Starlink satellites can look like a plume or train of light

A plume or line of lights in the sky

Starlink launches have people looking up and wondering what in the world they’re seeing. Depending on clear skies and the launch’s trajectory, the ascending SpaceX rocket with Starlink satellites can create a huge glowing plume in the sky. Then, after the satellites are released, people spot a strange line of lights like a train moving across their sky. Images flood social media as observers try to get an answer, often wondering if we’re being invaded by aliens. But the answer is no, it’s just another Starlink launch.

People who live on the coasts are more likely to see the launch plume as the rocket leaves either the Kennedy Space Force Base in Florida or the Vandenberg Space Force Base in California. Then, after the satellites are released from the rocket and head upward into their orbits, people see them as a line of lights that looks like a train. You can spot this line of lights for up to a day or two after launch. Each dot is a Starlink satellite, and generally there are 46 or more separate satellites heading upward from Earth, moving into their future orbits. When they reach their final orbit, they are often too high for people to see without optical aid. Astronomers, however, still must contend with them.

If you want to know if Starlink will pass over you, try this link.

In this video, you can watch as a train of Starlink satellites passes overhead.

Sharing Starlink sightings on Twitter

Grateful that my neighbor talked me down from us being attacked by aliens and that it was only the #starlink satellite. #rad #science pic.twitter.com/gCSDRQubpN

— ?? hi, i’m katie (@kswansondesign) August 21, 2022

We have received multiple calls into the newsroom about a line of fast-moving lights in the sky tonight. It's the #Starlink satellites @upnorthlive pic.twitter.com/ku3Xat7psW

— Amanda Skrzypchak (@AmandaTVNews) August 23, 2022

What are the Starlink satellites?

Starlink is the name of a satellite network from SpaceX that provides broadband coverage for high-speed internet access, particularly for rural and remote areas. Over the coming few years, SpaceX plans to send up at least 12,000 Starlink satellites. Satellite internet beams through space at a rate that’s reportedly 47% faster than fiber-optic cable internet. All well and good.

But the Starlinks are bright. People see them in the night sky. They create what’s being called a megaconstellation, that is, groups of satellites moving together. Is the sudden upsurge in the number of Starlink satellites also causing UFO sightings to increase? Plus, astronomers are worried. The Starlink satellites are photobombing astronomical images. They have the potential to interfere with the professional observations that have brought us our modern-day view of the cosmos.

Internet from space

SpaceX CEO Elon Musk announced the proposal for Starlink back in January 2015. Though it didn’t have a name at the time, Musk said that the company had already filed documents with international regulators to place about 4,000 satellites in low Earth orbit. He said in a speech when revealing the project:

We’re really talking about something that is, in the long term, like rebuilding the internet in space.

And his predictions so far have proven true. Musk’s initial estimate of the number of satellites quickly grew, as he hoped to capture a part of the estimated $1 trillion worldwide internet connectivity market. The U.S. Federal Communications Commission (FCC) has granted SpaceX permission to fly 12,000 satellites, and perhaps as many as 30,000 eventually.

To put things into perspective: as of January 1, 2022, there were 4,852 active satellites orbiting Earth. On September 1, 2022, 2,386 of them were Starlinks. When we first wrote this article in May 2021, humans had launched fewer than 9,000 objects into space in total. As of September 3, 2022, according to the United Nations Office for Outer Space Affairs, we’re up to 13,672.

Where are the satellites?

Starlink satellites orbit at an altitude of 340 miles (550 km). At that height, they’re low enough to get pulled down to Earth by atmospheric drag and burn up in a few years, so that they don’t become space junk once they die (a problem SpaceX may hope to tackle using Starship). Each one weighs 500 pounds (227 kg) and measures about the size of a typical coffee table, according to Skyandtelescope.com.

It was exciting to see the first few Starlink satellites, traveling together in the night sky. But then more were launched, and then more. And astronomers began to worry.

Read more: 1 of every 15 lights in the sky will be a satellite

So many Starlink satellites

SpaceX’s two test satellites, TinTinA and TinTinB, launched in 2018. The mission went smoothly. Using that initial data, the company decided it wanted its fleet to operate lower than originally planned. Regulators deliberated and the FCC approved the move.

The first 60 Starlink satellites were successfully launched on May 23, 2019, aboard a SpaceX Falcon 9 rocket. Since then, SpaceX has been launching from 46 to 60 Starlink satellites at a time.

Starlink controversy among astronomers

Despite the promise of high-speed broadband internet, SpaceX has taken criticism within the astronomical community for its Starlink satellites, due to their brightness and potential to disrupt observations of the night sky.

The National Science Foundation and the American Astronomical Society released a report on the situation in August 2020. Discussions among more than 250 experts at the virtual Satellite Constellations 1 (SATCON1) workshop expressed concern that the bright train of satellites marching across the sky will hinder their observations.

SpaceX response to astronomers

In response, SpaceX has begun outfitting their satellites with a blackened sunshade – called VisorSat – that the company hopes will reduce the satellite’s apparent brightness by reducing the amount of sunlight that’s reflected. This is just one of the six suggestions proposed by the SATCON1 team.

Initial efforts at mitigating the spacecraft’s impact involved launching a prototype Starlink satellite later dubbed DarkSat in 2021, which featured a black antireflective coating. Ground-based observations of DarkSat in orbit found it half as bright as a standard Starlink satellite, which is a good improvement, according to experts, but still far from what astronomers say is needed. Jeremy Tregloan-Reed, a University of Antofagasta astronomer on the observational team that assessed the prototype, commented:

I would not consider DarkSat as a victory but instead a good step in the right direction.

The team compared DarkSat with a typical Starlink sibling using a two-foot (0.6-m) telescope at the Ckoirama Observatory in Chile and found that although DarkSat’s antireflective coating rendered it invisible to the unaided eye, it remained far too bright to avoid interfering with the Vera C. Rubin Observatory – now under construction in Chile – and other major telescopes. Additionally, DarkSat’s darker color retains too much heat, so the company is sticking with the visor alternative instead.

Futured satellites in our sky

With SpaceX’s plans, plus Amazon’s Kuiper project, OneWeb, China’s Hongyan, and other projects launching their own global networks of hundreds or thousands of satellites with little to no regulation, the scale of astronomy’s satellite-constellation problem might only increase.

Bottom line: Have you seen a plume of light soaring through the sky? Or maybe a group of bright satellites crossing the night sky together? Then you’ve probably seen Starlink.