Editing Impact event (section)

===Evidence of massive past impact events===
[[Image:Aitken Kagu big.jpg|thumb|Topographical map of the [[South Pole–Aitken basin]] based on [[SELENE|Kaguya]] data provides evidence of a massive impact event on the Moon some 4.3 billion years ago]]
{{Main|List of largest craters in the Solar System}}

Impact craters provide evidence of past impacts on other planets in the Solar System, including possible interplanetary terrestrial impacts. Without carbon dating, other points of reference are used to estimate the timing of these impact events. Mars provides some significant evidence of possible interplanetary collisions. The [[North Polar Basin (Mars)|North Polar Basin]] on Mars is speculated by some to be evidence for a planet-sized impact on the surface of Mars between 3.8 and 3.9 billion years ago, while [[Utopia Planitia]] is the largest confirmed impact and [[Hellas Planitia]] is the largest visible crater in the Solar System. The Moon provides similar evidence of massive impacts, with the [[South Pole–Aitken basin]] being the biggest. [[Mercury (planet)|Mercury]]'s [[Caloris Basin]] is another example of a crater formed by a massive impact event. [[Rheasilvia]] on [[4 Vesta|Vesta]] is an example of a crater formed by an impact capable of, based on ratio of impact to size, severely deforming a planetary-mass object. Impact craters on the [[moons of Saturn]] such as Engelier and Gerin on [[Iapetus (moon)|Iapetus]], Mamaldi on [[Rhea (moon)|Rhea]] and [[Odysseus (crater)|Odysseus]] on [[Tethys (moon)|Tethys]] and [[Herschel (Mimantean crater)|Herschel]] on [[Mimas (moon)|Mimas]] form significant surface features. Models developed in 2018 to explain the unusual spin of [[Uranus]] support a long-held hypothesis that this was caused by an oblique collision with a massive object twice the size of Earth.<ref name="KegerreisTeodoro2018">{{cite journal|last1=Kegerreis|first1=J. A.|last2=Teodoro|first2=L. F. A.|last3=Eke|first3=V. R.|last4=Massey|first4=R. J.|last5=Catling|first5=D. C.|last6=Fryer|first6=C. L.|last7=Korycansky|first7=D. G.|last8=Warren|first8=M. S.|last9=Zahnle|first9=K. J.|title=Consequences of Giant Impacts on Early Uranus for Rotation, Internal Structure, Debris, and Atmospheric Erosion|journal=The Astrophysical Journal|volume=861|issue=1|year=2018|page=52|issn=1538-4357|doi=10.3847/1538-4357/aac725|arxiv=1803.07083|bibcode=2018ApJ...861...52K|s2cid=54498331 |doi-access=free }}</ref>