SOMETHING JUST HIT JUPITER: Last night, Sept. 13-14, German astronomer Harald Paleske was watching the shadow of Io create a solar eclipse in the atmosphere of Jupiter when something unexpected happened. "A bright flash of light surprised me," he says. "It could only be an impact." Follow the arrows to the fireball:
Paleske video-recorded the event. Reviewing the frames, he quickly ruled out objects such as airplanes and satellites, which might be crossing Jupiter at the time of his observation. The fireball was fixed in Jupiter's atmosphere. It first appeared at 22:39:27 UT on Sept. 13th and remained visible for a full two seconds.
The most likely explanation is a small asteroid or comet striking the giant planet; an asteroid in the 100m size range would do the trick.
This isn't the first time astronomers have seen things hitting Jupiter. The most famous example is Comet Shoemaker-Levy 9 (SL9), which struck Jupiter in July 1994. At the time, most astronomers thought such collisions were rare, happening every hundred years or so. Since SL9, however, amateur astronomers using improved low-light cameras have observed more than a dozen impact flashes in Jupiter's cloudtops. The Solar System is more dangerous than we thought.
Paleske pinpoints the fireball at Jovian latitude 106.9° (CM1), longitude +3.8°. Other observers are encouraged to monitor the location for debris. Previous impacts have sometimes created inky clouds -- probably the remains of the impactor itself mixed with aerosols formed by shock-chemistry during the explosion.
Brazilian observer José Luis Pereira captured a bright flash on the solar system's largest planet Monday night (Sept. 13), memorializing the fiery death of a space rock high in the Jovian atmosphere.
"I am an assiduous planetary observer," Pereira told Space.com in a written statement Tuesday (Sept. 14). "When the planets Jupiter, Saturn and Mars are in opposition, I try to make images in every possible night of clear skies. Especially [of] the planet Jupiter, my favorite."
On Sunday (Sept. 12) and Monday, Pereira set up his equipment in São Caetano do Sul, in the southeastern Brazilian state of São Paulo. As on many other nights, he aimed to photograph Jupiter and capture videos for the DeTeCt program, which seeks to spot and characterize impacts on the giant planet.
The weather didn't look like it would cooperate on Monday night, but Pereira persevered, collecting a series of 25 Jupiter videos, with no time gap between them.
"To my surprise, in the first video I noticed a different glow on the planet, but I didn't pay much attention to it as I thought it might be something related to the parameters adopted, and I continued watching normally," Pereira wrote. "So as not to stop the captures in progress for fear that weather conditions would worsen, I didn't check the first video."
He fed the videos into the DeTeCt program and then went to bed.
"I checked the result only on the morning of the 14th, when the program alerted me to the high probability of impact and verified that there was indeed a record in the first video of the night," Pereira wrote.
He then sent the information to Marc Delcroix of the French Astronomical Society, who confirmed that Pereira had indeed recorded footage of an impact that occurred Monday at 6:39 p.m. EDT (2239 GMT).
"For me it was a moment of great emotion, as I have been looking for a record of [such an] event for many years," Pereira wrote.
His observing setup consists of the following, he added: a Newtonian Telescope 275mm f/5,3 with a QHY5III462C camera, plus a Televue Powermate 5x (f/26,5) eyepiece and an IRUV cut filter. If you're looking to learn more about how to photograph planets, check out our astrophotography for beginners guide for the basics. You can also see how the Nikon Z6 camera stacks up for astrophotography here.
You can see more of Pereira's astronomical work on Flickr and YouTube.
Below are comments on why an object hits so hard when impacting Jupiter and what we may be able to learn from it.Here's a much clearer look at the object that struck Jupiter on Monday, via Harald Paleske. It was probably a comet or asteroid about 100 meters in diameter -- small but potent. https://spaceweather.com/archive.php?view=1&day=15&month=09&year=2021
If the object that recently impacted Jupiter had the same velocity as its own escape velocity, the same as Shoemaker-Levy, then it would have an impact energy that is approximately 10 times that of the average impact on Earth for the same physical properties in terms of mass and size.This illustration plots the log mass of the outer solar system planets against the minimum impact velocities of dust from Kuiper Belt objects for each body. Average impact velocities are still unknown. The impact velocities shown here are the escape velocities for the gas giants: 59.4 km/s for Jupiter, 35.4 km/s for Saturn, 21.2 km/s for Uranus, and 23.4 km/s for Neptune. Planetary mass is one factor that determines the velocity of objects impacting a planetary body. As the mass increases, so does the impact velocity. In the outer solar system, this holds true for all the gas giants. In comparison, Comet Shoemaker-Levy 9 impacted Jupiter at a velocity of 60 km/s. Impact velocities are plotted in kilometers per second on the lower x-axis and miles per second on the upper x-axis.
Illustration Credit: LPI (Andrew Shaner & David A. Kring). Background image of Saturn courtesy of NASA/JPL/Space Science Institute, PIA11613.
Source of Data: Moses, J. I. (2001) Meteoroid Ablation on the Outer Planets, Lunar and Planetary Science Conference XXXII, Abstract 1161.
When the discussed rainfall of satellites starts, we'll have ample material to compare regular meteorite impacts and burnt satellite metal junk remaining intact enough to smash house roofs.How do you reliably avoid confusing incoming space junk with a fireball?
In the past, I have been wondering if some of the observed fireballs were actually incoming space junk colliding with the atmosphere.