Tag Archives: extraterrestrial planets

The blistering hot exoplanet where it snows

The blistering hot exoplanet where it snows.

These results have led to a suggestion that [HD 189733b] could continually experience silicate snow. In the lower atmosphere of [the exoplanet], magnesium silicate sublimates, that is, it passes directly from a solid into a gas. But we know there are small silicate particulates in the upper atmosphere. Formation of these particulates requires that the temperature be lowered, and so must have been formed at a temperature inversion in the atmosphere. The generally windy conditions would help some of the tiny particulates grow into respectable snow crystals.

smaller planets are preferentially found in low-eccentricity orbits.

More Kepler results: From the abstract of a preprint paper published today on the Los Alamos astro-ph website:

The mean eccentricity of the Kepler candidates decreases with decreasing planet size indicating that smaller planets are preferentially found in low-eccentricity orbits.

In other words, the smaller a planet is, the more likely its orbit will be circular like the Earth’s. This result is encouraging news for the search for life on other worlds. Before Kepler, astronomers had found that the orbits of most exoplanets were far more eccentric than the orbits of the planets in our solar system, a condition that scientists thought was unfriendly for the development of life. These new results counter that conclusion. The orbits of the planets in our solar system might not be as unusual as first thought.