Shortly after Mercury reached its closest point to the Sun, its enormous comet-like tail became unusually visible in the night sky and was captured in a stunning new photograph.
Mercury’s comet-like tail in the sky as captured in this image on April 12.
In recent days, Mercury has been observed resembling a comet as the neighboring planet of the Sun approached its closest point, revealing a giant tail with a long streak in the night sky. An astrophotographer managed to capture a truly magnificent image of this moment.
Comets, which orbit frozen rocks, gases, and dust, are typically seen with two distinct tails: one created from gases leaking from within them and another generated by dust from their surfaces. These two tails are blown away from the comet in the same direction by charged particles from the Sun, known as solar wind.
Mercury, the smallest planet in the solar system, has a comet-like tail primarily composed of sodium ions, which disperse from the planet’s surface due to solar wind and the impacts of micrometeoroids.
Researchers have been aware of Mercury’s tail since 2001 and have since discovered that it grows and shrinks based on the planet’s distance from the Sun.
At its peak, the tail can extend up to about 24 million kilometers, according to Spaceweather.com, which is roughly 62 times the distance from Earth to the Moon. This enormous tail length is due to Mercury’s extremely thin atmosphere and its proximity to the Sun, making it easier for the solar wind to strip material from the planet’s surface.
For reasons that are still unclear, Mercury’s tail can be most clearly seen from Earth exactly 16 days after the closest approach to the Sun, or the point at which the planet is nearest to the Sun, according to Spaceweather.com.
Mercury reached its closest point to the Sun on April 1, meaning its tail was brightest on April 17. However, on April 12, astrophotographer Sebastian Voltmer captured a beautiful image of Mercury from a location near Spicheren, a commune in northeastern France.
For the average observer, it is quite difficult to see Mercury’s tail, which is why it remained undiscovered until the 21st century. But Voltmer was able to photograph the enormous plume thanks to a specialized filter that highlighted the wavelengths of yellow light emitted by the excited sodium particles in the tail.
“Without such a filter, Mercury’s tail is nearly impossible to see with the naked eye,” Voltmer said.
| Mercury is not the only celestial body in the solar system with a surprising comet-like tail. The Moon also has a tail that can only be seen once a month when Earth passes through it, wrapping around like a scarf. Like Mercury, the Moon’s tail is also primarily made up of millions of sodium atoms. |
