To quote:

"The favored simulation conditions outlined by the sweet spot suggest
an impact energy of around 1029 joules, which is equivalent to 100
billion gigatons of TNT. The impactor would have hit Mars at an angle
between 30 and 60 degrees while traveling at 6 to 10 kilometers per
second. By combining these factors, Marinova calculated that the
projectile was roughly 1,600 to 2,700 kilometers across."

With objects like that roaming the early Sol system, it is nothing
less than amazing in regards to the very recent news item I posted
elsewhere in this forum about Earth having liquid water and
continents 4.3 billion years ago, mere hundreds of millions of
years after the planet formed.

The Mars impact may also explain why there are no obvious signs
of Martian life past or present.