Caught in the iron grip of the galaxy's most powerful gravitational field, a star known as S2 passed within a scant 20 billion kilometres (12.4 billion miles) of the supermassive black hole lurking at the heart of the Milky Way this past May, streaking by at an astonishing 3 percent the speed of light, or more than 25 million kilometres per hour (15 million mph).
Numbers were in close agreement with predictions made using Einstein's theory of general relativity, revealing a phenomenon known as gravitational redshift in which light from S2 is stretched to longer wavelengths in the gravitational field of the black hole.
In other words, at that speed (0.03c), it could travel from the Earth to the Moon in... one minute. And, orbit the Earth in a mere... six seconds.
(Score: 2) by LVDOVICVS on Friday July 27 2018, @04:18PM (1 child)
I don't understand how it would take a minute to travel from the Earth to the Moon, the radius of a circle, but only six seconds to travel the circumference of the same circle. Isn't that approximately six times farther in one-tenth the time?
(Score: 3, Informative) by bob_super on Friday July 27 2018, @04:26PM
The "orbit the Earth" is pretty dumb, since the star is likely bigger than the Earth, and at that speed you can't orbit the Earth.
I think they are talking about the Earth being 40 000km around the Equator, while the moon is 380 000km away.