Surfing Into Saturday: Celestial sites search sky

By Daniel Sieberg
CNN

(CNN) -- Earlier this week, a mysterious object falling from the sky sparked renewed interest in how vulnerable the Earth is to such chance encounters. But scientists downplayed the significance of the occurrence, saying it was likely a stray meteor and happens more often than most people realize. Here are some sites to learn about the nuances of space activity.

NASA's Jet Propulsion Lab's Near-Earth Object Program

Nervous about NEO? No, it's not a friend of Chicken Little. "Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighborhood," reads this site from NASA. Check it out and Monday's streak in the sky will suddenly be put into perspective. NASA has assembled a chart detailing the frequency of NEOs approaching Earth so you can plan your next road trip accordingly.

• http://neo.jpl.nasa.gov/

NASA's Ames Space Science Center

This NASA site has detailed information on how NEOs are formed, as well as what some countries like Russia are doing to protect Earth from the impact of a NEO. Some evidence lends itself to the theory that a massive asteroid hitting the earth millions of years ago was responsible for the mass extinction of many floral and faunal species, including the large dinosaurs, and this site has more information on that premise as well as numerous graphics.

• http://impact.arc.nasa.gov/

International Meteor Organization

For a fee, you too can become a member of the International Meteor Organization. Its continuing mission is to collect meteor observations from around the world and disseminate the data to amateurs and professionals. The site offers tips on viewing meteors, as well as software downloads to assist with your quest. Remember: objects in telescope may be closer than they appear.

• http://www.amsmeteors.org/imo-mirror/index.html (mirror site)

Jet Propulsion Lab's Space Calendar

You're on your way out the door when you check the JPL Space Calendar and realize an asteroid is nearing Earth -- could put a damper on your day. Rest assured, it's likely millions of miles away, so there's no excuse to stay home and sleep in. The Jet Propulsion Laboratory, a branch of NASA, has put together an extremely detailed compilation of asteroid, meteor and NEO activity happening in the galaxies. Pick a day and find out what's flying around.

• http://www.jpl.nasa.gov/calendar/

Meteor Hunters

Next time you're looking for a gift for the person who has everything, why not consider a meteor? Yes, the Meteor Hunters site actually has meteor specimens for sale at a variety of prices -- guaranteed authentic. (Starter collections for under $50.) This site also helps prospective meteor hunters determine whether they've found the real thing or just another rock in the neighbor's yard. Numerous links are also provided to other sources on meteor showers.

• http://www.meteorhunters.com/