Lights in the sky from Elon Musk's new satellite network have stargazers worried

Lights in the sky from Elon Musk's new satellite network have stargazers worried
The panel of 60 Starlink satellites just before they were released to go into orbit around Earth. Credit: Official SpaceX Photos

UFOs over Cairns. Lights over Leiden. Glints above Seattle. What's going on?

The launch of 60 Starlink satellites by Elon Musk's SpaceX has grabbed the attention of people around the globe. The satellites are part of a fleet that is intended to provide fast internet across the world.

Improved internet services sound great, and Musk is reported to be planning for up to 12,000 satellites in low Earth orbit. But this fleet of satellites could forever change our view of the heavens.

Starlink's ambitious mission

Starlink is an ambitious plan to use satellites in low Earth orbit (about 500km up) to provide global internet services.

This is different from the approach previously used for most , in which larger individual satellites were placed in high geosynchronous orbits—that stay in an apparently fixed position above the Equator (about 36,000km up).

Communications with satellites in geosynchronous orbits often require , which you can see on the sides of residential apartment buildings. Communication with satellites in low Earth orbit, which are much closer, won't require such bulky equipment.

But the catch with satellites in low Earth orbit, which move quickly around the world, is they can only look down on a small fraction of the globe, so to get global coverage you need many satellites. The Iridium satellite network used this approach in the 1990s, using dozens of satellites to provide global phone and data services.

Starlink is far more ambitious, with 1,600 satellites in the first phase, increasing to 12,000 satellites during the mid-2020s. For comparison, there are roughly 18,000 objects in Earth orbit that are tracked, including about 2,000 functioning satellites.

Starlink satellites travel silently across the skies of Leiden.

Lights in the sky

It's not unusual to see satellites travelling across the twilight sky. Indeed, there's a certain thrill to seeing the International Space Station pass overhead, and to know there are people living on board that distant light. But Starlink is something else.

The first 60 satellites, launched by SpaceX last week, were seen travelling in procession across the night sky. Some people knew what they were seeing, but the silent procession of light also generated UFO reports. If you're lucky, you may see them pass across your skies tonight.

If the full constellation of satellites is launched, hundreds of Starlink satellites will be above the horizon at any given time. If they are visible to the unaided eye, as suggested by initial reports, they could outnumber the brightest natural stars visible to the unaided eye.

Astronomers' fears were not put to rest by Musk's tweets:

Satellites are very definitely visible at night, particularly in the hours before dawn and after sunset, as they are high enough to be illuminated by the Sun. The Space Station's artificial lighting is effectively irrelevant to its visibility.

In areas near the poles, including Canada and northern Europe, satellites in low Earth can be illuminated throughout the night during the summer months.

Hundreds of satellites being visible to the unaided eye would be a disaster. They would completely ruin our view of the night sky. They would also contaminate astronomical images, leaving long trails across otherwise unblemished images.

The US$466 million Large Synoptic Survey Telescope, based in Chile, is an 8-metre aperture telescope with a 3,200-megapixel camera. It's designed to rapidly survey the sky during the 2020s.

Lights in the sky from Elon Musk's new satellite network have stargazers worried
Will we lose the night sky to city lights and satellites? Credit: Jeff Sullivan, CC BY-NC-ND

With the full constellation of Starlink satellites, many images taken with this telescope will contain a Starlink satellite. Longer exposures could contain dozens of satellite streaks.

Dark skies or darkened hopes?

Is there any cause for optimism? Yes and no.

Musk has produced some amazing feats of technology, such as the SpaceX Falcon and Tesla cars, but he's also disappointed some on other projects, such as the Hyperloop tunnel transport plan.

While Starlink certainly blew up on Twitter, for now at least, Musk is 11,940 satellites short of his 12,000.

Also, initial reports may have overestimated the brightness of the Starlink satellites, with the multiple satellites closely clustered together being confused with one .

While some reports have indicate binoculars are needed to see the individual satellites, they also report that Starlink satellites flare, momentarily becoming brighter than any natural star.

If the individual satellites usually are too faint to be seen with the unaided eye, that would at least preserve the natural wonder of the sky. But professional astronomers like myself may need to prepare for streaky skies ahead. I can't say I'm looking forward to that.


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SpaceX launches first 60 satellites of its internet network

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Citation: Lights in the sky from Elon Musk's new satellite network have stargazers worried (2019, May 28) retrieved 21 September 2019 from https://phys.org/news/2019-05-sky-elon-musk-satellite-network.html
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May 28, 2019
The human species is boundless in its capabilities to achieve great things and terrible things. But these capabilities pale in comparisons to our innate ability to whinge about anything and everything.

Just imagine when in a billion years, the insane fact that humans in some form or another have survived is completely unnoticed, but a group of individuals are holding protests because the continents have drifted and the billion year old maps don't make a lick of sense anymore. They are angry at the continents of course, and are fervently against the idea of changing the maps with their ever so familiar and comfortable shapes.

Also we really need to get around to revising our collective definition of "natural". It has gotten so conflated with various contradictory, and non compatible definitions as to essentially make it a nonsense word.

May 28, 2019
I suppose this means that we need to start working on space-based solar collectors that absorb all nearly all light as Vanta-Black does. This would prevent a large number of satellites from interfering with astronomers in the future with the tens of thousands in low earth orbits flaring and ruining the view.

May 28, 2019
And those people out on the Cape think wind turbines would be bad...

May 28, 2019
Much ado about nothing.

May 28, 2019
The reason the model stinks is that it's a trojan horse.

A blanket of 12,000 satellites that low also would be able to suck up all wireless communications on earth. A global electronic surveillance web, sucking up wifi, broadband, cell phones, you name it. And the local governments couldn't control it like they can pull down a western intelligence hacked cell tower or re-route suspicious flyover commercial air with eavesdropping gear hidden in the belly.

They wouldn't do that though, would they?

May 28, 2019
Six times all existing satellites for one communications system is a bit obscene. But that's what it takes to be able to spy on everyone everywhere.


May 29, 2019
Who says you deserve a view of the night sky from your prison planet?

Jul 13, 2019
I suppose this means that we need to start working on space-based solar collectors that absorb all nearly all light as Vanta-Black does. This would prevent a large number of satellites from interfering with astronomers in the future with the tens of thousands in low earth orbits flaring and ruining the view.

Uh, wouldn't that also absorb all the heat from that radiation as well?
Spacecrafts are usually covered with white or reflective materials to reflect most of the light directed at them instead of absorbing it.

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