Using probe, NASA seeks to finally get wind of the sun
Craft will measure space weather in solar atmosphere
No one believed Eugene Parker in 1958 when he first hypothesized the existence of solar wind.
In fact, his fellow scientists told him the idea that solar wind could force plasma and other particles from the sun into space, impacting Earth, was nonsense — that is, until early space missions proved it was true.
Now, 60 years after Parker’s hypothesis, NASA finally is launching a mission to study this phenomenon. And that mission, called the Parker Solar Probe, is named after him.
Asked how he felt about it last week at a livestreamed event at the University of Chicago, Parker said “it feels good.”
Scheduled to launch Saturday from Cape Canaveral, Fla., the probe will rocket into the sun’s atmosphere, called the corona, where it will face upward of a million degrees Fahrenheit and transmit data about Earth’s star back to scientists on the ground. NASA’s launch window for the probe is through Aug. 23.
The $1.6 billion sevenyear mission seeks to improve predictions of major space weather events that impact Earth as well as astronauts living on the International Space Station. These events can impact satellite orbits, as well as disrupt radio signals and other technology.
This unmanned spacecraft will be the first visit to the sun, a mission that scientists say is long overdue.
“We’ve been studying the sun for decades, and now we’re finally going to go where the action is,” said Alex Young, associate
Disruptions on Earth
Though the sun appears to be unchanging from Earth, it actually has a turbulent surface where eruptions and radiation bursts launch solar material at high speed throughout the solar system, according to Astrobiology Magazine.
Just above the surface, the corona “roils with plasma” and stretches for millions of miles, eventually moving farther away from the sun as solar wind, the magazine stated.
This solar wind creates the beautiful aurora borealis (also known as Northern Lights), but it also disrupts Earth’s atmosphere — garbling radio signals and other technology — and makes space inhospitable for astronauts by exposing them to radiation, Young said last week.
“We’re living in the dynamic sun’s atmosphere. We’re living in solar wind,” he said.
And the more NASA understands how the solar wind works, the more it can mitigate these effects.
Scientists around the world have tried to study this topic for decades, but the great distance between their instruments and the solar winds’ origins makes it difficult to get appropriate measurements, NASA said.
“The key is getting close up, tracing the solar wind back to its source — and Parker Solar Probe will do just that,” according to NASA’s website.
‘It’s about time’ we went
The Parker Solar Probe is about the size of a small car and will travel into the solar atmosphere, about 4 million miles away from the sun’s surface.
During the spacecraft’s seven-year mission, NASA hopes to shed light on how and when solar winds accelerate to supersonic speeds. Data show that this happens in the corona, but NASA wants to know how.
Officials also hope to learn more about why the sun’s corona has such a high temperature. The surface of the sun is about 10,000 degrees Fahrenheit, but the corona can spike up to several million degrees Fahrenheit — NASA officials say “this is counterintuitive, as the sun’s energy is produced at its core.”
It’s also counter to what happens on Earth. The majority of Earth’s atmosphere gets colder as elevation increases.
NASA has outfitted the probe with numerous instruments to study these phenomena, including six to measure the solar winds, as well as the sun’s electric and magnetic fields.
It has taken NASA about 60 years to build this spacecraft partially because technology was not advanced enough to protect a probe from the Sun’s blazing heat. But now, scientists think they’ve worked it out.
A 4.5-inch thick, 8-foot diameter carbon shield protects the probe (and the instruments inside it) from the heat and energy of the corona. This shielding will protect the probe from temperatures upward of 3,000 degrees Fahrenheit. The spacecraft on the other side of the shield will remain at a balmy 85 degrees Fahrenheit, NASA stated.
Parker said last week he’s most excited to learn about the heating of the sun and the solar wind.
“I can’t say any more because I haven’t seen the data,” he said. “It’s the anticipation of the activity in the wind, particularly the heating.”
Scientists expect to receive the first data transmissions from the probe as early as December, though most will come in May 2019.
This probe is the first time NASA has named a mission after a living person.
“It’s about time we went up to see our own star,” said Nicky Fox, the project’s scientist at Maryland-based Johns Hopkins University Applied Physics Laboratory. Johns Hopkins is in charge of designing, building and operating the spacecraft.