An Australian amateur astronomer detected the first indications that a comet had slammed into Jupiter only fifteen years after the Shoemaker-Levy impacts. It left an impact signature on the giant planet the size of earth. William Harwood writes:
“We’re not sure how large this fragment could have been,” Leigh Fletcher, a researcher at the Jet Propulsion Laboratory in Pasadena, Calif., told CNET. …”We’ve compared it in size to the little red spot on Jupiter, you can see the two are roughly a similar order of magnitude in size,” he said. “It’s smaller than Earth-sized, but it’s certainly gargantuan by earthly proportions.”
Over the next few days and weeks, the Hubble Space Telescope, other space-based telescopes, and observatories around the world will focus on the impact site to learn as much as possible about what might have hit Jupiter and how the impact affected the planet’s atmosphere.
This is the second large hit on Jupiter we’ve observed in fifteen years. Does it tell us anything about the likelihood of an impact on earth? The answer is we don’t really know because we don’t have the detection systems in place to gather the data. Glenn Reynolds, writing in TCS notes that politicians have devoted a relative pittance to watching the skies. And even if an incoming object were detected, there are no established protocols to respond to the event, nor any realistic defenses against a massive incoming. This is probably a function of politics more than anything else, I think. Its deemed essential to spend trillions to prevent “climate change” in the name of the precautionary principle, but the ranging shots of the artillerist of the Solar System are left to amateur astronomers from Australia to observe.
But the most interesting issue that Glenn Reynolds raises in his TCS article is that, without a planetary defense and with an inadequate detection system, then humanity will at most have a short time between the detection of a life-ending incoming space projectile and impact. In that case, he asks, would we want to know? Should governments keep it secret from us?
Quite some time ago, I wrote about scientists’ questions on whether to deliver bad news. The news in question had to do with a potential life-ending asteroid strike. Perhaps, I suggested, it might be best not to deliver that news, if things were bad enough that nothing could be done. I also noted that this was an active question within the astronomical community.
Personally, I would want to know if the end were imminent. In the case Reynolds cites, the panic spawned by a sighting was premature. Further observations by astronomers showed the feared object was going to miss. Somebody should do a disaster movie like that one day, when everybody closes his eyes at the anticipated moment, only to look up to see, blazoned in flaming letters across the sky, “Nyah, nyah! Fooled you! Fooled you!”
Holst looked up at Jupiter and heard laughter. Here’s’s his Jupiter, Bringer of Jollity, from The Planets. On winter nights, after the last bus down Trapelo road had gone, I used to run the distance from Harvard Square to Belmont with a Walkman in my pocket. And the everything after 2:38 was my favorite on the track.