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A PAIR of satellites will work to blot out the Sun – all in a bid to solve puzzling space mysteries.

It's part of the Proba-3 mission that's due to blast off on Thursday, December 5.

The Proba-3 mission will launch two spacecraft towards the Sun
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The Proba-3 mission will launch two spacecraft towards the SunCredit: ESA / P. Carril
The spacecraft will separate in early 2025
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The spacecraft will separate in early 2025Credit: ESA / P. Carril

The mission was concocted by the European Space Agency (ESA) to "create an artificial total solar eclipse".

This will allow scientists to study the Sun's corona – the outer layer of the star's atmosphere.

Parts of the corona are very difficult to study, except during solar eclipses on Earth.

Now scientists want to simulate this effect by sending two probes up into .

Read more on space

"Proba-3 is ESA’s – and the world’s – first precision formation flying mission," the ESA explained.

"Flying together, a pair of spacecraft will form an artificial solar eclipse in space, casting a precisely-controlled shadow from one platform to the other to open up sustained views of the Sun's faint surrounding corona."

Each eclipse will last around six hours, allowing for a better view of the corona.

But don't worry: it won't be blocking the Sun for people on Earth.

One probe will be blocking the view for the other, creating an eclipse in space for the benefit of scientists.

One of the big mysteries scientists are hoping to solve is why the corona is so much hotter than the Sun.

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"We all know the sun is hot, but it is still a mystery how material in the sun's outer atmosphere, the solar corona, can reach million-degree temperatures," the ESA explained.

"The visible surface below it, called the photosphere, is just 4500–6000 °C."

It added: "Moving out into the corona, which is both less dense and further from the sun's core, you would expect to find lower temperatures. Instead, it gets around two-hundred times hotter!"

Proba-3 will be able to study the corona close to the surface than ever before.

One spacecraft will create a total eclipse for the other in space – but it won't affect the view of the Sun from Earth
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One spacecraft will create a total eclipse for the other in space – but it won't affect the view of the Sun from EarthCredit: ESA / P. Carril
The eclipse will allow scientists to study the Sun's corona
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The eclipse will allow scientists to study the Sun's coronaCredit: ESA / P. Carril

One spacecraft will block the direct light from the Sun.

And that will allow the other probe to see "the faint visible light" of the corona down to around 43,000 miles above the Sun's surface.

Proba-3 will be able to capture stunningly detailed data – including "waves moving through the loops and plumes of plasma" in the corona itself.

"This kind of movement is a likely cause for the corona's high temperatures," the ESA said.

WHAT IS SOLAR WIND?

Here's what the ESA says...

"The solar wind is the continuous stream of plasma sent out by the Sun, mostly made up of electrons, protons and alpha particles," the eSA explained.

"When the solar wind collides with Earth’s magnetic field it can produce auroras – the northern and southern lights.

"Just like wind on Earth, solar wind can be fast or slow, smooth or gusty. It comes in two main types, which differ not only in wind speed but also in composition and source region.

"‘Slow’ solar wind – which still reaches Earth with speeds up to 500 km/s, or 1.8 million km/h – is made up of particles that resemble the makeup of the Sun's outer atmosphere or corona.

"While the details remain elusive, this type of solar wind is known to be connected to active sunspot regions on the Sun which also produce solar flares and eruptions."

Picture Credit: ESA

"The coronagraph will be able to capture these small-scale, fast movements by imaging the inner corona as fast as every couple of seconds."

Scientists also hope the probe will be able to work out what accelerates solar wind to such high speeds, more about how coronal mass ejections work, and how the Sun's energy output changes over time.

The Proba-3 launch was originally scheduled for December 4, 2024.

But it's been pushed back to Thursday, December 5 at 10.42am London time – or 5.42am in New York City.

READ MORE SUN STORIES

The corona is a mysterious part of the Sun that is easiest to study during an eclipse
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The corona is a mysterious part of the Sun that is easiest to study during an eclipseCredit: ESA

It's expected to blast off from the Satish Dhawan Space Centre in India.

In early 2025, the craft will separate from each other – with plans for the first images to arrive as soon as March.

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