Sunday, November 18, 2012

Saturn Venus super close conjunction on 27 Nov 2012

Saturn and Venus will be very close to each other as seen from Singapore on Tuesday 27 November 2012 shortly before sunrise. They will rise from the horizon at about 5.00am. But the best time to observe them is an hour later at about 6.00am when they have risen high enough from the thicker atmosphere near horizon and the sky is still relatively dark shortly before twilight.

They can be located facing East-South-East and at the constellation of Virgo at about 15 degrees above horizon:

If the sky is clear enough for them to be visible, there is no way you can miss it while facing the correct ESE direction - two bright "stars" so close to each other. Close one eye, lock your elbow, extend your arm, raise your pinky finger and its finger tip can cover both of them with room to spare!

Venus will be blazingly brightly at magnitude -4.0 on the right and Saturn relatively dimmer at magnitude +0.7 on the left.

They are only about 30 arc minutes apart - the wide of a full Moon!

The implication of this is that they can be both viewed in relatively high magnification in the *same* field of view of a telescope. Most telescope at its lowest magnification will be able to fit both of them in the same view. This is quite a rare opportunity as sometimes planets come close together but they may be about 3 or 4  arc degrees apart. That means you will need a telescope capable of showing wide views (e.g. short focal length refractors) which implies lower magnification, which implies less planetary details observable.

This is how Venus would look like through a telescope:

I have deliberately overexposed this image to show how Venus look like through a telescope - like a bright Moon with phases. Venus's highly reflective and thick atmosphere makes it impossible to observe its surface detail. It is about 12 arc seconds in size.

This is how Saturn will look like through a telescope:

It's apparently size will be about 36 arc seconds (inclusive of the rings) - 3 times the wide of Venus.

Do take note it is not possible to discern the rings of Saturn in a small, low-power handheld binocular. You need at least a decent basic beginners telescope.

Would love to conduct a free public viewing session that morning but it is a weekday morning - good for students on school holidays but not so great for working adults? How many of you are keen to join in if there is such a session? Or you guys intend to organise a viewing session among yourselves and don't mind inviting me to come along with my telescopes? Drop me an email at

In any case, let's all pray for clear skies on that Tuesday morning and more people to be able to differentiate a planet from a star or satellite! :)

Update 27 Nov 2012:

A photo of the astronomical event at Bishan - Ang Mo Kio Park (in front of McDonald's):

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