SpaceX Starlink satellites dazzle but may cause headaches for astronomers - CNET

Toot toot!

Marco Langbroek/GIF by Nicole Archer/CNET

Those aren't an intelligent extra-terrestrial army moving in to take over planet Earth -- they're just SpaceX's Starlink satellites, designed to provide broadband services across the globe.

The first batch of satellites were successfully launched from Cape Canaveral, Florida and deployed to orbit by a Falcon 9 rocket on May 23. They contain a single solar array, which both captures and bounces sunlight off the satellites and, as a result, can sometimes be seen from Earth. On May 25, as the drifting luminescent army of satellites zoomed overhead, Dutch satellite tracker Marco Langbroek captured their marching, posting a stunning video to his Vimeo.

In time, the satellites will drift further apart and are designed to hold specific orbits so that satellite internet coverage can be beamed to every corner of the globe.

However, as the unusual display in the night sky quickly gathered steam across social media, some astronomers began to point out the potential problems the satellite system may pose for radio astronomy. At present, only 60 satellites are moving into their orbit, but eventually that number will reach 12,000 and a megaconstellation will encircle the Earth. That would nearly triple the current amount of satellites currently orbiting the Earth.

With such a huge number of satellites, will our view of space and the stars be forever obstructed?

The quick answer: Not forever, no -- SpaceX are designing Starlink satellites to fall back to the Earth after about five years of service, burning up in the atmosphere on their way back in. But the long answer is: Potentially. Astronomers already wrangle with the problems posed by space robots and satellites circling the Earth whenever they turn their ground-based telescopes toward the stars. Bright, reflective surfaces pose a problem because they obstruct our view of the universe and thus cloud our vision.

More satellites equals cloudier eyeballs and Starlink plans to launch more satellites than ever.

When the sun is reflecting off the satellite's solar panels, visual astronomers will have to account for the appearance of the satellites in their image. SpaceX was relatively mum about the design of the satellites leading up to launch, so it has come as a bit of a surprise to some astronomers just how bright they were. However, the satellites will position their solar panels as they establish themselves in orbit which should reduce their brightness.

Jonathan McDowell, an astronomer with the Harvard-Smithsonian Center for Astrophysics, perhaps summed it up best with this tweet:

So the good news: it seems that once the Starlink sats point their solar panels at the Sun properly they are significantly fainter (more like mag 5 than mag 2). That is still brighter than we had expected and still a problem, but somewhat less of a sky-is-on-fire problem.

— Jonathan McDowell (@planet4589) May 26, 2019

"Somewhat less of a sky-is-on-fire problem" sounds slightly reassuring, at least. But there does seem to be clear issues for the astronomy community and they are concerned with how Starlink will hinder their observations going forward.

Elon Musk, SpaceX CEO, jumped to the defense of his satellite system and noted on Twitter how "potentially helping billions of economically disadvantaged people is the greater good," while making it clear that SpaceX plans to limit Starlink's effects on astronomy. "We care a great deal about science," Musk tweeted. He claims that he has sent a note to the Starlink team to reduce albedo -- decreasing the amount of light the satellites reflect.

In addition, after a user suggested placing space telescopes using the same Starlink chassis into orbit to appease the astronomers, Musk said he "would love to do exactly that." That might ease concerns, but will it totally alleviate them? 

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https://www.cnet.com/news/spacex-starlink-satellites-dazzle-but-may-cause-headaches-for-astronomers/

2019-05-28 06:07:08Z
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