Attention is paid to ‘space sunshade’ due to climate change Intensification University of Utah proposes to use dust on the moon surface Reduces sunlight by 1.8% by scattering it toward the sun Bubbles and mirrors have also emerged as ideas
The concept of blocking sunlight with a space sunshade is shown in an imaginary drawing. Provided with Planetary Sunshade Foundation
American scientists have come up with a plan to use space dust to combat climate change. It is a strategy to block some of the sunlight reaching the earth from the sun by creating a ‘sunshade’ with dust in outer space. It is estimated that it can block about 1-2% of sunlight reaching the Earth. Benjamin Bromley, a professor of physics and astronomy at the University of Utah, USA, and Scott Kenyon, a researcher at the Smithsonian Astrophysical Observatory, USA, published this analysis in the international journal ‘Plos Climate’ on the 8th (local time).
The idea of creating sunshades in space is not new. Early James, then a researcher at the Lawrence Livermore National Laboratory in the United States, first suggested this idea in the 1989 international journal ‘Journal of the British Interstellar Association’. At that time, it was only an idea because it was not possible to come up with an implementation method. However, as climate change worsened, research on climate change response using outer space became more active, and the space sunshade theory is attracting attention again.
●“Using sunshades with moon surface dust, not Earth”
The concept of launching dust from the moon is expressed as an image. Provided by the University of Utah
The proposal of the University of Utah-Smithsonian joint research team is a concrete plan that can realize the idea proposed by researcher James 30 years ago. Researcher James said at the time that a 2,000-kilometer-long thin glass sunshade could be installed in space with the material contained in the moon rock, reducing 1.8% of sunlight reaching Earth.
The joint research team came up with a plan to create a sunshade by scattering dust on the moon’s surface towards the sun. Computer simulations have proven the analysis results that it is cheaper than distributing dust on Earth and that the unique characteristics of moon dust can maximize the shading effect. Installing a space sunshade at the first Lagrangian point (L1), which is about 1.5 million km away from the Earth toward the sun, is the same as the existing idea, but the difference is that moon dust is used.
The joint research team also deduced the optimal trajectory to launch lunar dust directly from a space station or settlement to be built on the moon and send it to L1.
When dust is sent from Earth to L1, it is easily deviated from its path due to solar wind or gravity, whereas when launched from the moon, it is analyzed that it will be easily transported to L1.
Previously, in July of last year, a research team at the Massachusetts Institute of Technology (MIT) in the United States suggested a method of using air bubbles as sunshades. It is a method of making a giant bubble raft in space with bubbles in the form of a thin film made of silicon. Soap bubbles on the water are closely connected. The research team analyzed that building a raft of space bubbles the size of Brazil could reduce 2% of sunlight reaching Earth. In addition, ideas such as a space sunshade made of small aircraft or a ‘space mirror’ that launches a huge mirror into space to reflect sunlight coming to the earth are being proposed.
To find solutions to climate change, satellite observation accuracy must be improved
As climate change deepens, scientists’ interest in space is growing. The United Nations, the United States, and the United Kingdom are unanimously emphasizing that “space technology will be a game changer in responding to climate change.”
Climate change patterns and analysis are also made possible thanks to satellites in outer space. Satellites play a key role in continuous, long-term observations of the Sun’s influence on the Earth’s environment and climate. About 150 satellites and 340 commercial satellites for earth observation are being used by the US National Aeronautics and Space Administration (NASA) or the European Space Agency (ESA) for Earth observation. It is observing the earth thoroughly, including the sea, land, ice, and atmosphere.
Efforts are also made to improve observation accuracy. The UK’s National Space Research Institute plans to launch a next-generation Earth-observing satellite within this year. The satellite can accurately measure sea surface temperature to within 0.2 degrees even at an altitude of 800 km. Standing on the landmark Big Van in London, England, you can see the Eiffel Tower in Paris, France in detail. It is expected to serve as the most accurate thermometer among Earth observation satellites ever launched.
As mankind’s advancement into space accelerates, voices calling for rapid response to climate change are also growing.
A research team at the Antarctic Environment Center in the UK published an analysis in the international academic journal ‘Geophysical Research Letter’ in September last year that the amount of space debris will increase due to the increase in global temperature. The research team said, “As the temperature rises, the density of the upper atmosphere decreases, and the time that space debris, which would have been dragged into the Earth’s atmosphere and burned, will remain in low Earth orbit will increase by 30% compared to the 2000s.” It will become frequent.”
Reporter Koh Jae-won, Donga Science jawon1212@donga.com
