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 ...

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 ...

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 ...

NASA’s Dawn spacecraft recently made its closest flyby of Ceres, sending back the most detailed views of its surface. Ceres is the largest object in the Main Asteroid Belt located between the orbits ...

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 ...

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 ...

Pluto, Ceres, Eris, Makemake and Haumea have another possible candidate to consider for their dwarf planet squad. A team of researchers have discovered the new, tiny candidate deep within the Kuiper ...

Pluto’s exaggerated and wildly varying tilt may have helped give the dwarf planet rivers and lakes of liquid nitrogen and an atmosphere that, at times, has exceeded that of Mars, according to ...

The gray surfaces of the dwarf planet Ceres (the asteroid belt's largest resident) and Pluto's biggest moon, Charon, both show signs of containing forms of graphite, the material in pencil lead. When ...

Water is a critical ingredient for life. And with the discovery of water ice in other planetary objects, scientists are abuzz over the probability of the presence of — and the prospect of supporting — ...