The “Eye of God”

Exploring the Planetary Nebulae

Dr. Santanu Bhattacharya
3 min readNov 22, 2020

The “ Eye of God” or The Helix Nebula is a planetary nebula located in the constellation Aquarius, at about 650 light years from the Earth. Discovered by Karl Ludwig Harding in the early 19th century, Helix is one of the closest of all the bright planetary nebulae. The central star of the Nebula, a white dwarf remnant of the star that exploded about 10,000–12,000 years ago, gives the resemblance of an eye.

The star is now approximately size of our planet, Earth!

The “ Eye of God” or The Helix Nebula. Source: NASA Astronomy Picture of the Day (APOD)

How God Created His Eye

The Helix Nebula was created when it reached end of its lifecycle of a star similar to the Sun, when the star evolved into a red giant and shed its outer layers. The star’s outer shell of ionized layer, ejected into space, are lit by the remnant central core of the star. Just for clarification, the term “planetary nebula” is a misnomer because they are unrelated to planets.

The Helix was the first planetary nebula discovered to have cometary knots.

A “cometary knot” contains bright cusps and tails, and they all extend away from the central star in radial directions. The Helix contains about 20,000 cometary knots, each roughly size of the solar system and is about 2.5 light year wide.

Helix Nebula in Infrared — still looking like a beautiful green eye. Source: NASA, JPL-Caltech, Kate Su (Steward Observatory, University of Arizona) et. al.

The Helix Nebula is one of the rare objects in the space that appears really similar across a wide spectrum, from ultraviolet to infrared. While there are are noticeable differences in the nebula’s appearance, it is easy to recognize at all most wavelengths

The Final Days of a Star

Before the star that created the Helix Nebula died, it’s comets, and possibly even planets, would have orbited the star in an orderly fashion. When the star ran out of hydrogen to burn, a stage our own sun is expected reach in about 5 billion years and blew its outer layers, it’s planets would have been swallowed after burning up as their dying star expanded. On the outer edge, icy bodies and outer planets would have been tossed about and into each other, kicking up an ongoing cosmic dust storm, which eventually were “lit” by the radiation from the dying, collapsing star.

Expansion of the whole planetary nebula structure is estimated to have taken place in the last 6,500 years, and 10-12,000 years for the inner disk — well within the dates when modern humans were evolving.

Can We See This Nebula?

The Helix Nebula is a popular target for amateur astronomers and can be seen with binoculars, where it looks like a hazy, greenish cloud.

From Earth, the nebula is almost one-half the Moon’s diameter. The ring shape can only be resolved with large amateur telescopes. The nebula’s radial streaks cannot be seen except through the largest ground-based telescopes, such as Gran Telescopio Canarias (GTC)in La Palma, (a 10.4 m/ 34 ft reflecting telescope) Canary Islands in Spain or the Keck Telescopes 1 and 2(10 m/ 32 ft 10 inches reflecting telescope each) at the summit of Hawaii’s Mauna Kea mountains in the USA.

Keck Telescopes 1 and 2 at the summit of Hawaii’s Mauna Kea. Source: Wikimedia Commons

Pop Culture

In the pop culture, some have also called it as the “Eye of Sauron”, The Lord of the Rings, “the Eye” or the Red Eye, the Evil Eye, the Lidless Eye, the Great Eye. Sauron’s Orcs bore the symbol of the Eye on their shields and helmets, and referred as the “Eye” because he forbade his name to be written or spoken, according to Aragorn.

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Dr. Santanu Bhattacharya

Chief Technologist at NatWest, Prof/Scholar at IISc & MIT, worked for NASA, Facebook & Airtel, built start-ups, and future settler for Mars & Tatooine