For at least a billion years of the distant past, Earth should have been frozen over but wasn't. Scientists thought they knew why, but a new modeling study has debunked that long-accepted scenario.
The plasma balls, twice as massive as the planet Mars, are zooming so fast through space that it would take only 30 minutes for them to travel from Earth to the moon.
When a star passes within a certain distance of a black hole, the stellar material gets stretched and compressed -- or "spaghettified" -- as the black hole swallows it.