Monthly Archives: June 2009

stargazing, stargazing equipment

Friday Musings

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Stargazing

Summer is almost here (for those of us in the Northern climes) and I imagine a lot of folks will head out for some star gazing while the weather’s good. Where we currently live, stargazing also means mosquito-slapping time. No sooner do you get the scope set up than the little bloodsuckers show up for a snack. I remember back in 2001 we were out doing some Mars gazing in the back yard. I had set up my scope and apparently an APB had gone out to the mosquito community — they were swarming in! So, I decided to break out the mosquito coils. If you haven’t seen these things before, they are some sort of clay material that has a mosquito repellent baked into it. You set them on fire and they send up smoke and supposedly ward away the skeeters.

Since the little pests were pretty numerous, I set up five or six coils around the area where I had the scope. We proceeded to check out Mars and some other cool sites, and the coils worked pretty well. It must have looked pretty funny to the neighbors to see us out there with a scope aimed at the sky and what looked like burnt offerings sending little coils of smoke up around us. Wonder if they thought we were appeasing the Mars gods.

But, those are the kinds of things you do when you go stargazing. You slap on bug spray (or Avon’s Skin so Soft — apparently it wards away bugs, too, so there’s a lesson there somewhere), you bring a jacket for when it cools down. You bring your favorite beverage, some food, music, and oh yeah — the star charts. If you’re lucky enough to have a GoTo telescope (with computer, essentially), you use the star charts as backup. It’s a great thing, star gazing. And, you don’t even need all that stuff. You can just do it with the old Mark I eyeballs… oh, and some skeeter repellent.

astrocast.tv, galaxies, galaxy interactions

The Cosmic Dance

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Galactic Minuets

Yesterday I talked about galaxy mergers and acquisitions, the subject of my latest segment on Astrocast.tv. These scenes fascinate me because galaxies are not exactly tiptoing through the tulips as they interact with each other.

Think of the sheer amount of mass involved!  For the Milky Way, you’re talking about the mass of what, somewhere between 300-400 billion stars.  If every star in the galaxy had the same mass as the Sun — which has a mass of 1.9 x 1030 kilograms — you’re talking about a LOT of mass. Of course, not every star is the mass of the Sun — some are more massive, some are less massive. And, of course, we have that pesky massive black hole at the center, and huge amounts of interstellar gas and dust also poking around the space lanes.

When two galaxies interact, however, that mass doesn’t all clash together in a huge crash.  Stars aren’t necessarily colliding with each other, although the action of the merger does compress the interstellar gas and dust, and sets off waves of star formation. But, all of that mass exerts a gravitational influence, which is the main “actor” in a galaxy collision.  That influence is what tears out streams of gas and dust from interacting galaxies, and reshapes the morphology (the shape) of all the galaxies doing the interacting.  While a galaxy interaction may look graceful in the images we see from HST and Spitzer and other observatories, it’s quite a massive and impressive undertaking.

To understand how these collisions and interactions take place, astronomers are creating impressive computer models. These get turned into animations that allow us to follow the galactic dance from start to finish, many many times faster than it happens in real life.  I used one from a scientist named John Dubinksi in my segment (see it below) to show the upcoming Milky Way/Andromeda Galaxy interaction, which will happen in our far future. Check it out!  And, head over to Astrocast.tv to see the rest of this month’s space news show!