The Parker Solar Probe

Tamima Rashid

The Parker Solar Probe, launched on August 12, 2018, is on a mission to “touch” the sun. On the closest approach, NASA has successfully reached within 8.5 million kilometers of the sun. The three objectives of the probe are to learn more about the energy that pushes and heats solar wind, determine the structure of the plasma and magnetic fields, and further research what mechanisms are in place to accelerate solar wind.


This probe is about the size of a small car, with a solar shield protecting it from heat. Over seven years, the Parker Solar Probe will eventually get as close as 3.83 million kilometers to the sun. As the outer layer of the sun (the corona) is the hottest of them all, this is a particularly daunting challenge. However, scientists have found many creative solutions to the impressive heat levels. The probe orbits the sun in an ellipse, also encountering Venus in orbit. Other than its primary orbit, the probe has also taken remarkable images of Venus.


Exploring the intricacies of solar wind and solar energetic particles is the main goal of this probe. Often referred to as “space weather”, the constant stream of charged particles from the sun’s corona affects life all around the Milky Way. The amount of particles being released is constantly changing. Occasionally, an immense explosion of energy occurs. Solar flares, when they are particularly strong, can even affect radio waves and power grids on Earth. One example transpired on March 13, 1989, in Canada, when a particularly powerful solar storm compromised the entirety of Hydro-Quebec. Understanding why this occurs, and even beginning to predict when these flares may be, is important to ensuring safety and advancing space technology.

In its almost five years of orbiting the sun, Parker has discovered some incredible things. Besides being the first man-made object to get 8.5 kilometers from the sun, it is also the first object to cross the Alfven critical surface. This is the boundary where solar wind is formed - going from solar material to wind. Scientists have never concretely known the complexities of this boundary. Now, we know that the boundary has dips, creases, and valleys, much like dust. Interestingly enough, the sun may be dust-free. All known parts of space are littered with dust, from the remains of space objects such as asteroids. However, it has been theorized that the sun could produce enough heat that all dust would be burned away. As the probe comes closer in each orbit, it has been able to find evidence of this long-debated theory. It could be possible that surrounding the sun, there will be no debris. With so many theories being proven correct by this probe, more and more knowledge is bound to come to light with future orbits.

The probe must deal with incredible temperatures - about 1,377 degrees Celsius. Luckily, its carbon-composite shield protects it from the sun’s harsh rays. It is 8 feet in diameter and 11.43 cm thick. Carbon-carbon is used for its outer layers, providing extra protection. The inner layer is made of carbon foam, which is incredibly light while very strong, being almost 97% air. The shield’s white surface reflects as much light and heat as possible. This shield keeps the probe fantastically protected, at only 30 degrees Celsius. 

One of the most important concerns while designing the probe is that it's constructed so it can function without the constant aid of humans. As the probe is 147.27 million kilometers away from the Earth, it must maintain itself. Parker can sense whether the shield is protecting the probe from the sun at the correct angle. Solar limb sensors are used, which are long, finger-like devices that are located on the edges of the probe. It can correct itself, ensuring the probe does not overheat. 


Researching our sun is the easiest way to find out more about stars all around space, and by extension, the galaxy and planet we live on. This research will reshape our knowledge of space and physics. With each orbit, we are closer to fully understanding our Milky Way.

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