by Man-made spacecraft have been exploring other planets for as long as 60 years.
On December 14, 1962, a NASA spacecraft called sailor 2 it flew away Venus in the first ever planetary flyby. The maneuver gave the spacecraft 42 minutes to observe what scientists now consider Landis the infernal twin — whose surface is hidden at the moment it was thought to be lush, tropical jungle or swamp.
However, data from Mariner 2 showed that the night side of Venus was also scorching hot, with surface temperatures as high as 421 degrees Fahrenheit (216 degrees Celsius), according to NASA. Scientists already knew of Venus’ super-slow rotation (a day on Venus lasts about 243 Earth days), but they expected the planet’s day and night sides to show a much greater temperature difference than Mariner 2 found.
At the time, agency officials wrote that the data from Mariner 2 painted a picture of “a warm, bright earth covered in thin, dark, cold clouds.” according to the New York Times.
Related: Venus, once heralded as Earth’s twin, is a hothouse (and a tempting target in the search for life)
Mariner 2 followed its sibling and predecessor to the launch pad just one month after Mariner 1’s failed launch in July 1962. Range personnel detonated Mariner 1 less than five minutes after launch because the booster was off course and it was expected to crash, according to NASA.
But Mariner 2’s launch went smoothly, and despite the hiccups along the way, the spacecraft endured its three-and-a-half-month journey to Venus. Also, that trip allowed Mariner 2 to confirm the existence of the solar windthe constant stream of charged particles escaping from the sun, and observing a major solar flare, according to NASA.
During the Venus flyby, Mariner 2 used its seven instruments to study both the day and night sides of the planet. In addition to measuring the planet’s temperature, Mariner 2 detected the thick cloud layer in its middle atmosphere; scientists now know those clouds are mostly sulfuric acid.
Although Mariner 2 performed the first planetary flyby, it wasn’t the first spacecraft to whiz past another object in our solar system. This honor goes to the Soviet Union’s Luna 1 mission, which flew by the moon in 1959.
Venus was a common destination for both the United States and the Soviet Union from the 1960s to the early 1980s before its popularity started to fade. Currently, only one spacecraft is dedicated to Venus, that of Japan Akatsuki mission that has been in orbit around the planet since 2015.
But the solar wind has returned the favor, so to speak. Both from NASA Parker solar probe and the European Space Agency (ESA) Solar orbit they are observing Venus as they make flybys to adjust their trajectories and venture closer to the sun.
And Venus is back on the agenda in a major way. NASA is committed to DAVINCI and VERITAS missionsand ESA al EnVision missionwho will explore the planet in 2030.
Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedot com and go Facebook.
