NASA's Parker Solar Probe makes it closest ever to the Sun

A NASA spacecraft has made history by surviving its closest approach to the sun at all.

Scientists received a signal from Parker Solar Probe Just before midnight Thursday after losing contact for several days during its extremely hot flight.

NASA said the probe was “safe” and operating normally after passing only 3.8 million miles (6.1 million kilometers) from the surface of the sun.

The probe plunged into our star's outer atmosphere on Christmas Eve, enduring extreme temperatures and intense radiation in a bid to improve our understanding of how the Sun works.

NASA then nervously waited for the signal, which was expected at 05:00 GMT on December 28.

The spacecraft is moving at speeds of up to 430,000 mph (692,000 km/h), and has endured temperatures of up to 1,800 F (980 C), according to NASA's website.

“This close study of the Sun allows the Parker Solar Probe to take measurements that help scientists better understand how material in this region is heated to millions of degrees, and trace the origin of the solar wind (a continuous flow of material escaping from the Sun).” The agency said, discovering how to accelerate energetic particles to a speed close to the speed of light.

“For centuries, people have studied the sun, but you don't feel the atmosphere of a place until you actually go there and 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 by the Sun 21 times, getting closer than ever before, but the visit on Christmas Eve broke the record.

At its closest point, the probe was 3.8 million miles (6.1 million kilometers) from the surface of our star.

This may not seem all that close, but Dr. Fox put it in perspective. “We are 93 million miles from the Sun, so if you put the Sun and Earth 1 meter apart, the Parker Solar Probe is 4 cm from the Sun — that's close.”

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

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

In fact, it moved 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.

Parker's speed came from the enormous gravitational force he felt as he fell toward 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 – the corona – it will have collected data that will solve a long-standing mystery.

“The corona is very hot, and we have no idea why,” explained Dr. Jennifer Millard, an astronomer at Fifth Star Laboratories in Wales.

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

Dr Millard said: “Understanding the Sun, its activity, space weather and the solar wind is extremely important to our daily life on Earth.”

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

Dr Fox had expected the team to send her a text message containing a green heart letting her know the probe was OK once the signal had been sent home.

She previously admitted she was nervous about the bold attempt, but had 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.”