Artificial Satellites

Satellites are everywhere:
Have you ever looked up at the night sky and noticed a “star” moving towards the horizon before disappearing after a few seconds/minutes? How about a “star” that flares in brightness before suddenly disappearing? Chances are good that you actually saw a satellite! Satellites in low-Earth orbit (LEO, any orbit that is less than 2000 km above the Earth’s surface) are often visible to the naked eye a few hours before sunrise or after sunset. This is because their solar panels or other design elements can unintentionally reflect the Sun’s light when the satellite is out of the Earth’s shadow. While they’re interesting to watch and even occasionally produce a bright flare when the angle is just right, bright satellites can wreak havoc on the images taken by professional astronomers who are often looking for the faintest objects in the Universe.

Safeguarding the skies:
In the past decade, the number of active satellites in low-Earth orbit has jumped from 1,200 to 9,900. These satellites are doing everything from providing valuable insight on how our planet works to bringing the internet to the most remote regions of the world. But near-Earth space is an environment just like any other and we need to be careful with how we use it, or we could end up damaging it beyond repair.
With the increased speed at which satellites are being launched into orbit, it has been predicted that as many as 60,000 satellites could exist in low-Earth orbit by the end of the decade. This could create dramatic problems for astronomical campaigns that rely on finding faint, moving targets (such as the search for Potentially Hazardous Asteroids), require long exposure times, or rely on the detection of radio waves, with which these satellites can interfere.

Satellite tracking:
As a Satellite Tracker, you can help us better understand the impact that tens of thousands of satellites will have on the night sky for both professional astronomers and backyard enthusiasts! Satellite companies often introduce new design elements and orbital maneuvers to reduce the glare from satellites. Your observations can provide valuable feedback on what options are most effective at eliminating stray reflections. If you’re interested in helping to shape the future of our night sky, check out the Tutorial page to learn how to get started, or head over to our Missions page to see which campaigns are currently underway.