Planets, Pluto | featured news

Astronomers have obtained an important first look at the dwarf planet Makemake - finding it has no atmosphere. One of five such dwarfs in our Solar System including former planet Pluto, Makemake had until now eluded study. But in April 2011, it passed between the Earth and a distant star, and astronomers used seven telescopes to study how the star's light was changed.

Pluto may have been kicked out of the planet club, but it has gained yet another companion. Scientists announced Wednesday the discovery of the smallest moon yet around the icy orb, bringing the tally of known moons to five. "We're not finished searching yet," said Hal Weaver of Johns Hopkins University, who thinks there may be more lurking.

But Dr. Brown has a unique distinction: He was, for a few hours in 2005, the only person on Planet Earth to know that the standard nine-planet solar system model was going to require rejiggering. He had just discovered a 10th potential planet, but he had also come to see that neither Pluto nor this new heavenly body (first nicknamed Xena, then officially named Eris) really measured up to the other eight.

Venetia Phair, who was 11 years old when she suggested Pluto as the name of the newly discovered planet, has died in England. She was 90.