5 THINGS ABOUT SPACE

1 SPACE JUNK IS CROWDING THE SKY

The rapidly growing cloud of satellites and space junk orbiting Earth is beginning to block our view of the universe around us, according to new research published in the Monthly Notices of the Royal Astronomical Society, a scientific journal.

2 EACH OBJECT REFLECTS SUNLIGHT

From bits of space garbage to the largest man-made satellites, each object reflects a commensurate amount of sunlight back toward Earth. Multiplied by the tens of millions, the collective amounts to a 10 per cent increase in illumination across the night sky. That increased sky glow is washing out our view of the cosmos, making it harder for scientists to peer into the farthest reaches of our galaxy and the universe beyond.

3 MEGA-CONSTELLATIONS OF SATELLITES A CONCERN

An area of concern is the rise of satellite mega-constellations, such as Spacex’s Starlink project, which has put more than 1,300 satellites in orbit since 2018 with plans to potentially launch tens of thousands more. Other companies, including Amazon and Oneweb, also have constellation plans. Those figures would represent a massive increase

over the current number of operational satellites in orbit, which the Union of Concerned Scientists estimates to be more than 3,300. The devices are used in telecommunications, navigation, weather monitoring, space science and other areas.

4 DEBRIS CHECKS IN AT 6,000 TONS, NASA SAYS

In addition to satellites, the European Space Agency estimates there are tens of thousands of large pieces of space debris orbiting the earth, a number that swells into the millions when considering smaller objects down to a diameter of 1 millimetre. According to NASA, the debris has a collective mass of about 6,000 tons.

5 ASTEROID COULD SNEAK UP ON EARTH

Every additional object contributes to an increase in the total luminosity of the light sky, as sunlight reflects off its surface and scatters throughout the atmosphere. It effectively washes out the visual contrast of the night sky, making fainter astronomy targets more difficult to see. It’s also plausible that we could be hampering our ability to detect hazardous asteroids on a collision course with Earth. “I think the answer is, ‘We don’t know,’” said John Barentine, director of public policy of the International Dark-sky Association and a co-author of the study, “but the idea that we might miss an object on a collision course with Earth is concerning.”