CLOSE CALLS

• Have we had close calls? YES

  • Near miss Feb 24, 2004. 15-m asteroid comes within 400,000 km.
  • Near miss in March 2002: 70-m asteroid < 461,000 km (288,000 miles) from Earth
  • Dec 1994, an asteroid passed within 100,000 km.
  • March 23, 1989: asteroid bigger than aircraft carrier (300 m) passed through Earth’s orbit < 700,000 km away. Earth had been at that spot 6 hours earlier. IF it had hit, the energy released would have been ~1000-2500 Mtons of TNT.

• NOTE:

  • Distance to moon is 384,000 km.
  • Tunguska object ~50m in size
  • Neither seen until AFTER since they came from the direction of the sun

Notes: