Mlm ini bulan memancar penuh. (100%)
dan juga berlakunya PERIGEE state.
dimana bulan berada pada jarak paling dekat dgn Bumi.
oleh sebba jaraknya lebih dekat, maka bulan juga kelihatan lebih besar daripada kebiasaannya.
14% lebih besar dari bulan pada mlm2 yg lain...
bulan pada jarak paling jauh dari bumi dikenali sbg APOGEE
perkara ini berlaku kerana bulan mengelilingi bumi pada kitaran elips dan bumi tidak berada pada pusat elips menyebabkan pada satu2 ketika, kedudukan bulan adalah lebih hampir dgn bumi.
Refer gambarajah dibawah...
marilah melihat bulan,
pada yg sudah terlepas, disini saya sertakan gmbr yg di ambil oleh seorang peminat bulan...
credit #1 to falak-online.net
perkara ini berlaku kerana bulan mengelilingi bumi pada kitaran elips dan bumi tidak berada pada pusat elips menyebabkan pada satu2 ketika, kedudukan bulan adalah lebih hampir dgn bumi.
hmm Me_ai , did u mean to say that , lengkungan eliptikal bulan pada satu satu ketika adalah lebih hampir dgn bumi "rather than" bumi tidak berada pada pusat elips? Because i am a bit confuse in a sense that the earth is moving around the sun in elliptical caurve and the fact written above - " bumi tidak berada di piusat elips"" i agak terkejut sebab takkan bumi terkelaur dari ellips nyer ?
so tak apa saya dah faham sebab u merujuk pada elips bulan..
bila baca balik pun ada gak kekeliruan dlm maksud tu...
tp apa yg cuba saya sampaikan, pada ketika2 tertentu,
lengkungan eliptikal ini lebih hampir dgn bumi...
(seolah2 bumi tidak berada pada pusat lengkungan elip bulan)
rajah atas tu melibatkan bumi dan bulan aje...
tidak melibatkan matahari...
If skies are clear Saturday, go out at sunset and look for the giant moon rising in the east. It will be the biggest and brightest one of 2009, sure to wow even seasoned observers.
Earth, the moon and the sun are all bound together by gravity, which keeps us going around the sun and keeps the moon going around us as it goes through phases. The moon makes a trip around Earth every 29.5 days.
But the orbit is not a perfect circle. One portion is about 31,000 miles (50,000 km) closer to our planet than the farthest part, so the moon's apparent size in the sky changes. Saturday night (Jan. 10) the moon will be at perigee, the closest point to us on this orbit.
It will appear about 14 percent bigger in our sky and 30 percent brighter than some other full moons during 2009, according to NASA. (A similar setup occurred in December, making that month's full moon the largest of 2008.)
High tides
Tides will be higher, too. Earth's oceans are pulled by the gravity of the moon and the sun. So when the moon is closer, tides are pulled higher. Scientists call these perigean tides, because they occur when the moon is at or near perigee. (The farthest point on the lunar orbit is called apogee.)
This month's full moon is known as the Wolf Moon from Native American folklore. The full moon's of each month are named. January's is also known as the Old Moon and the Snow Moon.
A full moon rises right around sunset, no matter where you are. That's because of the celestial mechanics that produce a full moon: The moon and the sun are on opposite sides of the Earth, so that sunlight hits the full face of the moon and bounces back to our eyes.
At moonrise, the moon will appear even larger than it will later in the night when it's higher in the sky. This is an illusion that scientists can't fully explain. Some think it has to do with our perception of things on the horizon vs. stuff overhead.
Try this trick, though: Using a pencil eraser or similar object held at arm's length, gauge the size of the moon when it's near the horizon and again later when it's higher up and seems smaller. You'll see that when compared to a fixed object, the moon will be the same size in both cases.
More lunacy
If you have other plans for Saturday night, take heart: You can see all this on each night surrounding the full moon, too, because the moon will be nearly full, rising earlier Friday night and later Sunday night.
Interestingly, because of the mechanics of all this, the moon is never truly 100 percent full. For that to happen, all three objects have to be in a perfect line, and when that rare circumstance occurs, there is a total eclipse of the moon.
A departing fact : The moon is moving away as you read this, by about 1.6 inches (4 centimeters) a year. Eventually this drift will force the moon to take 47 days to circle our world.
+ bleh aa usha malam ni!!! tuh pun kalau langit clear aa ..
+ sesapa yg ndak usha malam ni, amek aa gegambor yek! sharing is caring maaa
Apogee, Perigee, New Moon and Full Moon Days of 2009
Source: John Walker - Lunar Perigee and Apogee Calculator
The Perigee and Apogee Table
All dates and times are Universal time (UTC); to convert to local time add or subtract the difference between your time zone and UTC, remembering to include any additional offset due to summer time for dates when it is in effect. For each perigee and apogee the distance in kilometres between the centres of the Earth and Moon is given. Perigee and apogee distances are usually accurate to within a few kilometres compared to values calculated with the definitive ELP 2000-82 theory of the lunar orbit; the maximum error over the years 1977 through 2022 is 12 km in perigee distance and 6 km at apogee.
The closest perigee and most distant apogee of the year are marked with "++" if closer in time to full Moon or "--" if closer to new Moon. Other close-to-maximum apogees and perigees are flagged with a single character, again indicating the nearer phase. Following the flags is the interval between the moment of perigee or apogee and the closest new or full phase; extrema cluster on the shorter intervals, with a smaller bias toward months surrounding the Earth's perihelion in early January. 揊
Post time 13-12-2008 12:51 AM
变色卡
Author
...ok
