Hey, Sky Fans! Welcome back, and thanks, as always, for stopping by.
These last few days have been pretty exciting for the solar system, haven’t they? On top of the other news, yesterday was the 45th anniversary of the launch of Apollo 16, which carried Ken Mattingly, John Young, and Charlie Duke to the moon. Today’s the 47th anniversary of Apollo 13’s splashdown, safely bringing Jim Lovell, Fred Haise, and Jack Swigert home.
Just the other night, I was up late. One of my daughters was having a hard time sleeping, which, to paraphrase Jules Winfield, pretty much means I was having a hard time sleeping. She’s still young, and was having a bad dream. So, she tiptoed into my room and loomed over me, breathing just heavily enough to very politely scare me half to death. Just enough to make sure I wouldn’t get back to sleep again. She does this. It’s a cute age.
The curtains in her room were lit by soft moonlight. Not far away from the moon was a sharp yellow dot against the black; the planet Saturn: the hexagonal clouds one. Some hours before, NASA announced that Saturn’s moon Enceladus had some promise as a place where life could exist.
For some scale, Jupiter has four giant moons, the Galilean ones. Anyone with a pair of binoculars can see them without too much trouble. Those moons are enormous. Ganymede is bigger than the naked-eye planet Mercury. Yet, from the 400 million miles or so from your lawn to the evil Dr. Callisto’s laboratory, the moons appear only as immeasurably tiny dots lined up along Jupiter’s robust belt line.
Saturn, though, is nearly twice as far, close to a billion miles from us on average. Even its biggest moon, Titan, which is also bigger than Mercury, is tough to see. Binoculars in good skies work, though I’ve never seen it; a telescope is better. Enceladus is tiny, only about 300 miles across, far smaller than our own moon. Three hundred miles is about the distance from Albuquerque to Flagstaff, yet it’s thought to have more water on it, much more, in fact, than all of Earth’s oceans have. It’s so small, and so far that it’s impossible for most of us to see. It’s visible only through synecdoche.
NASA’s news last week was that the scientists who run their Cassini space probe, which is entering the final months of its long and amazing mission there, had discovered that the plumes of water that eject from Enceladus could be very welcoming for life, which means that the ocean beneath Enceladus’s thick and cracked layer of surface ice could also be. That same day, they announced similarly exciting news about the moon Europa, orbiting Jupiter.
I’m always struck when I see our neighbors in the sky. There’s something that seems, somehow, in some was, more inspiring than seeing far-off stars. Their light is mellower, just reflected. I guess the idea that all that light has bounced here, and bounced there, some absorbed, some not, but some of it, just enough photons, still managed to survive the trip to my eye amazes me. I like watching them move and change from one night to the next, see them more relative to to the background stars. I like to see them rise a little earlier, a little later, just like the ancients did.
Our Sun makes its own light, so it makes sense that the other stars in the sky would, too. Saturn, Jupiter, and the rest, though, are just batting light around, just like Earth does. The idea that somewhere out there, the light reflected off Earth isn’t just going off into space is something that I love to think about. Maybe there’s a retina right next door for a few of those photons to hit. Maybe (probably not) even a photon that bounced off my friend’s car, or my daughter’s window.
This news could be nothing. Just like the news from TRAPPIST-1’s planets could be nothing. We could be alone. The story could end with “…but there was nothing there.” Each time, though, we find some little change, some little shift in what we know, I can feel something bigger is on its way. Is today the day? I’ll keep looking up.
So, there we sat and talked about whatever we talk about at I-want-to-be-asleep o’clock. I thought about years ago, when we thought the only places were there could be life would be on another planet in our solar system. Then, maybe, on a planet in another star system. Now, two moons, one giant one tiny, seem like the most likely places. Beyond the maples and junipers, we could see Saturn, and Jupiter, where…, who knows. We could see own Moon, where there was once life.
Eventually, I felt her fall asleep in my arms, glad, for that little while the skies were good.
By the way, I’d like to say thanks again for reading. I’m not a religious man, so that part of this month’s holidays are lost on me. Yesterday, though, was a day that started with my matzo brei, and ended with my wife’s rosemary lamb. It’s hard to not feel fortunate and thankful for the things we have when you’re able to have that kind of day (and other non-food-related goodness). I hope everyone had a great weekend, and thanks for being a part of whatever it is I’m doing here.
Clear skies, everyone.