An uninhabitable planet that is approximately 63 light-years from home is thought by NASA experts to have the potential to rain glass. As far-fetched as that sounds, the science behind the planet's discovery illustrates how this is possible. Several clues about the planet's atmosphere have become evident through a close study of its azure-blue color and very hot temperature.
The name astronomers gave the planet is HD 189733b. That name alone is a clue about the vastness of space and the number of planets in it. In miles, the planet is a relatively close: 370.44 trillion miles away, or approximately 14.88 billion times around the Earth's circumference. HD 189733b is thought to have a daytime temperature of approximately 2,000 degrees Fahrenheit. This heat is part of the reason scientists suspect it may rain glass on the planet.
The planet's color was determined from data obtained from the Hubble Space Telescope's Imaging Spectrograph. More specifically, this was done by measuring changes in light as the planet orbited its sun. Since the blue levels of light measured diminished significantly as the planet passed behind the star, it was determined that this must be the color of the planet. This blue light, which is bluer than Earth, Uranus and Neptune, also sheds insight on why it might rain glass on the planet. Additionally, "chemical signatures" backdropped against the planet's star help sicentists gather data about HD 189733b's atomospheric conditions per Phys.org.
According to NASA, data from another telescope, called the Spitzer Space Telescope, shows the planet has daily temperature fluctuations as high as 500 degrees Fahrenheit. This is thought to heat the atmosphere's gas into a blue color. However, the blue light is also thought to be scattered by silicate thought to be present in clouds. NASA Science News states, “Silicates condensing in the heat could form very small drops of glass that scatter blue light more than red light.”
The reason color is such an important clue is because it helps explain what is going on. More specifically, the planet is believed to have a red sunset, but red light that is reflected in a process called albedo turns blue, per ESA/Hubble, the European Space Agency's division of the Hubble Space Telescope project. This supports the idea that silicate is in the atmosphere because it has the potential to reflect light in such a way. Moreover, if silicate does exist in the hot gaseous planet, then the potential for glass particles is supported by the data astronomers have gathered.
The vast distance between Earth and HD 189733b makes it difficult to know exactly what is floating around in the windy atmosphere of the latter of these two planets. Nevertheless, the information obtained from telescopes does present evidence supporting the hypothesis that it does rain glass on HD 189733b. This is because multiple studies have found proof of scattered light. Since the H2O molecules in the Earth's atmosphere scatter light in a different kind of blue, the substance reflecting light on the extraterrestrial planet is more likely to be comprised of silica.