The new image was taken by the Wide-field Imager for Parker Solar Probe (WISPR) during the close flyby of the second planet from the Sun on July 11, 2020.
When flying past Venus on July 11, 2020, the WISPR instrument onboard Parker Solar Probe detected a bright rim around the edge of the planet that may be nightglow. The prominent dark feature in the center of the image is Aphrodite Terra, the largest highland region on the Venusian surface. Bright streaks in WISPR, such as the ones seen here, are typically caused by a combination of cosmic rays, sunlight reflected by grains of space dust, and particles of material expelled from the spacecraft’s structures after impact with those dust grains. The number of streaks varies along the orbit or when the spacecraft is traveling at different speeds, and scientists are still in discussion about the specific origins of the streaks here. The dark spot appearing on the lower portion of Venus is an artifact from the WISPR instrument. Image credit: NASA / Johns Hopkins Applied Physics Laboratory / Naval Research Laboratory / Guillermo Stenborg / Brendan Gallagher.
“Parker Solar Probe whips by Venus a total of seven times over the course of its seven-year mission, using the planet’s gravity to bend the spacecraft’s orbit,” said WISPR project scientist Dr. Angelos Vourlidas from the Johns Hopkins Applied Physics Laboratory and colleagues.
“These Venus gravity assists allow the spacecraft to fly closer and closer to the Sun on its mission to study the dynamics of the solar wind close to its source.”
“But — along with the orbital dynamics — these passes can also yield some unique and even unexpected views of the inner Solar System.”
On July 11, 2020, Parker Solar Probe successfully completed its third gravity assist flyby of Venus.
The WISPR instrument captured a stunning image of the planet’s nightside from 12,380 km (7,693 miles) away.
“WISPR is designed to take images of the solar corona and inner heliosphere in visible light, as well as images of the solar wind and its structures as they approach and fly by the spacecraft,” the researchers said.
“At Venus, the camera detected a bright rim around the edge of the planet that may be nightglow — light emitted by oxygen atoms high in the atmosphere that recombine into molecules in the nightside.”
“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.
“That aspect of the image took the team by surprise,” Dr. Vourlidas said.
“WISPR is tailored and tested for visible light observations. We expected to see clouds, but the camera peered right through to the surface.”
“WISPR effectively captured the thermal emission of the Venusian surface,” added WISPR team member Dr. Brian Wood, an astrophysicist at the U.S. Naval Research Laboratory.
“It’s very similar to images acquired by JAXA’s Akatsuki spacecraft at near-infrared wavelengths.”
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This article is based on text provided by the National Aeronautics and Space Administration.
