There are thousands of Solar System objects classified as potentially hazardous asteroids (PHAs), which could hit Earth at some time in the future. Scientists estimate that there are thousands more PHAs yet to be discovered. Rubin Observatory is exceptionally good at discovering faint near-Earth asteroids because of its ability to frequently scan large areas of the sky and to image very dim objects. Over a ten year period, Rubin Observatory is expected to detect more than 80% of all potentially hazardous objects thought to exist.

Students analyze near-Earth asteroids, newly discovered by the Rubin Observatory, to evaluate a specific asteroid’s potential threat to Earth. They come to understand how uncertainty in measurements can cause the perceived threat level of an asteroid to change with time. Students learn how to calculate the size of an asteroid and evaluate the amount of potential damage an impact would cause.

Prerequisite Concepts

• Students should be familiar with how to calculate the kinetic energy of an object.
• Students should know the difference between common Solar System bodies: asteroids, meteoroids and comets.
• Students should be familiar with the brightness measurement of magnitude and its scale.
• Students should have been introduced to Newton’s Laws of Motion and gravity.

Learning Outcomes

• Students analyze orbits of near-Earth asteroids recently discovered by Rubin Observatory to estimate the likelihood of a serious threat to Earth.
• Students develop an appreciation for how uncertainty in observations of moving Solar System objects affects the predictions of their orbits.
• Students can explain the factors that affect the gravitational interactions between two Solar System objects, and how such interactions can alter the orbits of small Solar System objects.
• Students evaluate how the velocity and mass of an asteroid determines the amount of potential damage if it impacts Earth.
• Students come to understand that Earth impacts are rare events.

Essential Questions

• What factors determine if an asteroid could hit Earth?
• What is needed to accurately define the orbit of a newly-discovered Solar System object?
• What factors determine the amount of damage from an asteroid impact?