A NASA astronaut has captured brilliant specks of light floating above the Earth’s horizon, dancing in space. But instead of being a celestial miracle, it’s actually a phenomenon created by humans hijacking Earth’s orbit.
Earlier this week, astronaut Don Pettit shared a video he shot while aboard the International Space Station (ISS). The video shows a group of shimmering objects flying 250 miles (400 kilometers) above the Earth’s surface. Pettit called this breathtaking scene “space fireflies” and then explained what the flickering lights were. “In fact, they are Starlink satellites that flash sunlight momentarily in the direction of the [ISS],” Pettit wrote.
The video, which initially inspires space wonder, is actually a reflection of the reality of low Earth orbit today, cluttered with man-made objects that interfere with its natural beauty.
SpaceX first began launching its Starlink satellites in 2019 to provide connectivity to remote areas or areas where internet connectivity is unreliable. There are currently more than 6,700 Starlink satellites in orbit, and that number is only growing as SpaceX uses its Falcon 9 rocket to launch batches of satellites into low Earth orbit.
Orbiting satellites are a concern for astronomers because they add a lot of noise to images captured by ground-based observatories as they reflect sunlight in the same way as seen in Pettit’s video. Satellites spoil scientific data by appearing as bright streaks in astronomical images.
This is only the beginning, as SpaceX wants to launch more than 42,000 of its Internet satellites into orbit, although so far the US Federal Aviation Administration has granted the company permission to launch 12,000 Starlinks. And that’s not to mention other pending mega constellations, including China’s Thousand Sails initiative, which could include more than 13,000 satellites.
Earlier this year, SpaceX began launching Starlink’s direct-to-cell (DTC) satellites, which are five times brighter than the rest of the broadband constellation, a recent study found. DTC satellites, according to the study, may appear brighter because of their lower altitude. The conventional Starlink satellites orbit 340 miles (550 kilometers) above the Earth’s surface, while their DTC counterparts orbit at a much closer distance of 217 miles (350 kilometers). The satellites in low Earth orbit orbit the planet every 90 minutes and appear wider or out of focus when viewed through telescopes, which further scatters their light.
SpaceX is working with the International Astronomical Union and other astronomical groups on how to reduce Starlink’s interference with space observations by reducing their reflectivity, changing the orientation of the solar panels, or installing a “sun visor” on the satellites. These ideas are still under development, and SpaceX is not slowing down the pace of construction of its mega constellation.
