Monthly Archives: September 2006

General

Where in the Cosmos do You Want to Go?

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Distant black hole, courtesy National Observatory of Japan, Subaru Telescope.
Distant black hole, courtesy National Observatory of Japan, Subaru Telescope.

I’ve always wanted to be a space traveler, ever since I was a kid. The first place I remember wanting to visit was Saturn because I saw a picture of it in a book. It was such an alien-looking place.

Later on, as I grew older, I focused on Mars. Not sure why, but it was a great kids’ game to play “search for monsters on Mars” in the fields near our house. When I outgrew that it was the mid-60s and NASA was sending people in orbit around Earth and testing for the Apollo missions. Then I guess I wanted to go to the Moon.

Lately, I’ve been doing more work (writing and editing) about objects out as far in the universe as we can detect. These objects are galaxies, and some of them exist at a time when the universe was perhaps 700 to 800 thousand years old. That’s pretty darned early for a galaxy, given the current state of thought about galaxy evolution. But, if we’re seeing them that far back, then we’ll have to adjust our theories about how and when galaxies first formed. That’s the way science works. You observe it, then you explain it.

There are also black holes out there, not quite as far as the most distant galaxy, but darned close.

So, now I want to go to the most distant reaches of the universe and sample what happened back at the time when those distant galaxies and that black hole formed. Because, as you know, farther out in space takes you further back in time.

Of course, the best way for me to explore that era is to follow along as astronomers look farther out there, searching for the birth of the universe 13.7 billion years ago. It’s amazing to me, as that little kid who couldn’t wait to get to Saturn, that we can now see so far out in the cosmos.

So, where do YOU want to go?

astronomy

Seven Sisters

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Pleiades courtesy the Cassini spacecraft
Pleiades courtesy the Cassini spacecraft

Well this is kind of cool. The Cassini spacecraft orbiting Saturn took a fabulous view of the Pleiades as a “calibration” test for its camera electronics.

You can see some of the nebulosity that makes up the reflection nebula around several of the hundreds of stars that make up the Pleiades. It’s a nice, clear shot that I imagine lots of amateur astrophoto enthusiasts would love to get.

The Pleaides is one of my favorite clusters to watch, and every year I await its appearance in our autumn skies. It’s such a famous cluster and many cultures have stories about it in their star-lore. A few years ago I wrote a planetarium show that included the lore of the Pleiades in one section and I had a blast digging out stories like the one about the hen and her chicks, the seven sisters, the seven maidens, the little eyes of the heavens, the herd of camels, the Japanese name “Subaru,” and many, many others. One of the best write-ups was in a book called Burnham’s Celestial Handbook, Vol. 3, where the author compiled a culturally rich guide to this cluster. While the book is in need of updating with some more recent scientific discoveries, it’s still a treasure trove of information.

The Pleiades come in for a LOT of attention from fringe believers who think that some ancient civilization is visiting us from the Pleiades and bringing “enlightenment” and other useful goodies like using mind energy to go into other realms. It’s all very amusing, and useful to distinguish people who are interested in science from those who will believe anything if somebody plasters a mysterious astronomy-sounding name on it.

Truth is, the Pleiades are all hot young blue stars that formed sometime over the last 100 million years is too young for a star to have formed any planets around it (provided there’s anything left over from the starbirth sequence to form planets). So, if there’s a planet out there full of loving, helpful beings who are beaming their thought energy toward us, nobody’s seen it yet. The evidence just isn’t there.

This doesn’t mean the Pleiades aren’t an interesting bunch to study. There ARE brown dwarfs among the Pleiades stars, but these aren’t planets. They’re substellar objects that are somewhere between a giant planet and a small star, and they do NOT have nuclear fusion at their cores (as stars do). There are also white dwarfs in the cluster, which seems a little strange for such a young cluster. Most white dwarfs take longer than the life of the Pleiades to evolve. But, these white dwarfs could well be the remains of very massive stars that are born hot, live fast, die young, and leave shrunken little bodies behind to glow for millions or billions of years. Bad news for Pleiadeans believers: those stars would not have lived long enough to evolve planets with life on them either, or the planets would have been destroyed when the original stars lost much of their mass in old age. But, great news for astronomers, since this cluster gives us a great testbed to study stars at both ends of the age spectrum and categorize their chemical makeup and how they influence space around them!