Musk's satellites threaten astronomy

Thursday, 6 February 2020

OPINION: One of the biggest arguments currently raging in science came to life last week as a line of lights cutting across our night sky.

The linear formation is a group of 60 small satellites launched by SpaceX, the aerospace company founded by billionaire electric car pioneer Elon Musk.

SpaceX has now put nearly 200 Starlink​ satellites into orbit. But Musk's plan is to ultimately have a network of at least 12,000 and as many as 42,000, so he can deliver internet access anywhere in the world.

There are currently about 2000 active satellites in orbit and only 9000 have ever been launched.

**READ MORE:

* Kiwi astronomers among those worried by Elon Musk's plan to launch thousands of satellites

* SpaceX Starlink satellites could create a space junk nightmare, scientists warn

* How Elon Musk made - and spends - his fortune

* Elon Musk wants to provide internet service from space**

It is typical Musk. An audacious plan that could deliver better and cheaper internet access in places that are hard to reach with physical infrastructure on the ground.

But there's a big problem – the large satellites reflect a lot of light from the sun, making them brighter than many of the 9000 or so stars that are visible from Earth.

Astronomers, who use large telescopes in remote places to avoid light pollution, are already seeing bright streaks on their images of the night sky as Musk's fleet passes over. This has serious implications for their research.

Dunedin astronomer Dr Ian Griffin summed up the dismay of the astronomy community in a tweet last week: 'Feeling pretty depressed at the moment. NZ working hard to create a dark sky nation during a period that #starlink are filling the sky with space littering satellites. Another 60 going up tomorrow.'

SpaceX is experimenting with dark satellites, but painting them black could mean they absorb too much heat and stop working.

Scientists aren't convinced that's a solution anyway, particularly for the field of radio astronomy, which uses highly sensitive devices to pick up radio waves that originated millions of light-years from Earth.

When the planet is blanketed with satellites broadcasting to each other, detecting those distant bursts of energy which let us look into the history of the universe, could be a lot harder.

Ultimately the Starlink controversy foreshadows the issues we'll face as the commercialisation of space ramps up. If we can't balance competing interests in lower Earth orbit, how will we fare colonising Mars or mining asteroids?

Musk is a pragmatist. Now he needs to put his ingenuity into solving this problem and pause the Starlink launches until he does.