THE SOUTHWORTH PLANETARIUM
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Founded January 1970
2021-2022: XVI
"When G-d sneezed, I didn't know what to say."
-Henny Youngman
THE DAILY ASTRONOMER
Thursday, September 23, 2021
Something Hit Jupiter
on September 13, 2021. The many astronomers who observed this spectacle aren't quite sure what struck this king of the gas giants. Hence, the vaguely-worded announcement, "Something hit Jupiter." That the impact was even recorded in the first place was a sweet serendipity. Many astronomers,* including Brazilian astronomer* Jose Luis Pereira, were recording a Ionian transit, the passage of Jupiter's moon Io directly in front of the planet. During the recording, Pereira noticed a bright, two-second long flash. Astronomers in Germany also recorded the event and concluded that the outburst occurred on the giant planet as opposed to having happened merely along its sight line.
The videos were analyzed by astronomers and astrophysicists around the world, including Marc Delcroix at the NTT Communication Science Laboratories in Kyoto, Japan. Based on the initial studies conducted within the brief time immediately following the impact, astronomers estimate that the impacting body was approximately 20 meters in diameter. They speculate that this object might have been a fragment of a comet or asteroid that ventured too close to Jupiter and was split into pieces by the planet's gravity.
This latest impact event reminds us of the most famous astronomical cometary collision in modern history: the impact of Comet Shoemaker-Levy 9 onto Jupiter in 1994.
During that spectacular event, Jupiter's tidal forces tore the comet into pieces, all of which rained down onto the Jovian cloud tops with the power of thousands of tons of TNT. In the above image, we can see the doomed cometary particles prepared to meet their fate. The destruction of Shoemaker Levy 9 was observed and followed by thousands of astronomers around the world. This latest impact was seen only by a few astronomers, none of whom expected to see it.
Over the next few weeks. astronomers will closely examine the impact's light curve: the way the light intensity varied over the brief interval during which it remained visible. Such light curve analysis should yield information about the impact speed, as well as the composition, size and other characteristics of the impacting body.
Although the solar system has become much more quiescent since the ultra-violent heavy bombardment days , millions of asteroids, comets and other projectiles continue to tumble through inter-planetary space. They will occasionally strike larger bodies, including our home world. That is perhaps why we love to observe collisions on other planets. Such impacts events are all spectacle and no catastrophe. Then again, they also serve as reminders that menaces still lurk deep within the hollows of that perpetual night.
*Unlike most media sources, the DA will never use the term "amateur astronomer." We won't include that term in these articles for the same reason that we'll never include the words (censored), (censored) or (censored). "Amateur astronomer" is an appalling insult. [If you doubt this assertion, try the following experiment: Next time a plumber or electrician visits your home, present him/her with a plate of cookies and say, "These are for my favorite amateur." See what sort of reaction you elicit.] The proper term is "astronomer." PhD level research astronomers are all astrophysicists. Astronomers, such as those affiliated with the Southern Maine Astronomers [ www.southernmaineastronomers.org ] have performed sterling work in both research and educational outreach. Most of their members have forgotten more about astronomy than I'll ever know. They are no amateurs.
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