A Spacecraft Is About to Fly Into the Sun’s Atmosphere for the First Time

Almost no one has written about Parker Solar Probe Not anymore.

Of course, the spacecraft raised some eyebrows when it launched. After all, it is the fastest-moving object ever built by humans. Driven by the sun’s gravity, the probe reaches a maximum speed of 430,000 miles per hour, or more than one-sixth of one percent the speed of light. This speed can get you from New York City to Tokyo in less than a minute.

Another distinction of the Parker Solar Probe is that it is the first NASA spacecraft to be named after a living person. When it was launched in August 2018, physicist Eugene Parker was 91 years old.

But six years since a probe zipped through outer space and flew past the sun? Not so much. Let’s face it, the astrophysical properties of the Sun and its complex structure aren’t something most people think about every day.

However, the small probe—which weighs less than a ton and has a scientific payload of only about 110 pounds (50 kilograms)—is about to have its moment in stardom. Indeed. On Christmas Eve, the Parker Solar Probe will make its closest approach to the sun. It will fly just 3.8 million miles (6.1 million kilometers) above the sun’s surface, entering the solar atmosphere for the first time.

Yes, it can get hot. Scientists estimate that the probe’s heat shield will withstand temperatures of more than 2,500 degrees Fahrenheit (1,371 degrees Celsius) on Christmas Eve, almost the opposite of the Arctic.

Go straight to the source

I spoke with NASA science director Nikki Fox to find out why the probe is suffering so much. Fox, who was a program scientist for the Parker Solar Probe before moving to NASA headquarters, explained that scientists really want to understand the origin of the solar wind.

This is a stream of charged particles emanating from the sun’s outermost corona. Fox explains that scientists have been curious about this particular mystery for more than half a century.

“Quite simply, we want to find the birthplace of the solar wind,” she said.

Parker predicted the existence of this solar wind back in the 1950s, before we had satellites or spacecraft to measure the Sun’s properties. The scientific community was quite skeptical of the idea – in fact, many laughed at Parker – until the Mariner 2 mission began measuring the solar wind in 1962.

As the scientific community began to embrace Parker’s theory, they wanted to learn more about the solar wind, a fundamental building block of the entire solar system. Although the solar wind is invisible to the naked eye, when you see auroras on Earth, it’s the solar wind interacting with the Earth’s magnetosphere in a particularly violent way.