Friday, July 20, 2007

Analemma - How I wonder what you are!

If you take picture of sun in the sky at the same time of the day, from same place in regular intervals over one earth year and combine the position of the sun in the sky you will get this figure 8 curve (pic credits: Anthony Ayiomamitis). This is called Analemma, caused by two totally independent factors.

1. Earth is tilted on its axis by 23.5° in relation to the plane of its orbit around the sun.
2. Earth does not orbit the sun in a circle, but in an ellipse.

You can try working out how Analemma would look like in Mars sky!

(an imaginary dialogue in Tamil language between earth and sun...)

Earth : Hey Soorya edhuku vaanathula 8 podra?

Sun : Tamilnatula motorbike ottanumnu aasai adhaan license vaangarathuku RTO office edhirla 8 podraen...

Earth : license vaangrathuku ettu potta mattum pathaathu konjam thuttayum podanum oi... adhuku pesama... ikkada ra... ra ra raamaya... ettukula ulagam iruku raamayanu... rajini styla paaditu pora vazhiya paru.


pria said...

An awesome picture and detail information.

Thanks thiru.

Sree's Views said...

ha ha ha :))
I am reminded of Vivek's
"8 aa poda sollarel..ippo parungo..ezharai podren..pinnadee otkaarungo" :))

Thiru said...


you are most welcome.

Thiru said...


:)) yaa...

B. Ramana said...

What you describe is something awesome and unique! A chunk of the humor was above me, so here is when I don't understand you! ;-)

Mahendra said...

Hey - nice to see an astronomy post! Good one, nice pic and explanation.

Being moderately literate, I couldn't understand the dialogue either...:-)

Thiru said...

Hi Ramana and Mahendra

Thanks. Sorry, I forgot to mention that the humor piece is in Tamil language which requires prior watching of few tamil movies to appreciate it.

The gist of it is, Sun trying to ride an 8 in the sky to get a two wheeler driving license in India and Earth replies, that alone is not enough, you have to shell out some money as well. Followed by a Tamil song (Rajini movie) explaining philosophy of life by splitting life into divisions, each with 8 years period. Rhyming gets lost while translating it in English.
Thanks. Keep visiting.