It’s been ages since I posted my last entry here. I missed this blog so much.
I’ve been really busy doing and organizing a lot of stuff during the last couple of months that I rarely had time to write. Moreover, the observing conditions were very seldom good because of the rainy season – several typhoons hit the country and it’s too cloudy most of the time.
It is not until towards the end of September that the rainy season in the Philippines will start receding. Its normal termination usually occurs by the end of October.
Anyhow, the coming of October also marks the coming of longer nights in the Philippines. Just last October 1, the Sun rose at 5:46 AM and set at 5:46 PM (Manila time). This day signaled the transition point in nature when the light changes. The days are getting shorter in the Northern Hemisphere — everyone can feel the shortening of the days and sense, innately, that the changes in daylight and darkness are sudden and surprising.
During the equinox last September 23, the length of night and day across the world is nearly, but not entirely, equal. This is because the day is slightly longer in places that are further away from the equator, and because the sun takes longer to rise and set in these locations. The axial tilt of the earth affects the day/night duty cycle most strongly at the poles and has no effect at all at the equator. Equal day and night usually occurs a few days after the equinox. For simplicity, we may assume that it has actually occurred on October 1. Take note that there is really no equal day and night at the equator.
For amateur astronomers, longer nights mean extra hours of uninterrupted stargazing!
The fine meteor showers usually come in by October to December of each year. October 2011 has two meteor showers worth getting outside to see — the Draconid meteor shower on the evenings of October 7 and 8 and the more reliable Orionid meteor shower on the mornings of October 20 and 21.
As the Draconids and Orionids kicks off the meteor shower season, observing the night sky would be more fun and interesting.
Clear skies to all!
Just recently, a friend shared an article from Manila Bulletin’s website titled “36 hours of darkness in US likely on October 17”. I read it and had an impression that this could be another nonsense rumor like the Mars Hoax , based on my own knowledge of these things. However, the writer claimed that the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) said that this event “may partially hold true“.
Quoting the original article, it says
Online and text rumors claiming that the sun will rise continuously for 36 hours on October 17, 2010 in some parts of the world and leave the United States in darkness for 36 hours may partially hold true, an official of the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (Pagasa) said on Wednesday.
The report spreading through e-mails and text messages noted that this “coming October 17, 2010, the sun will rise continuously for 36 hours (1.5 days). During this time, the American countries will be dark for 1.5 days. It will convert three days into two big days. It will happen once in 2,400 yrs.”
I did my own research on this topic to know more and I learned that the same article with the same author, Ellalyn de Vera, was also featured in Yahoo News – Philippines and in another local newspaper, Tempo. Other than these, only a few websites had discussions which debunked this topic. Following are some of them:
“The further north you go, the longer the days. This may be true near the arctic circle, but not for the US, other than Alaska. And it certainly does not happen just over two to three days. Arctic days and nights are gradual things, lengthening and shortening over the course of a year. For it to happen just for the day, the Earth would need to slow down its rate of spin. Not possible for a body as massive as the Earth, without destroying itself as the energy from angular momentum changes so abruptly.” (This is one of the best logical explanations I found.)
Most of the websites above clearly said that this “hoax” originated in India and circulated in emails and text messages since 2008.
To further confirm the information contained in the article, I decided to visit the PAGASA Astronomical Observatory in U.P. Diliman to look for Engr. Dario dela Cruz, officer-in-charge of the PAGASA space sciences and astronomy section. Unfortunately, he was not there during that time so I just talked to Sir Mario, the head of the Observatory about the article.
I showed Sir Mario a copy which I printed from the Internet and he told me that it was the first time he had seen the news report.
We spent a few minutes talking. There were several important points raised during our discussion which I will list down here:
(1) Engr. dela Cruz’s statement below is true.
“After we experience the equinox during September, countries located in the Southern Hemisphere begin to observe longer days, as against those in Northern Hemisphere that observe longer nights, which include the northernmost part of the United States.
Starting September 24, there is a gradual decrease in the number of hours of nighttime as we go below the latitude. Countries located above 66.5 degrees are those that only experience a whole day of darkness.”
(2) However, if the “36 Hours of Darkness” will happen, the possibility of its occurrence will just be limited to the northernmost or southernmost part of the globe like the north of the Arctic Circle or south of the Antarctic Circle. (see diagram below for visualization)
(3) Currently, the most number of hours in which the sun would not set (also called the Midnight Sun) or rise is only for 24 hours and it happens mostly north of the Arctic Circle and south of the Antarctic Circle, never in any part of America which is located at lower latitudes.
(4) This event, the Midnight sun, is a natural phenomenon and it happens every year, not just every 2,400 yrs as was claimed in the article.
(5) There is still no scientific evidence based on data and computations that the 36 hours of darkness is likely to occur. The basis for the expected date October 17, 2010 wherein it was said to happen was still unknown to them.
(6) If this was to happen, it was only logical that the event should fall near solstices, and not near equinoxes.(September Equinox this year)
So based on Sir Mario’s explanations, the claim in the article about having “36 hours of Darkness” is more likely just a misinterpretation or simply a HOAX.
* * *
Equinox – occurs twice a year, when the tilt of the Earth’s axis is inclined neither away from nor towards the Sun. The term equinox can also be used in a broader sense, meaning the date when such a passage happens. The name “equinox” is derived from the Latin aequus (equal) and nox (night), because around the equinox, the night and day are approximately equally long. This year, equinox falls on March 20 and September 23.
Solstice – either of two times of the year when the sun is at its greatest distance from the celestial equator. The summer solstice in the Northern Hemisphere occurs about June 21, when the sun is in the zenith at the tropic of Cancer; the winter solstice occurs about December 21, when the sun is over the tropic of Capricorn. The summer solstice is the longest day of the year and the winter solstice is the shortest.
image credit: Google images