I wonder if an asteroid burning up in earth's atmosphere would look
similar from another planet?
9b7969699810176138a9ca6573a2e598.jpg (15.83 KiB) Viewed 3377 times
Awe; they gave us another kitty! Smug look;
maybe swallowed the canary!
And my Pluto!
Re: APOD: Video: Flash on Jupiter (2021 Sep 17)
Posted: Fri Sep 17, 2021 12:27 pm
by NCTom
Meteor Crater in Arizona was created by an object estimated to be 50 m in diameter. A bus size rock could still make a rather big hole here on earth!
Re: APOD: Video: Flash on Jupiter (2021 Sep 17)
Posted: Fri Sep 17, 2021 12:36 pm
by Ann
orin stepanek wrote: ↑Fri Sep 17, 2021 11:39 am
oma8ipU3qC8fCiRCijQy38-480-80.jpg
I wonder if an asteroid burning up in earth's atmosphere would look
similar from another planet?
But how can we be sure this rock the size of a bus was orbiting Jupiter?
I call this "Russell's Rock the Size of a Bus"
Re: APOD: Video: Flash on Jupiter (2021 Sep 17)
Posted: Fri Sep 17, 2021 2:18 pm
by Chris Peterson
dee_phlat wrote: ↑Fri Sep 17, 2021 1:13 pm
But how can we be sure this rock the size of a bus was orbiting Jupiter?
While it's possible that the body had been perturbed into a highly eccentric orbit around Jupiter that resulted in it dipping into that planet's atmosphere and burning up, it's far more likely that it wasn't in orbit around Jupiter at all, but like virtually all impactors in the Solar System, around the Sun.
APOD Robot wrote: ↑Fri Sep 17, 2021 4:05 am Explanation: There has been a flash on Jupiter. A few days ago, several groups monitoring our Solar System's largest planet noticed a two-second long burst of light. In the featured video, variations in the Earth's atmosphere cause Jupiter's image to shimmer when, suddenly, a bright flash appears just left of center. What hit Jupiter will likely never be known, but considering what we do know of the nearby Solar System, it was likely a piece of rocky and ice -- perhaps the size of a bus -- that broke off long-ago from a passing comet or asteroid.
But how can we be sure this rock the size of a bus was orbiting Jupiter?
The Magic School Bus is an American edutainment media franchise. Each of the stories within the franchise centers on the antics of a fictional elementary school teacher, Ms. Frizzle, and her class, who board a "magic school bus", which takes them on field trips to unusual times and locations, such as the Cretaceous Period, outer space, and the interior of the human body.
https://www.etymonline.com/search?q=frizzle wrote:
frizz (v.) also friz, 1610s (implied in frizzed), probably from French friser "to curl, dress the hair" (16c.), perhaps from stem of frire "to fry, cook" (see fry (v.)). Assimilated to native frizzle.
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fry (v.) late 13c., "cook (something) in a shallow pan over a fire," from Old French frire "to fry" (13c.), from Latin frigere "to roast or fry."
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frizzle (v.) "curl hair," 1560s, of obscure origin. There are words of similar sound and sense in Old English (fris "curly"), Old Frisian (frisle), French (friser "to curl") but their history is tangled; probably connected somehow to frizz (v.). Related: Frizzled; frizzling. As a noun from 1610s, "a short curl," from the verb. Frizzling iron was a 17c. term for "curling iron."
Re: APOD: Video: Flash on Jupiter (2021 Sep 17)
Posted: Fri Sep 17, 2021 4:27 pm
by johnnydeep
1. How can we be sure this was caused by an impact and not by some other mechanism? Stupid question I'm sure, and I'll bet the answer is that there simply is no other known mechanism!
2. This event seems to be different than the ones resulting from the breakup of comet Shoemaker-Levy 9. Did those impacts flash white like this one (presumably seen in visible light here)? I know they all left dark "scars" that later for weeks, but what did they look like upon impact?
Re: APOD: Video: Flash on Jupiter (2021 Sep 17)
Posted: Fri Sep 17, 2021 6:08 pm
by Eclectic Man
johnnydeep wrote: ↑Fri Sep 17, 2021 4:27 pm
1. How can we be sure this was caused by an impact and not by some other mechanism? Stupid question I'm sure, and I'll bet the answer is that there simply is no other known mechanism!
2. This event seems to be different than the ones resulting from the breakup of comet Shoemaker-Levy 9. Did those impacts flash white like this one (presumably seen in visible light here)? I know they all left dark "scars" that later for weeks, but what did they look like upon impact?
For a response to your second question, see the NASA page:
johnnydeep wrote: ↑Fri Sep 17, 2021 4:27 pm
1. How can we be sure this was caused by an impact and not by some other mechanism? Stupid question I'm sure, and I'll bet the answer is that there simply is no other known mechanism!
2. This event seems to be different than the ones resulting from the breakup of comet Shoemaker-Levy 9. Did those impacts flash white like this one (presumably seen in visible light here)? I know they all left dark "scars" that later for weeks, but what did they look like upon impact?
"If it walks like a duck and it quacks like a duck, then it must be a duck"
... but locating the tiny late asteroid wouldn't hurt.
Comet Shoemaker–Levy 9 was a comet that broke apart in July 1992 and collided with Jupiter in July 1994, providing the first direct observation of an extraterrestrial collision of Solar System objects. Although the impacts took place on the side of Jupiter hidden from Earth, Galileo, then at a distance of 1.6 AU from the planet, was able to see the impacts as they occurred. Jupiter's rapid rotation brought the impact sites into view for terrestrial observers a few minutes after the collisions.
The first impact occurred at 20:13 UTC on July 16, 1994, when fragment A of the nucleus entered Jupiter's southern hemisphere at a speed of about 60 km/s. Instruments on Galileo detected a fireball that reached a peak temperature of about 24,000 K, compared to the typical Jovian cloudtop temperature of about 130 K, before expanding and cooling rapidly to about 1,500 K after 40 seconds. The plume from the fireball quickly reached a height of over 3,000 km. A few minutes after the impact fireball was detected, Galileo measured renewed heating, probably due to ejected material falling back onto the planet. Earth-based observers detected the fireball rising over the limb of the planet shortly after the initial impact.
Despite published predictions, astronomers had not expected to see the fireballs from the impacts and did not have any idea how visible the other atmospheric effects of the impacts would be from Earth. Observers soon saw a huge dark spot after the first impact. The spot was visible even in very small telescopes, and was about 6,000 km across. This and subsequent dark spots were thought to have been caused by debris from the impacts, and were markedly asymmetric, forming crescent shapes in front of the direction of impact.
Over the next six days, 21 distinct impacts were observed, with the largest coming on July 18 at 07:33 UTC when fragment G struck Jupiter. This impact created a giant [Earth sized] dark spot over 12,000 km across, and was estimated to have released an energy equivalent to 6,000,000 megatons of TNT.>>
Re: APOD: Video: Flash on Jupiter (2021 Sep 17)
Posted: Fri Sep 17, 2021 6:57 pm
by johnnydeep
Thanks, Eclectic Man and Neufer. So we couldn't see the impacts in 1994 from Earth because they occurred on the night side of Jupiter, but Galileo saw them and recorded temps of 24000K, which I presume would appear white hot in visible light. Still, this recent white flash recorded by amateur telescopes seems much more impressive. I hope it leaves a dark scar as evidence like the impacts in 1994.
Re: APOD: Video: Flash on Jupiter (2021 Sep 17)
Posted: Fri Sep 17, 2021 7:17 pm
by Chris Peterson
johnnydeep wrote: ↑Fri Sep 17, 2021 6:57 pm
Thanks, Eclectic Man and Neufer. So we couldn't see the impacts in 1994 from Earth because they occurred on the night side of Jupiter, but Galileo saw them and recorded temps of 24000K, which I presume would appear white hot in visible light. Still, this recent white flash recorded by amateur telescopes seems much more impressive. I hope it leaves a dark scar as evidence like the impacts in 1994.
Unlikely. This event was minor, and pretty common on Jupiter. A small body like this burned up at the very top of the atmosphere. The long lasting disruption created by SL9 happened because the body (ultimately bodies) was orders of magnitude more massive and went much deeper.
johnnydeep wrote: ↑Fri Sep 17, 2021 6:57 pm
Thanks, Eclectic Man and Neufer. So we couldn't see the impacts in 1994 from Earth because they occurred on the night side of Jupiter, but Galileo saw them and recorded temps of 24000K, which I presume would appear white hot in visible light. Still, this recent white flash recorded by amateur telescopes seems much more impressive. I hope it leaves a dark scar as evidence like the impacts in 1994.
Unlikely. This event was minor, and pretty common on Jupiter. A small body like this burned up at the very top of the atmosphere. The long lasting disruption created by SL9 happened because the body (ultimately bodies) was orders of magnitude more massive and went much deeper.
How do we know how minor it was? No evidence of the impactor prior to the flash?
johnnydeep wrote: ↑Fri Sep 17, 2021 6:57 pm
Thanks, Eclectic Man and Neufer. So we couldn't see the impacts in 1994 from Earth because they occurred on the night side of Jupiter, but Galileo saw them and recorded temps of 24000K, which I presume would appear white hot in visible light. Still, this recent white flash recorded by amateur telescopes seems much more impressive. I hope it leaves a dark scar as evidence like the impacts in 1994.
Unlikely. This event was minor, and pretty common on Jupiter. A small body like this burned up at the very top of the atmosphere. The long lasting disruption created by SL9 happened because the body (ultimately bodies) was orders of magnitude more massive and went much deeper.
How do we know how minor it was? No evidence of the impactor prior prior to the flash?
We know it was minor because the size of the body can be reasonably estimated by the intensity of the flash. There is solid theory describing the relationship between mass and luminous intensity. (It's a primary method used to estimate the mass of bodies producing bright fireballs here on Earth.)
Unlikely. This event was minor, and pretty common on Jupiter. A small body like this burned up at the very top of the atmosphere. The long lasting disruption created by SL9 happened because the body (ultimately bodies) was orders of magnitude more massive and went much deeper.
How do we know how minor it was? No evidence of the impactor prior prior to the flash?
We know it was minor because the size of the body can be reasonably estimated by the intensity of the flash. There is solid theory describing the relationship between mass and luminous intensity. (It's a primary method used to estimate the mass of bodies producing bright fireballs here on Earth.)
Thanks. I do believe you’ve mentioned that before in other threads!