Fortunately not very often - because if one does hit, it would be a major catastrophe.
1km
1km = 1,000m which is larger than 334m
There are 1000 metres in one kilometre. Therefore, this is larger than 334 metres.
1 kilometer is 1,000 meters. That is much larger than 224 meters.
There have been about 300 identified Earth-crossing asteroids. The total number of asteroids that cross the Earth's orbit is estimated to be significantly greater than this; by one estimate, there are perhaps 1500 asteroids that are greater than 1km across, and 135,000 steroids that are greater than 100m across.
one mile is longer than one kilometer
Asteroids from 10m to 100m in diameter can cause national devastation (i.e. a country or state). Asteroids from 1km to 10km in diameter can cause global devastation (i.e. the world or several continents).
yes ,1km=100000cm 10km=1000000cm
1km = 1000m 1km > 50m 1km is bigger
1km = 1000m520m/1km:= 520/1000 or 13/25 of 1km
100000cm = 1km 50cm = 1km/1000000cm/1km 0.00005km = 50cm 50cm < 1km
1km -450 = -449