Surface features seen in WISPR images captured by Nasa’s Parker Solar Probe Credit: NASA/APL/NRL
NASA’s Parker Solar Probe launched in August 2018 with the goal of studying the Sun’s surface and atmosphere. To get close enough to the Sun, the probe is assisted by the gravity of Venus, passing close enough to this planet to use its gravity to accelerate. Scientists have also been using these flybys as an opportunity to study the atmosphere and surface of Venus. To date, there have been five flybys of Venus. The probe is equipped with a camera called the Wide-Field Imager, which successfully detected thermal emissions from the planet’s surface while the probe was on the night side of Venus.
Venus is called Earth’s twin due to its similar size and composition, but the geological histories of Venus and Earth diverged. Venus became inhospitable to life and was surrounded by an almost impenetrable layer of poisonous clouds, while Earth became capable of supporting complex life. This dichotomy has fueled decades of scientific research to better understand the evolution of Venus.
The first images of Venus collected by the Parker Solar Probe were intended to study the speed of clouds in the atmosphere. Scientists were thrilled when the Wide-Field Imager exceeded their expectations and captured images of the planet’s surface. These thermal images can help establish better compositional constraints on the geology of Venus because, when heated, different materials emit energy at different wavelengths, making them diagnostic of different rock types. Furthermore, these images of the surface included features that were detectable in the visible wavelength range. Parker Solar Probe’s last chance to image the night side of Venus is scheduled for November 2024, and the images collected will complement the infrared imaging capabilities of the recently selected DAVINCI and VERITAS missions to Venus.