Thursday, April 17, 2014
In deep freezes like we’ve had this winter, all you really want to do is get home.
It’s cold out there: Pluto and its moons cold in the distant glitter of the sun. Pluto is the large orb at center of image. Charon is the next larger orb to its right.
Photo courtesy of NASA/Hubble Space Telescope
But getting there is like crossing interplanetary space, when it’s this cold. On the highway the headlights from other lanes well up in an ominous glow, icy trees in the median glisten in Transylvanian crystal shells. Are any sparks of life even in them still?
When I left Augusta on New Year’s Eve, my dashboard thermometer registered minus 2 degrees (Fahrenheit) and home seemed eons away. In the blackness of highway space it dropped to minus 5 around the Sidney exit.
At Waterville it was minus 7. On the back road through Benton it went to minus 10. The farther out you go, the colder it gets, I thought. And thinking this, I found myself on a kind of intermunicipal trajectory whose map, if you were to draw it, would look like the curving lines traced out by spacecraft making their ways among the asteroids and planets. Cassini on its way to Saturn in the early 2000s. Voyager II bending around Jupiter and past Saturn, then to Uranus, Neptune and the trans-Neptunian space where it’s still speeding outward. New Horizons zeroing in on Pluto at this very frozen moment.
Colder and colder. The average temperature on nearby Mars is about minus 20. Next out by planetary orbit, Jupiter’s average atmospheric temperature is about minus 160, NASA calculates. At Saturn, it’s around minus 220, Uranus around minus 320, and Neptune around minus 340.
None of this seems too tough, really, compared to the wind chill factors between Augusta and Troy that are minus 451 or so. Just kidding. Sort of. The coldest temperature ever recorded on Earth was surprisingly not in Maine the last couple of weeks, but in Antarctica on July 31, when it hit minus 135.3, beating the old record by minus 7.2 degrees notched in July 1983.
Past a certain point, though, it gets a little squirrelly, in a counterintutive sort of way. The daytime surface temperature of dwarf planet Pluto is thought to be around minus 380, while its moon Charon’s daytime surface temperature may be around minus 370, a bit warmer. So to speak. Neptune’s nitrogen-geysering moon Triton, however, which most of the time is quite a bit closer to the sun than Pluto and Charon, has an average temperature of around minus 391 – colder than Pluto.
What are the reasons for this warmup over distance? It takes too many words to disentangle here, and no one is absolutely certain of the reasons anyway, at least not in the way everyone is certain it’s warmer near the sun because the sun is hot. I mean, something happens out there that is not consistent with the logic of the physical senses. Pluto is usually 9 or 10 Earth-sun distances farther from the sun – yet warmer – than Triton.
But I was going to say, before these facts broke in about the planets (and without even mentioning the ice storm), that when I reached Unity that night the dashboard thermometer said minus 12, colder than Benton, if that’s possible. Eastbound on Route 9, that temperature held pretty steady until I actually passed into the intermunicipal space of Troy. At that point the temperature started to rise. Just like on Pluto.
I turned carefully down the driveway and drove through the little tunnel of birches bent from right to left out of the straighter, darker firs. The headlights crazed the enamel of ice that bowed them down in the snowbound bramble. Eight below and glittering in the night. Up the grade to the other end of the driveway and into the slip beside the back door. Seven below.
Over the snow-crust to the steps, with the certain knowledge that inside the house, after this commute measured eventually in astronomical units, there was a spark of warmth. And sure enough, inside, wood and oil and other kinds of burning made a wealth of heat. The house was night-quiet.
Somehow Pluto was warmer than Benton. I wonder what’s going on inside it. Its name means the god of the underworld because different kinds of riches (in Greek: ploutos) well up from underground. New Horizons, by my calculation, is right now about the same distance from Pluto that Unity is from Troy. In July 2015, if all goes well, it will get some measurements that will reveal some of what’s in there, like sparks of light in deep space.
Dana Wilde lives in Troy. His writings on the Maine woods are collected in “The Other End of the Driveway,” available from Booklocker.com and online book sellers. Backyard Naturalist appears the second and fourth Thursdays each month. You can contact him at firstname.lastname@example.org.