December a Busy Month for Mars

Jupiter loses command of the night sky next month, exiting into the glow of the sunset to eventually emerge ahead of the sun in the morning sky. However, another planet moves into center stage, perhaps not as large and bright as Jupiter, but definitely holding its own set of mysteries. Mars reaches opposition next month, rising as the sun sets on Christmas Eve. Six days earlier, the Red Planet reaches its closest point to Earth's orbit, roughly 54.8 million miles away. These two Martian events, closest approach and opposition, happen roughly every two years as Earth catches up to slower Mars in its longer orbit around the sun. During opposition, Earth is between the sun and the fourth planet, resulting in Mars and the sun being opposite in the sky (opposition). Because Mars' orbit is not perfectly circular — in fact it's relatively oval — some oppositions are better than others. You may recall the Mars Madness that occurred in August 2003, where that opposition brought Earth and Mars closest in recorded history, or 60,000 years.