Last month, while the world was preparing for asteroid 2012 DA14 to fly inside the orbit of Earth's weather and communications satellites, a much smaller space rock was on a collision course with Russia. While the estimated 100-foot diameter DA14 was detected a year ago by an automated sky search program in Spain, the 55-foot meteor that crashed to Earth in Russia went undetected.
It wasn't the size of the Russian meteor that kept it hidden from technology, but rather its flight path from the inner solar system. In 2008, astronomers detected a small kitchen table-size asteroid with the NASA-funded 60-inch Mount Lemmon telescope at an observatory in Arizona. This was the first time that an impacting object was observed during its final approach, and a warning was given as to where and when it would enter our atmosphere.
There is currently no comprehensive map of our inner solar system showing the positions and trajectories of the asteroids whose orbits take them close to the sun and threaten Earth. Last year, however, the nonprofit B612 Foundation announced plans to build and operate a privately funded infrared space telescope that will be placed in orbit around the sun to discover, map and track these asteroids.
The Sentinel mission will be designed to discover and catalog 90 percent of the asteroids larger than 400 feet in Earth's region of the solar system. The mission should also discover a significant number of smaller asteroids down to a diameter of 90 feet. Sentinel is scheduled to be launched aboard a Falcon 9 rocket into a Venus-like orbit around the sun in 2018. This orbit will significantly improve its effectiveness in detecting asteroids during its six-year mission.
The foundation's name was inspired by the children's book written by Antoine de Saint-Exupery. B612 is the asteroid home of "The Little Prince."