NASA's Parker Solar Probe detected natural radio emissions from Venus

They could help understand how Venus' atmosphere changes.

NASA/Johns Hopkins APL/Naval Research Laboratory/Guillermo Stenborg and Brendan Gallagher

NASA's Parker Solar Probe is continuing to shed light on Venus despite its focus on the Sun. According to Futurism, the spacecraft detected a natural radio signal revealing that it skirted Venus' upper atmosphere (specifically, its ionosphere) when it flew 517 miles above the surface in July 2020. The probe's electric and magnetic field detector, FIELDS, picked up a low-frequency output similar to one scientists noticed when Galileo swung by Jupiter's moons.

Scientsts hadn't expected the brush with the atmosphere, although it wasn't a complete surprise given earlier data.

The findings are another matter. Scientists using Earth-based telescopes suspected Venus' atmosphere was thinning as the Sun settled into a solar minimum (when there's relatively little activity), but the Parker probe's data appears to have confirmed it. That's wildly different than Pioneer Venus Orbiter data from 1992, when the Sun was near its frenetic solar maximum.

The data could shed further light on how Venus transformed from an almost Earth-like planet into the hellish hothouse it is today. If nothing else, the Parker flyby underscores the value of collecting incidental data from spacecraft — it could provide answers that would otherwise require dedicated missions to collect.