Changes in the orbit of Mercury -- the planet closest to the Sun in the solar system -- has demonstrated the repercussions of an ageing Sun. As a result, the orbits of planets in the solar system are expanding. For long, scientists have studied Mercury’s motion, and have also charted a road map of Mercury’s orbit, called “ephemeris” to study its closest point to the Sun and its farthest point from the Sun. Other factors that could change Mercury’s orbit include Albert Einstein’s theory of general relativity, which proves that as a result of the Sun’s own gravity, it is capable of warping space time, causing a shift in Mercury’s orbit. The Sun’s interior structure and dynamics, one of which is its oblateness -- a measure of how much it bulges at the middle -- rather than being a perfect sphere, can also impact Mercury’s orbit.

Source: Hindustan Times January 22, 2018 10:18 UTC