On Eclipse Visibility

The year 2019 brings us 5 eclipses which is something people are excited about. However, not all of these are visible in the Philippines. Geographical differences affect our view in the sense that at the moment an eclipse takes place in one side of the globe, the other side of the globe does not see it. Of the 5 eclipses, only two are visible from the Philippines (with one needing a geographical advantage in the South).

Jan 6 Partial Solar Eclipse (Not visible in the Philippines)

Jan 20 Total Lunar Eclipse (Not visible in the Philippines)

July 2 Solar Eclipse (Not visible in the Philippines)

July 17 Lunar Eclipse (Eclipse at Moonset, part of eclipse not visible)

Dec 26 Annular Solar Eclipse (Partial for most of the Philippines, annular from the Southernmost tip of Mindanao)

Eclipses happen when an object of roughly the same apparent size covers the other object. In the case of a solar eclipse the configuration is Sun-Moon-Earth, and for lunar it is Sun-Earth-Moon.

The duration and area covered by an eclipse is dependent on how big the shadow is cast by the eclipsing object. For a lunar eclipse the Earth's shadow is cast on the Moon and since the Earth is much bigger it casts a larger shadow. Any area where the umbral shadow is cast when the Moon passes will see a total lunar eclipse. Now note that the Moon's orbit is tilted with respect to the Sun-Earth plane, therefore the angle in which the Moon passes behind the Earth varies. A lunar eclipse lasts longer when the Moon passes as close to the center of the shadow as possible.

The July 17 Lunar eclipse is partly visible from our reference. From our geographical location on the globe (that's right flat-earther's) the Earth will be rotating us away from the eclipse during the 'Blood Moon' phase. Meaning the Philippines will move or rather rotate to the Sun facing side of the Earth as the rest of the eclipse takes place in view from other geographical locations. From our view it can be seen as an eclipse during Moonset.

In the case of a solar eclipse it is the Moon casting a shadow on the Earth. Now since the Moon is smaller it casts a smaller shadow making the eclipsed area smaller. As a result the geographic location experiencing a solar eclipse is very limited. As you can see in the picture on the right (Image by NASA DSCOVR EPiC Team) the shadow of the Moon only covers a certain region. Since the shadow is relatively small a solar eclipse will only last for a short time.

In the case of the December 2019 Annular Solar Eclipse the image below (Fred Espenak|NASA GSFC) shows the eclipse path and regions of the globe they are visible in. The red band is where the center of the Moon's shadow passes where the eclipse will be seen as an "annulus" or ring. Note that when an annular eclipse happens it means that the Moon is further from the Earth on its orbit, which in turn results to an even smaller shadow. For observers in the Philippines the amount in which the Sun is eclipsed will vary depending on how close you are to the shadow. Observers in Luzon will see less of an eclipse as compared to observers in Mindanao.

Before making the Balut island simulation I ran it for Gen San. Even from Gen San it doesn't appear as an annulus.

Note: I accidentally edited the original post while updating the 2019 NAW calendar. I have tried to redo the general content as how I remember it.

Optics, Atmosphere & Astronomy

Several atmospheric phenomena exist that usually catches our eye. They usually result from optical effects in the atmosphere such as refraction, diffraction, scattering, etc. The most commonly known atmospheric effect is that of rainbows. The presence of water droplets in the atmosphere causes the sun's light to be reflected and refracted into its component colors. Here are some other atmospheric effects:

Cloud Iridescence - this rainbow colored cloud results from diffraction of light by tiny water droplets or tiny ice crystals. Diffraction is the process of bending light around an object.

 

Corona - Coronas are 'crowns' of light around the Sun or Moon. This process results also from the diffraction of light. Diffraction generates interference patterns that disperses the light outwards and sometimes into its component colors.

Halo - results from refraction of ice crystals in the upper atmosphere (cirrostratus clouds). The ice crystals are usually formed as a result of a LPA (low-pressure area) hence it is usually associated with upcoming rain or cloudy weather.

Silver Lining - another diffraction result that happens in the edges of clouds

Blood Moon - a total lunar eclipse results from atmospheric lensing. The atmosphere of the Earth acts like a lens that bends light. The component of the visible spectrum that is bent the most is that of the red end of the spectrum. So as the Sun-Earth-Moon alignment happens the red light is bent by the Earth's atmosphere and shines on the surface of the Moon. You can actually see the same effect happening as the Moon rises opposite to the Sun. Close to the horizon the Moon appear reddish orange and then turns yellowish as it continues to ascend and finally into the normal hue once it is no longer affected by the lensing.

Some atmospheric optics are more common than you think:

Blue Sky - The blue color of our sky is a result of Rayleigh Scattering or the scattering at certain wavelengths. Molecules of Nitrogen and Oxygen in the air are effective at scattering the blue component of the visible spectrum so light from the Sun is scattered in all directions.

White Clouds -  another scattering phenomena known as Mie Scattering. This results from cloud droplets of sufficient size (approximately 20 micrometers) being able to scatter light at all wavelengths.

Blood Moon 2014

We were initially set-up at Trinoma to have a good view of the moonrise. However, the cloudy skies made us want to call it a night. As we were leaving the Moon began to appear. One jeep ride and a short run after we were able to setup the telescope (thank God its a Dobsonian) and image away. Bible study goers at the UCCP-CHR as well as jeepney drivers joined in as we observed. Here are some of the images I took:

From Shades of Grey to Brilliant Red - December 10, 2011 Total Lunar Eclipse

Last night was the second total lunar eclipse of the year visible from the Philippines. I was fortunate enough to witness both however I failed to observe all phases of the second due to poor weather. We were suppose to go to PAGASA observatory with the RTU students but my companions decided to call off the observation since the sky remained covered with thick clouds by the evening. It also rained when the penumbral stage began.

I waited outside after the rain hoping the skies would clear up, but it remained heavilly clouded. I kept up with the updates from observers in Negros via txt and they were blessed with superb sky conditions to see the eclipse and the meteors that streaked by.

Later, gaps began to emerge and the red moon was revealed. I rushed to set up the camera to image the red moon. I was able to see the eclipsed moon till the end with occasional covering of clouds. I also failed to use the TravelScope 70 as lens attachment since the tripod that came with it couldn't hold the weight when pointed at the zenith.

 

December 10, 2011 - Total Lunar Eclipse

This coming Saturday, December 10, 2011, we will experience the 2nd Total Lunar Eclipse visible to the Philippines this year (A timely astronomical event for those still watching breaking dawn..hehe).

Here is the Eclipse time table provided by Fred Espenak on the Astroleague of the Philippines site:

Eclipse Phases	Time (PST)	Altitude	Azimuth
Moon enters Penumbra	07:33:32 pm	30 deg	72 deg E
Moon enters Umbra	08:45:42 pm	47 deg	72 deg E
Moon enters Totality	10:06:16 pm	64 deg	67 deg E
Maximum Totality	10:31:48 pm	70 deg	63 deg NE
Moon exits Totality	10:57:24 pm	75 deg	55 deg NE
Moon exits Umbra	12:17:58 am	80 deg	325 deg NW
Moon exits Penumbra	01:30:00 am	65 deg	294 deg NW

 The reddening effect of the moon during the total lunar eclipse happens when the Moon enters the umbra, or the darker shadow of the Earth. When this happens, light from the Sun reaching the moon is blocked completely by the Earth, however the atmosphere of Earth acts as a lens which bends light into its component parts (spectra). The light that is bent most is the red part of the spectrum, which also explains the red-orange hue of the sky during sunrise and sunset. In contrast, blue wavelengths are the easiest component of light that is scattered - hence the blue colored sky as particles in the air scatter the blue light.

Little Red Shinning Moon - An Eclipse Experience

Today was a wonderful experience for me since I was able to observe the first Total Lunar Eclipse of 2011. I was one of the participants in the RED MOON event at the Nido Fortified Science Discovery Center (SDC) in the SM Mall of Asia. The event began with a film showing in the Planetarium at the SDC entitled Passport to the Universe. It was my first time at the SDC and I enjoyed the beautiful planetarium experience. Following the film showing was the lecture discussion by Dr. Armando Lee, the first Philippine produced astronomer and proprietor of the Astrocamp Observatory. Dr. Lee is a contact of mine in Astronomy via the web and it was the first time we met face-to-face. He even recognized me and called me by name which kinda made me feel very fortunate that evening. The lecture discussion covered details of the eclipse, why it happens and what we expect to see. After the lecture we were served pizza and drinks before proceeding to the Astrocamp Observatory in the SM By the Bay (San Miguel Boulevard). The Astronomical League of the Philippines (ALP) were already assembling their gear there to do some serious astrophotography. Some of them were contacts and facebook friends who, like Dr. Lee,I was able to meet face-to-face for the very first time. One of them was James Kevin Ty, president of ALP who was also able to recognize me. Also members of the media were there to cover the event; first was Bandila from ABS-CBN, followed by HERO, and then GMA.
I was even given a short interview by HERO, unfortunately I don't have cable to see it. While this was happening in MOA I was also in keeping contact with other observers: Erika Valdueza in Quezon City, and Greg Morales (proffesional photographer) and Nina Abiquibil (BS Physics) in their respective sites in Negros
I was also able to chat with Dr. Lee and his wife about astronomy, observing experiences, astrophotography and the dealings of a observatory such as the Astrocamp. Dr. Lee even allowed me to teach a bit of stargazing tricks to members of the SDC.

Aside from the wonderful RED MOON event, I was also able to purchase Firefly Books' MOONWATCH, a complete starter set for lunar observations. I got it in Booksale for only 40Php right after I got the ticket for the eclipse. Talk about coincidence and good fortune, God is so good! During the night of the REDMOON while waiting for the event to start, my heart's MVP started acting up from the excitement. I'm glad everything turned out alright.

We were able to have good sky conditions of the eclipse except during moonset around 10 degrees from the horizon. It was my first time to observe all the stages including the penumbral stage which is less visible. This isn't my first total lunar eclipse observation but so far this was the best! Like what D. Levy says in his book, don't keep a "been there, done that" attitude in astronomy because each observing experience is unique. Each new observation, especially with a new group, is a new learning experience - Astronomy, I love it!

photo by Greg Morales from Negros

with Dr. Armando Lee, giving my astropainting to him.

Moonwatch set at 40Php

Total Lunar Eclipse of 2011

On June 16, 2011 there will be a total lunar eclipse visible to the Philippines. This is one of the two total lunar eclipses that will be visible in the Philippines, the other being on the 10th of Dec. The moon will pass almost exactly in front of the Earth's shadow and thus a totality of 1 hour and 40 mins. However, the moon will set before the moon exits the umbra.

Below is the time line of the eclipse phases predicted by Fred Espenak as provided by the Astronomical League of the Philippines

	TIME  (PST)	ALTITUDE	AZIMUTH
Moon Enters Penumbra	01:24:27am	45 deg	212 deg S
Moon Enters Umbra	02:22:57am	37 deg	225 deg S
Moon Enters Totality	03:22:29am	26 deg	234 deg SW
Maximum Totality	04:13:44am	16 deg	240 deg SW
Moon Exits Totality	05:02:42am	06 deg	244 deg SW
Moonset	05:30:00am	00 deg	246 deg SW
Moon Exits Umbra (not visible)	06:02:14am	----------	-----------
Moon Exits Penumbra (not visible)	07:00:41am	----------	-----------