At just before 1:50 pm EDT on Sept. 1, 2019, NASA’s Parker Solar Probe completed its third close approach (or perihelion) of the Sun. At the time of perihelion, the spacecraft was about 15 million miles from the Sun’s surface, traveling at more than 213,200 miles per hour.
Mission controllers at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland received a green “A” beacon from the spacecraft soon after perihelion, meaning all systems were performing as designed and that the spacecraft was in good health.
For this third solar encounter, the mission team turned on the instruments when the spacecraft was around 0.45 astronomical unit (1 AU, or astronomical unit, is about 93 million miles, the average distance between the Sun and Earth) from the Sun on the inbound side of its orbit. The instruments will be turned off when Parker Solar Probe is about 0.5 AU from the Sun on the outbound side, which will occur on about Sept. 20. For the prior two perihelia, the instruments were on from .25 AU prior to and after completing the close approach.
-Geoff Brown, APL
This orbit plot shows Parker Solar Probe's location at 2 pm EDT on Sept. 1, 2019, as the spacecraft was at its third closest approach, or perihelion, to the Sun.
Credit: NASA/Johns Hopkins APL