Radio telescope sees the sky in 20 primary colors

A state-of-the-art radio telescope in the West Australian outback has produced a picture of the night sky as it would appear to the human eye – if people could see in radio waves and 20 primary colors instead of three, that is. It's part of the GaLactic and Extragalactic All-sky MWA (GLEAM) survey being conducted by the US$50 million Murchison Widefield Array (MWA) telescope to gain a better understanding of the distant universe.

GLEAM is one of the biggest large-scale, high-resolution surveys of the radio sky at frequencies from 70 to 230 MHz, and includes 300,000 galaxies. Its goal is to look at the heavily-redshifted parts of the distant, early universe and to study its biggest road accidents – when clusters of galaxies collide – as well as the formation and deaths of supermassive black holes. It's hoped that these observations will provide new and unexpected insights for astrophysicists.

To conduct this survey, the researchers used the MWA radio telescope near Geraldton, Australia. Operational since 2013, it's the first of the Square Kilometre Array (SKA) telescopes being built by the four-nation SKA Organisation based at the Jodrell Bank Observatory near Manchester, UK. The other two primary arrays are being built in Australia and South Africa with other arrays being added. Eventually SKA will form a single gigantic telescope of hundreds of thousands of antennae and have an area of a square kilometer (10,764,000 sq ft).

The resolution of the MWA alone is such that if the data collected for the GLEAM survey could be seen by the human eye, it would be impossible to describe because it would include almost seven times as many primary colors than we can perceive. The combinations from these would make for an unbelievably large box of crayons.

"The human eye sees by comparing brightness in three different primary colors – red, green and blue," says Natasha Hurley-Walker of Curtin University. "GLEAM does rather better than that, viewing the sky in each of 20 primary colors. That's much better than we humans can manage, and it even beats the very best in the animal kingdom, the mantis shrimp, which can see 12 different primary colors."

The research was published in Monthly Notices of the Royal Astronomical Society (PDF)

Source: Royal Astronomical Society