# When the Earth was hit by a meteor in Jurassic era, did it change its orbit or not?

When the Earth was hit by a meteor in Jurassic era, did it change its orbit or not?

Undetectably.

The mass of the Chicxulub impactor is estimated at about $$m_1=10^{13} \ kg$$. The Earth's mass is nearly $$m_2=6 \cdot 10^{24}\ kg$$, while their velocities were similar (same order of magnitude).

Therefore the former played a very small effect in both the conservation of momentum

$$m_1 \cdot v_1 + m_2 \cdot v_2 = (m_1+m_2) \cdot v_{final}$$

and the conservation of energy after an inelastic collision

$$m_1 \cdot v_1^2 + m_2 \cdot v_2^2 = (m_1+m_2) \cdot v_{final}^2$$

This yields (some assumptions made for this example) a change in Earth's velocity of $$v_{final}-v_2 ~= 6 \cdot 10^{-7} km/h$$ , thirteen orders of magnitude smaller than the average orbital velocity of the Earth, $$107,000 \ km/h$$.

Undetectable after 65 million years and definitely negligible in comparison to many other changes in orbital speed such as those exerted by the Moon and other planets.

• Good morning . It was my first question on this website and I am feelling very well because you considered my question . lIttle by little I'll be interacting more with this interesting site. Have a grate day. Commented Jan 28 at 12:10

Not by a lot. Meteors have only a tiny fraction of Earth's mass, so at entry velocities roughly equivalent to our own orbital speed around the Sun (which would be typical of meteors) there is only a tiny impact on Earth's orbit. It would be something like what happened in the 1990s when Comet Shoemaket-Levy 9 was broken up and flew to its demise at Jupiter; the surface effects were spectacular but the impact on the orbit of the whole mass was negligible.

True, the meteor strike that apparently killed off most of the dinosaurs (what we now call birds may have evolved from survivors) had major impacts on the climate that could have led to this extinction. But both the biosphere and the troposphere (the latter is where weather occurs) are tiny fractions of Earth as a whole that were most directly exposed to the impact; the vast bulk of Earth's mass and volume went on about its business hardly affected.

• Good morning . It was my first question on this website and I am feelling very well because you considered my question . lIttle by little I'll be interacting more with this interesting site. Have a grate day. Commented Jan 28 at 12:10