Venus and Saturn Conjunction

This week and next week there are a couple of nice planetary alignments.
On Tuesday 27th November, Venus and Saturn were in conjunction  meaning than Venus (the faster and closer of the two) moves in front of Saturn and begins to overtake it.

When viewed from Earth they appear very close together in the sky during the early morning (6am-7am). Each day moving further apart as Venus flies past Saturn, further away from Earth towards the other side of the Sun.

I missed the actual conjunction on Tuesday morning, it was rainy, but managed to wake up half an hour early this morning (Wed 28th Nov) to take a few photos.
Fortunately, it was very clear, apart from a bit of mist and hazy. I didn't have a large tripod handy so had to make do with a small portable one (which I got free at an IT fair). Had to hold it steady with my hands whilst lying down on the ground. Got a few curiosity looks from some passer by on their morning run.
The photo turned out alright apart from a slightly elongated shape to Venus and Saturn due to the movement of the tripod.

Venus (brightest) and Saturn (above) - 28th Nov 2012 6:15am - Singapore

Next week is Jupiter's turn to align with Earth, in what's called opposition, where it will be at it brightest, but not by much compared to how it looks this week.

Halloween in the tropics - an astronomical event

Next week is Halloween. This festival is normally associated with death and spook things but it also has an astronomical significance, just like alot of other seasonal holidays.

Halloween occurs on 31st October every year, which is in the middle of the season of Autumn or Fall in the Northern temperate regions of the Earth. During this time the leaves on many trees (so called "deciduous trees") start to turn brown and fall to the ground, in preparation for the approaching winter months.
I'd imagine that the disappearance of alot of the summer flora and fauna was one of the key influences for the "death" theme of Halloween, as at this time life simply seems to fade away, to be replaced by a cold, barren, frozen landscape.

A typical British street during winter - with leafless trees and frost or snow covering the ground.

These changes are mainly triggered by a reduction in the amount of sunlight, resulting in a lose of chlorophyll (the green stuff responsible for photosynthesis) in leaves.

Basically Halloween signifies the middle point between the Autumnal Equinox (22nd Sept - where night and day are equal in length) and the Northern Winter Solstice (21st Dec - the shortest daylight hours of the year).

Although we don't experience the same seasons here in tropical Singapore, there are a few  astronomical clues that can be observed around Halloween:

1) Early Sunrise/Sunset
If like me you wake up for work around 6:30am-6:45am, you may have noticed recently that the sky is already bright compared to a few months ago when at the same time it was still dark.
This is because on the day after Halloween (1st Nov) Singapore (and other tropical areas) experiences its earliest sunrise for the whole year. Sunrise on this day occurs at 6:46am compared to the latest sunrise of 7:17am on 10th Feb (incidentally close to Valentine's Day and Chinese New Year).
In the tropics, early sunrise also means early sunset. So if you get home around 7pm, over this next week, it should be almost dark as sunset on 1st Nov (and Halloween) is at 6:50pm.
All this is a result of the orientation of Earth's tilt relative to the Sun at this time of year.

9am Morning Sun during June  - Sun located towards North-east (on the left).

9am Morning Sun in October - Sun is slightly higher and more towards the South (right) than earlier in the year.

2) Southern Sun
During Equinox (22nd Sept) the Sun is directly level with the equator, which from Singapore, results in the Sun rising due East and setting due West, with the midday Sun directly overhead.
On December 21st (solstice) the Sun rises from its most southern point in the sky. Around Halloween the Sun will be halfway between these two positions. So the daytime sunlight will come from a slightly southern direction. Bad news for those with south-facing windows, as for the next few months you can expect more and more sunlight on that side of your house.

This effect can also be seen in the orientation of shadows on ground.
Back in June (close to northern solstice) the Sun was at its northern most point so shadows appear to point south.

12:30pm - Midday shadows in June (solstice) - shadow are long and point south (left).

During Equinox, shadows pointed more or less east and west as well as directly below our feet.

12:30pm - Midday shadows in September (Equinox)  -  shadows are short, gradually pointing west and east in the morning and afternoon.

Lunchtime shadows in September (Equinox) are directly  below our feet

Around Halloween shadows now point slightly north (i.e. opposite the Sun).

12pm - Midday Shadows in October (close to Halloween) - shadows point slight North (towards the right)

Of course Halloween has alot of other cultural and religious influences, but its timing is primarily astronomical in basis and represents one of the four so called "cross-quarter dates" that occur between solstice and equinox.

Being an astronomer in Singapore has its uses, sometimes to share these little tidbits of information with others whilst walking out for lunch, to pause for a few seconds in order to look around and observe the small occurrences of the Earth's daily wanderings through space before we ourselves resume going about our own daily life.

June Solstice in Singapore

This week is June Solstice week, where the Sun reaches its most northerly point in the sky. Of course, this event is not due to the Sun's actual movement but instead the movement and tilt of Earth. Every year around 21st June, Earth's north pole points more towards the Sun than at any other time of year. This causes a number of significant effects here on Earth.

June Solstice signifies the start of summer in the northern parts of the Earth as well as the longest daylight hours for the whole year. At the same time, it also marks the start of winter and the shortest daylight hours in the southern hemisphere.
There's often a great deal of excitement and sometimes celebelation associated with solstice particularly in places like stonehenge in the UK, where crowds gather from sunrise (around 5am) to sunset (around 9:30pm). The stones themselves also mark the Sun's position at solstice.

Stonehenge - Credit: Pete Strasser - NASA.gov

In Singapore, the effects of solstice are a little harder to spot as near the equator the Sun's position varies only slightly throughout the year.
However, here are some of the signs to look out for in order to notice the solstice from 1 degree north of the equator:

1. Longest daylight hours and shortest night. As Singapore is technically in the northern hemisphere by 1 degree, we also experience the longest number of daylight hours for the year. How long? Exactly 12hours 11minutes 48seconds, from sunrise to sunset. Compare this to the shortest daylight hours of 12hours 3minutes 2seconds in December, the difference is only 8 minutes. Not much to celebrate about, but it is noticeable particularly if, like me, you find yourself reaching home around 7pm. Whilst walking home from the MRT station, bus stop or waiting for a ride, look up at the sky and see if it looks any brighter than usual. A slightly later sunset at 7:16pm should make the sky look brighter than at other times of the year.

Sunset/dusk in June - Longer daytime, later sunset, slightly brighter sky.

Sunset/dusk in April - slightly darker than in June.

2. Sunrise, Sunset and Northern Sun
If you're heading out to work or school around 7:30am or 8am, you may notice that the morning Sun is positioned slightly more to the left (i.e. North) than usual.

June morning Sun to the left (north) of the Science Centre entrance - After June 21st the morning Sun will gradually make its way south (towards the right)

After 21st June, take a look at the Sun every now and then over the next few months around 8am. You should find the Sun gradually moving more towards the right (i.e. south) every week, until it reaches the December solstice position on 21st December.
Similarly at sunset, the afternoon/evening Sun should be located more towards the right than usual. This can be a bit annoying if you happen to own a house, flat or condo with north-facing windows, thinking that you'll escape the brightness and heat of the afternoon/western Sun. Around June Solstice, you'll start to find what was once a nice shady spot is now lit by bright sunlight, as that north facing window is now tilted slightly towards the Sun for most of the day. Those with south-facing windows will experience the same thing in December.

3. Noontime Shadows
Between 12:30pm and 1:30pm, the Sun is at its highest point in the sky but as the June Sun is at its most northern point, midday shadows on the ground will be at their longest as compared to other times of year.

June Solstice Shadows - Longest noontime shadows. Shadows point South

Morning Shadows in June - Sun rises from north-east, shadows point south-west 

If you compare your shadow at midday over the next few months you should find it becoming gradually shorter and shorter until finally its directly below your feet around late September, when the Sun is directly overhead (Autumnal Equinox). Also, as the Sun is located towards the North, all the June shadows should point in the opposite direction towards the South.


All parts of the world, will experience the effects of solstice in one way or another, the most obvious being  in those parts furthest from the equator.In Singapore, the changes may be small, but the clues to spot them are all around us, we need only stop for a while and look around at the environment we live in.

There are a number of other times in year in which the Earth's tilt causes other seasonal effects, such as the the position of the Sun, daylight hours, sunrise, sunset, planet growth, animal migration and seasonal weather patterns. Some of these changes have even influenced the dates of well know holidays and celebrations such as May Day, Halloween, Mid-Autumn Festival, Christmas and Chinese New Year as the movement of objects like the Sun and Moon, have formed the basis of many calenders for thousands of years.
The world may be full of different cultures, but we all share the same sky.
Happy Solstice everyone!

This Morning's Sky

It was 5.45am. I could see something real bright outside my window the minute I opened my eyes. It looked like a star, or a planet. But it couldn't be, I would usually need my specs.

And so, this morning, I woke up without difficulty for a change. In fact, I jumped up from bed wide awake, and spent the next 30 minutes trying to figure out the whole beautiful clear dawn sky. Note: I can see a partially obscured view of the Southern sky from my window.


It turned out Canopus was shining through my window. It is the second brightest star in the sky, and is 65 times bigger than our sun, 15,000 times brighter. Thus from my window, this star was easily the brightest one of all, despite being approx 300 lightyears away. It had got to be really bright for me to spot it even without specs.

To the Chinese and the Japanese, this star is also known as 南极老人星, or 老人星 (Star of the Old Man) for short. It signifies happiness and longevity.

To see this in the evening, we have to wait till April 2010. Do drop by SCOB, and we can tell you all about Canopus, and Sirius, the brightest star of all.

Other objects in the sky this morning include our beloved planets Mars and Saturn. Mars was gleaming away above my head looking all reddish and sparkling. Try and catch it tomorrow morning if the sky is clear.

With that, time to go to work.

Good Morning Folks!

tonight's sky - 14th Aug

The sky tonight is.......CLOUDY! There is a familiar dull grey covering across the sky in the picture above, nicely taken by SK at 7:10pm.

Conditions do not look good.
Don't know if Jupiter's brightness can break through at about 9pm

Tonight's weather

Looks good tonight!
Could be our first clear Friday night sky of July.
In the picture above, the whitespeck at the top right corner is the Moon.

The weather tonight (24th July)

Tonight's sky looks better than last week. Still cloudy but a chance of clearing.

PS. In the end my prediction was wrong. Instead of clearing, more cloud came over and covered the sky. In the few gaps that appeared we did catch a brief glimpse of Saturn and the stars Arcturus (Bootes) and Antares (Scorpius).

I'm sad to say that I don't make a good weather man :(
That's the third week in a row that we've been clouded out. It seems July is a very cloudy month.

The Sky From The Office - Fri 4.45PM 19 June

Good news: Sky looks quite blue now! with some tiny fluffy clouds in the distance.

Hopefully as we Scobbers have dinner, the sky will turn blue-r and more cloudless, so that we can see the beautiful constellations and star clusters tonight! :)

OK, time for dinner! See you later, friends of the Observatory!

Some Favourite Photos :)

Door to the dome containing the main telescope:



View of the evening sky on a certain Friday night, as well as the smaller dome:

A typical night with a queue to the main telescope and visitors having fun all around the area. Picture is rather grainy, but do you see the full moon?