NASA maintains a curious tradition: the artifacts it sends into space last much longer than they should and end up doing things for which they were not programmed, and the Parker solar probe could not escape its heritage by sending a photo to Earth stunning view of Venus, showing more than she could technically capture.
The image was recorded by the Wide-Field Imager for Parker Solar Probe (something like “Parker Solar Probe Wide Field Imager”, or WISPR), during the probe’s passage through the neighboring planet on June 11 last year. These sweeps are necessary for Parker’s mission: in its orbit, it picks up Venus’s gravity to get closer and closer to the Sun. According to NASA, in seven years of mission the spacecraft will count seven flights over the planet.
A Venusian close-up was already expected; the probe clearly captured the bright outline of the planet’s night side, known as the nightglow. The phenomenon is caused by the sun’s ultraviolet light, which flows through the atmosphere and divides the molecules into atoms that, free, recombine, losing energy in the form of light.
The surprise, however, was in the center of the image, where it is possible to distinguish a darkened spot: Aphrodite Terra, the largest of the two main elevated regions of Venus (its size equals that of South America), with mountain ranges and cut by numerous and extensive lava flows (even so, the region appears darker because it is about 30 ° C colder than the regions around it). The problem is, theoretically, Parker couldn’t see it.
“WISPR is a device for observing visible light. We expected to see clouds, but the camera looked directly at the surface, ”said astrophysicist Angelos Vourlidas, scientist for the WISPR project at the Johns Hopkins Applied Physics Laboratory (APL).
The discovery that Parker would have been able to see the surface of Venus through the dense atmosphere made the researchers assess how sensitive the equipment is to infrared light.
If the probe can capture wavelengths of light close to this spectrum, this would open new opportunities for investigation not only of the planet but also of the dust around the Sun and even in the internal solar system.
On the other hand, Parker may have inadvertently discovered that Venus has a window in its atmosphere. “In any case, exciting scientific opportunities await us,” said Vourlidas.
Parker’s next flyby over Venus suddenly became a separate mission: on February 20, the spacecraft made a series of similar observations, also on the Venusian night side. The answer to what Parker saw, however, will not be known until late April, when the images reach Earth.
Parker’s last pass, on the 20th of this month, was the fourth of seven of Venus’s so-called gravity assists planned for the mission. The next ones, which will bring the probe even closer to the Sun, are scheduled for April 29 and August 9.
Each time, Parker breaks its own solar approach record, narrowing its orbit: it will now be 10.4 million kilometers from the Sun’s surface – about three million kilometers closer than the previous approach, in January 17th.
A menor distância que a Parker deve alcançar é a cerca de 6,2 milhões de quilômetros da fotosfera do Sol. Quando isso acontecer, a sonda estará viajando a mais de 700 mil km/h, o que fará com que seja o objeto mais veloz já lançado pelo ser humano.