The comet Tsuchinshan-ATLAS “appears once in a lifetime” seems to have developed a second tail after reaching its closest point to Earth in over 80,000 years, new images reveal. However, in reality, this additional tail is a visual illusion caused by the position of our planet relative to the visible object.
C/2023 A3, commonly known as Tsuchinshan-ATLAS, is an unusually bright comet believed to originate from the Oort Cloud, a reservoir of icy objects at the outer edge of the solar system. It was first discovered in early 2023 while traveling between Saturn and Jupiter as it headed toward the inner planets. Subsequent observations indicated that this comet has the potential to orbit the sun once every 80,660 years and may have undergone fragmentation.
The Tsuchinshan-ATLAS comet was discovered with a faint trail, referred to as the anti-tail, pointing in the completely opposite direction to its bright tail. (Photo: Michael Jäger).
Tsuchinshan-ATLAS became visible to the naked eye after it passed around the sun at the end of September. However, it reached its peak brightness in the past few days after coming closest to Earth on October 12, when it was approximately 70.6 million kilometers away, about 180 times farther than the Moon. This comet is likely visible to millions of people across vast regions globally.
On October 13, astrophotographer Michael Jäger captured images of Tsuchinshan-ATLAS gliding across the night sky near Martinsberg, Austria. In addition to showing the commonly seen bright tail, enhanced versions of the photos revealed a fainter trail, known as the “anti-tail,” emanating from its body in the opposite direction, according to Spaceweather.com.
On October 14, Jäger captured another even clearer image of the comet and its additional feature. The comet’s tail consists of two parallel trails of dust and gas blown away from the comet by solar radiation, meaning its tail always points away from the sun.
Consequently, the anti-tails seem to defy physics as they can point toward the sun. However, these additional tails are not formed from debris blown off the comet. Instead, they are made from dust that the comet recently left behind in its orbital plane around the sun. As Earth passes through this plane, as occurred over the weekend, the remaining debris is illuminated by the sun and reflected back to Earth, creating the illusion of a second tail.
