4 MAY 2021
During a close flyby of the planet Venus in July 2020, NASA's Parker Solar Probe detected something odd.
As it dipped just 833 kilometers (517 miles) above the Venusian surface, the probe's instruments recorded a low-frequency radio signal - a telltale sign that Parker had skimmed through the ionosphere, a layer of the planet's upper atmosphere.
This was the first time an instrument had been able to record direct
in situ measurements of Venus' upper atmosphere in nearly three decades, and the data recorded gives us a new understanding of how Venus changes in response to cyclic changes in the Sun.
"I was just so excited to have new data from Venus," said astronomer Glyn Collinson of NASA's Goddard Space Flight Center.