Orbital space around Earth must be protected amid rise in satellites, say scientists

Leading scientists say that the space around Earth must be protected by environmental rules and regulations like those that safeguard the planet.

An international team of researchers warn that a dramatic rise in the number of satellites is ruining the night sky for astronomy and stargazers, while increasing the risk of objects colliding in space and potentially striking people or aircraft when they fall back to Earth.

Mega-constellations involve placing tens of thousands of satellites in low Earth orbit to deliver broadband internet and other services.

While companies such as OneWeb are leading the way, others are interested, including Rwanda, which recently filed an application to launch 327,000 satellites in a single project.

Scientists from the UK, US, Canada and the Netherlands wrote in Nature Astronomy that the number of satellites in Earth's low-earth-orbit could reach 100,000 by the year 2030.

We need to get our act together. Andy Lawrence, a regius professor of astronomy at the University of Edinburgh, is the lead author.

We see the same problems in space as we do on land, the oceans and the atmosphere. We need to ask how we can solve this problem.

There are proposals for regulations based on a satellite's space traffic footprint and carrying capacity.

There were over 2,000 satellites circling Earth in late last year. In the past two years, that number has doubled. All went into the most congested low Earth orbit, which reaches from 100 to 2,000 km above Earth. The Aeolus observatory was moved by the European Space Agency to avoid colliding with a satellite. The Chinese moved their space station twice last year because of similar concerns.

While there is robust regulation to ensure satellites are launched safely and transmit signals only within certain frequencies, there is almost nothing to govern the impact of satellites on the night sky, astronomy, Earth's atmosphere or the orbital environment.

Light reflecting off satellites can ruin astronomy by leaving streaks across images, while broadcasts can drown out natural radio signals that are used to understand some of the most exotic objects in the universe. The International Astronomical Union asserts that the presence of so many satellites undermines the ability to enjoy the night sky.

There are other concerns as well. Satellite debris can cause damage to property or harm to life, but the risk is relatively low. As more satellites reenter Earth's atmosphere at the end of their lives, the danger will increase.

The first aircraft strike or ground casualty is only a matter of time, warn the researchers. Carbon dioxide, nitric oxide and soot are included in rocket launch emissions.

Chris Newman, a professor of space law and policy at the University of Northumbria, said that the governance of human space activity is at risk because of the problem of increasing debris.

A binding international treaty is a long way off because of the breadth of new actors. The law can only take us so far. Responsible leadership is required from countries and companies that are active in space.