Parker Solar Probe Gets Extra Observation Time

After Parker Solar Probe’s successful first year in space, the mission team has decided to extend science observations as the spacecraft approaches its third solar encounter.

Parker Solar Probe turned on its four instrument suites on Aug. 16, 2019 — earlier than during its previous two solar encounters, extending the observation period from 11 days to about 35 days.

During the spacecraft’s first two solar encounters, the science instruments were turned on when Parker was about 0.25 AU from the Sun and powered off again at the same distance on the outbound side of the orbit. (One AU, or astronomical unit, is about 93 million miles, the average distance between the Sun and Earth.) For this third solar encounter, the mission team turned on the instruments when the spacecraft was around 0.45 AU from the Sun on the inbound side of its orbit and will turn them off when the spacecraft is about 0.5 AU from the Sun on the outbound side.

“We’ve seen very intriguing phenomena below 0.25 AU, and are confident we will see interesting things all the way out to 0.5 AU,” said Nour Raouafi, Parker Solar Probe project scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “We cannot wait to see how this extended campaign data will compare to our previous data collected during the shorter periods and to the data from previous missions, such as Helios.”

A ray-like structure extends from the left edge of the frame in this image from Parker Solar Probe.
This image from Parker Solar Probe’s WISPR (Wide-field Imager for Solar Probe) instrument shows a coronal streamer, seen over the east limb of the Sun on Nov. 8, 2018, at 1:12 a.m. EST. Parker Solar Probe was about 16.9 million miles from the Sun’s surface when this image was taken. The bright object near the center of the image is Mercury, and the dark spots are a result of background correction. Credits: NASA/Naval Research Laboratory/Parker Solar Probe

The extended observation time before and after Parker Solar Probe’s perihelion — its closest approach to the Sun during a given orbit — will let scientists capture the evolution of the solar wind over greater distances as it travels away from the Sun. They also hope the additional data will yield more insight into the energetic particles surrounding the Sun, the corona and the overall solar environment.

The data gathered during this period will start downlinking immediately at the end of the extended campaign. The data from the first two encounters will be released to the public in 2019. Parker Solar Probe’s third perihelion will occur on Sept. 1.

By Justyna Surowiec

Johns Hopkins University Applied Physics Lab