Though she’s our closest neighbor and similar to Earth in size, Venus is an enigmatic member of our solar system family. Her atmosphere, a muggy haze of turbulent winds and a runaway greenhouse effect, still perplexes astronomers. Now a Japanese orbiter promises to explore her complex climate and atmospheric flows.
This past winter, Akatsuki, which means “dawn” in Japanese, deftly entered Venus’ orbit. But the probe’s success has been wobbly: The Japanese Aerospace Exploration Agency’s initial attempt to inject the spacecraft into Venus’ orbit sputtered after a problem with its main engine. Akatsuki has been on a detour around the sun since 2010.
Venus has remained a mystery so long because of her stifling atmosphere, which is made of mostly carbon dioxide and clouds of sulfuric acid. That means lightning on Venus doesn’t stem from water clouds like on Earth, Jupiter or Saturn. She traps so much of the sun’s heat, she could melt lead. Her rebellious nature doesn’t stop there: Venus’ sun rises in the west and sets in the east. The probes that have managed to land on the planet barely lasted a couple of hours.
The $300 million craft will peer at her at distances as close as 300 miles from her surface while hurtling on an elliptical orbit. Its bevy of sophisticated instruments — spectrometers, a plasma analyzer, and radio waves — will build on the European Space Agency’s (ESA) previous mission, the Venus Express, which took off almost a decade ago and concluded in 2014.
That mission’s spectrometer revealed Venus’ topography is rippled with active volcanoes and light shows, which Akatsuki will confirm, along with the presence of thunder. The probe will operate for two years, collecting Venusian images as well. Most curious of all are the planet’s storm winds which blow about 60 times the speed of her rotation — a feat that meteorology can’t quite explain. Meanwhile, surface winds, when combined with the atmospheric density, exert more force than anything here on Earth.
Together with the ESA’s data, Japan will continue to lift the corners of Venus’ clouds starting this month. And, in turn, we may get insight to Earth’s atmospheric evolutions.