Solar Probe Plus Mission by NASA Starting to Heat Up

The Solar Probe Plus mission by NASA is starting to heat up with a voyage planned next year that will get it within four million miles of the sun.

Solar Probe Plus is expected to liftoff during a 20-day window that opens July 31, 2018, according to NASA. The probe is part of the space agency's Living With a Star program that hopes to learn more about the sun and its impact on human lives.

Before the probe can answer some of the sun's mysteries, it will have to deal with its immense heat along with radiation, noted LiveScience.com. The Johns Hopkins University Applied Physics Laboratory has been collaborating with NASA to make sure the probe survives its close-up with the sun.

"Solar Probe Plus will be a historic mission, flying into the Sun's atmosphere (or corona), for the first time," said NASA's Goddard Space Flight Center website dedicated to the mission.

"Coming closer to the sun than any previous spacecraft, Solar Probe Plus will employ a combination of in situ measurements and imaging to achieve the mission's primary scientific goal: to understand how the sun's corona is heated and how the solar wind is accelerated. Solar Probe Plus will revolutionize our knowledge of the physics of the origin and evolution of the solar wind."

One of the biggest mysteries scientists hope to answer is why is the surface of the sun's photosphere, or surface, cooler than its atmosphere? The sun surface is about 10,000 degrees, downright chilly compared to its atmosphere that cooks at 3.5 million degrees.

"You'd think the farther away you get from a heat source, you'd get colder," Eric Christian, a NASA research scientist at the Greenbelt, Maryland-based Goddard Space Flight Center, told LiveScience.com. "Why the atmosphere is hotter than the surface is a big puzzle."

Christian said researcher hope to get answers to other questions, like solar wind speeds and why the sun occasionally emits high-energy particles, called solar energetic particles, that could endanger unprotected astronauts and spacecraft.

He told LiveScience.com that researchers have had problems finding out more about the sun because "we're 93 million miles away. (The distance makes) things get smeared out in a way that makes it hard to tell what's happening at the sun."

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