NASA’s Center for Near-Earth Object Studies (CNEOS) is responsible for determining the trajectory of asteroids and assessing their potential danger to Earth. Using observations from telescopes, mathematicians at CNEOS calculate the objects’ trajectories tracking their motion and running the coordinates through software that employs the laws of physics to constrain the trajectory. More data and observations help to decrease uncertainty and allow for more accurate prediction of an object’s path.
The process involves at least four observations of an asteroid over an hour, but usually, around 12 observations are obtained before an object is officially announced the International Astronomical Union’s Minor Planet Center. It is crucial to determine whether an asteroid will intersect Earth’s orbit during the time when Earth passes that point. However, it’s not just asteroids that pose a threat; comets made of ice and rocks can also cause significant damage upon impact. Calculating trajectories for comets is more difficult due to a process called outgassing, where the sublimation of ice into gases affects their paths. Nevertheless, comets cannot be overlooked when it comes to planetary defense.
The increasing number of small objects in the solar system makes manual trajectory calculation impractical. To address this, CNEOS utilizes automated systems like Scout and Sentry to detect potential impactors and predict trajectories. Time is an essential factor in planetary defense, and characterizing objects through ground-based telescopes, researchers can gather information about an asteroid’s composition, density, shape, and speed.
Overall, NASA’s ongoing efforts in detecting and assessing the potential danger of near-Earth objects play a crucial role in protecting the planet from catastrophic impacts.