16 March 2009, 10:06 AM ET
Pluto's status nowadays as a so-called plutoid and former planet may be official in the latest textbooks, but someone forgot to tell the astronomers.
04 March 2009, 05:05 PM ET
An in-depth study of Pluto’s atmosphere reveals it is warmer, and contains more methane, than previously thought.
29 October 2008, 04:24 PM ET
Nine mementos are riding to Pluto aboard NASA's New Horizons spacecraft.
17 October 2008, 06:58 AM ET
The next three weeks will present an excellent opportunity to view Mercury.
10 October 2008, 06:28 AM ET
Neptune is much too faint to be perceived without any optical aid.
19 September 2008, 04:18 PM ET
The International Astronomical Union (IAU) announced the name of the solar system's fifth dwarf planet.
19 August 2008, 06:45 AM ET
The word "planet" has meant many different things over the millennia and even still its definition is evolving.
15 August 2008, 09:10 AM ET
Two planetary scientists duke it out over Pluto.
05 August 2008, 06:48 AM ET
Scientists will convene this month to figure out what makes an object a planet.
31 July 2008, 06:41 AM ET
SETI invites scuba divers on an expedition to a destination of your choice.
28 July 2008, 07:00 AM ET
With planets, dwarf planets and plutoids, the solar system's getting crowded.
20 July 2008, 02:51 PM ET
A dwarf planet beyond Neptune has been renamed Makemake.
19 June 2008, 10:38 AM ET
Pluto went from planet to dwarf planet and the latest name, plutoid.
18 June 2008, 10:21 AM ET
Its existence would satisfy the long-held hopes and hypothesis for a "Planet X" envisioned by scientists and sci-fi buffs alike.
12 June 2008, 03:38 PM ET
Disgruntled scientists renewed their vows this week to call Pluto a planet despite an international governing body's latest ruling to reclassify the tiny world.
11 June 2008, 02:36 PM ET
The Pluto-bound New Horizons spacecraft crossed the orbit of Saturn on June 8.
11 June 2008, 10:30 AM ET
The IAU decides on a name for Pluto and other round objects way out there.
29 November 2007, 06:39 AM ET
Thoughtful astronomy books abound for the holiday gift-giving season.
26 November 2007, 06:44 AM ET
Colossal impacts may have bowled over remote, frozen moons
12 October 2007, 01:48 PM ET
New images bring Pluto and its moons into sharper view.
09 October 2007, 10:38 AM ET
Brief fly-by of New Horizons spacecraft captures an unusually calm Jupiter.
01 October 2007, 06:35 AM ET
Puffy debris disk around three nearby stars could harbor Pluto-sized planets-to-be.
17 July 2007, 04:20 PM ET
Slushy geysers on Plutoâ€™s moon Charon coat the tiny world in ice crystals and make it the outer solar system equivalent of an ice machine.
14 June 2007, 02:00 PM ET
The dwarf planet that forced astronomers to strip Pluto of its planethood is not only bigger than the former ninth planet, but also much more massive, a new study finds.
01 May 2007, 02:01 PM ET
NASA is presenting a series of stunning new images today of the Jupiter system snapped by its probe New Horizons earlier this year.
15 March 2007, 06:08 AM ET
Telescopes all over the southwest United States will turn toward Pluto as it meanders across the face of a star in the constellation Sagittarius on Sunday. The observations could help researchers better understand the diminutive world's atmosphere.
09 March 2007, 03:15 PM ET
The state of New Mexico State could effectively secede from the astronomical community if a resolution to call Pluto a planet is passed.
28 February 2007, 01:59 PM ET
We’ve been waiting for a long time and, finally, we’re on our way. But there are no “direct” flights to Pluto—the only way to get there is to first swing by Jupiter.
28 February 2007, 07:16 AM ET
Visions of a volcanic plume spewing out of Jupiter’s moon Io and a swirling storm were among the first images returned by a NASA probe as it approached an early-morning swing past the gas giant today.
18 January 2007, 04:57 PM ET
A NASA probe hurtling towards Pluto will hit the accelerator next month when it flies past the planetary giant Jupiter.
12 January 2007, 06:25 AM ET
NASA’s New Horizons probe bound for Pluto is headed for a Jupiter flyby, its camera eyes wide open, in preparation for its swing out towards the fringe of the solar system.
30 November 2006, 06:43 AM ET
BOULDER, Colorado -- Now heading outward on its lengthy trek to tiny Pluto, NASA’s New Horizons spacecraft is on course to zip by gigantic Jupiter early next year.
29 November 2006, 02:15 PM ET
A NASA spacecraft hurtling away from Earth has caught the first glimpse of its distant destination: the dwarf planet Pluto.
21 November 2006, 06:07 AM ET
The Great Pluto War in Prague failed to forge an accepted definition, but it succeeded in alienating astronomers and deepening rifts along theoretical and national lines.
15 November 2006, 05:43 PM ET
Space.com explains information about the planet Pluto.
23 October 2006, 09:43 AM ET
Pluto may be no more than a distant, icy rock in the minds of astronomers who stripped it of planethood, but its downgrade to a "dwarf planet'' has created a teachable moment in classrooms nationwide.