NOVA: "The Planets: Inner Worlds" (ARTE, BBC, BBC Studios, PBS, originally aired July 24, 2019)

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

Last night (Wednesday, July 5) I turned on KPBS for an intriguing NOVA episode from 2019 called The Planets: Inner Worlds. It was narrated by Zachary Quinto, who’s best known for playing the young Spock in J. J. Abrams’ rebooted prequel to the original Star Trek (for which he was personally selected by Leonard Nimoy, who had approval rights over the new Spock and also appeared in the first two films as the Yoda-like “Spock Prime”). Its basic thesis was that the various planets – particularly the four closest to the sun, Mercury, Venus, Earth and Mars – weren’t always in the same relationship to the sun, located the same distance from it, as they are now. Like other stars, the sun began life as a bright blue dwarf star and grew over time, becoming the mid-sized yellow one we know now, and then in the future it will expand into a giant red star before burning out, shrinking to the size of a red dwarf star, and ultimately running out of fuel and extinguishing itself. This show, directed by Stephen Cooter and Martin Johnson (who I’m presuming wrote it as well, though no writers are credited), argued that in its early blue-dwarf phase, the sun was far enough away from Mercury and Venus that they both could have had liquid water on their surfaces, the sine qua non for life as we know it. The show was divided into segments on Mercury, Venus (which – and this is something I didn’t know before – is actually hotter than Mercury even though it’s farther away from the sun, since Venus’s atmosphere is over 96 percent carbon dioxide and that traps the solar heat inside), Mars and Titan, the moon of Saturn that a number of science-fiction writers (notably Kurt Vonnegut, Jr.) speculated could have life because it has all the chemical elements necessary for it.

The information on this show came mostly from the National Aeronautics and Space Administration’s (NASA) probes sent to various planets, along with similar probes sent out by the Soviet Union (ya remember the Soviet Union?) to Venus between 1962 and 1983. The Soviet probes (there were 13 of them) only transmitted information for a few hours each before the hostile conditions on Venus’s surface extinguished them, but in that time they gave us a lot of valuable intelligence on just what makes Venus tick, including the revelation that millions of years ago Venus had liquid water on its surface and it was only the expansion of the sun from a blue star to a larger yellow one that evaporated it all and left Venus the hot, hostile hell it is today. Incidentally, this show also mentioned that Mercury is an oddly structured planet consisting of a thin core of rock and a center of almost pure metal, though I wondered just how they know this. Their information on Mercury comes from a NASA probe called “Messenger” (appropriate since the mythological Mercury was the messenger of the gods) that was launched in 2011 and managed to orbit Mercury for the next four years, but unlike the Soviet Venus probes it never landed on Mercury’s surface and so I’m wondering just how an orbital probe was able to detect the sub-surface composition of the planet. This episode first aired July 24, 2019 and was the first of a five-part mini-series, the rest devoted to Mars, Jupiter, Saturn and the so-called “Ice Worlds” beyond Saturn, Uranus and Neptune.

Perhaps the most interesting segment was the last one on Titan, which apparently has free-flowing oceans on its surface – though because Titan is so far from the sun, the oceans are not water but liquid methane. There are also hard rocks on Titan’s surface, which according to this program are actually super-hard blocks of ice that have not only frozen solid but turned a grey-brown rock color. The show’s writers speculated that as the sun expands and becomes a red star billions of years from now, all that super-hard water will melt and Titan will become a viable home for life as we know it. One of the best points made on this program is that we can’t take for granted that Earth will always be able to sustain life, and this was a singularly well-timed warning given that July 4, 2023 was the hottest day on record in the last seven years. It’s astonishing indeed that a show that for years was bankrolled by the “David H. Koch Fund for the Advancement of Science” (though that intro was conspicuously missing from this rerun now that David Koch is dead), when Koch and his brother Charles were also donating huge sums to Republican politicians who denied that humans were doing anything to change the earth’s climate and were taking political positions that retarded the advancement of science, came right out and said that human activity is screwing up the earth’s climate and threatening our planet’s ability to sustain us and all other life forms we know. The idea that David Koch’s donations were both funding shows like this that acknowledged we can’t take for granted that there will always be life on earth and helping elect candidates whose energy policies (damn the renewables, full speed ahead on fossil fuels!) hasten the day when Earth will be as dead as Venus is one of life’s grimmer ironies!