16 March 2011: Mark your calendar. On 19 March rising full moon of rare size and beauty in the East at sunset. It is a super "Perigee Moon"-the largest in almost 20 years.
"The last full moon the size and proximity to the Earth in March 1993," says Geoff Chester from the US Naval Observatory in Washington DC. "I would say it is worth a look."
Full moon vary due to the the oval shape of the orbit of the Moon in size. It is an ellipse with a page (perigee) about 50,000 km closer to earth than the other (apogee): diagram. Close to perigee moons are larger, around 14% and 30% brighter than less moons that occur at the height of the Moon's orbit.
"Full moon March 19 is less than an hour away from Perig?um--a near-perfect coincidence1, which happens, only 18 years or so," adds Chester.
Perigee full moon brings with very high "Perigean tides", but that's to mind nothing according to NOAA. In most places, lunar density at perigee, flood waters draws only a few centimetres (inches or so) higher than usual. Local geography may effect to 15 cm (6 inch)-strengthen not just a great flood.
In fact, contrary to some reports in the Internet circulating moons be perigee raised not natural disasters. The "super Moon" March 1983, passed without incident, for example. And proved Moon an almost Super in December 2008 also harmless.
Okay, the Moon is 14% greater than usual, but can you really tell the difference? It is difficult. There are no ruler floating in the sky, lunar diameter measure. Hanging high overhead with no reference to a sense of scale provide shows can seem a full moon much like any other.
To see the best time is when the Moon in the vicinity is the horizon. That is, if illusion mixed produce with reality, a truly breathtaking view. Reasons not completely by the astronomers or psychologists understood unnaturally large seek low-hanging moons if they by trees, buildings and other objects in the foreground. On 19 March, why not leave the "Moon illusion" strengthen the full moon, which is from the outset extra-big? The swollen ORB rises in the East at sunset may so near you can almost reach and touch.
Do not worry. Also a super perigee Moon is still 356,577 km away. In other words, it is a distance of rare beauty out.
See the ScienceCast of this story on YouTube: http://www.youtube.com/watch?v=r1yalg_Apdw
Author: Dr. Tony Phillips | Credit: Science@NASA
没有评论:
发表评论