It’s no illusion. Some full Moons are genuinely larger than others and this Friday’s is a whopper. Why? The Moon’s orbit is an ellipse with one side 50,000 km closer to Earth than the other: diagram. In the language of astronomy, the two extremes are called “apogee” (far away) and “perigee” (nearby). On Dec. 12th, the Moon becomes full a scant 4 hours after reaching perigee, making it 14% bigger and 30% brighter than lesser full Moons we’ve seen earlier in 2008.
This is both the brightest and (in the northern hemisphere) the highest-riding full Moon of the year. If you go outside around midnight it will be close to overhead and act like a cosmic floodlamp making the landscape absolutely brilliant, especially if there’s snow. Full moons are always high during winter and, indeed, the solstice is right around the corner on Dec. 21st.
Read the full article at Science@NASA.
(via emples)
