Like humans, our Sun loses mass as it ages, weakening its gravitational pull. To study the dynamics of our aging star, researchers have enlisted Mercury, the smallest, innermost planet in the solar system. Mercury’s proximity to the Sun and small size make it exquisitely sensitive to the dynamics of the Sun and its gravitational pull.
Now, a team of scientists has indirectly measured this mass loss and other solar parameters by looking at changes in Mercury’s orbit. The new values improve upon earlier predictions by reducing the amount of uncertainty and this new estimate of the rate of solar mass loss represents one of the first times this value has been constrained based on observations rather than theoretical calculations.
Seen here is Mercury backdropped by our Sun in an image taken by the Solar Dynamics Observatory.