Rising Concerns: Light Pollution and Space Junk Threaten Astronomical Studies
Once upon a time, gazing at the night sky was an escape from manmade messiness on Earth. The vast expanse of the universe provided solace and wonder, untouched by human interference. However, in the present day, this celestial sanctuary is under threat. Astronomers are growing increasingly concerned about the impact of light pollution and space junk on their ability to study the cosmos.
The launch of Sputnik nearly 70 years ago marked the beginning of a new era in space exploration. Since then, countless machines have been sent into orbit, cluttering the night sky with their presence. Astronomers fear that this light pollution will soon render it impossible to observe distant galaxies using terrestrial telescopes. The once pristine canvas of the night sky is gradually being marred by the glow of artificial satellites and rockets.
But it’s not just light pollution that astronomers have to contend with. Space junk poses an equally significant threat. There are currently around 30,000 objects larger than a softball hurtling through space at speeds ten times faster than a bullet, just a few hundred miles above Earth. These debris pose a danger to both existing satellites and future space missions.
Furthermore, recent scientific research conducted by NOAA’s Chemical Sciences Laboratory has revealed that the for-profit space race is altering the composition of the sky in measurable ways. High-flying aircraft used by NOAA to collect samples of the stratosphere have detected the presence of human-made materials, such as bits of metal from rockets or satellites falling out of orbit and burning up. The study predicts that manmade debris will make up 50% of stratospheric aerosols in the coming decades, matching the amount created naturally by the galaxy.
The implications of these findings are concerning. The addition of significant amounts of material to the stratosphere, coupled with the sheer mass of objects launched into space, could have harmful consequences for the ozone layer and Earth’s climate. While the exact impact remains uncertain, the study highlights the urgent need for further research and mitigation strategies.
The commercialization of space has only exacerbated the problem. The shift from solid rocket boosters on NASA’s Space Shuttles to the kerosene-fueled rockets used by companies like SpaceX has led to a significant increase in fossil fuel emissions with each launch. Aging satellites also contribute to the issue, as they create clouds of debris when they deorbit.
The number of satellites currently in orbit is staggering. According to the tracking site Orbiting Now, there are over 8,300 satellites overhead. Predictions about the number of satellites that will join them in the near future vary widely, with some estimates reaching as high as 478,000 by 2030. However, more conservative estimates suggest that the number is closer to 20,000. Regardless of the exact figure, it is clear that the exponential growth in satellite deployments poses a significant challenge.
The accumulation of space debris has been a concern since the late 1970s when NASA scientist Donald Kessler published a paper titled “Collision Frequency of Artificial Satellites: The Creation of a Debris Belt.” This paper introduced the concept of “Kessler Syndrome,” which refers to the potential for a cascade of collisions between space debris, leading to even more debris and rendering future launches increasingly difficult.
The risks associated with space debris are not to be taken lightly. Objects in low-earth orbit can collide at speeds of up to 23,000 miles per hour, posing a threat to both manned and unmanned missions. It is estimated that there are currently around 100 million pieces of manmade debris the size of a pencil tip orbiting Earth.
The growing concern over space debris has given rise to a new industry focused on orbital debris removal. Companies like Astroscale are developing technologies and strategies to address this pressing issue. Astroscale’s president, Ron Lopez, compares their role to that of the suppliers during the Gold Rush, providing the necessary tools to tackle the problem.
While the concept of orbiting garbage trucks and recycling centers may still be a long way off, Astroscale has made significant progress in the field. In 2022, they successfully used a satellite with a strong magnet to capture a moving target launched as part of a three-year mission. This demonstration showcased the technologies required for docking and rendezvous with other satellites, paving the way for future debris removal efforts.
Astroscale’s latest mission, launched in collaboration with Rocket Lab, aims to study space junk more closely. The satellite, named ADRAS-J, will observe the motions of a rocket stage left in low-Earth orbit since 2009. By analyzing the debris and its behavior, Astroscale hopes to develop effective strategies for removing it from orbit.
Amidst the growing pollution crisis on Earth, both on land and at sea, scientists from Japan and NASA are preparing to launch the world’s first biodegradable satellite made mostly of wood. This symbolic initiative
