Potentially Hazardous Asteroids
How many asteroids have a chance to hit Earth’s surface?
There are more potentially hazardous asteroids, PHAs, than we might realize!
Check it out: Intro video: NOVA http://www.pbs.org/wgbh/nova/space/asteroid.html
- Simulate an asteroid hitting Los Angeles: http://www.pbs.org/wgbh/nova/space/asteroid-calculator.html
- NASA’s Wide-field Infrared Survey Explorer (WISE) mission has attempted to locate and calculate the number of asteroids in Earth’s proximity. The image below compiles this mission’s data from 2011: What do you think the different color lines represent? What is the difference between the blue and the orange lines?
- This recent mission continues to support the rough estimate that 4700 asteroids are potentially hazardous to the Earth. Check it out: NASA Survey Counts Potentially Hazardous Asteroids What is the “bad” news from the mission? What is the “good” news?
- Are other planets in our solar system in jeopardy as well? Would you expect them to have more PHAs or fewer? Why? Use NOVA’s solar system interactive to familiarize yourself with the planetary orbits: Tour the Solar System