Interview with Professor Barbee: How NASA is Protecting Earth from Asteroids
Discover how NASA protects Earth from asteroid threats in this exclusive interview with Brent Barbee, aerospace engineer at NASA Goddard Space Flight Center and professor at the University of Maryland. We discuss the science of asteroid detection, the groundbreaking DART mission, and asteroid deflection strategies, from kinetic impactors to nuclear options.
SPACE EXPLORATION & PLANETARY SCIENCE
Vince Sanouvong and Professor Brent Barbee
2/24/20252 min read
Introduction to Brent Barbee's Career:
Brent Barbee is an aerospace engineer at NASA's Goddard Space Flight Center and an aerospace engineering professor at the University of Maryland - College Park. He grew up in the 1980s and was sparked by planetary defense while learning about the asteroid impact that caused the extinction of dinosaurs. Additionally, he was fascinated by the impact of the 1994 Comet Shoemaker-Levy 9 on Jupiter.
Detecting and Tracking Hazardous Asteroids
A global network of telescopes tracks near-Earth objects (NEOs). The Minor Planet Center processes observations, which are analyzed by NASA's Center for Near-Earth Object Studies (CNEOS) using an automated system called Sentry to calculate the probability of Earth impact. Sentry is a collision monitoring system that continually scans the most current asteroid catalog for possibilities of future impact with Earth.
Challenges:
Ground telescopes can only observe asteroids at night.
Many asteroids are not easily visible due to their non-reflective spots.
The NEO Surveyor Telescope will launch in late 2027 and will be able to pick up asteroids that are not visible. It will also enhance how early we can detect asteroids at the Sun-Earth L1 Lagrange point.
Strategies to Deflect Asteroids
Kinetic Impactor:
This involved the kinetic energy of a spacecraft or satellite colliding with an asteroid to transfer momentum and cause the asteroid to change course.
The momentum enhancement factor (from the ejecta that kicked off the asteroid) was calculated to be around 3.6, amplifying the impact's effect.
NASA's DART Mission successfully changed the course of the asteroid Dimorphos.
Nuclear Deflection:
This method involves detonating a nuclear device near an asteroid to vaporize part of its surface, providing a powerful push in the opposite direction. The momentum from the push causes the asteroid to change course.
Ion Beam Deflection:
It uses ion thrusters to push an asteroid off course over time gradually. Although
This is a slower but controlled method that requires extended spacecraft proximity.
What are some challenges in planetary defense?
First, asteroid detection must be early enough to ensure sufficient time to respond.
Second, we must be highly accurate when aiming and hitting minor asteroids from millions of miles away. Therefore, targeting precision is extremely important.
Third, we must understand the asteroid's composition(mass, shape, and density). This helps us choose the best deflection method.
Even after contact with the asteroid, we must predict and manage the fragments that shoot in different directions.
What is the future of planetary defense?
NEO Surveyor: Expected to enhance asteroid detection and early warning capabilities significantly.
Rapid Deployment: Developing faster methods for launching spacecraft in emergency scenarios.
Propulsion Systems: High-power, efficient solar electric propulsion advancements are key to future deflection missions.
AI in Defense: Although not widely used, AI could play a future role in detection and mission planning.
Additional Resources:
Visit the Center for Near-Earth Object Studies (CNEOS).
Experiment with the NEO Deflection App to design simulated deflection missions.
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