"If you lived in an omelette, and you lived on the edge of that omelette, you could measure the distance between all the pieces of mushroom in the omelette. If you were clever enough to work out how far it was to all the different parts of the omelette, you’d be able to reconstruct it."
Peering Into The Heart of Darkness
So, yesterday, S. and I were watching Doctor Who, two old episodes (The impossible planet; The Satan pit) and the story involved a black hole, and I was thinking about black holes for all the episodes.
So, this morning I searched something about black holes. In the image above you can see Sagittarius A*, a supermassive black hole (a black hole with a mass much greater than the most massive stars) in the center of Milky Way, our galaxy. Sagittarius A* is 25000 light years away from Earth, and its mass is found to be 3.61±0.32 million solar masses.
The Keck I Laser propagating, alongside the Keck II and Subaru lasers. WMKO Engineer Andrew Cooper took over 90 x 1minute exposures from near UKIRT on the summit ridge on May 26. The result has been combined into the attached image and a video. The image combines 23 exposures, each 1 minute long. During the exposure, the Keck II laser is aimed over the camera at the Milky Way’s Galactic Center. The image also shows a car driving down the summit road which appears as a stream of light. (via W. M. Keck Observatory)
Wide Field Imager view of a Milky Way look-alike, NGC 6744
This picture of the nearby galaxy NGC 6744 was taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla. The large spiral galaxy is similar to the Milky Way, making this image look like a picture postcard of our own galaxy sent from extragalactic space. The picture was created from exposures taken through four different filters that passed blue, yellow-green, red light, and the glow coming from hydrogen gas. These are shown in this picture as blue, green, orange and red, respectively. (via ESO)