Mercury and Jupiter cross paths in the predawn sky during tomorrow’s winter solstice

By | Published: December 20, 2018 | Last updated on May 18, 2023
Mercury will slide very near Jupiter on the morning of Friday, December 21, which also happens to be winter solstice for the Northern Hemisphere.
Jake Parks using StarDome
Mercury, which reached greatest elongation on December 15, has started to dip lower in the predawn sky as its orbit carries it back toward the Sun. But as the solar system’s innermost planet descends, Jupiter rises to meet it.

Friday morning, the two planets stand less than 1° apart.

At magnitude –1.8, Jupiter appears more conspicuous than magnitude –0.5 Mercury. Enjoy this pretty conjunction starting about 45 minutes before sunrise, when the pair lies 8° above the southeastern horizon.

As an added bonus, during the conjunction, observers with binoculars might be able to spot the 1st-magnitude star Antares 5° to Jupiter’s lower right.

The Mercury-Jupiter conjunction is not the only exciting event on Friday. Earth’s winter solstice occurs at 5:23 p.m. EST.

At that moment, the Sun reaches its farthest point south in the sky. The solstice marks the official beginning of winter in the Northern Hemisphere, and Friday night has more hours of darkness than any other.

From mid-northern latitudes, however, the earliest sunset occurred about two weeks ago, and the latest sunrise won’t happen until early January.

For more quick and easy observing tips, check out The sky this week for December 14 to 23.