Parker Solar Probe

What is Parker Solar Probe?

Probes & telescopes· Launched 2018-08-12 – 8th year ongoing (closest pass 6.1M km). The first craft to fly through the Sun's atmosphere and the fastest object ever built, tightening its orbit with seven Venus flybys.

The orbit of Parker Solar Probe at this moment: https://nowsky.org/solar/orbit?fw=probe%3Aparker&sp=1.6 — replayed live, no login.

Mission timeline

1. 12 Aug 2018Parker Solar Probe launch
2. 24 Dec 2024Parker Solar Probe at closest approach

Spacecraft specs

Figures are representative approximations. Source: compiled from NASA and IAU public data.

Frequently asked

When did Parker Solar Probe launch?

2018-08-12.

How close does Parker Solar Probe get to the Sun?

6.1M km above the surface.

How fast is Parker Solar Probe travelling?

692,000 km/h — fastest ever.

Closest approach out of contact — Christmas Eve 2024

At the moment Parker passed 6.1 million km above the Sun's surface on 24 December 2024, Earth could hear nothing. The spacecraft was nearly behind the Sun, its radio signal blocked, and while the shield pointed exactly sunward the antenna could not be aimed at Earth. The first signal the team received was a single beacon tone meaning "nominal", arriving around midnight on 27 December.

Those few days show the design principle of the mission: during each close pass the spacecraft must hold its attitude, run its instruments and store its data entirely on its own. The pass data came down over the following weeks, and the measurements of the source region of the solar wind made then became Parker's central result. Parker returns to the same distance every 88 days, and each time the days of silence repeat.

The mission in depth

Parker Solar Probe is the fastest thing humanity has built, and the first spacecraft to "touch" a star. Seven Venus flybys have tightened its orbit until closest approach passes 6.1 million km above the solar surface at 692,000 km/h.

One 11-cm carbon-composite heat shield does the protecting: its face bakes at 1,400 °C while the body behind it sits near room temperature. In 2021 Parker flew through the corona itself — the first entry into a star's atmosphere.

The mission's two driving questions: why is the corona hundreds of times hotter than the surface below it, and where does the solar wind get its push? Replay Parker's spiral and its 88-day perihelion passes in the orbit view.

Parker's secret is that near the Sun it's hot but sparse: the million-degree corona is so thin that the actual heat load stops at the carbon-composite shield (1,400°C on its face). In December 2024 it first swooped within 6.1 million km of the surface at a record 692,000 km/h — and its big surprise so far is the 'switchbacks,' zigzag magnetic kinks in the newborn solar wind.

Related

Figures are representative approximations. Simulated positions use J2000 mean elements.