Our galaxy, along with hundreds nearby, is hurtling towards an area of space dubbed the Great Attractor. Astronomers noticed something was amiss decades ago. The Milky Way was speeding through space at more than 2 million kilometers per hour. Speeds that can’t be explained by usual universal expansion.
Astronomers have been trying to explain what the Great Attractor is, but there’s one big problem. An area called the Zone of Avoidance. It’s the part of the sky that is obscured by the Milky Way.
Using a traditional telescope is a no-go. It can’t pierce through all the light created by the countless stars in the Milky Way to see what’s on the other side.
“We’ve used a range of techniques but only radio observations have really succeeded in allowing us to see through the thickest foreground layer of dust and stars,” said University of Cape Town astronomer Renée Kraan-Korteweg.
Using CSIRO’s Parkes radio telescope, an international team of scientists found 883 galaxies. A third of them had never been seen before until now. The galaxies were found 250 million light years away from Earth. That’s sounds far, but it’s not in astronomical terms.
“We don’t actually understand what’s causing this gravitational acceleration on the Milky Way or where it’s coming from,” said lead author Professor Lister Staveley-Smith.
“We know that in this region there are a few very large collections of galaxies we call clusters or superclusters, and our whole Milky Way is moving towards them at more than two million kilometers per hour,” said Staveley-Smith.
We still don’t know what the Great Attractor exactly is, but the first step is finding out what’s out there. There are galaxies in this region, but there doesn’t appear to be enough of them to explain why the Milky Way is moving so quickly towards it.
Then again, this is the first time scientists are seeing these galaxies. Follow-up observations and surveys will only tell us more about this region, the once-hidden galaxies and help answer what the Great Attractor is.
The Parkes Observatory
Better known as ‘The Dish,’ the Parkes Observatory has been looking up into the sky for more than 50 years.
The older generation might not know its name, but they remember the images received by the massive radio telescope. During the Apollo 11 broadcast from the Moon, three antennas received the signals. But, the signal from Parkes was so good – NASA used it for nearly all of the 2.5 hour TV broadcast.
More than 50 years later, scientists still turn to the ‘The Dish’ to help make new discoveries in the final frontier.