You are here

More Moon and Planets

April 25, 2016

The spacecraft that’s provided the most extensive look at any of the solar system’s giant planets is setting up its own demise. It’s changing its orbit through a series of rocket firings and encounters with a big moon. Eventually, that’ll lead to the craft’s end.

Cassini entered orbit around Saturn in 2004. It deployed a probe that touched down on the largest moon, Titan. Since then, it’s made dozens of close approaches to Titan and several other moons, snapped tens of thousands of pictures, and observed Saturn’s rings and magnetic field.

The craft is running out of fuel, though, and scientists don’t want to risk it contaminating Titan or Enceladus — two moons that have the basic ingredients for life.

So Cassini is being maneuvered into a new orbit. Several rocket burns over the last few months have been followed by close encounters with Titan. Those approaches use Titan’s gravity to fling the craft out of the plane of the rings and moons, and above Saturn’s poles.

The orbit will be changed again next year, allowing Cassini to pass closer to Saturn than ever — between the planet and the inner edge of its rings. After 22 of these approaches, Cassini will plunge into Saturn’s atmosphere next September — bringing its mission to a close.

Look for Saturn to the lower right of the Moon at first light tomorrow. It looks like a bright golden star. The even brighter planet Mars is about the same distance to the lower right of Saturn.


Script by Damond Benningfield

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.