New observations suggest that the dwarf planet Makemake is surrounded by faintly glowing methane gas. Scientists are unsure ...

A kindergartener in 2005 and a kindergartener in 2006 would have learned very different facts about the number of planets in the solar system. 2006, of course, was the year Pluto was reclassified as a ...

The word “planet” came from the ancient Greek words that mean “wandering star.” That makes sense, because for thousands of years, people have watched planets change position in the night sky – unlike ...

Pluto hasn't been a planet for almost 20 years. In the early 2000s, scientists discovered several objects of a similar size to Pluto. So, during the summer of 2006, members of the International ...

Animation made from still images of Ceres taken by Dawn on Feb. 4, 2015. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI New images from NASA's Dawn spacecraft reveal ...

In 2015, scientists got their best glimpse yet of dwarf planets, when two NASA spacecraft visited distant worlds. In March, the Dawn mission arrived at Ceres, which lies in the asteroid belt between ...

This month binocular and small telescope observers of Colorado skies will have a unique opportunity to observe a peripheral player in the ongoing controversy over the status of the outer solar system ...

In 2006, the International Astronomical Union (IAU) voted on the definition of a planet. Famously, Pluto no longer met the criteria and was demoted to a dwarf planet. Things have been a bit of a mess ...

If you woke up Thursday morning and sensed something was different about the world around you, you’re absolutely right. Pluto is no longer a planet. The International Astronomical Union, wrapping up ...

Am I seeing spots before my eyes? New images from the Dawn spacecraft show lots more detail on the asteroid Ceres. We're getting closer and closer to Pluto. Asteroid / dwarf planet Ceres mystery white ...