Humanity’s only active mission at Venus has officially come to an end. The Japan Aerospace Exploration Agency (JAXA) recently announced that its Akatsuki Venus Climate Orbiter mission has been terminated. In an official statement released on October 28, JAXA said that the mission team has accepted the “inevitable” after multiple failed attempts of establishing communications with the spacecraft. Akatsuki went incommunicado in May 2024, and JAXA officials had been trying to bring it online ever since. According to the agency, it started the termination procedure of the mission in September.
The mission
Akatsuki launched in May 2010 and was the only active mission around Venus. While it did survive longer than its expected lifespan of 4.5 years, Akatsuki faced setbacks right from the start. In December 2010, the fuel valve of the orbiter’s main engine malfunctioned, causing it to miss an orbital injection manoeuvre into the Venusian orbit. But the mission team improvised using secondary thrusters and five years later, in December 2015, managed to successfully insert it into orbit.
From this point on, began Akatsuki’s groundbreaking discoveries using its six instruments. While two of its infrared cameras stopped working, four other instruments were still functioning when Akatsuki went offline.
This planet, which is called Earth’s twin, has unbearable surface conditions due to dense carbon dioxide atmosphere which drives temperatures high enough to melt lead (464°C).
ALSO READ: China’s Tiangong Space Station Will Host Pakistani Astronaut In 2026
Akatsuki’s discoveries
Interestingly, a day on Venus (243) is longer than its year (225), and scientists were puzzled by how winds between 50–70 kilometres above surface whip 60 times faster than the planet retrograde rotation despite such a slow pace. With Akatsuki, scientists now know that the incredible rotation speeds were being maintained by solar heating.
Another interesting aspect of Venus’ rotation is the planet being almost tidally locked to the Sun, meaning one side experiences eternal day while other experiences everlasting night. While it is not completely locked like the Moon around Earth, the rotation speed is slow enough for similar conditions to arise. However, what’s fascinating is that despite or as a result of ‘near-lock condition’, Venus undergoes atmospheric circulation which circulates warm air from the dayside and cold air from the nightside.
Scientists say that if there’s no mechanism to redistribute heat on a tidally-locked planet, air on the planet’s nightside would freeze and cause global atmospheric collapse.
Another captivating discovery by Akatsuki was a drawn bow-shaped structure extending over 10,000 km from the north pole to south. This structure was undisturbed despite the ferocious winds and scientists think this was caused by mountain ranges pushing the dense lower atmosphere gas to higher altitudes to create a gravity wave. This is the first time gravity waves have been seen on this scale on a planet other than Earth.
JAXA revealed that Akatsuki’s data has resulted in 178 journal papers and deep insights into Venus’ atmospheric behaviour. “This was a mission that changed our view of our Earth-sized neighbour, and laid the path for new discoveries about what it takes to become heaven or hell,” the agency stated.
ALSO READ: Comet 3I/ATLAS: Should We Take Avi Loeb’s Alien Theory Seriously?
