APOD and General Astronomy Discussion Forum
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Comet Shoemaker-Levy 9 was solid; Jupiter is gas.ROC wrote:APOD 6/25/95 stated that Jupiter is a gas giant with no solid surface, APOD 7/14/95 stated that Comet Shoemaker-Levy 9 impacted Jupiter causing several explosions and sending dust into the atmosphere. Which is it solid or gas?
High density gas. If most meteorites burn up in the Earth's atmosphere and never reach the ground, think of how much harder it would be to penetrate Jupiter's atmosphere.ROC wrote:If Jupiter is gas, what did the comet collide with?
Wiki: Comet Shoemaker-Levy 9 wrote:The first impact occurred at 20:13 UTC on July 16, 1994, when fragment A of the nucleus slammed into Jupiter's southern hemisphere at a speed of about 60 km/s. Instruments on Galileo detected a fireball which 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 1500 K after 40 s. 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
Depends on pressure and temperature and the type of gas.mark swain wrote:When does Gas become a solid?
bystander wrote:Depends on pressure and temperature and the type of gas.mark swain wrote:When does Gas become a solid?
http://en.wikipedia.org/wiki/Gas_giant wrote:
<<The four solar system gas giants share a number of features. All have atmospheres that are mostly hydrogen and helium and that blend into the liquid interior at pressures greater than the critical pressure. On Jupiter and Saturn there is no clear boundary between atmosphere and body, but on Uranus and Neptune some models show that the boundary could indeed be sharp. In this regard, our four gas giants exemplify the classic "matter phase-gradient" in the materials sciences. They have very hot interiors, ranging from about 7,000 kelvin (K) for Uranus and Neptune to over 20,000 K for Jupiter. This great heat means that beneath their atmospheres the planets are most likely entirely fluid (liquid or supercritical). Thus, when discussions refer to a "rocky core," one should not picture a ball of solid rock. Rather, what is meant is a region in which the concentration of heavier elements such as iron and nickel is greater than that in the rest of the planet.>>
Probably not high density at all. At the height where SL9 burned up, the atmosphere of Jupiter is pretty tenuous. The only high density gas was that which was being compressed directly in front of the fragments- that compression being the source of energy that burned up the fragments and produced the light we were able to see.bystander wrote:High density gas. If most meteorites burn up in the Earth's atmosphere and never reach the ground, think of how much harder it would be to penetrate Jupiter's atmosphere.ROC wrote:If Jupiter is gas, what did the comet collide with?
I mostly remember the dark impact spots that remained for some months.Chris Peterson wrote:and produced the light we were able to see.
Are you talking about the atmospheric probe dropped by Galileo? It made it down about 150 km.mark swain wrote:How deep did the probe get before it shut down?
Sorry, not sure what you're saying here. What would be harsher? What flashing lights?I think it would of been a little harsher than a few flashing lights chris.
What densities was the probe able to with stand? If it shut down at 150 KM Would that be the depth of SL9 impacted? If the gas giants have been cleaning the solar system for 4.5 Billion years,, What else is inside them?Chris Peterson wrote:Probably not high density at all. At the height where SL9 burned up, the atmosphere of Jupiter is pretty tenuous. The only high density gas was that which was being compressed directly in front of the fragments- that compression being the source of energy that burned up the fragments and produced the light we were able to see.
To see much at all from earth based observatories, it must have been quite an event.mark swain wrote:You said lights we saw.. Made me think you meant they wasn't much of an event.
The probe failed at a pressure of about 2.3 MPa (23 atmospheres). But it had lost all its cosmic entry velocity before the pressure even reached a half atmosphere. So its "impact", and heat shield ablation, was very high, before the atmosphere became very dense at all.mark swain wrote:What densities was the probe able to with stand? If it shut down at 150 KM Would that be the depth of SL9 impacted?
No doubt, they've absorbed quite a bit of asteroidal and cometary material (as have the terrestrial planets). But in terms of their total mass, I'm sure it's a vanishingly small amount.If the gas giants have been cleaning the solar system for 4.5 Billion years,, What else is inside them?
Not at all! 6 million megatons equivalent is no small event. I only meant that the light we saw was from the heating of compressed atmospheric gases in front of the fragments, even though they themselves were still in a thin atmosphere.You said lights we saw.. Made me think you meant they wasn't much of an event.