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Transit of Venus 2012

Venus in transit

Venus in transit

Universe has a plethora of amazing views and sites to display to us astronomers.
The scale of our solar system is negligible to the vastness of the universe. Still, some of best views of the universe are right there in our backyard. Saturn and Jupiter are one of the best viewed objects in our solar system. Venus too shows beautiful phases just like our Moon. We just need to know where and when to look.

Celestial bodies strictly follow mathematical equations which were laid down by Kepler, Newton and many others. This makes it easy for us to determine the exact position and timings of rare events such as the transit of Venus. Earth’s orbit around the sun places us third to Mercury and Venus. This allows the earthlings to view not only the phases of these two planets but also, though rarely, the motion of these planets across the disk of the sun relative to earth. These are termed as transits.

TOV-w_o filter

Sun playing hide and seek amidst clouds

The transit of Venus follows a rather complex pattern; they occur in pairs separated by 8 years and these pairs occur every 105.5 years or 121 years. The next transit of Venus will occur in December of 2117. This makes it one of the rarest events for the living population of the planet. (Unless someone somewhere discovers the fountain of youth and makes it accessible only to astronomers or a breakthrough in cryogenics takes place and people can extend their lives at will)

Like many teams which were formed to witness this rare celestial event, we too formed a team and we called it Astrohams – which signifies the two hobbies which are astronomy and ham radio (also known as amateur radio). The team comprised of the following individuals


Core Team with their paraphernalia

1. Puneit Thukral
2. Neha Thukral
3. Kaustav Saha
4. Tarveen Bhasin Saha
5. Eshaan Saha

We not only called ourselves Astrohams but also, combined both the hobbies during the transit of Venus.


The primary objective was to view the transit safely. The secondary objectives were to photograph, web-stream and SSTV streaming of the event so that the not so lucky ones can also witness this rare, once in a lifetime event

Selecting the Venue

Once an experienced amateur astronomer told me, that for a rare astronomical event, concentrate on location location and location. Rest everything will fall into place. And this is what we did. The transit occurred on June 06 2012 and it was visible at sunrise across India and most parts of the world. This gave us a huge geographical area to choose our location. Now, we had to look for a location where the probability of clouds during sunrise was low and of course has a clear view of the horizon so that the event can be witnessed as early as possible.
We didn’t have to look too far, the terrace of our house turned out to be good location. It had several advantages
1. We had high speed Internet access which would allow streaming the event live on the Internet
2. Our ham radio setup could be relocated easily on the terrace which would lower the setup time
3. There was no need for travel thereby saving travelling cost and time.

Thus we finalised our terrace as the location for transit of Venus. Having done that we registered our event with NASA as well.


Weeks before the transit, we began arranging for the most crucial element to a safe observation – a solar filter. Our friend, Sneh, helped us with a sheet of a solar filter with which we created filters for our cameras, binoculars and newly acquired 10″ Skywatcher telescope. We were going to use 4 cameras & 1 webcam for the transit. Also, we ran some rehearsals to understand the position of sun at sunrise at the horizon and calculated when the transit will be actually visible to us in case of clear skies. We made a list of things needed and also tested out Ustream broadcasting as well as SSTV transmission on Ham bands. Many of the Delhi Hams participated in this rehearsal and helped us fine tune our setup.


We had planned for months that we will be staying home a day before the transit in case we have to travel in the event of a bad weather. As with any major astronomical event, I was studying satellite images for days now and understanding the movement of cloud cover. During the month of May and early June Northern India receives pre-monsoon showers which are accompanied by dust and thunder storms. This is due to the low pressure area created by the heating landmass which sucks in dust and moisture laden winds from surroundings. And it is now an established fact the cities being warmer than countryside are more prone to dust and thunder storms. It had been raining a few evenings before the transit which made the morning sky clear. However, during the first week of June, a big patch of cloud covered major cities in India. Upon studying visible, infra-red and water vapour channels images sent out by Kalpana-1 satellite, I decided to stay put in Gurgaon, even though the evening looked as if the cloud cover will not dissipate. I had seen a break in the cloud cover and the motion over time suggested that we will have broken clouds to clear skies by morning.

The morning of 6 June arrived and we were ready with our setup by the break of dawn. We did some final test runs and then waited for the sky to clear up. The south and west were clear and the north and east were covered with broken clouds. However, a nice and cool breeze gave us the confidence that the clouds will be soon dispersed and we shall soon be able to witness the transit.

The glowing disk of our nearest star was first visible at around 6.30 am local time and it was the most beautiful sight of the day. The broken clouds acted as a natural filter making it safe for us to view the sun directly. At this stage our solar filters were too dark for the faint disk of the sun. Amidst the clouds, we could clearly see a tiny black spot on the face of the sun. It is the best picture of the Transit that we took that day.

As our planet turned on its axis, the Sun gradually gained altitude in the sky, increase its luminance every second. The sky cleared up too and soon we were looking at the Sun through protective solar filters. Having witnessed the Total Solar Eclipse of 2009 which just lasted over 3 minutes, 5 hours of Venus transit was like a lifetime. There was so much one could do in 5 hours.

Kaustav and Neha attempted to transmit live image of the telescope through the webcast of the event – Kaustav’s office colleagues guiding him over phone (they were watching us from their office) on how to achieve a good focus with the webcam. This of course was not very stable as it was not planned earlier and thus they were trying it for the first time. Many first time observers stumbled upon to us and we formed a ritual that was to be followed – at first the were supposed to look through protective filter without any magnification and then with binoculars and finally with the telescope. No one was allowed to jump this and go directly at the scope. We shared with them the significance of the transit and how the first organised transit of Venus helped mankind to understand the scale of the solar system.

Parallely, we were uploading photographs on social networks such as Facebook and Twitter as well as transmitting near live images of the transit through amateur radio equipment using the SSTV mode on 2m & 20 m bands. Even though we did not get a response on 20 m; there was appreciable activity on 2 m. Days later, I saw one of the received images on Facebook which we had transmitted. The view from the telescope was mesmerising. The black drop of Venus among the sunspots looked so pretty that there are no words that can describe.

Back in Hanle, the sky was overcast and there was no hope to see the sun. Soon our friends who were sitting at IIA looking at Hanle, saw our webcast and decided to embed it on the AAAD’s website. The screenshot of our webcast was viewed by the team at IIA showed up few days ago on Facebook.

The transit lasted till about 10.19 am IST and we were glad that we witnessed and publicised the last Venus transit of our lifetimes. A lot of non-astronomers and non-ham radio users also came to observe the transit through our setup.

The transit of Venus was one of the most spectacular astronomical events we witnessed and observed. We consider ourselves to be lucky to have successfully observed it. As the saying goes, “at the right place and at the right time”
We now await for the next great astronomical event – Comet ISON in November 2013. Watch this space.


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