The Solar System – Neptune
Technical Data
| Date of Issue | March 20, 2018 |
|---|---|
| Denomination | Rs. 5 |
| Quantity | 500,000 |
| Perforation | 13 x 13½ |
| Printer | Security Printing Press, Hyderabad |
| Printing Process | Wet Offset |
| Watermark | No Watermark |
| Colors | Multicolor |
| Credit (Designed By) | Mr. Suresh Kumar Smt. Alka Sharma |
| Catalog Codes |
Michel IN 3376 Yvert et Tellier IN 3065 Stanley Gibbons IN 3489 |
| Themes | Outer Space | Planets |
The Distant Jewel of the Solar System
Neptune, the eighth and farthest planet from the Sun, stands as a symbol of mystery and discovery in our Solar System. Known as the Blue Giant, Neptune mesmerizes with its deep azure hue — a result of sunlight reflecting off methane in its atmosphere. It is the fourth-largest planet by diameter, the third-most massive, and the densest among the gas giants.
Discovered in 1846 through mathematical predictions rather than direct observation, Neptune marked a milestone in astronomical history. Its existence confirmed the precision of celestial mechanics and expanded humanity’s understanding of the cosmos.
Composition and Atmosphere
Neptune’s atmosphere is composed primarily of hydrogen and helium, with traces of water, ammonia, and methane — the latter giving the planet its brilliant blue tone. Despite its serene appearance, Neptune is a world of turbulence and extremes. It hosts the fastest winds in the Solar System, reaching speeds of over 2,000 kilometers per hour, creating massive storms that swirl across its surface.
Beneath the icy clouds lies a core made up of rock and metal, surrounded by a thick mantle of water, ammonia, and methane ices — earning Neptune the title of an “ice giant.”
Orbit, Temperature, and Moons
Neptune orbits the Sun once every 164.8 Earth years, traveling through the farthest regions of our celestial neighborhood. With an average temperature of –218°C (55 K), it is one of the coldest places in the Solar System.
The planet has a fascinating collection of 14 known moons, the largest being Triton, which orbits Neptune in the opposite direction of its rotation — a clue that it might once have been a captured dwarf planet. Triton’s icy surface and active geysers make it one of the most intriguing bodies in outer space.
A Philatelic Tribute to the Blue World
To celebrate the wonders of space exploration and the beauty of the cosmos, the Department of Posts issued a commemorative postage stamp on Neptune. The stamp artistically captures the planet’s striking blue color, symbolizing both scientific discovery and the endless curiosity that drives humanity toward the stars.
This issue serves as a tribute to Neptune’s mysterious allure, reminding collectors and space enthusiasts alike that even at the edge of our Solar System, beauty and wonder continue to shine.