Heading up to Fort Davis, TX from the Big Bend area makes sense if you have reservations for starwatching at the McDonald Observatory (a campus of the University of Texas at Austin), which we did. But it seemed very bad luck to get there at the same time the moon reached its full phase. Until we got there.
Upon arriving for McDonald’s “Star Party,” we and over 100 other guests were ushered into a one-hour informative theatre discussion about all things Lunar, which was great fun. A humorously-gifted researcher led the conversation on topics like “Why is it we only see one side – the lit surface with the familiar craters and ‘seas’ — of the moon’s surface, never the Dark Side?” (because the moon is in synchronous orbit with earth and always turns her lit side to us), and “What are the relative ages of the moon’s various ‘seas’ and craters?” (they range from one to four and a half billion years old. This confirms that the moon is almost the same age as the earth, having been formed from a large space object that collided with earth and combined with some of its fragments to form the moon we know). We now know a lot more about the moon’s Seas of Tranquility, Serenity and Crises, and the craters Tycho and Langrenus than before, and why the Apollo Moon Missions landed where they did.
At 7pm, the crowd went outside for a brief presentation about the constellations in the night sky. The moon had not risen yet, so the clarity of the stars was brilliant and not yet dimmed by lunar light. Even the Milky Way was visible. For those of us who can never find Cassiopeia, Pegasus or Orion up there, we had some mental Aha’s and think we can now find them when we are home on the farm. After the moon rose, we moved on to the telescopes, which number into the dozens at MacDonald. We got to see the Nebula in Orion’s Sword, Venus in her brightest phase, and several open-star clusters whose images are so far away that we were viewing what state they were in, some 1438 years ago (they’re 380 trillion miles away). We skipped the close-up of the moon’s surface, as the line to see it was about 50 people long and the temperature outside had sunk into the high 40’s.
It’s hard to keep a perspective on how large the cosmos is, but the rate of change is quite like the geologic calendar. Several of the stars visible in the sky have an orange cast, meaning that they are Red Giants (a star in decay, getting ready to explode and disappear). Our own sun will turn into a Red Giant in approx. five billion years. If earth and humans survive that long, we’ll have to find somewhere else in another galaxy to live by then, as our own galaxy will be annihilated by the explosion when the sun goes. So, earth is just about halfway through her life cycle. Fascinating.