MOSCOW, December 13. /TASS/. Residents of Russia will be able to observe the Wirtanen comet expected to draw near the Earth and the Sun quite close in mid-December, the Moscow Planetarium said on its website on Thursday.
The comet will be seen in the form of a green small cloud in the sky in the evenings and at nights in clear weather both using binoculars and to the naked eye, the planetarium said.
"A comet is flying towards us! This is the comet, towards which the Rosetta space probe was supposed to have flown to in 2004. The Wirtanen comet became the brightest comet of 2018. In mid-December, it will come closer to the Sun and the Earth, nearer than ever," the Moscow Planetarium said in a statement.
Astronomers say that on December 16, the comet will be just 30 times farther from the Earth than the Moon. The comet can be noticed moving in the starry sky when the celestial body is observed for at least 10 minutes with the naked eye and can be seen almost in real time through a telescope. On December 13, 2018, the comet will come as close as possible to the Sun and thus increase its brilliance, and on December 16, it will fly at a distance of 11.5 million km from the Earth. In the 21st century, only four comets have approached the Earth in closer range.
The Wirtanen comet can be observed during the month immediately after sunset in the evenings and at nights over the southern horizon.
"In its maximum luster, the Wirtanen comet is expected to reach the brightness of 3-4m, which will make it the brightest comet over the past five years," the Moscow Planetarium said.
The celestial body has turned emerald due to the evaporations of diatomic carbon whose green glow stems from the ultraviolet solar irradiation of a gas in the space vacuum.
In January 2019, the Wirtanen comet will become inaccessible for observations with the naked eye and later it won’t be possible to see it through binoculars either. The comet will be seen through a telescope only in 2029 and 2035. Later, this celestial body won’t be observed from the Earth.
The Wirtanen comet (46P/Wirtanen) with a 1.2-km nucleus was discovered on January 17, 1948 by American Carl Wirtanen.