In this scientific age, we are well aware of discreet light sources that illuminate our majestic sky. These include the Sun (the brightest object in the Earth’s sky), the Moon, stars, meteor showers, aurora, blazar, etc. These natural light sources cause luminance of the night sky via the emission of electromagnetic radiation (incandescence). The moon and visible individual stars are regular sights, lovely to gaze upon in the sky. However, in recent times, some strange lights in the sky have caught public attention in the US. Residents in several US regions, including Houston, New Mexico, etc., have seen a string of lights moving across the night sky. Are they some kinds of drones or UFOs (Unidentified Flying Objects)? This article explores the mystery of these strange lights in the sky.
The unusual string of lights in the sky
The strange line of lights traveling the night sky in recent weeks isn’t any UFO or has to do with aliens. Instead, these bright lights crossing the sky are Starlink satellites launched by SpaceX.
Starlink is a network of satellites developed by American aerospace company SpaceX, offering broadband internet coverage around the globe. It is a low Earth orbit satellite internet constellation providing internet connectivity to underserved areas. Hosting more than 4,500 tablet-sized satellites, Starlink is the world’s largest and most advanced broadband satellite internet constellation.
Under the Starlink project, SpaceX deploys thousands of small satellites into low Earth orbit to provide widespread internet access. The goal is to establish high-speed broadband internet connectivity in locations across the globe where traditional internet infrastructure is limited.
Elon Musk-owned Space Exploration Technologies Corp, aka SpaceX, is the operator of Starlink satellites. It offers satellite-based internet services using a constellation of Starlink satellites that orbit nearly 342 miles above Earth.
First launched in 2019, Starlink has grown to deliver commercial internet coverage in more than 60 countries. As of July 2023, Starlink consists of over 4,000 low Earth orbit (LEO) satellites, each of which weighs 573 pounds. More than 10,000 tablet-sized satellites are targeted for deployment in low Earth orbit in the coming years. The American spacecraft manufacturer SpaceX has proposed a constellation of 42,000 satellites to create a global network in outer space.
Starlink satellites are flat-bodied and move in unison in one line, creating a string of lights in the sky. SpaceX frequently launches these satellites, which circle the globe in low orbit. These satellites appear to make a perfect train of light across the sky as they march in a fixed path.
Each satellite in the Starlink constellation maintains two-way communication with ground stations to provide internet connectivity. The ground stations are responsible for data transmission, orbit control, system monitoring, and management of the overall satellite network.
How do Starlink satellites operate?
Equipped with advanced phased-array antennas, Starlink satellites use radio signals through the vacuum of space and communicate with user terminals on the ground. They form a constellation in low orbit, maintaining connections and receiving broadcast signals from multiple ground stations.
These ground stations function as gateways between satellites and global internet infrastructure by facilitating data exchange. They receive data from users’ terminals and transmit them to the satellites, which in turn relay the data back to the intended destinations on the internet.
The function of Starlink satellites
Starlink satellites, the line of lights in the sky, are responsible for offering high-speed, low-latency broadband internet. They provide low-cost internet services in over 60 countries, covering both underserved and urbanized areas of the planet.
These LEO satellites circle the planet only 550-1200km above the surface. Due to the low orbit of the satellites, they have improved internet speed and reduced latency levels.
Features of Starlink satellites
- Large and interconnected satellite network
- Small, flat-panel
- Lightweight, able to adjust their orbits
- Fitted with inter-satellite links (laser communication elements)
- Use Ku and Ka-frequency band
- Fitted with multiple-phased array antennas
- The lifespan of nearly five years
- Operate in low Earth orbit
Aims of Starlink mega constellation
- Provide global and remote internet coverage
- Develop a low-latency space network to enable edge computing
- Deliver high-speed internet service to rural and geographically isolated areas having limited or nonexistent internet infrastructure
- Bridge the digital divide by establishing low-cost internet connectivity in underserved locations.
Seeing a string of lights over the night sky: When?
You may see a line of bright lights on clear nights based on the expected path of Starlink satellites. These satellites are visible to the unaided eye and are easier to spot a day or two after their launch and deployment. They put on a spectacular show for observers by appearing as a string of pearls marching across the sky.
The train of bright lights in the sky isn’t a regular sight to spot. But you can access a handful of resources online to find out when you can next see these lights.
Findstarlink.com gives information regarding the visibility of Starlink satellites at different times from specific locations. By entering the country’s name and place or simply coordinates, users can find visible times of the newest Starlink. The website specifies timings with good visibility and timings with bad visibility for Starlink satellites at the user’s location.
Starlink ‘Good visibility’ timings at different US locations
- Dallas, Texas- 9:33 pm, 16 August 2023 (Look from Northwest to North)
- Colorado Springs, Colorado-8:31 pm, 16 August 2023 (Look from Northwest to East)
- Colonia, New Jersey- 8:49 pm, 14 August 2023 (Look from West to East)
- Colonial Heights, Virginia- 9:01 pm, 16 August 2023 (Look from Northwest to East)
- New York City, New York-8:49 pm, 14 August 2023 (Look from West to East)
- Los Angeles, California- 9:04 pm, 16 August 2023 (Look from Northwest to North)
- Columbus, Indiana- 10:17 pm, 13 August 2023 (Look from Northwest to North)
- Las Vegas, Nevada- 8: 51pm, 14 August (Look from Northwest to Northeast); 8:57 pm, 15 August (Look from Northwest to North)
- Meads, Kentucky- 9: 00 pm; 16 August (Look from Northwest to East)
Note: The visibility timings are subject to change since the orbit of satellites changes frequently without warning. Sometimes, even if they pass over you, the newest Starlink won’t be visible. To be seen, they need to reflect enough sunlight, which involves a complicated mechanism.
Bright lights on the sky: Reflecting the sunlight
While Starlink satellites appear like bright lights in the sky, they do not illuminate their light. They look bright because they reflect significant sunlight back toward Earth. Their brightness has attracted the attention of astronomers who worry that it might interfere with universe observations. There has been a concern among astronomers that the bright, orbiting objects contribute to light pollution, making the delicate telescope observation of the night sky difficult.
Elon Musk-funded SpaceX has since been working on cutting its satellites’ apparent brightness by applying dark coatings on their reflective parts. The incorporation of sunshades blocks the sunlight from reflecting off the satellites’ surface, lessening their impact on astronomy.
How does Starlink differ from other satellite internet services?
Megaconstellation Starlink differs from and has a competitive edge over other satellite internet services. First, it is a constellation of thousands of satellites that orbit approximately 342 miles above Earth. Starlink satellites retain the final orbital height of 342 miles, maintaining proximity to Earth yet covering the entire globe. Due to their proximity to the planet, the round trip data time between the user and satellite (i.e., latency) is lower-around 25ms vs 600+ ms. As a result, they offer unlimited high-speed data with download speeds ranging from 50Mbps to 150 Mbps or even higher.
In contrast, most other satellite internet services orbit the planet at 35,786 km, resulting in a higher latency. The higher the latency, the more difficult it becomes to support streaming, online gaming, and other data-intensive activities. The high Earth orbit of traditional satellites makes real-timing internet applications (esp. high data rate activities) less responsive.
Natural lights in the sky
Now that we’ve discussed the artificial satellite lights in the sky let’s have a quick look at natural light sources. Natural lights in the sky can be regularly observed and aren’t as hard to spot as satellite lights. The source of natural light in the clear sky can be one of the following:
The sun, the nearly perfect ball of hot plasma, is life’s most significant energy source. It is the brightest object in the Earth’s Sky, heated to incandescence by hydrogen fusion in its core.
The very sight of stars twinkling at night is mesmerizing. Stars with the Milky Way galaxy are visible to the naked eye, the brightest being Sirius, Canopus, Arcturus, Vega, etc.
Aurora is a natural luminous atmospheric effect caused by the interaction of the charged particles from the sun with the Earth’s magnetosphere. These are colorful or shimmering lights predominantly seen in the Polar Regions.