Category Archives: astronomy

Too Cool!

Spitzer Space Telescope Does the Helix Nebula
Spitzer Space Telescope Does the Helix Nebula

This is one of the neatest visions of the Helix Nebula (a planetary nebula) that I’ve ever seen. It’s from the Spitzer Space Telescope, which looked at this remnant of a dying, Sun-like star in infrared wavelengths of light at 3.6-4.6 microns, 5.8-9 microns, and 24 microns (in blue, green, and red, respectively).
So, this image is a snapshot of various events that happened as the star’s death progressed. First, the green-blue shell is the infrared view of the first layers of gas blown off as the star began its death throes. They’ve traveled the farthest from the star. The reddish diffuse shell just inside the blue-green clouds is dust that was kicked up when the outrushing atmosphere collided with dusty comets that survived the death of the star. The comets survived the first pulse of outgassing from the star, which is a rare occurrence. As events unfolded, the cometary ices melted away, leaving behind clouds of dust to bounce around in the swirling, outrushing gas. The red ball in the center is a shell of gas that was blown away from the star as it died. And, the white dot in the center (go here to see a larger image) is what remains of the Sun-like star.

People always ask what will happen with the Sun dies. Well, it might just look like this more than 5 billion years from now!

Useful Astronomy

I’ve always had this fascination with the first people to look up at the stars. What did they think? There are records of sky observations going back some thirty thousand years, but unfortunately none of those folks wrote down their thoughts. They lived in “oral” societies, where information was passed along by the spoken word or possibly even by sign language. So, a huge body of thought is lost to us. Modern folks don’t think the same way they did back then; we live in much more complex societies, use many more complex tools, write things down, and understand far more about the universe than the first humans did.

But, at heart, we’re still human, and we can still be amazed at the sight of sunrise, or a comet in the sky, or the beauty of the stars on a winter’s night. And, amazingly, the stars do connect us to our most distant ancestors because, for the most part, the sky pretty much looks the same to us as it did to them. There are some differences, which you’d expect to see across tens of thousands of years of time. The north pole star hasn’t always been Polaris. Over the centuries, supernovae and novae have brightened dimmed in various parts of the sky. But, by and large, the stars haven’t changed much, the planets still make their trips across the sky, and the Moon goes through its monthly cycle of changes.

What did the ancients do with the sky that we do very little of today? They used it. It was their calendar. And their timekeeper. Day followed night, months are made of weeks, and weeks become years. So, the sky was a tool—a very practical one that had implications for survival. Oh, sure, today we can look at the sky and know that it’s day or night, but how many of us know the star patterns for each season? How many of us chart the lunar months?

The Blanchard Bone Plaque: an early lunar calendar?
The Blanchard Bone Plaque: an early lunar calendar?

Back in “the day” the changing phases of the Moon were a handy way to keep track of time’s passage, and, for women, the monthly cycle of fertility. It may well be that women were humanity’s first time and calendar keepers, simply out of the necessity to know and predict their fertile times.

Beyond the very practical uses of the sky, I still wonder though, what did the first humans think of those shiny things in the sky? Was the view of the universe the birth of our cosmic consciousness? Of our feelings of mysticism (since our earliest ancestors had NO way to explain what they saw)? Interesting things to ponder.