SUNSET: 
0
Photographer:
bellavia
Location of Photo:
Surry, VA
Date/Time of photo:
Dec 03, 2025, 6:00 AM EST
Equipment:
Borg 90FL, ZWO ASI294MM, Edmund Optics 589nm sodium filter
Description:
A 24 million km long plume of gas is ejected from Mercury's thin atmosphere due to the sun, very much like a comet. This is only visible using a narrowband filter that captures the bright yellow sodium light at 589nm. A tail was predicted in the 1980s, and first discovered in 2001. Multiple observations by NASA's robotic MESSENGER spacecraft that orbited Mercury between 2011 and 2015 revealed more details of this tail. I have captured Mercury's tail in four previous attempts, with my first attempt on May 14th, 2021.
