,' Byrne said.
The new data will help scientists understand why the planet has shrunk so much.
'It is a very impressive piece of work -- just the amount of work involved,' said Caleb Fassett, astronomy fellow at Mout Holyoke College. 'They mapped all of the faults on Mercury basically to do this.'
Old ideas: Mercury's changing size may validate the theories of 19th century European scientists
European geologists believed Earth had shrunk during the 19th century but the idea was dismissed in the 1950s and 1960s as scientists better understood how Earth's shell was not a single layer that would wrinkle but instead tectonic plates that would move independently.
However the 19th century geologist's theories about how planets shrink may be correct when applied to Mercury.
'It proves something historians always say: Previous scientists were not silly to hold ideas that we now would say aren't right,' said Naomi Oreskes, professor of the history of science at Harvard University. 'It was a plausible idea, and it held up until evidence suggested the need for something different.'
source: http://www.dailymail.co.uk/news/article-2582445/Mercury-SHRUNK-9-miles-diameter-planets-surface-continues-cool.html
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