The American space agency (Nasa) is all set to launch one of the most daring ventures in its history. It’s going to send a satellite closer to the Sun than any mission has done before.
The Parker Solar Probe will dip directly into our star’s outer atmosphere, or corona.
The spacecraft’s data promises to crack longstanding mysteries about the Sun’s behaviour – assuming it can survive roasting temperatures above 1,000C.
Parker will begin its quest with a ride on a mammoth Delta-IV Heavy rocket.
This powerful vehicle is scheduled to lift off from Cape Canaveral, Florida, at 03:33 local time (08:33 BST) on Saturday.
The Delta will hurl the probe into the inner Solar System, enabling the Nasa mission to zip past Venus in six weeks and make a first rendezvous with the Sun a further six weeks after that.
Over the course of seven years, Parker will make 24 loops around our star to study the physics of the corona, the place where much of the important activity that affects the Earth seems to originate.
The probe will dip inside this tenuous atmosphere, sampling conditions, and getting to just 6.16 million km (3.83 million miles) from the Sun’s broiling “surface”.
“I realise that might not sound that close, but imagine the Sun and the Earth were a metre apart. Parker Solar Probe would be just 4cm away from the Sun,” explained Dr Nicky Fox, the British-born project scientist who is affiliated to the Johns Hopkins Applied Physics Laboratory.
Why is this mission important?
Parker will help us better understand how the Sun works.
The star is constantly bombarding the Earth with charged particles and magnetic fields. This perpetual flow, or “solar wind”, is responsible for generating the beautiful auroral lights that appear in polar skies, but there are some interactions that initiate much more troubling effects.
The biggest outbursts from the Sun will rattle the Earth’s magnetic field. In the process, communications may be disrupted, satellites can be knocked offline, and power grids will be vulnerable to electrical surges.
Scientists try to forecast these “storms” and Parker promises new and valuable information to help them do that.
What is Europe doing?
The European Space Agency has its own version of Parker.
Solar Orbiter, or SolO as it’s sometimes known, is undergoing final assembly and testing in the UK. It is expected to launch in 2020, arriving at its closest position to the Sun towards the end of Parker’s planned seven years of operations.
SolO will go to within 42 million km of the Sun’s surface. That’s further away than Parker but it will still need an impressive shield.
