Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Saturday, June 2, 2012

The Transit of Venus

Second contact of Ingress taken in 2004Providing the skies are cloud free, Venus Bay will be a great place to observe the Transit of Venus. Remember you must not look directly at the sun SERIOUS EYE DAMAGE MAY RESULT.
The transits of Venus, they are like an eclipses, are very rare but when they occur there are two such events 8 years apart. During the transit Venus is positioned between us and the sun and casts a shadow. Unlike an eclipse of the moon this show is small and seen as a small dark dot as it moves across the face of the sun.
This is only the fifth transit since James Cook travelled to Tahitti in 1769 to make observation there. Astronomers back in England wanted to know exactly how long the transit took and from that they predicted they would be able to compute the distance of the earth and Venus from the sun. This trip is also famous because on the way back to England he reach Australia, called it New South Wales and claimed it for England.

When?

There are four key events in the transit
First touches the sun
8:18 AM
Just inside the Sun, ingress
8:34 AM
Just inside the Sun, egress
2:27 PM
Last Touches the Sun
2:45 PM

 

Where is the best place to observe?

Well really anywhere around Venus Bay you can see the sun at the times above. Remember the sun will be relatively low in the sky during the Ingress. So I might start my own observations just near lees Road and Jupiter avenue intersection, on the bike track as it comes off the little rise. There is a very clear view of the eastern sky from here. During the Egress the car park at Beach One is a good location as it has a good view of the north western sky.


The Venus Bay, Tarwin Lower Men’s Shed are having activities around observing the transit, weather permitting, including a sausage sizzle & live music from local artists. They will have a solar telescope for safe viewing of the transit, solar flares, sunspots and active regions of the sun. Gold Coin Donation. Check the May edition of Matter of Fact Newsletter for more details.

How to Observe?

I will be using the same method used by captain cook. I will project an image of the sun onto a screen using my telescope. I took the picture below of the transit in 2004 and I’m hoping I can do better this time.
Taken in Wheelers Hill on 8 June 2004
The Sydney observatory has a great factsheet on the 6 June 2012 Transit of Venus. If you’d like more information of making observations yourself, it will even help you do the calculations of distance to the sun and Venus if you want to independently verify the astronomers work.

Tuesday, August 24, 2010

Mars close encounter internet myth or ...

There are a lot of stories circulating on the internet about a close encounter with mars on the 27th August. Well they are not true, the earth does come close to the orbit of mars on 30th October (if 69 million kilometers is considered close) and it will be visiable to the naked eye, but it already is. The really bright start after sunset at the moment in the western sky is venus and mars is the dimmer reddish star above it. The bright star close to the full moon is jupiter.

Find out more about this "real" photo at the NASA mars-mythbuster site

The planets Mars, Venus & Jupiter can have a slight affect on tides. However the largest effect would have been at the last new moon when all three, the sun and moon where in close alignment and the effect was apparently minimal!