How fast can you go? Intentionally, I mean. Not effortlessly as in getting whisked around the sun at 66,600 mph (107,200 kph) by the orbiting Earth without lifting a finger. If you’ve traveled by air you’ve sped across the sky in a metal tube at around 550 mph (885 kph). The International Space Station zips along its orbit at more than 17,000 mph (27,350 kph) crossing the continental U.S. in just under 10 minutes. But all that’s nothing compared to the Parker Solar Probe, which broke a record this week.
First, it broke its own record for the fastest moving human-made object on Wednesday, Jan. 29 at 244,440 miles per hour (109.2 km/sec), four times faster than the Earth orbits the sun. At that speed it would take only about 30 seconds to fly from Washington, DC to Los Angeles. The probe travels so fast because it’s falling toward the sun in a mission of exploration. More on that in a minute.
It’s also closer to the sun than any human-made object. As I write, the probe is 12.6 million miles (20.3 million km) from the sun, well within the orbit of the planet Mercury. No surprise, things heat up when you get closer to the sun. Parker is equipped with a heat shield to protect its instruments from overheating. On Jan. 30, the heat shield temperature measured 322° F (612° C). Toasty!
The previous record for closest solar approach and fastest speed (153,454 mph) was set by the German-American Helios 2 spacecraft in April 1976. As the Parker Solar Probe mission progresses, the spacecraft will repeatedly break its own records, with a final, sizzlingly-close approach of 3.83 million miles from the Sun’s surface expected in 2024. To keep track of its current speed, distance and temperature, click here.
The spacecraft will face brutal heat and radiation conditions while providing us with unprecedented close-up observations of our star to help us understand its behavior and how it affects the Earth and its inhabitants. Launched in 2018, Parker is on a 7-year journey to explore the sun’s corona and the solar wind. The corona or outer atmosphere of the sun is the softly-radiant nimbus of light you see around the moon’s silhouette during a total solar eclipse. And the solar wind is the flow of subatomic particles — protons and electrons — that streams from the sun in all directions at a million miles an hour.
Already, the probe has discovered some amazing things we never knew about the sun that include:
- “Rogue” magnetic waves in the solar atmosphere that can instantly bump up the speed of the solar wind as much as 300,000 miles an hour (480,000 km/h).
- A “dust-free” zone within 3.5 million miles (5.6 million km) of the sun’s surface. Dust from asteroid collisions and comets spreads throughout much of the solar system and is responsible for the zodiacal light. Parker found that heat from the sun appears to vaporize the dust close to our star. The burned-out leftovers then mixes with and becomes part of the solar wind.
- Flips in the direction of the magnetic field, which flows out from the Sun, are embedded in the solar wind. Dubbed “switchbacks,” they appear to be common in the solar wind flow inside the orbit of Mercury, and last anywhere from a few seconds to several minutes as they flow over the spacecraft. Oddly, they don’t appear to be present farther from the sun where Earth orbits, for instance.