Meteoroids and Meteors

Meteoroids

• 100,000 million enter the Earth’s atmosphere every day
  • micron to cm-scale diameter
• most meteoroids vaporize before they reach 35 miles above the surface
• speeds of 25,000 to 70,000 mph
  • atmosphere acts like a solid and destroys them
• some of the biggest meteors/meteorites to hit Earth are:
  • Hoba meteorite
  • this hit Namibia
  • Willamette Meteorite
  • found in the Willamette Valley, but isn’t thought to have hit there
  • Cape York Meteorite
  • hit northwest Greenland
  • Mbozi Meteorite
  • found in Tanzania
  • Bacubirito meteorite
  • hit in Sinaloa

Meteorites

• meteoroid must be about 1 gram (0.04 oz) or more to make it to the surface
• frictional resistance of the atmosphere melts their exterior
  • hit the atmosphere at such high speeds
• interiors are protected from melting
• gives glazed and blackened appearance
• create mini sonic booms when they hit the atmosphere
  • $sonic booms:$ a loud explosive noise caused by the shock wave traveling faster than the speed of sound itself
  • air compressed in front
  • sends sound waves down towards Earth