(This was first published as an Op-Ed in the Arizona Daily Star and is the opinion of PSI director and CEO Amanda Hendrix.). When I was a third grader in 1976, I was struck by a Viking 2 image taken ...

The march of the planets around the Sun may seem interminable, but new research suggests that the likelihood of another star in our galaxy passing by and disrupting our Solar System is slightly higher ...

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Centaurs are mysterious icy small-bodies that are neither purely comets nor purely inactive asteroids, but they all orbit the Sun between Jupiter and Neptune in unstable orbits. They’re relatively ...

Ancient river valleys carved less than 3 billion years ago during Mars’ Early Amazonian Epoch dissect the flanks of the Martian volcano Alba Mons. To understand Mars’ more recent geologic and ...