SUPER BLUE MOON
WHY IN NEWS ?
- Recent full moon, which is on the Purnima of the month of Shravan will be unusual as it will be both a “blue moon” and a “super moon.
ABOUT MOON FACES :
- The orbit of the moon around the earth is not circular; it is elliptical, that is, an elongated or stretched-out circle. It takes the moon 27.3 days to orbit the earth.
- This is because while the moon is orbiting the earth, both the earth and the moon are also moving around the sun.
- It takes additional time for the sun to light up the moon in the same way as it does at the beginning of every revolution around the earth.
- The new moon is the opposite of the full moon — it is the darkest part of the moon’s invisible phase, when its illuminated side is facing away from the earth.
- A full moon occurs when the moon is directly opposite the sun (as seen from earth), and therefore, has its entire day side lit up.
- The full moon appears as a brilliant circle in the sky that rises around sunset and sets around sunrise.
- The moon appears ‘full’ not just on Purnima, but also on the night before and after the full moon night.
ABOUT SUPER MOON:
- The point closest to earth in the moon’s elliptical orbit is called perigee, and the point that is farthest is called apogee.
- A super moon happens when the moon is passing through or is close to its perigee, and is also a full moon.
- This happens with a new moon as well, just that it is not visible.
- According to NASA, a full moon at perigee (super moon) is about 14% bigger and 30% brighter than a full moon at apogee (called a “micro moon”).
WHAT IS A BLUE MOON ?
- There are a couple of definitions of a blue moon, but the one that is most commonly understood — and is endorsed by NASA — describes the situation when a full moon is seen twice in a single month.
- Such a month, in which the full moon is seen on the 1st or 2nd, will have a second full moon on the 30th or 31st.
- According to NASA, this happens every two or three years.
- The first full moon of August 2023 occurred on August 1.
- That was also a super moon, but the super moon of August 30-31 will be bigger because the moon is now closer to the perigee.
SYLLABUS: PRELIMS, GEOGRAPHY