By Dr. S.N. Prasad, Amateur Astronomer, Mysuru
A cosmic dance of planets Jupiter and Venus, low down in the western sky after sunset, has kept observers enthralled in the past few days. These two objects, easily the brightest in the night sky till they disappear below the western horizon, are said to be in conjunction, a term generally used to signify the close proximity of two or more heavenly bodies as viewed from Earth.
On the night of Mar. 2, these two planets were at their closest, both visible in the same field of view of a low-power telescope, with less than one degree of angular separation. To appreciate what this amounts to, the full moon or the sun has an angular diameter of just about half a degree.
While it was easy to see the conjunction of the two planets with the unaided eye, only a telescope could capture the giant planet Jupiter together with its four famous Galilean satellites and the dazzling Venus, all in the same picture.
My friend Krishnamurthy and I successfully did this around 7.30 pm yesterday at his home, with my Canon EOS 1100D DSLR camera attached to his Celestron 8” Schmidt- Cassegrain telescope.
The slightly overexposed picture here was captured with an exposure of 0.5 sec, set at ISO 3200. The visual appearance of a conjunction of two objects in the night sky is rather deceptive since they are generally far apart in their actual location in space.
In the present case, Jupiter was 787 million kms away while Venus was much closer, at 170 million kms. In contrast, the moon is just 0.38 million kms away.