Planetary Defense: Surveying the skies for killer asteroids - Dr. Vishnu Reddy
Impacts due to near-Earth objects (~90% NEAs and ~10% comets) are one of the natural hazards that can cause the extinction of the human race, but one that can potentially be mitigated if the threat is detected with sufficient lead-time. While the probability of such an event is low, the outcome is so catastrophic that we are well justified in investing a modest effort to minimize this threat. Historically, asteroid impacts have altered the course of evolution on the Earth. The most recent significant event took place 65 million years ago when a 10-km object impacted off the Yucatan Peninsula coast, Mexico, leading to the extinction of dinosaurs and ~75% of all species. This probably provided mammals (including our ancestors) an opportunity to thrive. Within our lifetime, the collision of Comet Shoemaker-Levy 9 (SL-9) with Jupiter served as reminder to us that asteroid impacts could be a real threat to life on Earth. The probability of such impacts appears to be significantly higher than initial estimates with the recent discovery of at least five asteroid/comets impacts on Jupiter. More recently the Chelyabinsk meteor over Russia, which injured hundreds of people and damaged thousands of buildings, only reinforced the importance of detecting and characterizing small NEAs that pose a greater threat than most large NEAs discovered so far. Following the SL-9 impact, the U.S. Congress-mandated NEO searches have been very successful with over 24,000 NEOs discovered as of October 2020. But NASA will fall short of meeting the 2020 Congressional mandate of discovering 90% of asteroids larger than 140 meters. NEO Surveillance Mission is a space-based infrared telescope that will help accelerate the discovery of hazardous asteroid and answer the question if Earth will be impacted by an asteroid larger than 140 meters in the next 100 years. The talk will give a historical overview of asteroid impacts and the state of planetary defense today.
Biography: Vishnu Reddy
Vishnu Reddy is an associate professor of planetary sciences at the Lunar and Planetary Laboratory, University of Arizona (UoA), in Tucson. Prior to serving as a faculty member at the UoA, he was a research scientist at the Planetary Science Institute in Tucson, Arizona, from 2012-2016.
Prof. Reddy is the investigation team lead on NASA Near-Earth Object Surveillance Mission (NEOSM) to discover 90% of near-Earth objects (NEOs) larger than 140 meters to fulfill the George E. Brown Congressional mandate. Prior to that he was a member on NASA’s Dawn mission working with the Framing Camera team at the Max Planck Institute for Solar System Research in Germany.
Since 2005, Prof. Reddy has been using the NASA IRTF on Mauna Kea, Hawaii to spectrally characterize small NEOs that make close flyby of the Earth. In addition to his work with NASA, Prof. Reddy is part of the Space Situational Awareness (SSA) program at the University of Arizona where he has developed a network of small optical sensors to characterize orbital debris and active resident space objects (RSOs) for the United States Air Force Research Laboratory (AFRL).
Prof. Reddy is an avid amateur astronomer and has built several telescopes. He regularly observes and images the night sky with his 20-inch F/2.8 Newtonian from his backyard observatory just north of Tucson, Arizona.