8.1K views · 689 reactions | Why are the orbits of planets in our solar system expanding like the waistband of a midlife couch potato? It happens because the Sun’s gravitational grip gradually weakens as our star ages and loses mass. Now, a team of NASA and MIT scientists has indirectly measured this mass loss and other solar parameters by looking at changes in Mercury’s orbit. Read more: https://go.nasa.gov/2DOh1GX | NASA’s Goddard Space Flight Center | Facebook