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NASA probe snaps 'great conjunction' photo of Jupiter and Saturn from the moon

(Image credit: NASA/GSFC/Arizona State University)

A moon-orbiting probe got a stunning up-close view of the "great conjunction" of Jupiter and Saturn from Earth's rocky satellite. 

Monday (Dec. 21), Jupiter and Saturn appeared closer in the night sky than they had in about 800 years during what's known as a "great conjunction." People all around the globe watched and photographed the planets, which looked almost like a single, bright "star" in the sky. However, us Earthlings weren't the only ones who got a celestial show. 

NASA's Lunar Reconnaissance Orbiter (LRO), which launched in 2009 and has enough fuel to keep orbiting the moon for another six years, spotted the cosmic event all the way from the moon. 

Related: This is what Jupiter and Saturn look like from Mars

The Lunar Reconnaissance Orbiter Camera's (LROC) Narrow Angle Camera (NAC) captured an unbelievable image of the two planets just a few hours after the pair's point of closest separation (0.1 degrees). Now, while Jupiter and Saturn may have looked like one glowing orb to the naked eye, with the detailed view of the NAC, you can clearly resolve the individual planets. In fact, the image provides so much detail that you can even faintly see Saturn's rings. 

Here on Earth, skywatchers were able to see Jupiter's moons with DSLR cameras and even basic telescopes, though Saturn's rings were usually only visible with higher-powered telescopes. 

On Dec. 21, 2020, Jupiter and Saturn appeared just one-tenth of a degree apart, or about the thickness of a dime held at arm's length, according to NASA. During the event, known as a "great conjunction," the two planets (and their moons) were visible in the same field of view through binoculars or a telescope.  (Image credit: NASA/JPL-Caltech)

When the NAC captured this image of the two planets, Jupiter was about four times brighter than Saturn, so the brightness of the original image was adjusted to make both equally visible. 

While Jupiter and Saturn have a close conjunction once every 20 years, the planets haven't appeared this close since 1623. Additionally, the planetary alignment came just a few days before Christmas, with many dubbing the bright event a "Christmas Star," adding even more to the astronomical excitement. 

Email Chelsea Gohd at cgohd@space.com or follow her on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

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