What is that strange string of lights in the sky?

Many people have reported seeing these lights in the sky. They periodically pop up in different places. In May it was Northern California, in July it was New Mexico, and they most recently were spotted in Chicago. While it may be natural for even the most ardent skeptic to assume an extraterrestrial origin for such a strange phenomenon, UFO sightings do not usually happen with this frequency and regularity (real aliens are a little more unpredictable than that.)

These lights are not even UFOs, in the sense that they are not unknown. They are the Starlink satellites operated by Elon Musk's Space X corporation, which provides Internet access to over 60 countries. The Starlink constellation of satellites currently consists of around 5,000 satellites, with plans to deploy another 12,000. Eventually, it is hoped that there will be 42,000 Starlink satellites in orbit.

So, why does their visibility come and go, popping up as a brilliant streak in the night sky here and there? Well, that's because Starlink satellites are most visible when they're newly launched. They disappear from visibility to the naked eye as they climb to their final orbital height of 550km (342 miles.) This is a relatively low orbit, but the satellites are invisible because of measures SpaceX has taken to ensure they do not interfere with ground-based astronomical research and observation.

Starlink is not without issues

Concerns still remain about the impact the satellites will have on astronomy. Professional astronomers have disputed the efficacy of the measures taken to minimize the visibility and brightness of the satellites. SpaceX has said that it's committed itself to exploring new mitigation measures.

Even if the visibility issue is resolved, there are other concerns, such as the hazard they may pose to spaceflight, or the climate change effects of decommissioned satellites burning up in the atmosphere.

Starlink delivers near-broadband speeds to areas where a decent connection is not possible. With just Starlink's (admittedly pricey) proprietary satellite dish and router, you can get an Internet connection anywhere there's a clear night sky. This has been invaluable in war zones such as in Ukraine.

In Ukraine, Starlink Internet connections have been used to coordinate the counteroffensive against the Russian invasion. Elon Musk has been reluctant about his service being used to commit acts of war, and at one point limited its use to thwart a drone strike against the Russian fleet. Musk reversed that decision after an emergency request from both the Pentagon and Ukraine's government.

According to biographer Walter Isaacson, Musk said “Starlink was not meant to be involved in wars. It was so people can watch Netflix and chill and get online for school and do good peaceful things, not drone strikes.” While Musk's feeling is understandable, the result was an unelected billionaire making decisions for an active battlefield in another country.

If Starlink reaches its target of 42,000 satellites, these sightings will become a lot more frequent, and the issues involved will be on top of everyone's minds.