Special Edition: December 21, 2020
Mount Washington — This evening, reach way out beyond Earth to our neighbors in the solar system to enjoy a rare and magnificent event: a greatest Grand Conjunction of planets Jupiter and Saturn. Be a part of the drama by looking up to the sky close to home outdoors, and/or join a later livestream from a great observatory in a different time zone. Outdoors, best viewing begins at 5 p.m. To visit with astronomers and look through their telescopes, note that livestreams begin at 7 p.m. It is sure to be breathtaking to see the most picturesque planets in our solar system together in one field of view through the eyepiece of a telescope! See the illustration, above, for a preview as seen through a small telescope.
Outdoors, low in the southwest at twilight, planet Jupiter, a brilliant point of star-like light, and dimmer Saturn, now to its left, appear nearly inseparable to the naked eye, their closest proximity in four centuries. More remarkable, it has been eight centuries, since 1226 CE, that a Great Conjunction was visible to the naked eye. The great conjunction of 1623 was hidden in the Sun’s glare. Today, Jupiter and Saturn are about 15 degrees above the horizon when we see the two 35 minutes after sunset. To see Saturn in the early dusk light, bring binoculars. Sunset is 4:24 p.m. at the horizon. Twilight begins at 4:56 p.m. Jupiter sets at 6:45:05 p.m. and Saturn just 12 seconds later at 6:45:17 p.m. In the Berkshire Hills, setting times can be more than an hour earlier.
But pause a moment to appreciate how close the two planets appear: just 12 seconds difference in their setting times.
At 7 o’clock, livestreams from Southwestern observatories begin. I have traveled to the McDonald Observatory in Davis, Texas, a world-renowned research and education center with an ambitious calendar of public programs. Click here for the conjunction livestream.
Check Resources, below, for much more information.
In closing, the dynamic play between Jupiter and Saturn continues to be visible for about two weeks, until they are too close to the setting Sun to be seen naked eye.
Resources
Livestreams
The Great Conjunction Livestream, Dec. 21 at 7 p.m. EST
McDonald Observatory, Davis, Texas
https://www.youtube.com/watch?v=_gGt19vNU4E&feature=youtu.be
Roster of public programs: https://mcdonaldobservatory.org/visitors/livestream
The Great Conjunction Livestream, Dec. 21 at 7 p.m. EST
Lowell Observatory, Flagstaff, Arizona
https://www.youtube.com/watch?v=XrRcfaWutLQ&feature=emb_title
University of Exeter, UK weather-dependent, Dec. 15-23, 11 a.m-1 p.m. EST (4 p.m.-6 p.m. GMT)
http://jupitersaturn2020.org/
Recommended reading
Illustration (top) and scientific papers by Dr. Thomas Hartigan, Rice University, Houston, Texas
https://sparky.rice.edu/public-night/jupsat.html
https://sparky.rice.edu/~hartigan/public-night/jupsat2.html
http://web.horde.to/sparky.rice.edu/~hartigan%2Fvenjup.htmland
Dr. John Keller, planetary scientist and director of the Fiske Planetarium at the University of Colorado, Boulder
https://theknow.denverpost.com/2020/12/09/jupiter-saturn-conjunction-colorado-2020/250275/
