Find Moon

First of all, we’d like to thank everyone who has read the quiz recently posted on our LearnKPAstrology page and we extend our special thanks to those who have responded and participated.

For your convenience, the question we asked on 10^th April’16:

“On this auspicious day of year, Moon is throwing a party today at 11:30 PM IST. You all are cordially invited. Suppose you are standing at Long-75E44 Lat-26N56, Jaipur, Rajasthan (India) and following are the planetary details at 18:48:55 HRS IST:

Sun Pis 27-01-45 (D-M-S)
Moon Tau 10-26-06

Mar Sco 14-32-33

Mer Ari 14-03-50

Jup(R) Leo 20-26-32

Ven Pis 11-55-18

Sat(R) Sco 22-07-11

Rah Leo 27-24-06

Ket Aqu 27-24-06

Sunrise: 06:08:01 HRS | Sunset: 18:48:55 HRS

Where will you find moon in the sky at the exact given time (11:30 PM IST)? ”

But here’s the secret. Moon is feeling sad. She has invited everyone all over the world and approx. 3500 people got invitation letter. Out of which 160 people liked it but only 2 people have actually responded to her invitation within the given time. Our host (moon) has got hurt now as all of her party decoration and arrangement got wasted.

ASTROOOOON

Let’s prove this and also determine the solution:

It was an educational quiz. Only two known facts to be considered in order to find out the answer:

1. Moon’s rotation around earth
2. Earth’s rotation on its axis

Let’s see Earth’s rotation first:

As we all know our Earth completes one round on its axis in 23 hrs 56 min 4 sec which results in the formation of day and night.

For the simplicity of calculation, let’s consider this figure as 24 hrs (also as per our clock). Hence,

One round to complete 360 degree = 24 hrs

In minutes = 24 x 60 = 1440 min.

1 degree = 4 min

i.e. Earth takes 4 min to complete 1 degree on its axis

Now let’s understand from the below diagram the position of Sun and Moon at the time of sunset from the earth’s surface:

Sunset time 18:48:55 hrs

Sun in Pis 27D:01M:45S (at the sunset point S)

Moon in Tau 10D:26M:06S (at the sky point M)

As we know Earth rotates on its axis and Moon rotates around Earth from West to East direction.

Remember, Earth is taking 4 min to complete 1 degree and for the simplicity of calculation, consider Moon takes 2 hrs to complete 1 degree (Approx. Moon completes 12 to 15 degrees in 24 hrs).

Now we have to study rotation of both Earth and Moon to proceed further:

Time taken by Earth to reach Point M of Moon from sunset Point S:

3 degrees of Pis left

30 degrees of Aries

10 degrees of Tau (Let’s round-off and consider Moon 10 deg. in Tau and Sun 27 deg. in Pis)

i.e. Total time taken by Earth from sunset Point S to reach Point M by rotating on its axis is:

Total distance: 3 deg. + 30 deg. + 10 deg. = 43 deg.

Time: 43 deg x 4 min = 172 mins (as 1 deg. = 4 min)

Or, 2 hrs 52 mins

If we add this to sunset time (18:48 hrs), results 21:40 hrs or 9:40 PM IST

Hence, Moon will be around sunset Point S at 9:40 PM. To get more detailed picture, we can also add Moon’s rotation time as it will also cover approx. 2-3 deg. in 2 hrs 52 min.

But Moon has invited us to party at night 11:30 PM. It means till 11:30 PM, Earth will continue rotates on its axis and Moon will also move from sunset Point S (West) towards North direction of Earth which is downside.

Hence, the correct answer is: Moon will not be visible in the sky at 11:30 PM from the given location Jaipur, Rajasthan, India with Long. 75|44 E and Lat. 26|56 N. It means she invited us at 11:30 PM for party but got absconded. Enjoy now!

Happy Learning!