Image of Milky Way’s black hole marks new era in space science

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• Judy Woodruff:

  For decades, scientists have believed there is a black hole at the center of our galaxy, the Milky Way.

  Yesterday, for the first time, they released a photograph of it, an astonishing sight. Its shadow is surrounded by light that is being bent by immense gravity coming from the black hole. And it is just about 27,000 light years away from Earth.

  Miles O'Brien is here to explain some of the mysteries around all this.

  So, Miles, tell us, what is the significance of this image?

• Miles O’Brien:

  Judy, it's our black hole.

  We have seen a picture of a black hole before. The same team delivered a picture of a much larger black hole, M87, in 2019. But this one is at the center of our galaxy. And while it look — might look kind of benign there, there's a lot going on there. The gas is spinning around that black hole at impossibly difficult speeds to comprehend.

  It has a mass that is four million times our sun. And the researchers were saying that, as they were looking at it, they could see it moving in minutes' time. They described it as burbling and gurgling. So it's a crazy place to be.

  If you and I were there at the edge of that black hole and set foot in it, we would be spaghettified. So, it's kind of a mean place in our galaxy, kind of a tough neighborhood, but important for everything that is around us and makes us who we are.

• Judy Woodruff:

  How were they able to get this image in the first place.

• Miles O’Brien:

  They have a telescope the size of Earth.

  So, I know that doesn't sound logical, but, basically, what they did was, they connected eight telescopes all over the planet, in pairs, and made sure they took observations at exactly the right moment, synchronized with atomic clocks. And then what they did was, they compiled all that data, collated all that information, and then used an algorithm to sort of fill in the gaps.

  So it's kind of like you can imagine a piano keyboard with some keys missing. If you can fill in enough of those keys. You can figure out the tune. And so, basically, they figured out the tune using computational techniques that had never been done before.

  It's quite — quite an amazing accomplishment of engineering.

• Judy Woodruff:

  And for the scientist, Miles, what makes this so important, so fascinating to them? I mean, do we worry about Earth getting sucked into this black hole?

• Miles O’Brien:

  No, we're in a safe neighborhood. Don't worry about that one.

  But it is fascinating for a couple of things. First of all, this is probably the strongest proof yet of Einstein's theory of relativity, which goes back to 1915. He theorized that these things existed. And then, for the longest time, we looked and looked and didn't see them. In 1974, scientists found the spot where it was likely to be.

  And now we have finally see it — seen it. And so that gives us this amazing validation of a scientific theory, in addition to being pretty darn cool on top of that.

  The other thing that they found that was interesting is that it matched, in many ways, the image of M87, the other black hole that they imaged. It has that same doughnut pattern. So, that tells them that what they saw initially was not a fluke, not just a coincidence. And now they say they have seen an extraordinarily big black hole, an M87, and now they have looked at ours, and it's kind of a more run-of-the-mill black hole.

• Judy Woodruff:

  And so now that these scientists have this, Miles, what's next? What do they next want to do?

• Miles O’Brien:

  Well, we have got the selfie. Up next is the movie.

  They're going to try to expand the number of telescopes on the surface of the Earth, so they can have another opportunity to image this black hole and others in greater detail, enough detail to capture the motion.

  Basically, the time exposure was long enough that the motion around it, the gas that was spinning around that black hole, was blurred. It's just like shooting a waterfall in a time exposure.

  So, with a few more telescopes on the surface of Earth, they should be able to freeze the action as it were and create movies. And then maybe, someday, they hope, we can put interferometers, these kinds of paired telescopes, into space, which will be, of course, much farther apart, and which would create a much bigger lens virtually, and who knows what we will find then.

• Judy Woodruff:

  Miles O'Brien, thanks very much.

• Miles O’Brien:

  You're welcome, Judy.