Not to worry, super moon isn’t bad omen : 20 Mar 2011
source: Philippine Daily InquirerMANILA, Philippines—An unusually large “super moon†that rose soon after sunset to herald the vernal equinox—when night and day are of equal length—has sparked speculation that it may have played a role in the devastating earthquake and tsunami in Japan.In the Philippines, the super moon will be seen at its peak at 3 a.m. Sunday, March 20. During that time, the moon will be about 356,577 kilometers away, the closest to earth since March 1993. The average distance between the earth and the moon is about 382,900 km.The popular speculation of a super moon being a harbinger of disasters is based on the fact that when a super moon—or lunar perigee—happens, the moon makes its closest approach to earth, a phenomenon that happens once in 18 years.
Scientists estimated that the super moon, rising in the east at sunset on Saturday, would appear 14 percent bigger and 30 percent brighter at its peak.
Mere superstitionAstrologer Richard Nolle posted in his website astropro.com, that when a super moon happens, it triggers massive earthquakes, volcanoes and powerful storms.
This set the Internet buzzing with speculation that the nearing super moon might have had something to do with the 9-magnitude earthquake and subsequent tsunami that struck Japan last March 11.
However, scientists dispute this. There is no truth to the superstition that super moons cause natural disasters, they say.
While the moon helps drive the earth’s tides, it is not capable of triggering devastating earthquakes, experts say. The super moon tends to bring a range of high and low tides, but experts say that’s nothing to worry about.
They noted that the last full moon of similar size occurred in March 1993 and passed without incident.
No connectionIn a statement, Jim Garvin, chief scientist at Nasa’s Goddard Space Flight Center in Maryland, said that there is no connection between the moon’s position and the earthquake in Japan.
“The effects on Earth from a super moon are minor, and according to the most detailed studies by terrestrial seismologists and volcanologists, the combination of the moon being at its closest to Earth in its orbit, and being in its ‘full moon’ configuration (relative to the Earth and sun), should not affect the internal energy balance of the Earth since there are lunar tides every day,†said Garvin.
Dario de la Cruz, chief of the astronomy section of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa), said Filipinos should “enjoy this rare occurrence†and not believe in rumors about the super moon’s dangers.
According to De la Cruz, the super moon will “only cause a lower than usual low tide and a higher than usual high tide due to the gravitational pull.â€
Full moons vary in size because the moon’s orbit around the earth is not a perfect circle, but an ellipse. When the moon’s orbit takes it the farthest away from earth, the moon is at its “apogee.†When it is closest to earth, the moon is at its “perigee.â€
The full moon on Saturday night was also at its perigee, which put it about 8 percent closer to Earth than usual.
Astronomers say the best time to look at the full moon is when it’s near the horizon at moonrise, or at dawn when it is setting in the west. That is when optical illusion blends with reality to produce a truly spectacular view. Low-hanging moons look unnaturally large when seen beside trees, buildings and other foreground objects.
Closeness to earthIt is the moon’s closeness to Earth at perigee that has given rise to fears that its gravitational pull would induce natural calamities like floods, earthquakes, or volcanic eruptions. No such thing, say scientists.
In most places, lunar gravity at perigee pulls tide only about an inch or so higher than usual. Local conditions can amplify the effect to about six inches.
No natural disasters occurred during the super moon of March 1993, and a near-super moon in December 2008 also proved eventless.
In the northern hemisphere, the vernal equinox occurs on about March 20 or 21, celebrated as the official start of spring.
On vernal equinox, the first day of spring in the northern hemisphere, the sun stands exactly above the equator, resulting in equal hours of night and day. From this day the daylight hours will progressively grow longer than night-time until we hit the longest day of the year at the summer solstice on June 20 or 21, the official beginning of summer.
Lunar illusionThe moon has not been in a position to appear this large since March 1993. A near super moon occurred in December 2008, when the moon turned full four hours away from its perigee. But this month, the full moon and perigee are just under one hour apart, promising spectacular views, if local weather conditions permit.
In contrast, on October 11, the full moon will closely coincide with apogee. On that night the moon will appear 12.3 percent smaller than it did this weekend.
When the perigee moon is close to the horizon, it can appear remarkably spectacular. That is when the “moon illusion†produces a stunning view.
For reasons not fully clear to astronomers, a low-hanging moon looks surreally large beside trees, buildings and other foreground objects.
Very late EasterA super moon, either rising in the east at sunset or setting in the west at sunrise, might seem to make the moon appear so close that you could almost touch it. You still can’t do that, but you will have plenty of time to make Easter eggs this year.
That’s because Easter falls on April 24, the latest it has arrived in 68 years. Easter hasn’t come this late since 1943 and won’t be this late again until 2038. In 1943 and 2038 Easter occurs on April 25, which is as late as it can theoretically be.
Easter last occurred on April 24 in 1859, and it will not fall again on the 24th until 2095.
On the other hand, the earliest possible date for Easter is March 22. That’s because Easter is calculated to fall on the first Sunday after the full moon that follows the vernal equinox.
That is the case this year but not every year, because the precise calculation—used by Christian churches according to rules going back to the 16th century—is more complicated.
That calculation puts the vernal equinox—the first day of spring—as March 21, although that date can vary. The equinox this year falls on March 20.
But in the next two years, by a fluke of the physics that determines orbital mechanics, we will have to work on the Easter eggs earlier. Easter falls on April 8 in 2012 and March 31 in 2013 before being late again on April 20 in 2014.
With Inquirer Research, AP and Winston A. Marbella, contributor
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