New Delhi, June. 7 (PTI): Astronomers and star-gazers witnessed a rare celestial spectacle tonight as seven planets marched across the night sky, bringing out the beauty of the heavenly bodies.

Sky-watchers relished the rare opportunity of watching all the planets in a single night as they trained their telescopes, binoculars and other astronomical aids towards the skies.

At sundown, the elusive Mercury, nearest to the sun, put up a brief appearance on the western horizon.

A brilliant Venus followed in the footsteps of Mercury, wowing a gathering of school students and enthusiasts at the G D Goenka School here.

On June 9, Venus will reach its greatest elongation at 45.3909 degrees east of the sun and can be spotted as a very bright star-like object in the western sky above the horizon after sunset.

Saturn, the Lord of the Rings, was to make an appearance in the wee hours, presenting a magnificent view of its rings along with gas giant Jupiter and its satellites.

One could also spot Neptune, Uranus and Mars in the wee hours of the day.

A key difference between planets and stars is that the former reflect light from the sun while the latter are luminous bodies and, like the sun, emit their own light.

Planets are found on ecliptic -- sun's path across the sky. As announced by the International Astronomical Union, there are currently eight planets and three dwarf planets.