Latest news with #RichardLinares
Yahoo
17-03-2025
- Science
- Yahoo
How climate change could make Earth's space junk problem even worse
When you buy through links on our articles, Future and its syndication partners may earn a commission. Growing concentrations of greenhouse gases are making the upper atmosphere thinner, decreasing its ability to pull space junk out of orbit. As a result, far fewer satellites will be able to safely operate in near-Earth space in the coming decades, with local space debris emergencies likely to become a norm, a new study suggests. Scientists have known since the 1990s that complex processes taking place in Earth's atmosphere because of climate change could reduce the density of the upper layers of the planet's gaseous shroud. When the upper atmosphere becomes thinner, satellites and old space junk encounter less drag as they hurtle around the planet. They therefore stay afloat longer, and the lower regions of space become more cluttered. Over the past decade, studies have emerged estimating how much exactly these atmospheric changes affect those satellites. A team of aerospace engineers at the Massachusetts Institute of Technology (MIT) has now taken a deeper dive into the problem and estimated the knock-on effects of this reduced drag on safety of orbital traffic. The results are astounding: By the end of this century, some orbital regions might be able to safely carry up to 66% fewer satellites than they do today because of the increasing amount of space junk. The discovery comes at an important juncture in humankind's use of space. With the proliferation of large satellite constellations such as SpaceX's Starlink or Amazon's Project Kuiper, the quantity of satellites in orbit is set to skyrocket. Yet, what the scientists call the "satellite carrying capacity" of low Earth orbit will dwindle, unless greenhouse gas emissions are significantly curbed. Related: The Kessler Syndrome and the space debris problem "The megaconstellation is a new trend, and we're showing, because of climate change, we're going to have a reduced capacity in orbit," study co-author Richard Linares, associate professor in MIT's Department of Aeronautics and Astronautics (AeroAstro), said in a statement. "And in local regions, we're close to approaching this capacity value today." The researchers analyzed individual orbital altitudes and found that some of these shells are already reaching the limits of their carrying capacity, threatening to spawn local runaway space debris collision cascades. Such cascades would produce further fragment clouds that would further decrease the safety of orbital traffic. RELATED STORIES: — 6 types of objects that could cause space debris apocalypse — Our warming Earth: 2024 was hottest year on record, NASA says — Solving space junk problem may require lasers and space tugs, NASA says All is not lost, however: Humankind has a chance to thwart the trend by making sure greenhouse gas concentrations in the atmosphere stop rising. "Our behavior with greenhouse gases here on Earth over the past 100 years is having an effect on how we operate satellites over the next 100 years," Linares said. The study's lead author, William Parker, a graduate student at AeroAstro, added: "The upper atmosphere is in a fragile state as climate change disrupts the status quo. At the same time, there's been a massive increase in the number of satellites launched, especially for delivering broadband internet from space. If we don't manage this activity carefully and work to reduce our emissions, space could become too crowded, leading to more collisions and debris." The study was published in the journal Nature Sustainability on Monday (March 10).
Yahoo
11-03-2025
- Science
- Yahoo
Climate change could be threatening satellites as they orbit in space: Study
The ongoing surge of greenhouse gas emissions in the near-Earth environment could cause dramatic declines in the number of satellites orbiting the planet by the end of the century, a new study has found. By the year 2100, the 'satellite carrying capacity' of the most popular low-orbit regions could decline by 50 to 66 percent due to the impacts of these emissions, according to the study, published on Monday in Nature Sustainability. 'Our behavior with greenhouse gases here on Earth over the past 100 years is having an effect on how we operate satellites over the next 100 years,' senior author Richard Linares, an associate professor at the Massachusetts Institute of Technology (MIT), said in a statement. Linares and his colleagues determined that carbon dioxide and other greenhouse gases can cause the upper atmosphere to shrink. The researchers found that the contraction of the thermosphere — the atmospheric layer where the International Space Station orbits today — causes a plunge in density, leading to ripple effects. Specifically, that decrease in density reduces 'atmospheric drag,' or a force that pulls old satellites and other debris down to altitudes where they will combust from interactions with air molecules. Less drag, therefore, means longer lives for 'space junk,' which the researchers said would litter popular orbital regions for decades and raise the risk of collisions. 'The upper atmosphere is in a fragile state as climate change disrupts the status quo,' lead author William Parker, an MIT graduate student, said in a statement. Despite this fragility, there has been a significant surge in the number of satellites launched in recent years, particularly for delivering broadband Internet from space, Parker explained. 'If we don't manage this activity carefully and work to reduce our emissions, space could become too crowded, leading to more collisions and debris,' he added. The thermosphere naturally contracts and expands every 11 years in response to the sun's routine activity cycle, the scientists noted. When that activity is low, the Earth receives less radiation, and the outermost atmospheric layer cools and contracts before expanding again. While modeling from the 1990s already showed that greenhouse gases trap heat in the lower atmosphere, more recent research determined that the same gases also radiate heat at much higher altitudes — thereby cooling the thermosphere. Yet only in the past decade have scientists been able to measure shifts in satellite drag, indicating that the thermosphere could be contracting in response to influences other than the sun's natural cycle, the authors explained. 'The sky is quite literally falling,' Parker said. Today, more than 10,000 satellites are in low orbit, or up to 1,200 miles from the Earth's surface, per the study. And while these satellites deliver essential services to humans, collisions among them can generate debris that stays in orbit for decades or centuries, the authors warned. Aiming to understand whether the current trajectory is sustainable in the long term, the scientists simulated different greenhouse gas emissions scenarios over the next century. For each altitude range of interest, they modeled the orbital dynamics and the threat of satellite collisions, based on the number of objects floating in that area. Through this approach, the researchers could identify each range's 'carrying capacity,' or the number of satellites that could be supported. Ultimately, they estimated that the number of satellites that could be safely accommodated within the altitudes of 124 to 621 miles might plunge by 50 to 66 percent — if emissions remain at year-2000 levels. If satellite capacity were to be exceeded, the researchers forecast that a given area could experience what's known as a 'runaway instability,' or a cascade of collisions that would close the range to safe satellite operations. 'We rely on the atmosphere to clean up our debris. If the atmosphere is changing, then the debris environment will change too,' Parker said. 'We show the long-term outlook on orbital debris is critically dependent on curbing our greenhouse gas emissions.' Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
The Hill
10-03-2025
- Science
- The Hill
Climate change could be threatening satellites as they orbit in space: Study
The ongoing surge of greenhouse gas emissions in the near-Earth environment could cause dramatic declines in the number of satellites orbiting the planet by the end of the century, a new study has found. By the year 2100, the 'satellite carrying capacity' of the most popular low-orbit regions could decline by 50 to 66 percent due to the impacts of these emissions, according to the study, published on Monday in Nature Sustainability. 'Our behavior with greenhouse gases here on Earth over the past 100 years is having an effect on how we operate satellites over the next 100 years,' senior author Richard Linares, an associate professor at the Massachusetts Institute of Technology, said in a statement. Linares and his colleagues determined that carbon dioxide and other greenhouse gases can cause the upper atmosphere to shrink. The researchers found that the contraction of the thermosphere — the atmospheric layer where the International Space Station orbits today — causes a plunge in density, leading to ripple effects. Specifically, that decrease in density reduces 'atmospheric drag,' or a force that pulls old satellites and other debris down to altitudes where they will combust from interactions with air molecules. Less drag, therefore, means longer lives for 'space junk,' which the researchers said would litter popular orbital regions for decades and raise the risk of collisions. 'The upper atmosphere is in a fragile state as climate change disrupts the status quo,' lead author William Parker, an MIT graduate student, said in a statement. Despite this fragility, there has been a significant surge in the number of satellites launched in recent years, particularly for delivering broadband Internet from space, Parker explained. 'If we don't manage this activity carefully and work to reduce our emissions, space could become too crowded, leading to more collisions and debris,' he added. The thermosphere naturally contracts and expands every 11 years in response to the sun's routine activity cycle, the scientists noted. When that activity is low, the Earth receives less radiation, and the outermost atmospheric layer cools and contracts before expanding again. While modeling from the 1990s already showed that greenhouse gases trap heat in the lower atmosphere, more recent research determined that the same gases also radiate heat at much higher altitudes — thereby cooling the thermosphere. Yet only in the past decade have scientists been able to measure shifts in satellite drag, indicating that the thermosphere could be contracting in response to influences other than the sun's natural cycle, the authors explained. 'The sky is quite literally falling,' Parker said. Today, more than 10,000 satellites are in low orbit, or up to 1,200 miles from the Earth's surface, per the study. And while these satellites deliver essential services to humans, collisions among them can generate debris that stays in orbit for decades or centuries, the authors warned. Aiming to understand whether the current trajectory is sustainable long-term, the scientists simulated different greenhouse gas emissions scenarios over the next century. For each altitude range of interest, they modeled the orbital dynamics and the threat of satellite collisions, based on the number of objects floating in that area. Through this approach, the researchers could identify each range's 'carrying capacity,' or the number of satellites that could be supported. Ultimately, they estimated that the number of satellites that could be safely accommodated within the altitudes of 124 to 621 miles might plunge by 50 to 66 percent — if emissions remain at year-2000 levels. If satellite capacity were to be exceeded, the researchers forecasted that a given area could experience what's known as a 'runaway instability,' or a cascade of collisions that would close the range to safe satellite operations. 'We rely on the atmosphere to clean up our debris. If the atmosphere is changing, then the debris environment will change too,' Parker said. 'We show the long-term outlook on orbital debris is critically dependent on curbing our greenhouse gas emissions.'
