Make binoculars ready: Venus and Jupiter conjunction on 30th June

Ahmedabad
Write up by Shri Narottam Sahu
Scientists, Gujarat Science City

The two brightest stars in the sky aren’t actually stars. They’re the planets Venus and Jupiter, and tomorrow, they’ll be snuggled up next to each other in the evening sky. The configuration, called a conjunction, isn’t all that rare, but it does look cool.

Tomorrow, on a clear night, look for the conjunction to be seen just after the sunset at 7.29 pm and will continue up to next two hours in the western sky.

The union will be visible even from a city street. The closest approach—the two bright planets will appear just one moon-width apart.

Jupiter-Venus alignments happen every few years, sometimes in the morning sky, sometimes in the evening sky. That’s because Venus orbits closer to the sun that Earth does—so it’s geometrically impossible for Venus to appear more than about a quarter of the sky away from the sun—hence its nicknames, the morning and evening star.

Along with the planet conjunction, visitors can see the four bright moons of the Jupiter, namely Io, Europa, Ganymede and Callisto. Jupiter has 63 moons and is the largest planet in the Solar System.

Jupiter is a far bigger planet, but Venus is closer and more reflective, so it appears the brighter of the two.

Although these planets are aligned on nearly the same line of sight, they are hardly close together in space. Venus, the second planet outward from the sun, presently resides a little over 0.5 astronomical units from Earth. In contrast, Jupiter, the fifth planet outward, looms way beyond Venus some 6 astronomical units away from Earth. One astronomical unit is about 150 million kilometers approximately.

Venus and Jupiter both appear bright in Earth’s sky because the cloud cover on these worlds effectively reflects sunlight. Although Jupiter is so much farther off than Venus, Jupiter’s sheer size guarantees the king planet’s brilliance. Jupiter’s diameter is nearly twelve times greater than Venus’ diameter, yet Jupiter is nearly twelve times farther away from Earth than Venus.

The planets move throughout our sky due to our movement and theirs as we travel around the sun.

If you have a pair of binoculars, you can try taking a closer look at the two jewels of the night sky over the next week as they get closer to each other.

Gujarat Science City has arrange special show of the planets at its Amphitheater from 7.00 pm onwards. Several high focused telescopes have been arranged to be zoomed to the Venus-Jupiter conjunction to show the celestial beauty to the children and the visitors along with interactive sessions with the experts and scientists.

Gujarat Council on Science & Technology (GUJCOST) has also arranged Venus-Jupiter conjunction at its Community Science Centers across the State.

If the sky will be clear from clouds, it would be an exciting moment to see the two planets so closely and to understand the science interestingly.

So be sure to catch the two planets at their closest: it won’t happen again until Aug. 27, 2016.