When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

The fact that our solar system has eight planets (unless you’re a Pluto apologist) is one of the first things we learn in our educational journey (anyone remember the “Blue’s Clues” planet song?). But ...

Estimating ages of specific events is one of the most difficult problems in astrophysics. While we have a precise (and probably accurate) age for the solar system, we do not have precise ages for each ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...