A new study has found that the smallest planet of our solar system is even getting smaller as its radius has witnessed reduction by some 7 kilometers over the past four billion years.
The sparkling revelations have been made by the US space agency NASA after analyzing the data beamed back by its Messenger spacecraft.
The first spacecraft sent to explore Mercury was Mariner 10. The spacecraft had gathered images and data over just 45 percent of the surface during three flybys in 1974 and 1975.
However, NASA’s Messenger, which was launched in 2004 and inserted into orbit in 2011, is providing much more data and information about the planet. It is set to complete its 2,900th orbit of Mercury later this month.
Scientists Paul K. Byrne and Christian Klimczak of the Carnegie Institution of Washington used the images and topographic data of NASA’s Messenger spacecraft to build a comprehensive map of tectonic features.
The data and images showed the planet has shrunk more than what was estimated earlier. The map showed Mercury shrunk substantially as it cooled, as rock and metal that comprise its interior were expected to.
Co-author Steven A. Hauck of Case Western Reserve University says, “”With Messenger, we have now obtained images of the entire planet at high resolution and, crucially, at different angles to the sun that show features Mariner 10 could not in the 1970s.”
For studying the shrinking pattern of the planet, the researchers looked at tectonic features which result from interior cooling and surface compression. The features resemble long ribbons from above, ranging from 5 to more than 550 miles long. Scientists say, some of these are cliffs caused by thrust faults that have broken the surface and reach up to nearly 3.2 km high.
Researchers say, estimates suggest that the planet has contracted between 4.6 and 7 kilometres in radius.
“This is significantly greater than the one to maybe two kilometers reported earlier on the basis of Mariner 10 data,” Hauck said.
The findings of the study were published in the latest edition of the journal ‘Nature Geoscience Sunday’.