[Update: My apologies: due to a cut-and-paste error, I had mistakenly listed the perihelion distance as the average distance of the Earth to the Sun (147 versus 149 ...

Question: How is the Sun’s gravity strong enough to hold distant planets like Jupiter and Saturn in orbit, but not strong enough to have already swallowed Mercury? Answer: To understand this, first, ...

An overhead view of SpaceX's Starship on the launch pad ahead of its planned orbital test flight. SpaceX is gearing up for a huge milestone: the first orbital-velocity launch of its combined Super ...

Edited to add: I have taken the topic of this post and logically continued it in a post about Pluto. Every now and again I get an email from someone who tries to tell me that the moon orbits the Sun ...

Why is Voyager 1 travelling at 17 km/s? originally appeared on Quora: the place to gain and share knowledge, empowering people to learn from others and better understand the world. Answer by Robert ...