The cosmic art work – the eye in the sky formed as the dying stars outer layers are unravel.
.How many stars are out there ? More than grains of sand ?
The Helix nebula – constellation of Aquarius discovered by Karl Ludwig Harding, is one of the closest to the Earth of all the bright planetary nebulae.
Its the nearest example of what happens to a star, like our own Sun, as it approaches the end of its life when it runs out of fuel, expels gas outward and evolves into a much hotter, smaller and denser white dwarf star.
Some observers “dark adapted” at high altitudes and under dry sky claim to have seen the Helix without optics and filters. Binoculars or telescopes are required for detailed observation.
Rhodopsin is the photopigment used by the rods (receptors in the eye) to enable vision in low light conditions. Bright light causes these pigments to decompose. Darkness causes the molecules to regenerate ie “dark adaptation”
The eye is made up of over 200 million parts and is the second most complex organ after the brain.