NOVA: "The Planets: Ice Worlds" (BBC Studios, Tencent Penguin Pictures, The Open University, PBS, 2019)

by Mark Gabrish Conlan • Copyright © 2023 by Mark Gabrish Conlan • All rights reserved

Shortly after the Lifetime movie ended I got on the computer and watched an online stream of the final episode of the PBS series NOVA on “The Planets” – a mini-series within the overall NOVA series from 2019 (actually produced by the BBC) on the solar system and the various probes the National Aeronautics and Space Administration (NASA) have launched and sent out to explore its outer regions. This episode was called “Ice Worlds” and dealt with Uranus (pronounced “YOUR-uh-nus” instead of “Your-A-nus,” as was standard when I went to school until people started thinking it sounded too much like “your anus” to be acceptable), Neptune and Pluto. It also dealt with the NASA Voyager II probe, launched in 1977 after NASA’s scientists realized in 1974 that three years from then there’d be a rare (only every 200 years!) alignment of the planets that would allow a probe to visit them in turn and use the gravity of each to bounce the spacecraft to the next; and New Horizons, launched in 2006 specifically to explore Pluto and the so-called “Kuiper Belt,” which appears to be a second asteroid belt of some kind beyond Pluto the way the first asteroid belt lies between Mars and Jupiter and demarcates the boundary between the inner and outer solar systems. The show featured some of the same interviewees as previous episodes, including Dr. Fran Bagenal, professor of astrophysical and planetary sciences at the University of Colorado (and a woman who wears her lack of conventional attractiveness with an obvious if rather quirky sense of pride) and Noah Hammond of the University of Toronto (now he is hot!).

All three of the so-called “ice worlds” turned out to have odd characteristics; in Uranus’s case it’s that the entire planet is turned over on its side in space. While it orbits the sun in the same counter-clockwise direction as all the other planets, its rotation is clockwise (only it and Venus rotate backwards from their orbits) and its orientation in space is sideways. Uranus has a set of rings like Saturn’s (and Jupiter’s), but the rings are up-and-down instead of sideways. It’s also a formless, featureless planet with no apparent weather – just an atmosphere that’s a big block of ice (80 percent nitrogen, 19 percent carbon monoxide and the rest methane) and a surface temperature even colder than Neptune’s even though Uranus is closer to the sun than Neptune. Uranus also has two so-called “satellite moons,” Cordelia and Ophelia (after the profusion of names from Greek mythology used to describe the solar system it’s refreshing to see objects named after Shakespearean characters – King Lear’s favorite daughter and Hamlet’s girlfriend, respectively), whose main purpose seems to be to exert enough gravity on the rings to keep them in place. (I was a bit disappointed that the show didn’t offer an explanation of just what Uranus’s rings are made of, especially given that one of the most compelling bits of the previous episodes was the revelation that Saturn’s rings are made of ice – that’s right, ice, frozen dihydrogen oxide, water to you.)

Neptune is in some ways far more interesting than Uranus; it has a moon called Triton that actually has a layer of liquid water under its solid crust of ice and frozen gases, and periodically geysers erupt on Triton. The current guess as to how that happens is that radioactive elements in Triton’s core keep the water warm enough to remain liquid and it occasionally erupts as geysers on Triton’s surface. There’s also another theory which holds that Triton was once an independent planet on its own until it got grabbed by Neptune’s gravity and turned into a moon. It’s an interesting counterpoint to an idea I remember encountering in a children’s astronomy book when I was a kid that suggested Pluto, with its eccentric orbit that sometimes dips inside Neptune’s even though overall it’s farther out from the sun than Neptune is, was the opposite: an errant moon of Neptune that somehow escaped into full-fledged planethood. This show discussed the controversy over whether Pluto is a planet or not but didn’t take a hard position either way, though they did a good job outlining why Pluto was de-listed from full-planet status in the first place: among other things, it doesn’t dominate its region of space the way the other planets do. I’m still upset at the de-listing of Pluto – as I see it, it’s still there, it hasn’t self-destructed in some cosmic accident, and therefore it’s still a planet no matter what arbitrary criteria you choose to stick on it. And though this show didn’t come down one way or the other on whether Pluto is a full-fledged planet, they treated it seriously enough to discuss the New Horizons probe and depict its observations accurately.

Among other things they did with New Horizons was include aboard the probe some of the cremains of the late Dr. Clyde Tombaugh, who discovered Pluto in 1930 (and the show featured some of the star plates Tombaugh used to spot the object in the sky, moving too fast and changing position too radically to be a star, later identified as Pluto; incidentally, by the time Pluto was de-listed Tombaugh was dead but his daughter protested the insult allegedly done to her dad by the de-listing) and put the entire probe under hibernation. In order to avoid draining its batteries on the ultra-long trip to the farthest reaches of the solar system, NASA’s engineers and designers decided to keep the probe’s electronics turned off until it actually entered Pluto’s space. There were anxious hours at NASA’s command center as to whether the probe would turn on when their signal told it to, which it did with just 3 ½ hours to spare. New Horizons was designed for a fly-by of Pluto and then out to the Kuiper Belt and the object Ultima Thule, described in a 2018 dispatch from NASA’s Web site (https://blogs.nasa.gov/pluto/2018/11/27/the-pis-perspective-share-the-news-the-farthest-exploration-of-worlds-in-history-is-beginning/) as “formed 4.5 or 4.6 billion years ago, 4 billion miles from the Sun. It’s been stored at that enormous distance from the Sun, at a temperature of nearly absolute zero, ever since, so it likely represents the best sample of the ancient solar nebula ever studied. Nothing like it has ever been explored.”

Like the previous episodes on “The Planets” mini-series within the overall NOVA series, “Ice Worlds” was made in 2019, a year after NASA posted that item on its Web site but still four years ago, and unlike some of the other episodes there was no visible updating: what we saw here was pretty much to be what they got. The entire mini-series has had me thinking of Werner Heisenberg’s comment, “The universe is not only stranger than we imagine, it is stranger than we can imagine,” and even within our own solar system there are so many anomalies we can’t say for sure whether our system is a representative of the mainstream of star and planetary formation or an outlier in more ways than one, including the presence of sentient life on the third planet out.