5 things to know about ESA's Solar Orbiter mission

On 9 February, a new mission is started by the European Space Agency (ESA) to study the Sun was lifted off from Cape Canaveral in Florida, USA. The spacecraft is Called as Solar Orbiter. This European Space Agency (ESA) mission will travel within the orbit of the planet Mercury to study the Sun’s surface like never before. It will give us the stunning images of its surface.

Image Credit- ESA

It is equipped with new and well-developed instruments and high tech cameras, the decade-long mission is set to provide the scientists with the key information in their ongoing solar researches. Here are the five unanswered questions about the Sun it might finally help us to solve.

1. When Solar Eruptions Are Heading Our Way

SolarOrbiter will reach very close to the Sun. The minimum distance between the spacecraft and the Sun will be 0.28% of the distance between Earth-Sun, throughout its mission, which could last the rest of the 2020s. No other mission will have come closer to the Sun, either than NASA's Parker Solar Probe mission, which will reach just 0.04 times the Earth-sun distance.

Dr. Emilia from the University of Helsinki in Finland is the coordinator of a project called SolMag, which is studying eruptions of plasma from the sun known as Coronal Mass ejections (CMEs). ‘The equipment and a suite of cameras on the Solar Orbiter spacecraft will gather the data that is significantly better than any spacecraft before, it will help us in the monitoring of CMEs’ she said. The Parker Solar Probe lacks in all these things.

The Solar Orbiter will cover a lot of different distances which helps us in capturing these coronal mass ejections when they are evolving from the Sun to Earth. These eruptions can cause space weather events on Earth, so this will help us to get early-warnings when they are heading in our way.

2. Why The Sun Blows A Supersonic Wind

Another most important unanswered question about the sun is its outer atmosphere. Its temperature is more than a million degrees, and we don't know the reason behind its extremely high temperature.The coordinator of a project studying solar wind called Slow Source,' Dr. Alexis Rouillard said.

As the result of this hot corona (sun’s atmosphere) is cannot be contained by its gravity which means that it has a constant wind blowing the particles out into outer space, known as the solar wind. The speed of the wind is more than 250km per second and goes up to the speed of 800km per second, and we currently do not know how that wind is pushed outwards at a very high speed.

Dr. Rouillard hopes that the study of the slower solar wind will possibly be using Solar Orbiter, which may help us in explaining how the sun creates supersonic winds. 'Due to this closeness to the sun we can collect more (pristine) particles,' he said. 'Solar Orbiter will provide us the measurements of the solar wind composition by which we will be able to create the models for studying how the wind is pushed out into space.'

3. What Its Poles Look Like

During the whole mission, Solar Orbiter will make repeated encounters with the planet Venus. Each time it encounters the Venus, the angle of the spacecraft's orbit will be slightly raised. Until the spacecraft raised above the planets, this process will be repeated. After 10 years (in 2030) it will reach an inclination of 33 degrees. Then it will able to provide the first-ever photographs of the sun’s poles. If the mission will go as hoped, it will succeed in doing this. 

By measuring the sun's magnetic fields at the poles, scientists hope to the understanding of that how and why the sun flips its magnetic poles after every 11-year cycles of activity. They will flip in the mid of the 2020 (this year). 

'This will helps us in a better understanding of how the magnetic fields are distributed and evolve in these polar regions. After every 11 years, the sun goes from a minimum activity state to a maximum activity state known as the solar cycle. By the measurements of these latitudes, it will provide new insights on the cyclic evolution.

4. Why It Has Polar 'crowns'

Sometimes the sun erupts huge arm-like loops of material from its surface, which are known as prominences. They extend from the surface of the sun into the atmosphere of the sun known as the corona, but the formation is not well defined. However, the Solar Orbiter will give us the best information about it till now.

'We're going to study of some of these active regions with the help of Solar Orbiter,' says Professor Rony Keppens from KU Leuven in Belgium, coordinator of a project called PROMINENT in which they are studying some solar prominences. 'It will give us more than several images per second. By which we can visualize some of the dynamics for the first time that had not been seen before.

The sun's largest prominences will come from its poles, so by raising the inclination of Solar Orbiter, it will give us a unique look at these phenomena. 'They're called as polar crown prominences because they are like crowns on the head of the sun. They create a boundary around the polar regions and they live there for very long on end. The Solar Orbiter is going to give the first views of the polar regions that are going to be very exciting.

5. How It Controls The Solar System

With the help of Solar Orbiter scientists hope to study and better understanding that how the sun’s eruptions travel out into the solar system, which creates a bubble around the sun in our galaxy known as the heliosphere. This can create the earth’s weather like space, So the study of it is very important for our own planet Earth.

'One of the things that we can do is that we have to take measurements of the solar magnetic field in active regions of the sun,' said Professor Keppens. 'We're going to study that data into the sun’s atmosphere (corona) and then we use simulations in understanding how some of these eruptions happen and progress out into the heliosphere.'

Thus, the Solar Orbiter will not just give us a better understanding of the sun itself, but also how it affects our planet (Earth) too. Although it will provide us the first-ever images of the sun’s poles and its surface, Solar Orbiter will give us an understanding of how the star we call home works.