Although the Sun dominates the Solar System in almost every way, humanity is still mostly ignorant of the Sun’s inner workings. Technology has advanced significantly over the years, particularly in the last few decades, enabling us to disobey our mothers’ warnings and spend as much time as we like gazing at the Sun. All those observations have taught us a lot.
A recent study demonstrates how the Sun has its own’meteor showers.’
These’meteor showers’ are nothing like the ones we experience on summer nights. They are actually plasma clumps created by localized cooling. Images of them were taken by the Solar Orbiter of the European Space Agency.
When the Earth travels through a cloud of dust, typically from a comet, meteor showers happen. These microscopic particles ignite as they collide with the Earth’s atmosphere due to friction. More than 1000 meteors are produced every hour during some meteor showers.
On the Sun, there are no meteor showers. Dust cannot enter its space because of the strong solar wind. However, recent findings from European scientists indicate that the Sun is undergoing some peculiar processes. Plasma fireballs that resemble meteors have been known to land there.
At the National Astronomy Meeting at Cardiff University, a group of scientists led by Patrick Antolin, assistant professor at Northumbria University, presented their findings. They’ll also be included in an article that will appear in the journal Astronomy and Astrophysics, titled “Extreme-ultraviolet fine structure and variability associated with coronal rain revealed by Solar Orbiter/EUI HRIEUV and SPICE.”
Astrophysicists refer to this peculiar occurrence as “coronal rain.” The Sun’s outer layer is called the corona. It is incredibly hot and extends millions of kilometers into space. The corona is comprised of plasma because of the intense heat. However, it is also susceptible to temperature changes.
Just detecting coronal rain is a huge step forward for solar physics because it provides crucial information about the big mysteries of the sun, like how it is heated to millions of degrees
Patrick Antolin, Northumbria University
The plasma can condense into enormous, extremely dense clumps when the local temperature drops. These clusters can only descend and return to the Sun. The new measurements show that the aggregates are massive, measuring up to 250 kilometers across. They also don’t fall softly. They are dragged downward at a speed of over 100 km/s by the Sun’s strong gravity.
The Solar Orbiter approached the Sun by 49 million kilometers in order to take these pictures. The highest-resolution photos of the Sun’s corona have ever been captured thanks to this close proximity. The orbiter also saw that the gas directly beneath the solar rain clumps was heating up and contracting. The clumps experience a sharp surge in temperature and pressure, followed by a slow drop in temperature as they descend back toward the Sun.
These aggregates don’t burn up like meteor showers on Earth when they return to the Sun. Instead, they are partially ionized and fall to the surface along the strong magnetic field lines of the Sun. When the aggregates reach the surface, they can cause a fleeting yet powerful illumination. The shock waves and upward surges of material caused by strikes can re-heat the material.
The inner solar corona is so hot we may never be able to probe it in situ with a spacecraft,” said the study’s lead author, Patrick Antolin. SolO, on the other hand, orbits close enough to the Sun to be able to detect minute coronal occurrences, such as the impact of rain. This provides us with a priceless indirect probe of the coronal environment that is essential to understanding its composition and thermodynamics. The mere discovery of coronal rain is a significant advance in solar physics since it sheds light on some of the biggest questions surrounding the sun, like how it is heated to millions of degrees
It’s entertaining to imagine what would occur if Earth were exposed to these plasma blobs as a pure thinking experiment. If it hit Earth, a glob of super-heated plasma measuring 250 km would cause unimaginable destruction. That is obviously impossible; it is all merely theoretical. However, it serves as yet another stark reminder of how little and defenseless humanity is in the face of nature’s brutality.
Antolin joked, “We would constantly be rewarded with amazing views of shooting stars if humans were alien beings capable of living on the Sun’s surface, but we would need to watch out for our heads!”
