Friday, March 02, 2012

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?

4 comments:

Anonymous said...

Beautiful! I love astronomy too. The universe just fascinates me sometimes.

Got a quick question though. Did you ever have to take Calculus in high school or college? I'm sadly going to have to take that dreaded class next year to fulfill my economics minor prequisite requirements, and I'm kind of freaking out over it. Math has never been my strongest subject and intregrals and limits look like foreign, Chinese characters to me right now. My college courses don't even start until September, but I'm panicking because I think I might fail them. Any advice on how to brush up on my math skills to get ready for it? Any trigonometry involved?

Eddie Fitzgerald said...

Roberto: I never took calculus but friends who have told me they absolutely loved it. One said that it was the reward for taking trig and all the other boring math classes that led up to it.

But...if it's not your thing, then beware! Take it in a year when you have a light course load and can devote more time to it. Resist the temptation to load up on courses. See a tudor frequently from the very start, even if you have to pay for it, and even if it seems easy at first.

If there's a "bonehead" version of calculus for non-majors, maybe you could take that.

I'm a big believer in taking the minimum number of credits every semester...the minimum necessary to graduate in four years. That way you can immerse yourself in the subjects and actually become good at them. I'm also a big believer in taking core subjects and not getting sidetracked into fluff courses that are easy but waste your time and money.

Dave Carley said...

Galactic lobes were recently discovered emanating from the center of the Milky Way:
NASA Galactic Lobes



This structure is made from gamma rays, constructed from the interaction of photons and electrons. Because it is located in the center, it seems to be created from the interactions from the black hole at the center of our galaxy.

Eddie Fitzgerald said...

David: Many thanks! I'd never heard of that before!