The Great Conjunction

Skywatchers are in for an end-of-year treat. What has become known popularly as the “Christmas Star” is an especially vibrant planetary conjunction easily visible in the evening sky over the next two weeks as the bright planets Jupiter and Saturn come together, culminating on the night of Dec. 21. It’s been nearly 400 years since the planets passed this close to each other in the sky, and nearly 800 years since the alignment of Saturn and Jupiter occurred at night, as it will for 2020, allowing nearly everyone around the world to witness this “great conjunction.”

-- NASA

Jupiter and Saturn were all smiles when they ran into each other in the southwestern sky.

“Why if it isn’t Mr. Ring-a-Ding!” Jupiter shouted as his fellow planet approached. “Saturn, how the hell are you?”

“Jupiter, you bloated ball of helium! Imagine running into you here in the night sky! How long has it been?” They thoughtfully substituted an elbow bump for a handshake or embrace.

“Give me a minute,” Jupiter said. “Last time I saw you -- 1623! Am I right?”

“1623! Seems like yesterday! Well, you look good!” Saturn said cheerily, then added, perhaps tactlessly, “I see you still have that red spot.”

“Yeah, yeah, it doesn’t change very much. No one knows how I got it.”

“Is it active?”

Jupiter shrugged. “Turns out, yes.”

“You ought to see a doctor about that,” Saturn advised.

“Oh, enough about me!” Jupiter protested, changing the subject. “You -- you look great! Your rings – so shiny, lustrous! You’re the envy of the solar system!”

“Oh, this old bling? Frankly, you get up close to them, they’re just swarms of cosmic rubble, no big deal, really. So, what’s the news by you?”

“The usual. Rotating, orbiting Sol, thousand mile-an-hour ammonia windstorms, getting hit by stuff. You?”

“The same,” Saturn said.

“Let me tell you -- I got whacked by an asteroid about a dozen years ago, ouch! The thing must have been the size of the Terra in the inner rings!”

“Ooooh! That’s gonna leave a mark!”

“It kicked up quite a plume. And twelve years before that, it was a comet. Boom! Right in the flank!”

Saturn was sympathetic, but realistic. “Well, what are you going to do? You’re a big planet, you’re going to get plunked. I got dinged a few years back, too.”

“Asteroid?”

“No! Get this – a spacecraft!”

“What, made by creatures?”

“Uh-huh!”

Jupiter’s expression became severe. “Where does it stop? You hear them buzzing by, there’s got to be a limit. When the Terrans were ferrying themselves to their moon and back, who gave an eruption? But you got to respect your neighbors.”

“Absolutely. They crap on their own planet and then go bother us.”

Jupiter nodded resignedly. “Yeah, but what are you gonna do? They’re fascinated by us -- they knew who we were before they built pyramids.” The two nodded in agreement before he smiled and changed the subject. “So, how many moons do you have now?”

“Sixty-two,” Saturn replied proudly.

“Sixty-two! Well, look who’s got the big mass! Do you have pictures?”

“Yeah, yeah, here, take a look. We’ve only named fifty-three of them. You need a very high-powered telescope for some of them. They’re really just balls of ice.”

“Shh! Don’t let them hear you say that stuff,” Jupiter chastised. “They’ll think you’re not attracted to them. Besides, they’re lovely moons – not like those little brats, Deimos and Phobos.”

“That whole Mars family’s a pain. I can’t believe you have conjunctions with him.”

The two tittered as Jupiter looked at the pictures. “Oooh, this one’s nice! What a moon! So big, lovely yellow color…”

“Of, that’s Titan. You’re not supposed to have favorites,” Saturn blushed, “but, well, he’s a good moon. Rocky core, methane lakes, dunes of frozen hydrocarbon particles, all sorts of features. And his own atmosphere! I’m very proud of him. And this one…is Enceladus.”

She’s adorable.”

“Liquid water!”

“Ooooh,” Jupiter cooed. “You must be very proud.”

Saturn could not help but smile. “But she erupts in geysers. I wish she’d settle down.”

“Sooner or later they do. Wait a minute, who’s this?”

“Oh yeah. That’s Hyperion.”

“She’s –”

“Yeah, she’s nonspherical. It’s OK, you can say it.”

Jupiter could not help but be taken aback. “Really!”

“And she has an elliptical orbit, too.”

“Oh, my!” Jupiter gasped, quickly recovered. “But different isn’t wrong anymore.”

Saturn agreed. “There was a time when a non-spherical moon was seen as worse than wrong -- perverse, aberrant. And a non-elliptical orbit! Don’t start me!”

“Well, it makes no difference, as far as I’m concerned. I mean, what would you rather, that she was out somewhere in the asteroid belt, like Ceres?”

“Don’t even say it! I’d never see her again! She's my moon and I'm her planet and we exert a strong gravitational pull towards each other. That ought to be enough.”

“I agree,” Jupiter commiserated. “Besides, you know how it is. Moons start out close to you, but then they start to drift away. It happens to every planet. I guess it’s just centrifugal force.”

They nodded together, deferent to the ways of the universe. “And you?” Saturn asked eagerly. “How many?”

“Seventy-nine.”

“Seventy-nine moons? Who’s got the big mass now?! The last time I saw you, you just had the Galilean quadruplets – wait, wait, give me a minute – I can do this -- Io, Europa…”

Jupiter smiled. “So far, so good.”

“Ganymede – “

“That’s right. One more…”

“Calisto! Am I right?” Saturn asked proudly as Jupiter nodded. “How are they doing?”

“Well enough. Io’s having her first volcanic activity – fountains of lava miles high!”

“Poor thing. How old?”

“A billion years, I figure.”

“So young! Other than that, she doing alright?”

“The doctors say she’s caught between my gravitational pill and those of her larger sibs. Generates a lot of heat.”

“The middle moon’s always the most active. Say, did you hear about Pluto? Downgraded!”

“No!”

Saturn tried not to be judgmental. “I can see their point. Between you and me, he’s so damn little he ought to break free of Sol’s pull and just find an orbit through deep space, where he’d get some respect. And a better name!”

“Pluto is some kind of a dog or something, right? If he was an asteroid, he’d be Moskowitz-Lupowitz N-424 or something.”

“He’s never been on the same plane as the rest of us.”

“Can you imagine the Terran creatures sent some object to fly past him? To see what? Ice? They could have opened the refrigerator!”

“And did you listen to that disc they put on the thing they sent?”

“Chuck Berry!”

“Absolutely. Was that supposed to be the music of the spheres or something? The only song I know is Holst’s The Planets.”

“And the surface pictures! Forests, deserts, oceans”

“Planet porn,” Jupiter scoffed. “Do we post pictures of churning blue clouds of methane?”

Saturn nodded emphatically. “Exactly. And they’re so beautiful!”

The two heavenly bodies shared a quiet moment before Saturn spoke up. “So, 1623, huh?”

“Oh, yeah. That’s a long time,” Jupiter replied, animated by the memory. “Galileo’s little peepshow. Big boats all over Terra taking people across their liquid ocean. And some of them packed together in chains – what was that about?”

Saturn shrugged. “Beats me. If I judged creatures, I couldn’t do my job.”

“I agree. But what a miserable lot! Terra must be embarrassed. People in chains, famine, disease – witches! Don’t like the weather, blame a witch! Crop fails – blame a witch! Remember how they used to burn them?”

“Sure, but I’ll tell you what was even worse than 1623 -- 1226!”

“Boy, that’s a while ago! The Crusades! Genghis Khan!”

“If he were a planet, he’d have so many moons he could fill the Kuiper Belt on his own!”

“And how about 6 BC!”

“6 BC!,” Jupiter roared with laughter. “That's a ways back, but I remember! That was a riot!”

“Yeah, those three guys with the turbans. Remember how excited were they to see us?”

“Yeah -- Balthasar and Melchior racing around, gathering spices and gold and loading them onto their camels, hollering about how you and I being together meant the Son of God was being born somewhere below us!”

“Like we were a neon sign, right?” Jupiter said, laughing in agreement. “LOOK! SON OF GOD BELOW THIS SIGN! And the third one – Gaspar, wasn’t it? -- rolling over on his blanket and saying, ‘Relax, it’s just Jupiter and Saturn, go back to bed.’”

They smiled and sighed together once again.

“So, where you heading?” Saturn asked.

“That way,” Jupiter replied, indicating the southeast.

“I’m going there,” Saturn said, hitching his thumb to the northeast. “Great seeing you, but you know, can’t stop.”

Jupiter nodded. “Yeah, I gotta go – places to be, people to see.”

“Well, that’s how it is when you’re us. When will we run into each other again?”

Jupiter shrugged. “2400 or so? Somebody will figure it out.” He looked out into the vast expanse of space, where he was headed. “Well, you take care of yourself. Keep spinning!”

“And you, big guy,” Saturn replied.

And with that the two friends parted.