On a daily basis, about a hundred tons of comet dust and asteroid fragments collide with the Earth. Most burn up in the atmosphere. However, a kilometer-size or larger asteroid could someday collide with the Earth, causing a global disaster. The asteroids or comets whose orbits bring them close to Earth are ra
re, but there is the possibility of a collision of titanic proportions.
Some believe that the fall of the dinosaurs and the rise of man were triggered by a giant asteroid impact in Mexico some 60 million years ago. It seems prudent to discover and watch all the asteroids and comets that have the potential to impact Earth.
For years, the University of Arizona has pioneered in the discovery and study of the largest and most dangerous asteroids and comets that come close to the Earth. Using telescopes on Mt. Lemmon and Mt. Bigelow in the Tucson area, the Catalina Sky Survey is responsible for nearly 70 percent of the new discoveries each year.
Ed Beshore, the former director of the Catalina Sky Survey, will talk about the search for dangerous asteroids and comets and a mission to explore one of them at 3:30 p.m. Thursday (May 24) at Academy Village.
His talk, free and open to the public, is sponsored by the Arizona Senior Academy. It will be held in the Academy’s Great Room, adjacent to the Community Center at Academy Village, an active-adult community located off Old Spanish Trail six miles southeast of Saguaro National Park East.
At the present time, there are 8,844 asteroids and comets known to have orbits near Earth, with 1,301 of them identified as “Potentially Hazardous Asteroids,” or PHAs.
Near-Earth Asteroids are ideal targets for scientific exploration because their velocity relative to Earth is low, making it easy for a spacecraft to match their velocity and land on them. Earlier this year, Beshore left the Catalina Sky Survey and assumed the role of deputy principal investigator for OSIRIS-REx, an $800 million mission to the near Earth asteroid 1999 RQ36. The spacecraft will be launched in 2016 and arrive at the asteroid in 2019 where it will spend nearly a year studying the asteroid before grabbing a sample and returning it to the Earth in 2023.
This Near-Earth Object, while representing one of the largest impact threats to the Earth, also harbors what may be some of the most primitive materials found in the solar system, and thus may hold clues to the origin of Earth’s water and the organics that seeded life.
Beshore has a long history of scientific exploration, working at the MMT Observatory on Mt. Hopkins south of Tucson and the Pioneer 11 mission to Saturn before coming to the Catalina Sky Survey in 2002. He maintains his own robotic telescope observatory in Colorado.
Submitted by Drew Potter, Academy Village Volunteer