The Parker Solar Probe will be the first spacecraft to ‘deep dive’ into the Sun's atmosphere so it can study its corona, getting closer to the Sun than any other mission ever has. It will orbit the Sun 24 times and pass by Venus seven times, using the gravity of the planet to slow the spacecraft down a little bit each time so it can pass closer to the Sun. NASA plans to launch the spacecraft sometime between July 31 and August 20 next year. It will take just three months to make the first flyby of the Sun. It will come closest to the Sun on December 19, 2024. Travelling at more than 720,000 kilometres per hour, the probe will eventually come within less than 6.4 million kilometres of the Sun's surface. This may not sound very close, but if you think of the Sun and Earth as being one metre apart, then the craft would be located just 4 centimetres from the Sun. The probe will be in regions of the corona where temperatures exceed 1,400 degrees Celsius.
The two big questions scientists are asking are:
- Why is the corona on the outside of the Sun at least 300 times hotter than the surface?
- Why does the solar wind speed up?
These questions are important because we literally live in the atmosphere of the Sun. This outer region gets accelerated and moves away from the Sun, bathing all of the planets. When large events such as sunspots or coronal mass ejections happen, they can have dramatic effects on our planet, causing spectacular aurorae but also disrupting communication systems. Understanding solar winds is also integral to understanding how much radiation we could be exposed to in space.
The probe is about 3m tall and weighs about 685kg. A white light imager will analyse the solar wind in front of the spacecraft so scientists can "see" what the other instruments are about to detect. The front of the spacecraft will have a shield, 2.3 metres wide and 11 centimetres thick, made up of a special carbon foam sandwiched between two thin sheets. The front face will be covered in aluminium oxide to reflect light and heat. So while the shield will get up to 1,400C, the instruments inside will stay at room temperature.
Source Reference: http://www.abc.net.au/news/science/2017-06-01/parker-solar-probe-nasas-journey-to-touch-the-sun/8572540
Featured image at top of page: (Supplied: Johns Hopkins University Applied Physics Laboratory)