Gravity is usually presented as the most familiar of nature’s forces, the quiet background pull that keeps feet on sidewalks ...
Gravity used to be the most down-to-earth of ideas, the thing that kept apples falling and planets in line. Now a growing ...
New simulations examine whether the seven planets in the TRAPPIST-1 system could host moons, showing that only small, close-orbiting moons could remain stable over long periods ...