Why astronomers are worried that SpaceX’s satellite network will pollute the night sky

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The Verge By Loren Grush 5/29/2019

Over the weekend, astronomers and space enthusiasts everywhere caught a glimpse of SpaceX’s recently launched Starlink satellites in the sky. They’re the first 60 spacecraft of nearly 12,000 the company plans to launch for its massive “internet from space” initiative. For many on the internet, it was an amazing sight to see. For the astronomy community, it was devastating to watch.

The satellites, strung out like a line of glowing army ants, shone brightly as they moved along their orbit around Earth, clearly visible to the naked eye. Now, many in the astronomy community are concerned that this mega constellation might be too bright, and the sheer number of satellites that SpaceX wants to launch could muck up their telescope observations of the Universe.

“It’s going to become increasingly likely that the satellites will pass through the field of view and essentially contaminate your view of the Universe,” Darren Baskill, an outreach officer of physics and astronomy at the University of Sussex, tells The Verge. “And it’s going to be really difficult to remove that contamination away from our observations.”

Satellites are already an issue for astronomers studying celestial objects in deep space. In order to get detailed images of objects many light-years away from Earth, astronomers take long-exposure shots of the sky with their telescopes. This type of imaging entails leaving the telescope exposed to light for minutes or hours. As a result, scientists can gather light from a very distant, faint object and figure out more about it. For instance, it’s a great way to learn what kinds of gases are in a faraway galaxy. Each type of gas emits different types of light, which astronomers can detect and identify.

But whenever a super bright object passes through the field of view of a long-exposure shot, the observation gets muddied. The light from that object tears through the image, causing a long, bright streak through the sky. Satellites can be particularly bright since they’re often made with reflective materials or have solar panels that bounce light from the Sun. “If it was just a point in an image, that wouldn’t be too bad,” Phil Bull, a theoretical cosmologist at Queen Mary University of London, tells The Verge. “You could just ignore the bit around that point. But because it’s a big line going through your image, it really gets in the way.”

More: https://www.theverge.com/2019/5/29/18642577/spacex-starlink-satellite-constellation-astronomy-light-pollution

[bigheadfred]

There is an easy fix. Set up shop on the dark side of the moon.