NASA's Parker Solar Probe is trying to get closest to the Sun ever

A NASA spacecraft is trying to make history with its closest ever approach to the sun.

The Parker Solar Probe dives into our star's outer atmosphere, enduring extreme temperatures and intense radiation.

Communication was lost for several days during this hot flyby, and scientists will wait for a signal, expected on December 27, to see if it has survived.

We hope the probe will help us better understand how the Sun works.

“For centuries, people have studied the sun, but you don't feel the atmosphere of a place until you actually go visit it,” Dr. Nicola Fox, NASA's chief of science, told BBC News.

“So we can't really experience our star's atmosphere unless we fly through it.”

The Parker Solar Probe launched in 2018, heading for the center of our solar system.

It has already passed the sun 21 times, and is getting closer than ever, but the visit on Christmas Eve broke the record.

At its closest point, the probe is 3.8 million miles (6.2 million kilometers) from the surface of our star.

This may not seem very close, but NASA's Nicola Fuchs puts it into perspective: “We are 93 million miles from the Sun, so if you put the Sun and Earth one meter apart, the Parker Solar Probe is four centimeters from the Sun.” “So this is close.”

The probe will have to withstand temperatures of up to 1,400 degrees Celsius and radiation that could disrupt the electronic devices on board.

It is protected by 11.5 cm (4.5 in) thick carbon composite armor, but the spacecraft's tactic is to get in and out quickly.

In fact, it will move faster than any man-made object, hurtling at 430,000 miles per hour, the equivalent of flying from London to New York in less than 30 seconds.

So why go to all this effort to “touch” the sun?

Scientists hope that, as it passes through our star's outer atmosphere – the corona – the spacecraft will be able to solve a long-standing mystery.

“The corona is really hot, and we have no idea why,” explains Dr. Jennifer Millard, an astronomer at Fifth Star Laboratories.

“The surface temperature of the Sun is about 6,000 degrees Celsius or so, but the corona, that fragile outer atmosphere that you can see during a solar eclipse, is millions of degrees — that's farther away from the Sun. So how does this atmosphere get hotter?”

The mission should also help scientists better understand the solar wind, the continuous stream of charged particles emanating from the corona.

When these particles interact with the Earth's magnetic field, the sky lights up with a dazzling afterglow.

But so-called space weather can also cause problems, disrupting power grids, electronics and communications systems.

“Understanding the Sun, its activity, space weather, and the solar wind is very important for our daily life on Earth,” says Dr. Millard.

NASA scientists face an anxious wait over Christmas while the spacecraft is out of contact with Earth.

Nicola Fox says that once the signal is sent home, the team will send her a text message containing a green heart to let her know the probe is OK.

She admits she's nervous about the bold attempt, but she has faith in the investigation.

“I would be worried about the spacecraft. But we really designed it to withstand all these harsh, brutal conditions. It's a tough, tough little spacecraft.”