NASA’s Parker Solar Probe is on a mission to explore the sun, but it keeps discovering fascinating new things about our mysterious planetary neighbor, Venus.
This past summer, NASA’s spacecraft flew by Venus and detected a natural radio signal from Earth’s twin. That signal revealed that the probe was indeed passing through Venus’ upper atmosphere, recording the first direct measurement in nearly 30 years.
The scientists were surprised to discover that Venus’ atmosphere now looks very different, and they published their findings Monday in the journal Geophysical Research Letters.
Amazing close-up of Venus taken by NASA’s Parker Solar Probe
Astonishing close-up of Venus taken by NASA’s Parker Solar Probe.
The solar mission, which will launch in 2018, is designed to explore the sun and unlock some of its mysteries. Over the course of seven years, the probe will traverse the sun’s atmosphere and get closer to the surface of our star than any space probe before.
Venus is critical to the probe’s success. The spacecraft uses Venus’ gravity as it orbits the planet, called gravity assist, to curve the probe’s orbit and bring it ever closer to the Sun.
During one of these Venus flybys on July 11, 2020, the spacecraft collected some evidence that Venus’ upper atmosphere is undergoing some unusual changes that are influenced by the solar cycle, or our Sun’s 11-year cycle of activity.
During the July 2020 flyby of Venus, the Parker Solar Probe’s WISPR instrument detected a bright rim around the edge of the planet that may be night glow.
During its July 2020 flyby of Venus, the Parker Solar Probe’s WISPR instrument detected a bright rim around the planet’s edge that may be night glows.
The spacecraft also captured an amazing image showing an unexpected side of our planetary neighbor. This was the third Venus flyby for the Parker Solar Probe. During the flyby, the probe came within 833 kilometers of the planet’s surface.
Information Parker has gathered so far about Venus is helping scientists understand why it is so different from Earth, even though the planets are often referred to as twins.
Both planets are rocky and similar in size, but something happened to make Earth and Venus evolve differently. Unlike Earth, Venus has no magnetic field. Its inhospitable surface has blazing temperatures that can melt lead.
NASA's mission to touch the sun unravels our star's mysteries.
NASA mission to touch the sun unravels the mysteries of our star
Attempts to explore Venus with space probes are tricky because they can only survive a few hours at most when they try to descend to the surface. Past missions to explore Venus include NASA’s Pioneer Venus Orbiter from 1978 to 1992 and the European Space Agency’s Venus Express from 2005 to 2014, both of which orbited the planet.
Understanding why Venus became this way may help scientists figure out why some Earth-like planets appear habitable and others do not.
During the third Venus flyby, Parker Solar Probe’s FIELDS instrument, which measures electric and magnetic fields in the sun’s atmosphere, detected a natural radio signal at a low frequency. This appeared as a “frown” in FIELDS’ data.
Parker Solar Probe sends back images of its orbits of the sun
Farmer Solar Probe sends back images of its orbits of the sun
“I was just so excited to have new data from Venus,” Glyn Collinson, lead author of the study and a research associate at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “To see Venus now, it’s all about those little glimpses.”
Collinson, a Venus expert who has studied data from previous missions to the planet, said the signal looked familiar. He previously worked on the Galileo orbiter, which studied Jupiter and its moons from 1995 to 2003.
The same kind of frown would appear in the Galileo data as the spacecraft passed through the ionospheres of Jupiter’s moons, Collinson noted.
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Earth and Venus both have an ionosphere, an electrically charged layer of gas at the top of the atmosphere. This plasma emits natural radio waves that v