Approaching the Black Hole

The first image in NASA's Astronomy Picture of the Day showcases an observer in empty space gazing at the Orion constellation. Orion's belt, comprising three stars, is visible on the right side of the screen. The brightest star in the sky, Sirius, lies below and to the left of Orion's belt, while Betelgeuse, a reddish star, sits above the belt.

As the animation progresses, the observer begins to approach the black hole. A strange, diffused glow appears at the center of the screen, gradually giving way to a black spot – the black hole itself. Black holes are nearly invisible because even light cannot escape their immense gravitational pull. However, they do emit faint light as they slowly evaporate, as theorized by Stephen Hawking.

As the observer draws nearer to the black hole, the original star images seem to be pushed away from it. This is due to the intense gravitational force of the black hole, which attracts and deflects starlight, redirecting it away from the observer. Only starlight that passes farther from the black hole has a chance to be drawn toward it and deflected towards the observer's eye.

Near the black hole, new, dimmer images of stars become visible. This occurs because the black hole's immense gravity has pulled another image of the stars around its far side towards the observer's eye. By connecting these secondary images to their corresponding primary images with a straight line through the center of the black hole, stars of similar color can be matched.

The computer-generated animation continues as the observer stops just 42 kilometers away from the black hole. From this proximity, the universe appears as an incredibly strange place. To explore further, one can play the movie segment titled "Approaching the black hole," then move on to "Circling the black hole at some distance" through the hypertext provided. For a deeper understanding, the American Journal of Physics has an article detailing this captivating subject.