Albert McKeon

Dec 6th 2018

Parker Solar Probe Will Stare at the Sun and Offer New Discoveries


As children, we’re taught to never stare at the sun, a lesson that ironically shrouds our solar system’s brightest — and only — star in mystery.

Fortunately, we will soon learn more about the sun thanks to the Parker Solar Probe, a robotic spacecraft about the size of a car. The probe is bravely going where no other spacecraft (or human) has dared to go: 3.83 million miles away from the sun.

If that doesn’t seem close enough, well, it isn’t. But sun exploration isn’t like climbing a mountain. Earth is roughly 91 million miles away from the sun. For obvious reasons, objects can’t get too close to the hot sun. Inverse said that a spacecraft would probably melt within 1.3 million miles of the gaseous star.

So 3.83 million miles is a big deal. What’s an even bigger deal is the promise of Parker Solar Probe’s mission: new data on solar activity that could reshape how we view the sun, our solar system and solar forecasting.

The Sun Has Mysteries To Solve

Parker Solar Probe launched in August and has already delivered good news. In September, NASA reported it had received “first-light” data from each of the probe’s four instrument suites. These weren’t significant scientific findings but rather a test of how well the instruments will work in tandem once they get within range of the sun. The instruments will measure the sun’s electric and magnetic fields, as well as charged particles, known as the solar wind, that are released from the sun’s upper atmosphere, or hot corona. The instruments will also capture images of the environment around the probe.

The mission aims to shed light on the connection between our planet and the sun. The data could help us understand and potentially forecast space weather. Such knowledge could provide insight on why the unstable corona produces solar wind, flare and mass ejections. Millions of tons of highly magnetized material can erupt from the sun at speeds of several million miles an hour, which, as NASA points out, is a speed that would get you from Washington D.C. to Los Angeles in seconds. It would be beneficial to know more about the distant magnetic storms that could eventually affect satellite technologies outside of Earth.

NASA wants to know why the corona is much hotter than the visible surface of the sun, which is also known as the photosphere. It also wants to understand how solar wind accelerates. Answers about the sun could answer questions we have about Earth. These answers can only come by getting close (3.83 million miles close) to the sun.

Surviving and Studying in Space

Because it is within the relative ballpark of the sun, the solar-powered probe had to be a marvel of engineering. A 4.5-inch thick carbon-composite shield will protect it from the sun’s heat. It also has “solar arrays that will retract and extend as the probe moves toward or away from the sun during several loops around the inner solar system,” ensuring the panels stay at proper temperatures and power levels, according to NASA.

At its closest passes of the sun, the spacecraft has to survive solar intensity of about 475 times what spacecraft experience while orbiting earth. According to NASA, temperatures outside the probe will reach as high as 2,500 degrees Fahrenheit.

Understanding Our Source of Light

The probe mission is named after Eugene Parker, a University of Chicago astronomy and astrophysics professor who laid down a foundation of understanding about how stars produce energy, what he called the solar wind. He was also the one who theorized that the sun’s corona is hotter than its surface. The Parker Solar Probe’s mission is the first one in NASA history to be named after a living individual.

The sun exploration mission will start in earnest this November, when the probe will first get within close enough range of the star. It will travel many orbits around the sun over a seven-year period, with its closest venture being when it’s 3.83 million miles out. That is more than eight times closer than Mercury gets to the sun, and the closest we’ve been yet to learning about the star that provides us light and heat every day.