With the rapid expansion of the commercial space, the number of satellites in orbit around our planet is growing. Most of them are in low Earth orbit, which is becoming increasingly crowded.
This has led some to worry about the catastrophic growth of space debris, as well as the growing frustration of astronomers with the amount of satellite footprints in the sky.
Currently, the biggest player is SpaceX’s Starlink project, which currently has over 1,700 satellites in low Earth orbit. They became famous for creating bright bands on astronomical images. But Starlink will soon be followed by other projects such as OneWeb and Amazon’s Project Kuiper.
The aim of all these projects is to provide an easily accessible Internet to the whole world, which is a noble goal. But the visibility of these satellites will also pose serious problems for critical astronomy. Although the impact of these satellites on astronomy is still small, as a recent study shows, it will soon become serious.
Published in Letters from an astrophysical journal, the study looks at the number of Starlink trails visible in images taken by the Zwicky Transient Facility (ZTF) at the Palomar Observatory.
They found that from November 2019 to September 2021, more than 5,300 bands were seen on ZFT images. Most of the bands were visible in twilight images taken at dusk or dawn.
Starlink satellite trail across the Andromeda galaxy. (Optical Observatories of the California Institute of Technology/IPAC)
In 2019, only half a percent of twilight images had stripes, but now they are visible in about one in five twilight images. This is a concern because twilight images are the most important for finding near-Earth asteroids.
The potential meteorite impacts that pose the greatest threat to us are the ones that are the hardest to detect because they come from a trajectory close to the Sun’s position in the sky.
The authors note that this number of bands is not enough to significantly affect the search for potential asteroid impacts. But when the number rises to 10,000 or 15,000, astronomers will start to miss some asteroids. Given current trends, this number will be reached within a year or so.
There are ways to soften the effect of these bands. Painting the satellites and adding reflective panels can reduce their brightness, especially in the infrared, which is important for detecting near-Earth asteroids.
But the study indicates that the mitigation strategy currently being proposed by Starlink will not be enough to avoid impacting astronomy.
It is clear that we will soon have to make difficult choices regarding satellite internet. While this can expand human connection to even the world’s most impoverished and remote regions, it can also destroy our ability to look to the heavens and more deeply understand the universe we call home.
If we don’t set our priorities and benchmarks soon, SpaceX, Amazon, and other mega-companies will make the decision for us.
This article was originally published by Universe Today. Read the original article.
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