This is the nightside of Venus (!) but how you can capture the nightside? The Parker Solar Probe can with the WISPR camera at near-infrared wavelengths. This stunning image was captured during its close flyby from 12,380 km away in July 2020. WISPR effectively captured the thermal emission of the Venusian surface.
The nightside of Venus – the thermal emission of the Venusian surface. Credits: NASA/Johns Hopkins APL/Naval Research Laboratory/Guillermo Stenborg and Brendan Gallagher
The bright rim around the edge of the planet might be nightglow — light emitted by oxygen atoms high in the atmosphere as they recombine into molecules.
The prominent dark feature in the center of the image is Aphrodite Terra, the largest highland region on the Venusian surface. The feature appears dark because of its lower temperature, about 30 degrees Celsius cooler than its surroundings.
The bright streaks could come from cosmic rays, dust reflecting sunlight, or bits of material expelled from the spacecraft’s structures after those dust grains make impact, though scientists are still discussing which of these more likely explains the streaks here. (The dark spot appearing on the lower portion of Venus is an artifact from the camera.)
A bonus for the stargazers is the constellation of Orion: do you recognize the familiar stars of Orion’s belt and sword at lower right?
—
Konstantinos Sakkas
