Trying to take a picture of even the nearest black hole is like trying to resolve a DVD on the surface of the Moon. To do so, astrophysicists will need an Earth-sized observatory. Many people are drawn to astronomy by its beautiful pictures. Who hasn't been fascinated by a glowing planetary nebulae, or the glittering sweep of a spiral galaxy? But sometimes astrophysicists study things you simply can't take a picture of.
A game-changing exoplanet light-years away might be known only by its U-shaped light curve. And, of course, black holes by their very nature discharge no light for us to see.
The black hole problem is strange. Of course, you can't see something that neither discharges nor reflects light. It is a physical impossibility. But black holes are ferocious places with vast environments of turbulent gas and extremely energized material that lights up brilliantly -- think of the gorgeous collimated jets of M87, for instance.
The loudest closest black hole (by some measurements, at least) is the Milky Way's own central supermassive black hole, Sagittarius A* ("A-star"). And we might be about to get an actual picture of its heart.
Feryal Ozel from the University of Arizona is part of the Event Horizon Telescope, and she presented its abilities on the second day of the American Astronomical Society's meeting in Kissimee, Florida. This telescope will take a picture of the innermost area of a black hole: its event horizon, where material passes the "point of no return" on its way toward being consumed.
But even for Sgr A*, the nearest black hole, trying to image this area is like trying to resolve a DVD on the surface of the Moon. To do so would need building a telescope the size of the whole Earth. But fortunately, Ozel and her team can do just that.
Silhouette of a singularity
They use a procedure called interferometry to link telescopes together from around the world to form one massive virtual dish. And by looking at millimeter wavelengths, they can peer through the flow of material swirling around the black hole to see right down into its center.
Such resolution still will be likely for only the most nearby black holes like Sgr A*. But the rich collection of information the telescope will return will shed light on other black holes as well, even if they won't return quite such spectacular imagery.
The data will allow scientists to comprehend the flow of material around black holes and even perform tests of general relativity.
The singularity that is the black hole itself will remain continually out of our sight. But seeing the scientifically precious event horizon heart of a black hole will produce enormous science. The observatory will come online in early 2017. So stick around, and before too long, we won't have to say "artist's depiction."
This post was written by Usman Abrar. To contact the writer write to firstname.lastname@example.org. Follow on Facebook