Criss-Crossed Rings
At first glance, Saturn’s rings appear to be intersecting themselves in an impossible way. In actuality, this view from NASA’s Cassini spacecraft shows the rings in front of the planet,...
Astronomers discover a giant world – but is it a planet?
When is a planet not a planet?’ is a lot more than the beginning of a poor joke at a drunken astronomers’ Christmas party (but we laughed nonetheless). It is actually a serious question that cuts to...
Astronomers measure the motions of stars in a nearby galaxy
When you look up at the night sky, the stars appear fixed — but things are not as they appear. In fact, every star in our galaxy is moving. While it’s easy for astronomers to measure whether a star...
The story of the fossil meteorites
Visitors Imagine a traveler from outer space, hurtling through the atmosphere of a bright, blue planet to land upon a world populated by strange, multi-tentacled creatures. It sounds like something...
Space missions that dodged disaster
A tiny problem can have huge consequences for a space mission. Sometimes a huge endeavor hinges on the smallest detail — three seconds’ worth of fuel, an engineer’s stubbornness, a speck of paint,...
Did life hitchhike through the Solar System?
Astronomers have long believed that asteroid (or comet) impacts were the only natural way to transport life between planets. However, a new study published November 6 in Astrobiology suggests...
Cassini’s farewell to Saturn
Cassini’s wide-angle camera recorded 80 images in just over two hours on Sept. 13 for a final full mosaic of Saturn. This view includes 42 of those images taken in red, green and blue spectral...
The first known interstellar interloper
For an example of the prophetic powers of science, check out the February 1997 issue of Astronomy. In the article “Seeking Rogue Comets,” planetary scientist Alan Stern confidently predicted that...
