Saturn probe Cassini captures first-ever pics of Uranus

NASA's Cassini spacecraft has clicked its first-ever image of the pale blue ice-giant planet Uranus in the distance beyond Saturn's rings.

When this view was obtained, Uranus was nearly on the opposite side of the Sun as seen from Saturn, at a distance of approximately 28.6 astronomical units from Cassini and Saturn. An astronomical unit is the average distance from Earth to the Sun, equal to 93 million miles (150 million kilometers). At their closest-once during each Saturn orbit of nearly 30 years-the two planets approach to within about 10 astronomical units of each other.

In addition to its aesthetic appeal, Cassini's view of Uranus also serves a practical purpose.

Scientists working on several of Cassini's science investigations expect that they will be able to use images and spectra from these observations to help calibrate their own instruments.