Could impacts affect earth's orbit

How large would an impact on earth have to be in order to have a
material change to earth's orbit? That at least our best time pieces
and/or our calander has to be adjusted? Would there be enough
cilivalization left to care?

"Luke J. Nester" wrote in message
om...
How large would an impact on earth have to be in order to have a
material change to earth's orbit? That at least our best time pieces
and/or our calander has to be adjusted? Would there be enough
cilivalization left to care?
I suspect that not only would there be no cicilization, but no life, and
probasbly not even continents. Such an impact would likely melt the crust.

Could be wrong, but the kinetic energy/mass required would have to be
substantial.

Sany

(Luke J. Nester) wrote in message . com...
How large would an impact on earth have to be in order to have a
material change to earth's orbit? That at least our best time pieces
and/or our calander has to be adjusted? Would there be enough
cilivalization left to care?

No

Pragmatist

"LJN" == Luke J Nester writes:

LJN How large would an impact on earth have to be in order to have a
LJN material change to earth's orbit? That at least our best time
LJN pieces and/or our calander has to be adjusted? Would there be
LJN enough cilivalization left to care?

Consider that the mass of the Earth is about 6E24 kg and its velocity
around the Sun is about 30 km/s. Under even the most extreme
scenario, the velocity of an impactor is not going to be more than
about 100 km/s (e.g., a long-period comet on a retrograde orbit).

Now the question becomes, How significant a change would you consider
significant? I think it is clear, though, that even a modest change
(e.g., 0.1%) in the Earth's orbit would require a fairly massive
impact, far larger than the impact that killed off the dinosaurs.

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