galaxies rotate once every billion years tagged posts

This Hubble image reveals the gigantic Pinwheel galaxy, one of the best known examples of “grand design spirals”, and its supergiant star-forming regions in unprecedented detail. The image is the largest and most detailed photo of a spiral galaxy ever released from Hubble. Credit: ESA/NASA

Astronomers have discovered that all galaxies rotate once every billion years, no matter how big they are. The Earth spinning around on its axis once gives us the length of a day, and a complete orbit of the Earth around the Sun gives us a year. “It’s not Swiss watch precision,” said Professor Gerhardt Meurer from the UWA node of the International Centre for Radio Astronomy Research (ICRAR)...