What’s the weather like on Venus at night? Scientists are finally discovering the truth.

Venus is only one planet away from Earth and has been studied for a long time, with the first Venusian spacecraft reaching the planet in 1978. Scientists, on the other hand, know relatively little about the weather on Venus at night. Until now, that is.

For millennia, astronomers have studied numerous planets in our solar system. While contemporary scientific gear and telescopes have provided us with extensive information on planets like Venus, other elements of planets in our social system remain unknown. Nighttime weather on Venus is an example.

The lack of sunlight makes imaging weather patterns difficult, therefore little is known about the weather on Venus at night. Researchers recently devised a method for using the infrared sensors aboard Japan’s Venus spacecraft Akatsuki to disclose nocturnal characteristics on the planet. Other planets in the solar system, such as Mars, could potentially be studied using analytical approaches.

Researchers have created a new approach to use infrared sensors on the Japanese Venus climate satellite Akatsuki, which arrived in orbit around Venus in 2015, to finally show what the planet’s weather is like at night, according to a new study. Those sensors discovered some unusual wind circulation patterns as well as evening clouds.

Scientists working on the project say that researching Venusian weather with their new technology could help them learn more about the factors that control weather on Earth.

Earth and Venus are very different, but they share a number of similarities. They’re both around the same size and mass, and they orbit the sun in the same orbital region known as the habitable zone. Both planets have a solid surface and a thin atmosphere that is affected by the weather.

“Small-scale cloud patterns in the direct images are faint and frequently indistinguishable from background noise,” co-author Takeshi Imamura, a professor at the Graduate School of Frontier Sciences at the University of Tokyo, said in a statement.

But since Venus and Earth are so similar, scientists can learn more about our planet by studying the weather on Venus. Only the dayside of Venus had hitherto been freely accessible to scientific instruments.

Scientists didn’t need sunshine to make observations because of Akatsuki’s infrared imager. They are clear, however, that the orbiter’s infrared vision cannot clarify details on Venus’ nightside, but it does provide researchers with data that allows them to view things indirectly.

Members of the team were able to merge photos to reduce noise, which often obscures small-scale cloud patterns. The entire weather system on Venus rotates swiftly, and scientists have to correct for this movement, known as super-rotation, in order to examine fascinating structures.

The team is looking into the mechanisms that keep Venus’ super-rotation going, and they believe that weather patterns at night could help explain it.

One noteworthy finding based on the data is that the nighttime North-Southwinds rotate in the opposite direction as their daytime counterparts. In the future, further information on the strange weather will be obtained. In the following years, NASA will send two missions to Venus to investigate the planet.