Dr. Gerhard Drolshagen (ESA und Uni Oldenburg)

Near-Earth Objects - Overview, impact risk and ongoing studies

As of mid-January 2020, about 21700 Near-Earth Objects (NEOs) are known. These are objects that can come closer than 45 Mio km to Earth. Asteroids and comets provide information about the history of the solar system and they could be exploited by space missions as resources. But they also form a potential hazard. About 1000 of the known NEOs have a small but non-zero chance to impact Earth within the next 100 years. And most of the NEOs are still unknown. The total number of NEOs larger than 10 m in size could exceed 100 Mio. Impacts from asteroids and comets have happened throughout the history of Earth and will happen again.  This talk will give an overview of the history of NEO discoveries and present the status of our present knowledge on the numbers and characteristics of NEOs. This will be followed by an assessment of the impact risk and address potential measures to mitigate the impact threat. The talk will also briefly address ongoing and planned space missions to asteroids which include sample return missions and a mission to the double asteroid Didymos to demonstrate the capability to deflect such an object.