Over 30 years, Pepperberg taught Alex not just words, but how to count, recognize shapes and colors. Read the brainy parrot's last words.

A recent study suggests that, by the 2080s, extreme summer warming in cities such as Chicago and Atlanta could hover above 100 degrees Fahrenheit. Read more.

David Carroll is getting closer to creating a new kind of solar cell, one made of plastic that would be lightweight, flexible, and more efficient than the more familiar silicon solar cells. Read more about how nanotechnology is improving solar cell efficiency.

He has created a device that could help doctors identify what are called "oncoproteins." This research might eventually enable doctors to better diagnose and treat early-stage cancer.

Jupiter, Saturn, Uranus and Neptune - the giant outer worlds in our sun's family - all have many moons. Since the late 1990s, astronomers have found that most moons of these outer planets are 'irregular moons,' probably captured from heliocentric orbits. In many cases, the moons orbits are so tilted that they go around their planets backwards.

In 2007, when astronomers measured the mass of the dwarf planet Eris, they found that it's 27% more massive than Pluto. Astronomer Mike Brown, who discovered Eris, said, "We got lucky in that Eris has a moon going around it. And by tracking the orbit of the moon around the dwarf planet, you actually get to weigh how much the dwarf planet weighs."

They call it 'Einstein's dream come true.' In 2004, astronomers reported the discovery of the first known double pulsar system. Both pulsars have masses greater than that of our sun, but are only 20 kilometers across. Their orbital separation is less than the sun's diameter, and they orbit each other in only 2.4 days. This pulsar pair provides confirmation for Einstein's theory of gravity.

BlogBurst rewarded EarthSky Communications for the 2nd quarter of 2007 for ranking second on BlogBurst's Leaderboard of most distributed blogs.

Did Earthly life originate on Mars? Robert Hazen, a scientist at the Carnegie Institution, talked to Earth & Sky about where signs of life off Earth are most likely to be found.

Some astronomers believe that the first signs of life on alien worlds might come from the gentle breathing out of plants. Read more about alien plants here.