Meteor-like streaks rain on Sun's surface, seen for the first time

Astronomers have recently observed a remarkable phenomenon as never-before-seen meteor-like streaks appeared to rain down on the surface of the sun. However, experts caution against any attempts to catch these captivating "shooting stars."

Lead author Patrick Antolin, a solar physicist from London's Northumbria University, shared his excitement, saying, "If humans were alien beings capable of living on the sun's surface, we would constantly be rewarded with amazing views of shooting stars, but we would need to watch out for our heads!"

Distinguishing them from shooting stars witnessed on Earth, which are typically composed of space dust, rock, or small asteroids that burn up upon atmospheric entry, these solar shooting stars manifest as enormous clumps of plasma hurtling towards the sun's surface at incredible velocities, Space.com reports.

Unlike Earth, where the majority of meteors fail to reach the surface due to our planet's dense atmosphere, the sun's corona—the outermost layer of its atmosphere—is significantly thinner. This thinness allows the clumps to maintain their structure during descent, potentially reaching the sun's surface intact.

A diagram with red lines showing the trajectory of solar rain as it falls towards the surface of the sun with Earth shown to scale.

This groundbreaking observation, made possible by the European Space Agency's Solar Orbiter spacecraft, marks the first time such impacts have been witnessed. The findings have shed light on a fascinating process that generates brief but intense periods of brightening, along with an upward surge of stellar material and shock waves that reheat the gas in the corona above the impact points.

Scientists believe that this discovery may hold the key to unraveling a long-standing mystery surrounding the sun's corona. Despite predictions by solar models that the sun should become hotter as one moves closer to its core, the corona is inexplicably hotter than the layers beneath it. This perplexing contrast could potentially be explained by studying the phenomena associated with these solar shooting stars.

The Solar Orbiter, equipped with high-resolution cameras and sensitive remote-sensing instruments, spotted the solar shooting stars during its close encounter with the sun. At a distance of just 30 million miles (49 million kilometers), closer than the orbit of Mercury—the innermost planet of our solar system—the spacecraft detected gas being heated to approximately a million degrees and compressed beneath the "coronal rains." This awe-inspiring event, resulting from the falling clumps, lasted only a few minutes.

On Earth, shooting stars are characterized by the radiant tails generated when friction in the atmosphere heats the material of a meteoroid. This process, known as ablation, rapidly converts solid matter into gas. However, solar shooting stars lack these bright tails due to the influence of powerful magnetic fields in the sun's corona. These magnetic fields funnel stripped gas away from the falling clumps, effectively preventing the formation of luminous tails that had previously hindered observations of solar meteors.

Antolin highlighted the significance of the Solar Orbiter's proximity to the sun, stating, "The inner solar corona is so hot we may never be able to probe it in situ with a spacecraft. However, Solar Orbiter orbits close enough to the sun that it can detect small-scale phenomena occurring within the corona, such as the effect of the rain on the corona, allowing us a precious indirect probe of the coronal environment that is crucial to understanding its composition and thermodynamics."

Antolin is scheduled to present the team's research at the upcoming National Astronomy Meeting (NAM 2023). Furthermore, the research findings will be published in an upcoming special issue of the journal Astronomy & Astrophysics, captivating readers and furthering our understanding of the sun's remarkable phenomena.