Buckshot from the sun: possible risk from NEO Sungrazers?

Just curious if there are any articles out there that may discuss this kind of thing and the risk it presents.

NEO obviously is the acronym for Near Earth Object, which is a planetary body where its known orbit crosses that of Earth. And everyone who paid enough attention to interesting astronomy articles knows about Shoemaker-Levy and what it did during its approach to Jupiter before being consumed by the planet. Sungrazers, as their name suggests, go really close to the sun in their orbital track and graze the sun.

From what I understand, sungrazers have been known to break up in the past. But most are not NEOs, and often the fragments fall into the sun if the approach is close enough to cause a break-up.

Now what would happen to a "predictable" NEO orbit model if a sungrazer happened to break up Shoemaker-Levy style during its perihelion? But at a point where most pieces may go outwards rather than inwards. Remember momentum is conserved, but masses of resulting fragments are fairly random. I think buckshot seems a fairly apt description for what it would do.

Out of curiousity, how much research (if any) has been done on this? If there's some risk of this occuring, would there be a chance of a coverup if an NEO is known to fragment somewhere on its orbital track? (And it could happen as it goes around the back where we can't see.)

Not to panic anyone, but I think ISON may qualify in both those categories. (Hopefully if it does anything unusual, Earth still remains in the clear. Yet if it happens to a noticable degree, it would be a good learning experience.) Still I'd rather this not be another "insert X here = doom!" thread, it's just something current that may fit such a scenario.

reply to post by pauljs75


www.abovetopsecret.com...
I did a thread on tour very point with concerns to ISON and the 1 million plus NEOs that inhabit our part of the solar system. It stemmed from a 60 minute broadcast.

S&F for your thoughts

List Of The Potentially Hazardous Asteroids (PHAs)
www.minorplanetcenter.org...

reply to post by pauljs75

Remember momentum is conserved, but masses of resulting fragments are fairly random.

Remember that a comet in orbit around the Sun is actually in freefall around the Sun.
Remember that the mass of an object does not affect the manner in which it falls.

reply to post by Phage


Elliptical orbits are a tad bit different than freefall straight towards a gravitational body. Different masses at the same velocity form different ellipsoid trajectories. The force that pulls objects back is the same as in the formula F=ma. They experience the same acceleration while in orbit (that of gravity), but the masses are different. There has to be at least one physics simulator out there where you can mess with this concept.

Shoemaker-Levy also may make part of the case in a real example. After it broke apart, the pieces didn't all hit in the same spot on Jupiter, did they?

Also I know the topic of NEOs or potentially hazardous asteroids has been covered before, but I'm thinking of a fairly specific case where the typical orbital prediction model may break down. All it would take is the object passing through the solar system to break up at some point.

I also know most of the debris cloud would still stay fairly close together on its trajectory (like meteor showers do) as there is some gravity between them, but the amount of spread after passing near the sun (or large planet like Jupiter) and breaking up could still be the difference between hitting another planet or missing it. A predicted orbit that says you manage to be safe with no break-up, can easily put you in the path of a fragment cloud originating somewhere along that same track.

reply to post by pauljs75

Elliptical orbits are a tad bit different than freefall straight towards a gravitational body. Different masses at the same velocity form different ellipsoid trajectories.

No. The acceleration due to gravity is what determines the shape of the orbit. Acceleration due to gravity is not dependant upon the mass of the falling object. A basketball, set on the same orbit as Earth, would follow that orbit.

Shoemaker-Levy also may make part of the case in a real example. After it broke apart, the pieces didn't all hit in the same spot on Jupiter, did they?

No they didn't, mostly because Jupiter rotates.

breaking up could still be the difference between hitting another planet or missing it.

Perhaps. If the original orbit took the object very near that planet. The orbit of the fragments will not vary significantly from the orbit of the original object.