Dark side of Venus revealed in new NASA photos
A NASA spacecraft has captured never-before-seen images of Venus, providing stunning views of the hellishly hot surface of the second rock from the sun.
Appearing radiant against the cosmic backdrop, the images show Venus in visible light, which is the part of the electromagnetic spectrum that the human eye can see. A detailed analysis of the images, taken of Venus' "night side," or the side facing away from the sun, was published Wednesday in the journal Geophysical Research Letters.
"The surface of Venus, even on the nightside, is about 860 degrees," Brian Wood, an astrophysicist at the U.S. Naval Research Laboratory and the study’s lead author, said in a statement. "It's so hot that the rocky surface of Venus is visibly glowing, like a piece of iron pulled from a forge."
In addition to revealing characteristics of Venus' landscape and geological makeup, the photos could help scientists understand more about Earth's neighbor and "twin," including why Venus ended up so inhospitable despite being a similar size and density to Earth.
"Venus is the third-brightest thing in the sky, but until recently we have not had much information on what the surface looked like," Wood said in the statement.
Venus' thick atmosphere and clouds of sulfuric acid typically obscure the planet's features from view, but NASA's Parker Solar Probe was able to see through the hazy shroud, down to the planet's ultra-hot surface.
The images were captured in February 2021, when the Parker Solar Probe flew past Venus and the spacecraft was able to see the planet's night side in its entirety.
The Parker Solar Probe launched in August 2018 and is designed to study the sun’s atmosphere. The probe snapped other photos of Venus during a previous flyby in July 2020. At the time, the scientists planned to use those observations to measure the speed and motions of Venus' clouds.
To their surprise, the Parker Solar Probe saw through to the planet's surface.
Last February, when the spacecraft again sailed past Venus, the astronomers trained the probe's eyes on the planet's enigmatic night side.
The resulting images were taken across a range of wavelengths, from visible light to near-infrared, which is just beyond what the human eye can detect. And when stitched together into a video, it's possible to pick out dark patches indicating cooler, higher altitude regions against the lighter, warmer lowlands.
A bright ring can also be seen around the planet, a halo of light known as "airglow" that is caused by oxygen atoms emitting light in the atmosphere.
"The images and video just blew me away," Wood said.
The researchers compared the new images to observations from NASA's Magellan spacecraft, which launched in 1989 on a mission to map the entire surface of Venus. The Parker Solar Probe's views aligned with topographical landmarks seen by the Magellan spacecraft, including the Tellus Regio plateau in the northern hemisphere of Venus and a continent-sized highland known as Aphrodite Terra.
Wood and his colleagues said the flyby images will help researchers better understand the planets in the inner solar system. Venus, Earth and Mars all formed at around the same time, but the planets diverged wildly in their evolution. While Venus' thick, heat-trapping atmosphere makes it the hottest of our solar system's planets, Mars is cold and dry and is thought to have been stripped of most of its atmosphere billions of years ago.
Insights into how Venus came to be could shape some of the upcoming missions to the planet. NASA's DAVINCI+ mission, scheduled to launch in 2029, is designed to descend through the atmosphere, analyzing its chemistry and temperature, before landing on the surface. Ahead of the DaVinci mission, in 2027, the agency is planning to launch a spacecraft named VERITAS into orbit around Venus to study its hot conditions.
The European Space Agency also has its sights set on Venus, with a probe called EnVision that is designed to sample trace gases in the planet's atmosphere. The EnVision mission is expected to launch in the early 2030s.
"By studying the surface and atmosphere of Venus, we hope the upcoming missions will help scientists understand the evolution of Venus and what was responsible for making Venus inhospitable today," Lori Glaze, director of the Planetary Science Division at NASA Headquarters, said in a statement.
Quelle: NBC News