Astronomers “shocked” by earliest known spiral galaxy
|July 19, 2012||Posted by News under Cosmology, News|
From “First spiral galaxy in early Universe stuns astronomers” (BBC News, 19 July 2012), we learn “Astronomers have spotted the earliest known spiral galaxy, dating to just three billion years after the Big Bang”:
Theories of galaxy formation held that the Universe was still too chaotic a place to allow such a perfectly formed or “grand-design” spiral to form.
It should take far longer for gravity to bring matter into thin, neat discs.
But a team reporting in Nature says the galaxy BX442 got the gravitational “kick” it needed to form a spiral from a smaller “dwarf galaxy” orbiting it.
They first spotted BX442 as the one and only spiral-looking object in a survey of 300 galaxies carried out by the Hubble space telescope, when they were shocked to see what looked to be a spiral galaxy.
Here at UD News, we have developed a little macro for “earlier than thought.” Because we hear it so often.