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 ...

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 ...

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 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 ...

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 ...

Ceres is the largest object in the asteroid belt, and NASA’s Dawn spacecraft will arrive there on March 6. Pluto is the largest object in the Kuiper belt, and NASA’s New Horizons spacecraft will ...

Watch live online as the dwarf planet Ceres swoops in front of the 'grand design' spiral galaxy Messier 100 this weekend. When you purchase through links on our site, we may earn an affiliate ...

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My Very Educated Mother Just Served Us Nine Pizzas. Back in the day, that was a popular acronym to help children remember the names of the nine planets in the solar system. Mercury, Venus, Earth, Mars ...

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 ...