Observations of Venus with NASA’s Parker solar probe, JAXA’s Akatsuki mission, and astronomers around the world have provided a rare opportunity to see Earth’s neighboring planet from the surface of the clouds. The results will be presented this week at the European Science Congress (EPSC) 2020, which will be held in a virtual format from 21 September to 9 October, Europlanet reports.
On July 11, 2020, the Parker Solar Probe, which travels through the inner solar system to capture particles of the sun’s outer atmosphere, completed the third in a series of orbital flights of Venus. From June 19 to July 18, astronomers and members of the Akatsuki mission team teamed up to support the probe meeting with a coordinated observation campaign. Ground-based observations were mainly attended by amateur astronomers. A similar campaign will be carried out in support of the Venus flyby by ESA’s BepiColombo mission on October 15, 2020.
“The campaign resulted in many multi-level observations right from the surface to the top of the clouds and airglow phenomena that gave us a unique view of the atmosphere of Venus,” said Ricardo Ueso, a former ESA Venus Express mission member and one of the project coordinators. “Being able to observe Venus with so many instruments, using such a massive collaboration means we can add scientific value to these short visits by the Parker Solar Probe and BepiColombo to Venus”.
Venus is the brightest object that a person sees in the night sky, besides the moon. And, although this is the closest planet in size to Earth, it is a radically different world. Venus’s dense atmosphere, made up mostly of the greenhouse gas carbon dioxide, maintains a surface temperature of 460 degrees Celsius and pressures comparable to those found in the depths of Earth’s oceans. Spacecraft passing close to Venus as they travel through the inner solar system can collect valuable data that will help us understand the properties of the planet and its evolution.
During the campaign, Parker Solar Probe observed the night side of the planet from the surface to the upper atmosphere, and the Akatsuki received data on the upper clouds. Back on Earth, the researchers used the Infrared Telescope (IRTF) in Hawaii and the Northern Optical Telescope (NOT) on La Palma to probe the deeper clouds of Venus on the planet’s night side. Additional observations of deeper clouds and the surface of Venus were obtained at the Pic du Midi in France.
Civilian astronomers have observed the upper and middle clouds in the ultraviolet, violet, and near-infrared wavelengths. Some amateur observers have also been able to observe the surface of Venus through warm radiation emanating from the planet through the clouds of Venus.
Global ground support from professional telescopes was spearheaded by Javier Peralta, an astronomer who has coordinated similar campaigns in support of past missions. The amateur ground support campaign was coordinated through the Europlanet 2024 Research Infrastructure.
Observations continued and intensified during August when Venus was best observed from Earth and will culminate in October when the BepiColombo mission will orbit Venus on its way to Mercury.
There are clear signs of temporal changes in the clouds of Venus if we compare the observations of the Venus Express mission in 2006-2014 with the later observations of the Akatsuki from 2015. The data gathered by amateurs and professional observers from these campaigns in the summer and fall will expand knowledge about the weather on Venus and its variability, the scientists conclude.