Spacecraft attempts closest-ever approach to Sun
A NASA spacecraft is making history with an unprecedentedly close approach to the Sun.
The Parker Solar Probe is diving into the Sun’s outer atmosphere, braving extreme temperatures and intense radiation.
During this scorching fly-by, the probe will be out of contact for several days. Scientists eagerly await a signal, expected at 05:00 GMT on December 28, to confirm its survival.
The mission aims to deepen our understanding of the Sun’s workings.
Dr. Nicola Fox, NASA’s head of science, told BBC News: “For centuries, we’ve studied the Sun, but you can’t truly experience the atmosphere of a place until you visit it. We can only grasp the Sun’s atmosphere by flying through it.”
Launched in 2018, the Parker Solar Probe has been journeying toward the center of our solar system.
Having completed 21 passes near the Sun, this Christmas Eve encounter sets a new record.
At its closest, the probe will be just 3.8 million miles (6.2 million kilometers) from the Sun’s surface.
While this might not seem close, Dr. Fox offers perspective: “The Earth is 93 million miles away from the Sun. If you imagine that distance as one meter, the Parker Solar Probe is just four centimeters from the Sun. That’s remarkably close.”
The probe must withstand temperatures of 1,400°C and radiation strong enough to damage its electronics.
It is equipped with an 11.5 cm (4.5-inch) thick carbon-composite shield, and its strategy is to approach swiftly and retreat just as quickly.
In fact, it will be moving faster than any human-made object, hurtling at 430,000mph – the equivalent of flying from London to New York in less than 30 seconds.
Parker’s speed comes from the immense gravitational pull it feels as it falls towards the Sun.
So why go to all this effort to “touch” the Sun?
Scientists hope that as the spacecraft passes through our star’s outer atmosphere – its corona – it will solve a long standing mystery.
“The corona is really, really hot, and we have no idea why,” explains Dr Jenifer Millard, an astronomer at Fifth Star Labs in Wales.
“The surface of the Sun is about 6,000C or so, but the corona, this tenuous outer atmosphere that you can see during solar eclipses, reaches millions of degrees – and that is further away from the Sun. So how is that atmosphere getting hotter?”
The mission should also help scientists to better understand solar wind – the constant stream of charged particles bursting out from the corona.
When these particles interact with the Earth’s magnetic field the sky lights up with dazzling auroras.
But this so-called space weather can cause problems too, knocking out power grids, electronics and communication systems.
“Understanding the Sun, its activity, space weather, the solar wind, is so important to our everyday lives on Earth,” says Dr Millard.
Nasa scientists face an anxious wait over Christmas while the spacecraft is out of touch with Earth.
Nicola Fox says that as soon as a signal is beamed back home, the team will text her a green heart to let her know the probe is OK.
She admits she is nervous about the audacious attempt, but she has faith in the probe.
“I will worry about the spacecraft. But we really have designed it to withstand all of these brutal, brutal conditions. It’s a tough, tough little spacecraft.”
If it survives this challenge, the probe will continue its mission around the Sun into the future.
