Not too long ago the Earth had a near miss fly by of a big rock. Apparently it came out of our “blind spot” from behind the Sun.
So what else might be lurking in our blind spots? And what are the big blind spots?
Big local blind spot: Other side of the sun. There could be some huge space ship orbiting the Sun directly opposite the Earth and we would never know right? Unless a space probe or something happened to look for it.
Big galactic blind spot: Isn’t there a blind spot in the center of the Milky Way Galaxy? I don’t know how big it is, but we cant see through the very center right? It is too dense? Is it possible that there is a galaxy or something closer then the Great Galaxy NGC 224 in Andromeda, but we don’t see it because it is blocked from view by the center of the Milky Way?
Sure. The dwarf galaxy in Sagittarius that they found a few years ago was obscured by the center of the Milky Way. That galaxy is colliding with our galaxy, but of course, it’s a long long way off.
We know a little bit about what’s on the other side of the Sun, matching the Earth orbit, because of the effect on other planets. Plus, our orbit is not quite circular, so we get an occasional glimpse.
The Astronomy Picture of the Day for yesterday had a nice picture of a “molecular cloud” that blacks out the stars behind it–but we can see some of them fine in infrared. One of the links on that page take you to an infrared view of the same area of the sky.
You’re correct that the center of the galaxy is hard to see with visible light. Fortunately, much more is revealed at X-Ray, Infrared and Radio frequencies. Here’s an IR closeup of the innermost lightyear of the Milky way, including the location of its’ 2 million solar-mass black hole.
