The first photo of a black hole is coming Wednesday. What are we going to see and what will we learn?

Astronomers will supposedly release the first-ever photo of a black hole on Wednesday. What's all the fuss about, and what will we learn from it?

What's a black hole?

First of all, black holes are collapsed stars with gravity so strong that even light cannot escape their grasp. One of the black holes we're expecting to get a glimpse of this week – known as Sagittarius A – is the "supermassive" one that's at the center of our Milky Way galaxy.

Supermassive black holes are millions to billions times more massive than our sun, and appear to be in the center of almost all galaxies, the National Science Foundation said.

Astronomers this week are also expected to release images of another supermassive black hole, one that's 53.5 million light-years away.

What will we see?

As its name suggests, a black hole is black, so it'll be impossible to "see" against the black backdrop of space. But nearby objects, such as the event horizon – the edge of the black hole where light can't escape – could be visible.

So the photo may show a dark blob surrounded by a ring of bright light, according to Yahoo.

But that also might be a challenge, since the black hole at the center of our galaxy is "shrouded in a thick cloud of dust and gas," Science Alert reported.

What's "taking" the photo?

As you might expect, this won't be your run-of-the-mill photo of the night sky from your smartphone. Images will come from the Event Horizon Telescope, a collection of telescopes around the world specifically designed to peer at black holes. The telescopes are in Chile, Hawaii, Arizona, Mexico, Spain and at the South Pole.

The telescope will catch whatever light it can detect from near the black hole. By combining the data from the various telescopes placed around the world, the Event Horizon Telescope has as much magnifying power as a telescope the size of the entire Earth.

What does this have to do with Einstein's theories of relativity?

The image from the black hole may give us more insight into Albert Einstein’s theory of general relativity, which he came up with in 1915. According to CNET, the shape of the black hole's event horizon could prove Einstein's theory or possibly cast new doubt upon it.

But even if it casts doubt, the finding would not necessarily mean that his theory is wrong, but it would imply that we have more physics to understand, the Event Horizon Telescope website reported.

The discovery will be unveiled Wednesday by the National Science Foundation at a 9 a.m. ET press conference.

This article originally appeared on USA TODAY: The first photo of a black hole is coming Wednesday. What are we going to see and what will we learn?