Astronomers call for Earth Day to curb satellites

Astronomers say this sequence in a Hubble Space Telescope image was likely created by a Starlink satellite flying a few miles above Hubble. (MAST image via Nature Astronomy/Simon Porter)

Astronomers have called on Earth Day for environmentalism to be extended more fully to the final frontier, and for companies such as SpaceX and Amazon to recall their mega-constellation plans.

Among the authors of today’s comment in the journal Nature Astronomy is Meredith Rawls from the University of Washington.

Astronomers have worried about the impact of having thousands of satellites in low Earth orbit for years, starting with SpaceX’s launch of the first operational satellites for its Starlink broadband constellation in 2019. Rawls and the other authors of today’s comment point out that they are not. They are only worried about interference with their astronomical observations, but are also concerned about the wider impact on appreciation of the night sky.

“We need everyone on deck to deal with the rapidly changing satellite situation if we can hope to co-create a future with dark and calm skies for everyone,” said researcher Rawls. to Vera C. Rubin Observatory and U.W. DIRAC Institutesaid in a Press release.

“The Rubin Observatory will be one of the hardest hit astronomy facilities by a large number of bright satellites because of its large mirror and wide field of view – the same characteristics that make it such a powerhouse of discovery. remarkable,” Rawls said. “I care a lot about how satellite footage affects science, but the case of dark, calm skies is much more important than that.”

The comment cites other threats to the space environment, ranging from in-orbit collision threats and orbital debris to pollution from rocket launches. But his main focus is on projects like Starlink and Amazon’s Project Kuiper, which aim to put thousands of satellites into low Earth orbit, or LEO, to provide global high-speed internet access from above.

Both Starlink and Project Kuiper are headquartered in Redmond, Washington. SpaceX builds dozens of satellites per month and already offers limited internet service. Just this week, JSX, a Texas-based hop-on airline, said it use Starlink for in-flight Wi-Fi. The Kuiper project, meanwhile, is still under development.

Many other companies, including OneWeb, Telesat and Boeing, have their own plans for broadband satellite constellations. If all of these plans come to fruition, there could be tens of thousands of satellites spinning in the sky within a decade. For the purposes of their commentary, the authors of the Nature Astronomy commentary assume that 100,000 satellites will be orbiting at altitudes on the order of 600 kilometers (373 miles) by 2030.

SpaceX and other companies have worked with astronomers on ways to minimize the impact of their satellites on observations of the night sky, but the authors of today’s commentary say that’s not enough. “None of these mitigations can entirely prevent LEO satellite constellations from harming astronomical science; launching far fewer satellites is the only mitigation that could do this,” they write.

Among the recommendations of the researchers:

  • Regulators such as the Federal Communications Commission should further assess the impact of space projects on Earth’s space environment during the licensing process. The authors define the space environment as the region between 62 miles (or 100 kilometers, the so-called “Karman line”) and 22,000 miles in altitude (the orbital distance of geostationary satellites).
  • Scientists should develop measures for a global “space traffic footprint”, loosely interpreted as the burden that any intentionally launched object places on the safety and sustainability of other objects in orbit and on the orbital environment itself. . The concept is analogous to “Carbon footprint” which figures so prominently in the assessment of human-induced climate change.
  • In February, the International Astronomical Union created a new center to address concerns about satellite interference with night sky observations, and the authors call for the creation of a satellite observing center under the organizational umbrella. of the Center. “Such a long-term mitigation activity will require significant sustainable resources,” they say.

Some of the commentators are involved in a legal challenge to FCC rulings regarding SpaceX’s Starlink networkand the arguments in their amicus brief parallel the arguments of today’s commentary.

The primary author of the Nature Astronomy commentary, titled “The case of space environmentalism”, is Andy Lawrence from the University of Edinburgh. In addition to Lawrence and Rawls, co-writers include Moriba Jah, Aaron Boley, Federico Di Vruno, Simon Garrington, Michael Kramer, Samantha Lawler, James Lowenthal, Jonathan McDowell, and Mark McCaughrean.

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