Christmas is an official national holiday in the United States and the day that Christians around the world celebrate the birth of Christ about 2000 years ago.
This year we are being treated to a heavenly sky show involving a dance between the most spectacular planet in the sky — Jupiter — and our favorite satellite — the Moon — which are less than 2 degrees apart on Christmas evening. Click HERE for details.
The Moon and Jupiter are two of the closest friends the Earth has ever had!
(Courtesy D.A. Seal/JPL)
As you enjoy this cosmic Christmas spectacle, keep in mind that the Moon and Jupiter are credited with playing major roles in making Earth habitable for humans!
For example, Earth’s axial tilt of 23.5 degrees — which produces the annual seasons — is anchored by the Moon’s gravity. In its absence our axial tilt would chaotically vary from 0 to 85 degrees, producing either no seasons and enlarged polar ice caps (for near-zero tilts) or winter-like snows near the equator (for larger tilts). This kind of climate instability would have made life for early humans (i.e., ~200,000 years ago) much more difficult, if ...