A poorly kept secret is now official: the Hubble Space Telescope has discovered carbon dioxide (CO₂) in the atmosphere of a planet outside our solar system. That's a first in the study of extrasolar planets, or exoplanets, which have been quite the hot topic this year.

The exoplanet HD 189733 b, roughly the mass of Jupiter, orbits a star 63 light-years away in extremely close company. Although the planet can't be seen directly, scientists used Hubble data to analyze its atmospheric composition and turn up CO₂ as well as carbon monoxide (CO). They did this by comparing the light spectrum from the star with that from the star and planet combined, as the planet passes in front of its star.

Although HD 189733 b is way too steamy for life as we know it—roughly 1,950 degrees Fahrenheit (1,065 degrees Celsius) by one estimate—the finding, leaked to media outlets two weeks ago, shows that techniques exist to find markers of life on other planets. (The paper has been submitted to Astrophysical Journal Letters.)

On the heels of the first photographs of planets orbiting other stars comes another first for so-called extrasolar planets: an atmosphere containing carbon dioxide (CO₂). Nature News and Science News report that a forthcoming journal article will detail the discovery of CO₂ around HD 189733 b, a planet roughly equivalent to Jupiter in mass that orbits a star some 63 light-years away.

HD 189733 b, discovered in 2005, has already yielded other exoplanet milestones: it was the first found to host an atmosphere containing methane and was also among the first found to harbor water vapor. All of these discoveries have been made without seeing the planet in the conventional sense: to ascertain a planet's traits, the light spectrum of the parent star is compared with the star's emission as the planet passes in front of it. In the latest finding, the data came from the Hubble Space Telescope.

Increased carbon dioxide (CO2) in the atmosphere is making the Pacific coast acidic far more rapidly than previously believed, potentially wreaking havoc for creatures living in it that are unable to tolerate the swiftly changing environment.  

Ecologists at the University of Chicago tracked the acidity of the Pacific off an island close to Washington state over the course of eight years. Their results, published today in Proceedings of the National Academy of Sciences: the waters here are becoming acidic 10 times more quickly than had been predicted using other models. Their data also shows that populations of mussels—key animals in that ecosystem—are declining rapidly as the ocean becomes less alkaline.

You may recall that President George W. Bush pledged to do something about climate change when campaigning for the presidency back in 2000—but reneged on that promise once in office. But it appears that President-elect Barack Obama will not follow suit, telling a gathering of governors yesterday that "few issues facing America—and the world—are more urgent than combating climate change":