Astronomers detect first carbon-rich exoplanet
Although most of the 500 exoplanets, or planets outside the solar system, that have been discovered to date are too hot to be habitable, the odds of finding an exoplanet small and cool enough to host life are expected to increase over the next few years as telescope technology improves. Bigger and better telescopes should help astronomers probe the atmospheres of smaller exoplanets to determine if they contain molecules like water and oxygen, which are essential for most life as we know it.One important clue about the atmosphere and interior of a planet is the ratio of carbon to oxygen in its atmosphere. The rocky, or terrestrial, planets in the solar system — Mercury, Venus, Earth and Mars — all have more oxygen than carbon, just like the sun around which they formed, which has a carbon-to-oxygen ratio of one to two, or 0.5. But that ratio is not known...