could "extinction level event" meteors cause a change in the earths rotation?

Question

what im saying is, what if the meteor 65million years ago, hit at such an angle as to to slow the earths rotation? would that increase the gravity felt on earth?
the final result being, big old dinosaurs find they are 5 tonnes heavier. is that possible?

Answer 1

No, the K-T event was nowhere near large enough to cause a substantial change in the Earth's rotation or axial orientation. To do so, would require an impact of an object a substantial proportion of the Earth's size itself ......at least something on the order of 1000kms across. Even that would be hard pressed to do it. A 10-12km wide asteroid travelling at 45-60kms/sec just doesn't have enough kinetic energy to move the planet in the manner you mentioned.

However, it can make it ring like a bell, and either slow it down or speed it up by milliseconds. How you ask? By producing a massive seismic event. The K-T event produced earthquakes on the order of 12.4 on the Richter Scale, which would be more than large enough to effect the rotation by milliseconds.

You have to remember, the Earth is not a small planet. By Gas Giant standards it is, but by terrestrial standards it's very large. There are larger ones around (two of the extrasolar planets are terrestrials.....one is 7.5 times more massive, the other 5 times), but for a normal terrestrial, they don't come much bigger. The Earth is heavier than all the other terrestrial planets and most of the moons of the Solar System, combined. It's 5.998 septillion tons in mass (~6 x 10^24kgs).....which is a lot of rock!!!!.

Answer 2

Yes, a large enough meteor could knock the Earth on it's side or disrupt the planets rotation or orbit due to the impact.

For the added mass of a meteor to increase the gravity by any noticable amount it's mass would have to be a significant fraction of the Earth's and manage not to destroy the planet at the same time.

Answer 3

Hmmm - not exactly. I don't think the one that hit affected the rotational speed. The earth holds it's orbit in the solar system because of the consistency of rotation. If that gets effected - slow - we should be pulled towards the sun - Fast - we should get thrown away from the sun.

If the earth's rotation is effected either way, yes it should effect the gravitational force. however, effect on rotation might even break the globe in to several pieces (from the plates), which will not be a nice sight.

Answer 4

Yes, such an impact could change Earth's rotational velocity slightly. The catastrophic earthquake in the Indian Ocean that generated the killer tsunamis was so strong that it actually changed Earth's rotational velocity minutely...something on the order of a couple of microseconds.

Answer 5

Don't know...but although impacts from space happen, it's strange that scientists actually use the same term as they did in "Deep Impact." I never heard impacts referred to that way until seeing that movie.

I'm wondering though, if the size, not just the angle, would have the effect of changing the Earth's rotation.

Answer 6

No. No object which is even remotely likely to strike the earth has anywhere near enough mass to significantly change any of the earth's rotational or orbital parameters.

Answer 7

Gravity has nothing to do with the rate of rotation, gravity is a function of mass.

Answer 8

forget earth's rotation...
if another extinction level meteor hits the earth
the least of your troubles is weather or not the earth spins left, right or counter-clockwise!

Answer 9

nope, if it slowed the spin, gravity would be lighter. It may have sped up the spin. though

Answer 10

Yep, anything is possible.