A SOLAR probe assembled in the UK has made its first close pass of the Sun today as it swept by the Earth’s nearest star at a distance of around 47.8 million miles.
In comparison, Earth orbits the Sun at a distance of around 93 million miles, on average. The European orbiter, called SolO, is a European Space Agency craft.
It was launched in February this year.
Its close pass is still some distance from the Sun – indeed, its closest pass has put it in between the orbits of Mercury and Venus.
But the spacecraft is not yet entirely up and running for routine operations. That particular milestone is around a year away, the BBC reports.
Since its launch, scientists have been testing the systems of the probe and sorting out the 10 scientific instruments that are on board as it sails through space.
So far, the magnetometer, which can detect magnetic fields that are emitted from the Sun, is up and running.
This is important for tracking huge explosions that the Sun regularly gives off. Called coronal mass ejections, these explosions give off solar wind that cause magnetic disturbances.
Tracking these explosions is interesting to scientists, not least because of the potentially devastating effects they could have on Earth.
The Earths own magnetic field helps to protect our planet from these extreme solar flares. But particularly violent ones could interrupt satellites that are in orbit, and even disrupt power grids.
Researchers already have a lot of data about what these solar flares look like when they reach Earth, but they tend to change a lot during their journey from the Sun to our home planet.
This is why studying the solar flares mid-journey provides scientists with more insight about them, and could lead to more accurate forecasts of space weather, according to Imperial College London (ICL).
Professor Tim Horbury, principal investigator for the magnetometer at ICL, said the instruments and close orbit allow scientists “to go in close to the Sun and see whats going on [on] its surface, and then see how that expands out into interplanetary space.”
In addition, the SolO has imagers aboard, which will be able to take photos of the Sun.
As might be expected, one of the biggest challenges that engineers face when developing solar probes is how to protect them from the intense heat that the Sun gives off, but also cope with the extreme cold of space.
The SolO orbiter has a heat shield to help with this, which is capable of coping with temperatures up to 500 degrees Celsius.
The magnetometer is only rated to operate at a maximum of 55 degrees, so it will need to be shielded from most of this. Conversely, it can handle minimum temperatures as low as -110 degrees.
And this is before other challenges such as radiation doses and heavy g-force loads are taken into consideration.
But as challenging as it is to build a solar probe, SolO is not the first one. NASAs Parker Solar Probe is probably the most well-known. It was launched in 2018, and its going to get a lot closer to the Sun than SolO will.
Eventually, the Parker Solar Probe will pass within just 4 million miles of the Suns surface, exposing it to heat and radiation that no other spacecraft has ever faced.
In contrast, Mercury – the closest planet to the Sun – orbits at a distance of 42.5 million miles on average.
At its closest approach, the Parker probe will be travelling at 430,000 miles per hour, and its solar shield will face temperatures of around 1,400 degrees Celsius.
This shield will have its work cut out for it, since the probes internal instruments have to be kept at near to room temperature.
Like SolO, the Parker probe will help scientists make predictions and forecast space-weather events that impact life on Earth.
