A bright green "Christmas comet" will fly the closest to Earth in centuries


Look at the night sky on Sunday and you may see a bright, fuzzy ball with a greyish-gray hue.

That's because a comet that orbits between Jupiter and the Sun will make its closest approach to Earth in centuries.

"The imprecision is just because it's basically a gas ball," said Tony Farnham, a research scientist at the University of Maryland astronomy department, on Saturday morning after a long night studying the comet on the Discovery Channel Telescope, about 64 kilometers to the southeast. of mast, arizona. "You have a solid core of 1 km in the middle and the gas leaves hundreds of thousands of kilometers."

The comet shines in green because the gases emit light at green wavelengths.

The ball of gas and dust, sometimes called the "Christmas comet," was named 46P / Wirtanen, named after the astronomer Carl Wirtanen, who discovered it in 1948. It orbits the sun every 5.4 years, passing through Land every 11 years, but the distance varies and is rarely so close. As the comet passes, it will be 30 times farther from Earth than the Moon, NASA said.

The proximity of the 46P / Wirtanen provides an opportunity to research the tail of the comet and see further in the nucleus.

"The fact that it is brighter means we can study many different types of gas that we can not normally study because they are very weak," Farnham said, adding that researchers can learn more about where the comet formed and how it evolved.

The comet is also interesting to scientists because it is hyperactive, which means it emits more water than expected, a relatively rare phenomenon.

The comet is visible now, but will shine even more on Sunday when it reaches its closest approach, 7.1 million kilometers from Earth. It is among the 10 closest approaches by a comet in 70 years, said NASA. Only a few of them could be seen with the naked eye.

Do not worry if you miss the comet on Sunday. It should be so visible for a week or two because its appearance will gradually change.


Source link