The larger asteroid was pretty much the same size as the one that created meteor Crater in AZ.....had it impacted it would have been a very bad day:
" Formation of the crater
The crater was created about 50,000 years ago during the Pleistoceneepoch when the local climate on the Colorado Plateau was much cooler and damper. At the time, the area was an open grassland dotted with woodlands inhabited by woolly mammoths and giant ground sloths. It was probably not inhabited by humans; the earliest confirmed record of human habitation in the Americas dates from long after this impact. The object that excavated the crater was a nickel–iron meteorite about 50 meters (54 yards) across, which struck the plain at a speed of several kilometers per second. Impact energy has been estimated at about 10 megatons. The speed of the impact has been a subject of some debate. Modeling initially suggested that the meteorite struck at a speed of up to 20 kilometers per second (45,000 mph), but more recent research suggests the impact was substantially slower, at 12.8 kilometers per second (28,600 mph). It is believed that about half of the impactor's bulk was vaporized during its descent, before it hit the ground. The meteorite itself was mostly vaporized upon impact. Very little of it remained within the pit that it had excavated"