Three instruments from the Solar Orbiter spacecraft, including the Imperial magnetometer, have released their first data.
The European Space Agency’s (Solar Orbiter) spacecraft launched in February 2020 with the aim of studying the Sun and starting to collect scientific data in June. Now three out of ten instruments have released their first stage data, which reveals the state of the sun in a “calm” phase.
The Solar Orbiter does what it says on the tin. We always knew this was going to be a fantastic mission and the first measurements showed just how much potential unprecedented insight into the sun could be. Profesor Tim Horbury
The sun is known to follow an 11 year cycle of sunspot activity and is currently almost completely sunspot free. This is expected to change in the coming years as sunspot activity increases, making the sun more active and increasing the likelihood of adverse space weather events in which the sun releases large amounts of material and energy in solar flares and the release of coronal mass.
Solar activity is closely related to the state of its magnetic field and is measured using an Imperial instrument aboard the Solar Orbiter, Magnetometer (MAG). Since June, MAG has recorded hundreds of millions of “vectors” – measurements of the direction and strength of the Sun’s magnetic field.
The Sun orbiter has flown into the orbit of Venus and has gathered some of the data that is closest to the Sun so far and will continue to get closer in the years to come. It is currently orbiting near the Sun’s equator, which would have a highly curved magnetic field during periods of high activity.
Today, however, the Sun’s magnetic “equator” is very flat with the true equator, allowing spacecraft to observe fields from the northern magnetic hemisphere for weeks when they are only a few degrees north of the equator. In times of high solar activity, when the sun’s magnetic equator is more distorted, it is impossible to detect a single polarity of the magnetic field during that time.
Solar wind structure
MAG also observes waves caused by protons and electrons flowing from the sun. Farther, closer to Earth, these particles are more evenly distributed in the solar wind than the charged particles flowing from the Sun, but in the Solar Orbiter there are also “rays” of protons and electrons coming from the Sun.
There appears to be more structure in the solar wind closer to the Sun, and this was further demonstrated by MAG, which confirmed the existence of “serpentine” – a dramatic fold in the solar wind first launched by Parker Solar Probe, a 2018 one NASA mission, noted .
Solar Orbiter and Parker Solar Probe will work together in coming years to compare data about the same phenomenon at different distances and orbits around the sun as it wakes up and enters the next phase of the sunspot cycle.
Evidence of hard work
The data released today are part of Solar Orbiter’s commitment to release data within three months of arriving on the ground – a tight schedule for any space mission, but one that is especially challenging during a pandemic. Professor Tim Horbury, Principal MAG Investigator of the Department of Physics at Imperial, said the fact that the data was timely was a testament to the hard work of the engineering team at Imperial.
“You have worked really hard over the last few months. It is a very tough job, “he said. But it paid off. “We publish many articles that have never been seen by anyone in detail. So I’m sure there will be many other miracles – we don’t know what they are yet. There is a lot people have to do and I really hope people will dive in. “
MAG has shown excellent performance for seven months. We tested it here on Earth before launch, but we weren’t able to perfectly recreate the harsh space environment, and certainly not for the long period of time that MAG experiences. Helen O’Brien
One of the team’s first challenges was to remove tiny magnetic field marks from the spacecraft itself. Nearly everything that runs on electrical energy on the spacecraft creates a variable magnetic field that must be extracted from the data in order to get an actual signal from the sun. This includes solar panels, plungers, other scientific instruments, and more than 50 separate heaters.
When various parts of the spaceship start up, the team must take data from all of them to erase their signals. But Professor Horbury said it was all worth it: “This is just the beginning, but the data are already very interesting and very rich.
“Solar Orbiter does what it says on the tin. We always knew this was going to be a fantastic mission and the first measurements show how much potential unprecedented insight into the sun is, “he said.
Helen O’Brien, MAG Instruments Manager, said, “MAG has had an excellent performance for seven months. We tested it here on Earth before launch, but we weren’t able to perfectly recreate the harsh space environment, and certainly not for the long period of time that MAG experiences.
“So it’s amazing to see the first data come out, and this is just the beginning. In December, the spacecraft will fly past Venus, and in February next year we will be in the middle between the sun and the earth again. We are so proud! “
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