Space probes · the Sun

Parker Solar Probe: the closest anyone has been to the Sun

The Parker Solar Probe: its heat shield and antenna, drawn from its model in Exo-View

The Parker Solar Probe has flown closer to the Sun than any spacecraft before it, passing through its outer atmosphere, the corona, at about 190 km a second, the fastest speed any human-made thing has reached. Exo-View shows where it is today and lets you fly alongside it.

Fly to the Parker Solar Probe Fly to the Sun

Closest to the Sun: About 6.1 million km from its surface, on 24 December 2024
Top speed: About 190 km/s, or 690,000 km/h
Heat shield: 11.5 cm of carbon foam, facing about 1,400 °C while the craft behind it stays near room temperature
Launched: 12 August 2018
Mass: 685 kg
Orbit: Seven passes by Venus tightened it, to a loop round the Sun of 88 days

Touching the Sun

In April 2021 Parker flew through the corona, the Sun's hot outer atmosphere, and so became the first spacecraft to 'touch' the Sun. The corona is millions of degrees, hotter than the surface, and nobody knows exactly why. Parker's instruments sample the solar wind, the stream of particles that leaves the Sun, where it is born, and have shown that its flow is made of twisting, switchback-shaped kinks in the Sun's magnetic field.

Why it does not melt

Space is cold, and Parker is hot only on one face. A shield 2.4 m wide takes the heat while the craft sits in its shadow, and its solar panels fold back into the shade as it nears the Sun. Its path was shaped by Venus: each pass of the planet pulled it into a smaller orbit, the last in December 2024 leaving it on a loop that comes in close every 88 days.

Named for a living scientist

Eugene Parker proposed in 1958 that the Sun must blow a stream of particles through space, which he called the solar wind. People doubted him, until probes found it. Parker's was the first NASA spacecraft named for someone who was alive to see it launch.

In Exo-View

The key below flies from the Sun out to the probe, seen with its shield and its antenna, with the trails of its orbits round the Sun beside it. Its place comes from NASA's Horizons system, and like all the positions here is approximate.