CHICAGO — If you hear a loud noise from a jet Monday or Tuesday it may be due to a NASA research project.

According to a news release, NASA’s Armstrong Flight Research Center’s DC-8 aircraft will fly at a low-altitude over the Chicago area on Monday “and/or” Tuesday from mid-morning to mid-afternoon.

The project measures atmospheric emissions and reactions observed from megacities to marine areas.

NASA said while it will be flying low, all flyovers will be conducted at a safe altitude. However, the agency said it will be “very loud” and those with sensitivities to loud noises should be aware.

The aircraft will be collecting data for air quality and sources of pollution.

To follow the plane, visit flightaware.com and enter the tail number “N817NA”.