Johns Hopkins APL Spacecraft Capture Planetary Portraits
Parker Solar Probe was making a close approach to the Sun on June 7, 2020, when its Wide-field Imager for Solar PRobe (WISPR) captured the planets Mercury, Venus, Earth, Mars, Jupiter and Saturn in its field of view.
Credit: NASA/Johns Hopkins APL/Naval Research Laboratory/Guillermo Stenborg and Brendan Gallagher
Wed, 01/27/2021 - 09:43
Its proximity to the Sun not only puts NASA’s Parker Solar Probe in position to grab unprecedented information on the nascent solar wind and solar activity, it also affords the spacecraft some unique (and pretty cool) views of our solar system.
Built and operated by the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, Parker Solar Probe was wheeling around the Sun last June 7 — making the fifth in its series of 24 planned close approaches to our star — when its Wide-field Imager for Solar PRobe (WISPR) captured the planets Mercury, Venus, Earth, Mars, Jupiter and Saturn in its field of view.
WISPR’s job is to take images of the solar corona and inner heliosphere in visible light, as well as images of the solar wind, shocks and other structures as they approach and pass the spacecraft. The imager was doing just that last June, at the closest approach (or perihelion) of its orbit, when its field of view swept away from the edge of the Sun and toward the planets beyond. It’s an interesting perspective: Mercury, the innermost planet, appears farthest away from the Sun. The image also includes the six planets visible to the naked eye.
“Imagine being able to stand on the Sun and gaze toward the stars,” said Nour Raouafi, Parker Solar Probe project scientist from APL. “It’s just awe inspiring to see so many worlds in our solar system — including our own planet — in the same portrait. We often think of viewing our solar system from the outside in, and this allows us the unique opportunity to see it from the inside out. It’s a view few spacecraft can provide, and Parker Solar Probe has given us an entirely different perspective on our place in space.”
This graphic illustrates Parker Solar Probe’s position and view of the solar system when it took the “six planet” image on June 7, 2020. The green loops overlapping the inner planets mark Parker Solar Probe’s path around the Sun. The inset shows the orientation of the spacecraft as well as WISPR’s location. The slightly brighter region between the fields of view is the imager telescopes’ overlapping views.
Credit: NASA/Johns Hopkins APL/Yanping Guo
The spacecraft was approximately 11.6 million miles from the Sun’s surface, and about 98.3 million miles (158 million kilometers) from Earth, when WISPR gathered the images. Parker Solar Probe has since completed two additional close approaches — the latest on Jan. 17 — that brought it within a record 8.4 million miles (13.5 million kilometers) of the Sun’s surface.
Parker Solar Probe launched in August 2018. It holds records for closest approach to the Sun (8.4 million miles/13.5 million kilometers) and spacecraft speed (289,932 miles per hour/466,600 kilometers per hour). On its final passes through the Sun’s atmosphere — its corona — Parker Solar Probe will come within 4 million miles of the Sun’s surface, moving approximately 430,000 miles per hour.
NASA’s Solar and Terrestrial Relations Observatory saw most of the solar system’s planets in one image on June 7, 2020. The dark columns in the image are related to saturation on the instrument’s detector, caused by the brightness of the planets combined with the long exposure time.
A STEREO View
At around the same time Parker Solar Probe was imaging the solar system, the APL-built Solar and Terrestrial Relations Observatory (STEREO) captured a similar view.
STEREO’s position in the solar system — moving ahead of Earth in its orbit — gave it a different perspective on the planets. The image came from one of the Heliospheric Imagers on STEREO, which views the outer atmosphere of the Sun, the corona, and the solar wind, allowing scientists to study how solar material travels out into the solar system.
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