I’m not entirely sure where to begin with this one. First, in all the kerfuffle over China’s wandering weather spy balloon which, coincidentally (or not), initially entered US airspace on January 28th, I (we?) missed out on the news that on that same date, bright green lasers shot over the night sky in Hawaii. No, really.
Initially, the lasers were thought to have come from a NASA spacecraft:
A camera attached to a telescope on Hawaii’s tallest peak recently captured footage of a series of eerie, bright green lines that shot across the night sky for just over a second. Experts say the unexpected light show resulted from a rapid burst of lasers fired toward Earth by a NASA spacecraft.
The laser lines appeared on Jan. 28, flashing across the sky one by one in just over one second. A video(opens in new tab) of the lasers was captured by the Subaru-Asahi Star Camera — co-owned by the National Astronomical Observatory of Japan (NAOJ) and Japanese news agency Asahi Shimbun — attached to the Subaru telescope on top of Mauna Kea, a dormant volcano on Hawaii’s Big Island.
A time-lapse image of the lasers firing next to one another has drawn online comparisons with “digital rain,” or the lines of green computer code that fall vertically down the screen during the Matrix movies. But instead of being a glitch in a simulated reality, the lasers were actually emitted by a device onboard NASA’s ICESat-2 satellite, NAOJ representatives wrote on Twitter(opens in new tab).
On Jan 28, 2023, HST, Subaru-Asahi Star Camera captured green laser lights in the cloudy sky over Maunakea, Hawai`i. The lights are thought to be from a remote-sensing altimeter satellite ICESAT-2/43613.
Watch the video:https://t.co/xqoJvSa24s#SubaruTelescope pic.twitter.com/5hhIsewuNp— Subaru Telescope Eng (@SubaruTel_Eng) January 31, 2023
Now, however, rather than NASA, the lasers are being attributed to a Chinese satellite. A correction note on the YouTube video reads:
** Correction 2023-02-06 ! *** According to Dr. Martino, Anthony J., a NASA scientist working on ICESat-2 ATLAS, it is not by their instrument but by others. His colleagues, Dr. Alvaro Ivanoff et al., did a simulation of the trajectory of satellites that have a similar instrument and found a most likely candidate as the ACDL instrument by the Chinese Daqi-1/AEMS satellite. We really appreciate their efforts in the identification of the light. We are sorry about our confusion related to this event and its potential impact on the ICESat-2 team.
So, what is the Daqi satellite? Per Science Alert:
China’s Daqi-1 satellite was launched in April last year and similar to ICESat-2, it’s an atmospheric environment monitoring satellite.
That means it’s in orbit around Earth in order to monitor global carbon levels, as well as atmospheric pollution.
(See? Not surveillance — “atmospheric environment monitoring”!)
Daqi-1 contains five instruments to help it do this, including ACDL, which stands for Aerosol and Carbon dioxide Detection Lidar.
Lidar is an acronym for laser imaging, detection, and ranging, and it works a little like sonar. But instead of sending out sound waves to map an area, it sends out laser beams.
And it’s these lasers that are believed to have lit up the sky over Hawaii at the end of January.
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It’s early days for Daqi-1 so we’re still waiting for results from its scans.
But if all goes to plan, the satellite is just the start of China’s plans to keep tabs on air pollution.
I guess China is worried about pollution after all.
President Xi Jinping argues that fighting pollution is one of his top priorities, labelling this environmental issue as one of China’s ‘three tough battles’ – along with reducing poverty and improving financial stability. The long-term strategy focuses primarily on carbon emission intensity reduction through the primary use of non-fossil fuel energy. In recent years, China has placed a very strong emphasis on clean energy such as wind and solar. The latest Five-Year Plan (FYP) – one of the country’s most important policy blueprints – has set out a new strategy involving investment in onshore clean energy technologies, transmission grid, nuclear, as well as offshore wind in the coastal region.
The China Aerospace Science and Technology Corporation issued a press release regarding Daqi-1 in March of 2021:
China’s first satellite dedicated to comprehensive monitoring of the atmospheric environment is expected to be completed in the second half of this year.
The satellite, named Daqi-1 and developed by the Shanghai Academy of Spaceflight Technology (SAST) of the China Aerospace Science and Technology Corporation in Shanghai, is designed to operate in sun-synchronous orbit.
Daqi-1 can monitor fine particle pollution like PM2.5, pollutant gases including nitrogen dioxide, sulfur dioxide and ozone, as well as carbon dioxide concentration.
It combines both passive and active sensing, which can realize comprehensive monitoring of the atmospheric environment in a better way, according to a chief designer with SAST.
China will produce a series of Daqi satellites in the future, which will be used to monitor atmospheric pollution, provide remote sensing data support for environment authorities, and also support scientific research into global climate change.
Daqi-2, the second in the series, will be a high-precision greenhouse gas observing satellite. Daqi-1 will be networked with other satellites, including Daqi-2, to realize greenhouse gas monitoring and help China achieve reduction of carbon emissions.
So, don’t fret if you happen to look up into the night sky and notice green laser beams shooting across it — you’re not in The Matrix or about to have a Close Encounter with an alien. It’s just China monitoring air quality. With lasers. Over the U.S. It’s fine. Everything’s fine.
There'll be no living with MTG after this. https://t.co/HrFlX2piCd
— Joe Cunningham (@JoePCunningham) February 9, 2023
