Have you noticed two bright objects in the sky getting closer together with each passing night? It’s Jupiter and Saturn doing a planetary dance that will result in the Great Conjunction on Dec. 21. On that day, Jupiter and Saturn will be right next to each other in the sky -- the closest they have appeared in nearly 400 years! Want to learn when and where to look up? Join our expert astronomer Dr. Henry Throop on #NASAScience Live.