Solar System Astronomers recently discovered that Scholz’s star passed close to the Sun 70,000 years ago. Wouldn’t its gravity have sent Oort Cloud comets raining into the inner planets?
Exoplanets, Planets, Solar System Europa’s ocean sits under a thick ice shell. If this ocean covers the moon’s solid core, does the shell rotate at a different speed?
Human Spaceflight, Robotic Spaceflight, Solar System Rusty Schweickart: From the Apollo program to the asteroid threat
The Sun The Sun has an 11-year sunspot cycle. Do we know if other stars have similar lengths, or is our star unique?
Stars Proxima Centauri is a red dwarf star, so would it appear red from the surface of an Earth-like planet in that star’s habitable zone?
