This video shows how fictional planets from books, TV, film, and video games compare in size, from the impossibly small to the unfathomably big. The post Comparing the Sizes of Fictional Planets ...

A neutron star is the densest object astronomers can observe directly, crushing half a million times Earth's mass into a sphere about 12 miles across, or similar in size to Manhattan Island, as ...

NASA's Space Launch System is built to return astronauts to the moon. Photos and one chart show how it compares to other rockets in size and strength.

This clever size comparison shows how "large" different time scales are by translating them into cubes of space with definitive length measurements.

This video shows how fictional planets from books, TV, film, and video games compare in size, from the impossibly small to the unfathomably big.