Parker Solar Probe Mission Turns a Terrific Two

Credit: NASA/Johns Hopkins APL

Wed, 08/12/2020 - 13:34
Justyna Surowiec

Perched atop a powerful Delta IV Heavy rocket, NASA’s Parker Solar Probe roared into the predawn skies over Florida’s Cape Canaveral Air Force Station on Aug. 12, 2018. The durable spacecraft, built and operated at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, has already set speed and solar-distance records, and continues on its journey to unlock the mysteries of our star. We mark the second launch anniversary with a look back at the discoveries and milestones reached during Parker Solar Probe’s most recent year in space.

Shining New Light on the Sun

Shining New Light On The Sun
Credit: NASA/Johns Hopkins APL

The Parker Solar Probe mission returned unprecedented data from near the Sun, culminating in several discoveries published in the journal Nature on Dec. 4, 2019. Among the findings were new ideas on how the Sun’s constant outflow of material, the solar wind, behaves. Seen near Earth — where it can interact with our planet’s natural magnetic field and cause space weather effects that interfere with technology — the solar wind appears to be a relatively uniform flow of plasma. But Parker Solar Probe’s observations revealed a complicated, active system not seen from Earth.

The Solar Wind’s First Whispers

Credit: NASA/Johns Hopkins APL

Scientists have studied the solar wind for more than 60 years, but they’re still puzzled over some of its behavior. While they know it comes from the Sun’s million-degree upper atmosphere called the corona, the solar wind, for example, doesn’t slow down as it leaves the Sun — it speeds up, and it has a sort of internal heater that keeps it from cooling as it zips through space. Yet through the wind’s roar, NASA’s Parker Solar Probe heard the small chirps, squeaks and rustles that hint at the origin of this mysterious and ever-present wind. In January, scientists got to hear these sounds for the first time.

“We are looking at the young solar wind, being born around the Sun,” said Nour Raouafi, Parker Solar Probe project scientist of the Space Exploration Sector. “And it’s completely different from what we see here near Earth.”

Speed, Distance Records Fall on Fourth Close Pass

Longest Science Observation Campaign Begins

Longest Science Observation Campaign Begins
Credit: NASA/Johns Hopkins APL

On May 9, Parker Solar Probe began its longest observation campaign to date. The spacecraft, which had already completed four progressively closer orbits around the Sun, activated its instruments while 62.5 million miles from the Sun’s surface — some 39 million miles farther out than during a typical solar encounter. The four instrument suites continued to collect data through June 28, markedly longer than the mission’s standard 11-day encounters.

The nearly two-month campaign was spurred by Parker Solar Probe’s earlier observations, which revealed significant rotation of the solar wind and solar wind phenomena occurring much farther from the Sun than scientists previously thought. The earlier activation of the science instruments allowed the team additional space to trace the evolution of the solar wind as it speeds away from the Sun.

Successful Fifth Solar Encounter