As SpaceX prepares to make its sixth Starlink launch on Saturday, March 14, 2020, the space company founded by Elon Musk is taking more and more seriously the discomfort caused by its satellites in low-Earth orbit for night sky observation. The company asked to meet with astronomers from the European Southern Observatory (ESO) to discuss the problem of light pollution caused by the satellites of its Starlink mega-satellite, which is supposed to provide fast and cheap Internet access from space.
The call comes days after Elon Musk said at the Satellite Conference 2020 that the Starlink satellite mega-spying would “not have the slightest impact on astronomical discoveries,” contradicting a recent study published by ESO. In this study, the group of astronomers made it clear that large fleets of commercial satellites such as SpaceX, OneWeb and others could interfere with the work of telescopes in the early morning when satellites still reflect the sunlight.
“We are encouraged by the fact that SpaceX has contacted us about the telescope that would be most affected and by their cooperative and constructive suggestions made so far. We look forward to working with SpaceX, in cooperation with other astronomy groups and governments, to find a mutually acceptable solution,” Andy Williams, one of the study’s co-authors, told Business Insider US.
He added: “Honestly, they [SpaceX] seem quite willing to work with the astronomer community, which is very positive, and I look forward to seeing what they can suggest when we can talk to them.” However, he did not elaborate on SpaceX’s suggestions so far.
Some images could be damaged or even lost
In detail, ESO researchers have estimated that satellite interference would have only a “moderate” effect on ESO’s Very Large Telescope (VLT) and the future Extremely Large Telescope (ELT), which monitor only relatively small areas of the sky. nocturnal. But it still means that some images could be damaged or even lost, due to the brightness of the satellites.
For large-field observation telescopes, which monitor larger parts of the sky, the impact would be even greater. For the Vera C. Rubin Observatory, formerly known as the Large Synoptic Survey Telescope or LSST, the study estimated that 30-50% of exposures could be “severely affected”. “The problem with the American Vera Rubin telescope is that because of the brightness of the satellites, its detector can actually saturate and cause the entire image to be lost,” Williams said. “Because of their unique ability to generate very large data sets and find observation targets for many other observatories, wide-field surveys are essential to the future development of astronomy,” he added.
A coating specially designed to make them less reflective
SpaceX has already taken a first test step to try to remedy this problem of light pollution caused by its satellites. Indeed, the space company decided to paint some parts in black rather than white. One of SpaceX’s recently launched satellites has a background coating specifically designed to make the spacecraft less reflective and therefore less likely to interfere with sky observations. But SpaceX President Gwynne Shotwell said it was a test and it was impossible to know if it would work. In fact, at this time, we still do not know if this track has paid off.
Since the launch of SpaceX’s first 60 satellites in May 2019, astronomers had been concerned about the significant light pollution caused by them. Just after sunset or early in the morning, satellites can be struck by sunlight and become visible to sophisticated astronomy telescopes but also to ordinary amateur binoculars, as explained by Cees Bassa, from the Dutch Institute of Radio Astronomy, Forbes magazine: “These things are big enough that when they are illuminated by the Sun, they are bright enough to be spotted with ordinary binoculars or an instrument more powerful.”