NASA's Parker Probe to the Sun
By Amanda Jermyn

Without the energy of the sun we would not be here. The ancients worshipped it as a God but now we know better. It is by far the closest star to us, and our planet revolves around it. We know that the sun is a sphere of incredibly hot plasma, a gas so hot that the atoms are broken up so that the electrons and atomic nuclei aren't bound to one another. Its mass is about 300,000 times that of Earth, and its diameter is about 110 times that of our planet. We know that it formed about 4.6 billion years ago from the gravitational collapse of a cloud of gaseous matter, mostly hydrogen. Under the force of gravity this matter became so hot and dense that it initiated nuclear fusion in its core. This is the source of the sunís energy. When that radiates away into space some of it falls on the Earth, and we perceive it as heat and light.

But thereís a lot we donít know about the sun, and weíre hoping that the Parker Solar Probe, due to launch in August 2018, will help solve some of its mysteries. This robotic spacecraft, designed by the Johns Hopkins University Applied Physics Laboratory for NASA, will approach within four million miles of the sunís surface, where it will gather data on solar activity and how this affects life on Earth. It was named after solar astrophysicist Eugene Parker, and is the only NASA spacecraft named for a living person.

The probe will travel to within the corona, the wispy region around the sun, coming more than seven times closer to the sunís surface than any spacecraft has done before. Designing it presented major challenges, as it must withstand tremendous heat and radiation, traveling so close to the sun. The probe and its instruments will be protected from the sunís heat by a 4.5 inch thick carbon-composite shield, designed to withstand temperatures outside the spacecraft of nearly 2,500 degrees Fahrenheit, and to fully block the sunís direct radiation from reaching the craftís interior.

The Parker Solar Probe will study the solar wind, solar flares, and coronal mass ejections, which are huge explosions of magnetic field and plasma from the sunís corona. There are many questions we want answered, including why the corona, above the sunís surface, is hotter than the surface itself. Intense magnetic fields at the sunís surface may be the cause, and having the probe examine these up close will hopefully help resolve this issue.

The probe should also enhance our ability to forecast major space weather events that can affect life on Earth. The intense heat of the sun causes a flow of hot plasma to radiate in all directions, including towards Earth. This is called the solar wind. During periods of heightened sun spot activity, the greater intensity and frequency of coronal mass ejections increase the intensity of the solar wind. While the Earthís magnetic field acts as a shield against damage from the solar wind, particularly large solar eruptions could wreak havoc with technology on Earth, including our communications systems and electric grid. This could leave us without power for up to a year, with severe financial and social consequences. Less severe impacts have already been observed. Back in 1989 a solar eruption caused a nine hour power outage throughout the province of Quebec in Canada.

The solar wind travels fast, at about a million miles an hour, taking between two and four days to reach Earth, so advance warning of unusual solar activity would be very helpful. The Parker Solar Probe will hopefully enhance our understanding of the dynamics of the sun, and help us predict major solar events in time to take action to protect the Earth. While the sunís intense radiation may at times pose a danger to us, its warmth and light bring life and beauty to our planet.

Join the Springfield Stars Club on Tuesday, October 24th at 7:00pm at the Springfield Science Museum for a talk by Dr. David Wexler on ďThe Parker Solar Probe Mission.Ē A Stars Club board member, Dr. Wexler studied neuroscience and engineering at Case Western Reserve University, and completed medical studies at Stanford University. He works as an ear, nose and throat specialist at Baystate Wing Hospital in Palmer. Dr. Wexler has a Masterís degree in astronomy and is currently participating in solar research at MITís Haystack Observatory. Refreshments will be served, and the public is welcome. The meeting is free of charge for members, with a suggested donation of $2 per non-member.

Also, on Friday, November 3rd at 7:30pm, the Stars Club and the Springfield Science Museum will host ďStars over Springfield,Ē an astronomy adventure for the whole family. Amateur astronomer Ed Faits will present ďLooking for Planets: What Goldilocks can tell us about Venus, Earth, and Mars.Ē A fee of $3 for adults and $2 for children under 18 will be charged.

On Wednesday, November 15th at 7:00pm, at the Springfield Science Museum, Jack Megas will give a talk for The Naturalistsí Club commemorating ďEighty years of the Korkosz Planetarium.Ē The talk will focus on the history of the planetarium and on learning the constellations through the four seasons. Refreshments will be served, and the public is welcome free of charge.