COVID-19 wreaked havoc on Earth, but a new study has suggested that the impact of this global pandemic extended far beyond our planet.
Researchers found that the moon’s surface may have been indirectly affected by the global lockdown.
The team found that nighttime temperatures on the lunar surface dropped significantly during the strict COVID-19 lockdown period from April to May 2020.
They believe this strange phenomenon can be explained by a significant decrease in greenhouse gas emissions during the lockdown, which eventually led to a cooling of the moon’s surface.
New research suggests that nighttime temperatures on the lunar surface at six different locations dropped significantly during the strict COVID-19 lockdown period from April to May 2020
“The moon may have experienced the effect of the COVID-19 lockdown, visualized as an anomalous drop in lunar nighttime surface temperatures during that period,” the researchers said in their report.
A pair of researchers from the Physical Research Laboratory in Ahmedabad, India, analyzed the moon’s nighttime surface temperatures at six different locations on the near side of the moon – or the side that always faces Earth.
These temperature records were taken by NASA’s Lunar Reconnaissance Orbiter (LRO), which was launched in 2009.
The LRO is equipped with an instrument that uses seven thermal infrared cameras to measure the temperature of the moon’s surface.
The team looked at temperatures between 2017 and 2023 and noticed something strange in the data collected between April and May 2020.
At all six locations, the researchers found an anomalous temperature drop ranging from eight to ten degrees Kelvin (or about 14 to 18 degrees Fahrenheit) that appeared to correspond with this period of lockdown.
The lowest of all temperatures was recorded at one of two locations in Oceanus Procellarum: a large, dark expanse on the moon’s underside.
There, temperatures dropped as low as 96.2 K, or -286 F. By comparison, temperatures at this site dropped as low as 131.7 K, or -222 F, in 2022.
The average lunar temperature at the equator and midlatitudes ranges from -298 F during lunar night to 224 F during Monday.
The researchers analyzed data on the moon’s surface temperature collected by NASA’s Lunar Reconnaissance Orbiter.
The researchers hypothesize that this cooling was caused by a sudden drop in radiation emitted from Earth as human activity ground to a halt during the lockdown, which in turn reduced the amount of heat escaping the atmosphere.
They published their findings in the journal this month Monthly communications of the Royal Astronomical Society: letters.
The first wave of COVID-19 swept the world in March 2020. There were no vaccines available at that time.
Therefore, governments around the world have issued strict lockdown protocols in an attempt to slow the spread of the virus. By April, about half the world’s population had been asked or ordered to stay indoors.
This has significantly reduced the amount of terrestrial radiation generated on Earth. That’s because the lockdown has interrupted many greenhouse gas-generating activities, such as commuting, industrialization and mining.
Lockdown reduced global daily greenhouse gas emissions, which in turn reduced the amount of heat radiating from the Earth
A reduction in Earth’s radiated heat could explain why the moon’s surface cooled in spring 2020, researchers claim
In fact, research has shown that daily global CO2 emissions fell by roughly 17 percent as of early April 2020 compared to 2019 average levels.
When sunlight reaches Earth, some of that radiation is absorbed by our planet’s surface and atmosphere. This causes the Earth to warm, causing terrestrial infrared radiation – or radiated heat.
When there are high concentrations of greenhouse gases, such as CO2, water vapor and methane, these gases absorb the Earth’s heat and then release it back into space.
But during the lockdown, a global reduction in emissions led to a decrease in cloud cover and air pollutants in many countries. Therefore, the amount of heat emitted by the Earth also decreased, the researchers explained in their report.
The temperature drop the researchers observed on the near side of the moon (or the side that always faces Earth) suggests that some of the heat radiated by our planet is affecting and warming the moon’s surface.
This would explain why the moon’s surface temperature dropped during a period of reduced greenhouse gas emissions.
More research is needed to establish conclusive links between the two phenomena, the researchers said in their report. But this study points to the moon’s surface temperatures as a new way to study the effects of climate change on Earth.