Until now, all our knowledge of black holes has come from theory and indirect observations of the effect they have on the space around them. But now scientists are getting ready to take their first picture of these enigmatic phenomena.
The Event Horizon Telescope will be a global network of 50 radio telescopes all working together to create an Earth-sized virtual telescope. The network will include many of astronomy’s radio telescope A-listers.
As well as the Submillimeter Telescope on Mt. Graham in Arizona, telescopes on Mauna Kea in Hawaii, the Combined Array for Research in Millimeter-wave Astronomy in California and the Atacama Large Millimetre Array (ALMA) in Chile will be bending its not inconsiderable talents to the task. The array will eventually include several radio telescopes in Europe, a 10-meter dish at the South Pole and a 15-meter antenna atop a 15,000-foot peak in Mexico.
Their task will be to capture an image of the black hole hiding at the centre of our galaxy, the Milky Way. Which isn’t as easy as it sounds.
Although classed as a supermassive black hole that weighs in at an impressive 4 million times the mass of our Sun, from Earth it would appear to be about the same size as a grapefruit on the surface of the Moon. By their very nature, which prevents anything (including light) from escaping, black holes are impossible to image directly. The Event Horizon Telescope, which does what it says on the tin, will photograph the swirling mass of matter and energy that is sucked like water through a plughole. It will look for the point at which the black holes gravity prevents anything from escaping – called the event horizon. This will give scientists an outline of the black hole.
Astronomers, physicists and scientists from across the world will convene in Tucson, Arizona on January 18 to discuss the endeavour.