climatic effects of impacts

[Threeofnine]

I notice on many youtube videos the effects of asteroid/astronomical object impacts on earth's climate are dramatic and long lasting. However, when I send anything, even mars, crashing into the earth using the preloaded solar system simulation the earth is pretty much back to normal within a year or two (minus the craters). What am I doing wrong?

[Minhoca]

The Earth is at the best position in Solar system and it is going to go back to normal in very short time. Still weird that this happens in only 1 or 2 years... i am going to test it out and see if this is intended to happen.

[Minhoca]

I've tested it and... nope.

 The impact changed Earth's orbit and now it has a very cold winter that freezes the ocean and then the ocean gets liquid again(it is very unstable). I think you didn't see right what happened in like 10 years, because after the impact Earth got only ~52% of life likelihood(there are still lights but that is probably a bug, since Japan was right in the impact and it still had a lot of lights.
 But this may be because i've hit Earh two times with Mars,  which was probably why it changed orbit... But i still think Earth would be screwed up even with only 1 impact.

EDIT: Madee it again with only one hit, Earth didn't change the orbit but the life likelihood dropped to 66%.