Who doesn’t love a rainbow? Those beautiful, multi-colored arcs are awe-inspiring to behold and well-known for their symbolism of hope and new beginnings. But have you ever wondered whether other planets experience rainbows? Though different in many ways from the rainbows here on Earth, Venus is home to a related type of phenomenon known as a "glory."
On Earth, rainbows form when sunlight shines on water particles (either rain, mist, spray, or dew) from a low altitude angle behind the observer. They are caused by the reflection, refraction, and dispersion of light and appear as colorful, long-reaching circular arcs across the sky. Glories, on the other hand, can be seen when the observer is directly between the Sun and spherical cloud particles of a uniform size that reflect sunlight. They are most commonly observed from airplanes and appear as a series of concentric, colorful rings in a bullseye pattern.
On Venus, glories occur when there is an interference of light waves within the sulfuric acid droplets in the atmosphere. In July 2011, a Venusian glory was observed by the European Space Agency's Venus Express orbiter when the spacecraft photographed the clouds with the Sun directly behind. The glory was spotted at a height of around 43.5 miles (70 km) above the planet's surface. Based on this observation, scientists were able to determine that the atmospheric cloud particles have a diameter of approximately 1.2 micrometers. The glory had rings of varying brightness, suggesting that the clouds may also contain other compounds, such as water, iron, and chloride.
More about Earth's "evil twin":
- Venus has been humorously nicknamed "Earth’s Evil Twin.” It is similar to our planet's structure and size but has an average surface temperature of 870°F (465°C), which is hot enough to melt lead.
- Though not the closest to the Sun (that's Mercury, of course), Venus is nevertheless the hottest planet in the solar system due to the greenhouse effect produced by its thick atmosphere, which is almost entirely composed of carbon dioxide.
- Venus' distinctive yellow color is the result of sulfuric acid clouds. The top layer of these clouds are whipped around the planet at speeds of 224 mph (360 km/h), which is around 60 times faster than Venus itself rotates.
