Dark matter is the mysterious substance that accounts for most of the universe’s mass, but it doesn’t interact with light, making it effectively invisible. So how do astronomers know dark matter exists?
NASA’s Psyche probe will launch to a metal asteroid on Oct. 12 — and scientists are sneaking a peek at the target
The James Webb Space Telescope and the now-retired SOFIA telescope, impressive as they may be, have hit their limits when it comes to studying Psyche.