The U.S. company SpaceX plans to build a constellation of 42,000 low-Earth-orbit communication satellites called Starlink. A new study, led by Przemek Mróz of the Astronomical Observatory of the University of Warsaw, looks at the impact of satellites on ground-based astronomical research. Since 2019, SpaceX has been launching an increasing number of internet satellites into orbit around Earth. The satellite network, also called a constellation, now includes nearly 1,800 members orbiting at altitudes of about 550 kilometers. Astronomers have expressed concerns that these objects, which can appear as streaks in telescope images, could hamper their scientific observations.
To quantify these effects, a team of researchers studied archival images captured by the Zwicky Transient Facility (ZTF), an instrument that operates from the Palomar Observatory near San Diego, California, US. ZTF scans the entire night sky every two days, cataloguing cosmic objects that explode, blink, or otherwise change over time. This includes everything from supernovae to near-Earth asteroids. The team says that they decided to specifically study the effects of Starlink satellites because these satellites currently represent the largest low-earth orbit constellation and they have well-characterized orbits.