Jonathan Eberhart's name lives on in a new planetary-sciences award.

MESSENGER flew past Mercury for a third time on September 29. The spacecraft's mission will continue, with MESSENGER due to settle into a yearlong orbit around Mercury in March 2011. (p. 10)

The moon isn’t bone-dry: Its surface and interior contain an abundance of water, new studies reveal. (p. 10)

Researchers have found the first compelling evidence for a rocky planet beyond the solar system. (p. 8)

Newly released images provide graphic evidence that repairs have transformed the Hubble Space Telescope into a brand new observatory. (p. 7)

At least once a second, a dim, elderly star somewhere in the cosmos turns into a thermonuclear bomb. Briefly outshining its home galaxy, the explosion, known as a type 1a supernova, unleashes the equivalent of 1028 megatons of TNT — enough energy to destroy an entire solar system. Astronomers have marveled at these cosmic firecrackers for centuries. But so far nobody has explained in detail how these supernovas explode. Now, theorists are on the verge of attaining that understanding — and just in time, because astronomers are observing type 1a supernovas with a new urgency. In fact, t... (p. 22)

COVER STORY: Scientists probe debris trapped by white dwarfs to learn more about what faraway Earthlike planets are made of. (p. 22)

The next constellation of telescopes will dramatically extend and sharpen scientists’ view of the universe. (p. 30)

Four hundred years ago, astronomy embraced all that was visible. For Galileo, looking through his primitive telescope, the vistas included jewel-like stars, mountains on the moon, moons orbiting Jupiter and the glow of comet tails. Today astronomy is often about what cannot be seen. Astronomers have known for decades that stars and galaxies are mere baubles floating on a vast sea of dark matter. More recently, astronomy’s roster of Darth Vaders has expanded to include an even more mysterious force: dark energy, an entity that drives the universe to accelerate its expansion just when gra... (p. 22)

The launch of the European Space Agency’s Planck mission, set for late April or early May, will put into orbit a new tool —the microwave equivalent of polarized sunglasses — that may offer a view of the dawn of time. (p. 16)