NEW DISCOVERIES IN ASTRONOMY

There's (above) the good 'ol Milky Way. Not much new to say about it, you say? Just the opposite. So much has been discovered about it in the last year and a half that it's doubtful that anyone will regard it in the same way again.

For one thing, what you see in the sky is not the disk of the galaxy seen edge on. Actually, that's not visible to us...too many dust clouds in the way. What you see in the night sky is an arm of the galactic pinwheel that's between us and the main part of the disk.

  We're on a spur (above) of the Carina-Sagittarius Arm...or is it the Orion Arm? I can't remember. Anyway, the the band you see in the night sky is that arm, not the denser part of the galactic disk.

I'd imagine that some part of the Earth should be able to see the arm on the other side of  us, the Perseus Arm, but maybe not. You never hear about a second band in the sky. Maybe it's always daylight here when we face that arm, I'm not sure.

Recently it became apparent that we're a bar galaxy (above). We're also a spiral, but the spiral emanates from either end of the bar, not from the center of the pinwheel. Nobody knows what caused the bar.

Our own galaxy is surrounded by 20-25 dwarf galaxies. Two of them are colliding with us at this very moment, but they're small and don't have much of an influence on things. I haven't been able to find a good graphic to illustrate this, but here's (above) a picture showing the impact of a dwarf galaxy colliding with our galactic neighbor, Andromeda.  Look at the hole that's been opened up in Andromeda's outer ring.

 Talking about rings, our galaxy is now known to be surrounded by a ring of stars.  It's believed to have been caused by a collision with a large galaxy several billion years ago.

I added this one (above) after receiving a comment about it from David Carley. This is an artist's rendering of a ballooning some 25,000 light years tall, above and below the galactic plane. The bubbles appear to be made up of gamma rays, possibly from the black hole at the galaxy's center.

Here (above) are the stars at the center of our own galaxy. They're orbiting a super massive black hole. It may be only the size of our Earth, but it's a million times as massive. The stars whirl around it at super speed...3 million miles an hour...but oddly enough, only a few are sucked into it. In fact, against all odds, this has been shown to be a  fertile area for star formation. Nobody knows why. Many will remain in orbit, but an equal number will be cast out at blinding speed, becoming rogue stars.  Rogues sometimes have tails like comets.

Nifty, huh?