A telescope at the $473 million Vera C. Rubin Observatory, under construction in Chile, could cut the visual interference from satellites in its images by half 鈥� but at the cost of sacrificing about 10 per cent of the time spent observing the night sky. That may become necessary as growing swarms of commercial satellites fill the night sky and outshine stars, planets and other objects of interest.
The US-funded observatory will house a telescope that looks for near-Earth asteroids and distant supernovae while photographing the entire available night sky using the world鈥檚 largest digital camera. But the telescope鈥檚 planned 10-year survey may have to eventually change its viewing routine to avoid satellites.
The two main commercial satellite operators, OneWeb and SpaceX鈥檚 Starlink, have already launched hundreds of satellites, and the two may be operating as many as 40,000 before the end of 2023. Computer simulations run by at the University of Washington in Seattle and his colleagues suggest that about 10 per cent of all the telescope鈥檚 images may have a streak of light from the Starlink and OneWeb satellites.
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鈥淔rom the start we鈥檝e always known that we would have some satellite streaks,鈥� Yoachim says, but 鈥渂y the end, things could be much worse than they are at the start.鈥�
The researchers also explored what might happen if they updated the scheduling algorithm that automatically points the telescope away from parts of the sky with high concentrations of bright satellites. Those simulations showed it is possible to reduce satellite streaks by a factor of two while giving up 10 per cent of observing time.
For now, it鈥檚 probably not worth the sacrifice, Yoachim says. But that could change if the planned satellite constellations grow considerably or if more companies launch significantly brighter satellites, such as AST SpaceMobile鈥檚 BlueWalker 3, which outshines 99.8 per cent of visible stars. As it stands, the sky may be studded with 400,000 or more satellites if various companies follow through on their plans.
鈥淚t鈥檚 nice to see that we can come up with algorithms to still make use of this huge observatory that has had millions of taxpayer dollars poured into it,鈥� says at the University of Regina in Canada. 鈥淏ut look at all this time that astronomers are spending trying to get around this new pollution by for-profit companies.鈥�
Astronomers could better understand how to avoid the worst of the disruptions if companies shared more details about their satellites鈥� orbits and materials that affect satellite brightness, she says, but companies should also take more steps to actively minimise the impact of their satellites on science.
SpaceX has previously responded to astronomers鈥� concerns about the by experimenting with darker paint coatings, sunshades and other methods for reducing satellite reflectivity. SpaceX and OneWeb have not respond to New 杏吧原创鈥檚 request for comment.
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