Scientists from NASA in July 2013 have discovered a blue planet that possibly rains glass, orbiting a star 63 light-years away.
This is the first time an exoplanet’s true colour has been determined. Astronomers has used NASA’s Hubble Space Telescope and made visible light observation spotting the planet HD 189733b which is one of the closest exoplanets that can be seen crossing the face of its star.
Scientists continuously observed changes in the colour of light from the planet before, during and after a pass behind its star and observed that there was a small drop in light and a slight change in the colour of the light.
The light was actually becoming less bright in the blue but not in the green or red. Light was missing in the blue but not in the red when it was hidden. Also, earlier observations by scientist reported evidence for scattering of blue light on the planet. The latest Hubble observation confirms the evidence.
Some of observation of Planet as recorded by the scientist
• If seen directly, this planet would look like a deep blue dot, reminiscent of Earth’s colour as seen from space.
• On this turbulent alien world, the daytime temperature is nearly 1093 degrees Celsius, and it possibly rains glass – sideways – in howling, 7242kph winds.
• The cobalt blue colour comes not from the reflection of a tropical ocean as it does on Earth, but rather a hazy, blow-torched atmosphere containing high clouds laced with silicate particles.
• Silicates condensing in the heat could form very small drops of glass that scatter blue light more than red light.
• Hubble and other observatories have made intensive studies of HD 189733b and found its atmosphere to be changeable and exotic.
• HD 189733b is among a bizarre class of planets called hot Jupiters, which orbit precariously close to their parent stars. The observations yield new insights into the chemical composition and cloud structure of the entire class.
HD 189733b was actually discovered in 2005. It is only 4.6 million kilometres from its parent star, so close that it is gravitationally locked. One side always faces the star and the other side is always dark.
In 2007, NASA’s Spitzer Space Telescope measured the infrared light, or heat, from the planet, leading to one of the first temperature maps for an exoplanet.