Santa Claus is not the only one coming to town this season.
It's also time for the return of a comet we only see once every five years — 46P/Wirtanen, or as it's more commonly known, the Christmas comet. This glowing green speck has been growing brighter in the sky since November, but on Sunday it will reach its peak, becoming visible even to the naked eye.
At its closest, comet 46P will be less than 7 million miles from the Earth, the tenth-closest comet we've seen since 1950, CNN reported. It won't get this close again for another 20 years, so grab your binoculars or telescope, find a patch of clear sky, and start looking.
CNN noted that the comet, while visible, usually appears with a fuzzy halo. Because comets are made of ice, as 46P passes the sun, parts of it melt and are absorbed into the expansive atmosphere that travels with it, creating the glowing green cloud that we'll be able to see this weekend.
You can check Time and Date to figure out when is best to try to see the Christmas comet for your location. But if you're worried that light pollution will hurt your chances, the Virtual Telescope Project will also be livestreaming the comet's trajectory on Sunday starting at 5 p.m. ET. Read more about the Christmas comet at CNN. Shivani Ishwar
It's green. It's sparkly. It's the size of a baseball. And it's 4.6 billion years old. Meet "Northwest Africa 11119," the meteorite that's helping scientists learn about the early days of our solar system.
Although researchers have found space rocks that date back further before, NWA 11119 is unique because it's the oldest igneous meteorite ever discovered. Igneous means that it was formed by the cooling of hot magma. As a result, NWA 11119 looks very similar to volcanic rock that forms here on Earth — so much so that scientists weren't even sure it was a meteorite at first. But on closer examination, it was confirmed to be "alien in origin," Newsweekreported. And because it's right around the age of this solar system, it must be from "one of the very first volcanic events to take place" in this part of the universe, said Carl Agee, a meteorite curator at the University of New Mexico.
Researchers aren't yet sure which body NWA 11119 originated from, but they theorize it must be an asteroid that has a crust similar to Earth's, Live Scienceexplained. Agee and a doctoral student, Poorna Srinivasan, have also linked the meteorite to two others, called "NWA 7235" and "Almahata Sitta," suggesting that they may have all come from the same place. This might help researchers piece together what "an earlier version of Earth" looked like, Srinivasan said.