Skip to main content

Astronomers are worried about satellite constellations like Starlink

Ever since SpaceX began the process of launching its Starlink satellite constellation, consisting of thousands of satellites that work together to create a global broadband network, astronomers have been expressing worry about the effects such constellations could have on the sky. SpaceX is not the only company that plans to launch thousands of satellites in a constellation, and their combined presence overhead could have worrying consequences for astronomical observations.

Now, the International Astronomical Union (IAU) has announced it is setting up a new center to tackle this issue, called the IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference. The idea is to bring together astronomers and satellite operators from different geographic regions to work on the problem together.

Starlink Satellites pass overhead near Carson National Forest, New Mexico, photographed soon after launch.
Starlink Satellites pass overhead near Carson National Forest, New Mexico, photographed soon after launch. M. Lewinsky/Creative Commons Attribution 2.0

The concern about satellite constellations is that satellites are typically made of highly reflective metal, so they reflect sunlight and appear as bright dots which interfere with astronomical observations. In addition, they can also interfere with radio telescopes. Constellations are a particular concern because of the sheer number of satellites that are launched, and the fact they are designed to cover large portions of the entire globe.

“The International Astronomical Union (IAU) is deeply concerned about the increasing number of launched and planned satellite constellations in mainly low Earth orbits,” the IAU wrote. “The IAU embraces the principle of a dark and radio-quiet sky, not only as essential to advancing our understanding of the Universe of which we are a part, but also for the cultural heritage of all humanity and for the protection of nocturnal wildlife.”

The formation of a center to study this issue has been welcomed by other astronomical organizations, such as Britain’s Royal Astronomical Society (RAS).

“The new constellations are already affecting optical and radio astronomy,” the RAS writes. “By design, the satellites provide coverage to the whole Earth, so unlike light pollution and radio interference on the ground, it is impossible to escape their effects through relocation to remote sites. The most obvious impact is the appearance of many more trails across images made with optical observatories, both on the ground and in space, which require time consuming and expensive mitigation with software or repeat observations, and in some cases render data useless. Observations of short-lived phenomena often simply cannot be repeated.”

The new center aims to become a unified voice for astronomers in order to protect the dark sky, including those like RAS Deputy Executive Director Robert Massey, who said: “It’s important to protect our view of the night sky so that future generations continue to be inspired by looking up at the stars.”

Editors' Recommendations