Space image shows the moon crossing the face of Saturn

Sep 1, 2015 15:40 GMT  ·  By

NASA's Cassini spacecraft left Earth in 1997 and reached the Saturn system many years later, in 2004. The probe has since kept busy studying the giant planet and its accompanying moons. 

A few months back, on May 21, the probe caught a glimpse of the Saturnian moon Dione just as it was circling the planet. The view, included in the gallery below, was released by NASA astronomers this Monday.

The probe obtained this image of Dione and part of Saturn from a distance of about 1.4 million miles (2.3 million kilometers) from the planet, the scale being 9 miles (14 kilometers) per pixel.

Having a planet's satellites cross its face when orbiting it is a phenomenon known as transit. Such events can help researchers better document the position and the movements of the orbs that form a specific system.

“By carefully timing and observing transits in the Saturn system, like that of Dione, scientists can more precisely determine the orbital parameters of Saturn's moon,” NASA astronomers explain.

Cassini is nearing the end of its mission

As mentioned, it was over a decade ago, in 2004, that NASA's Cassini probe reached the Saturn system and began exploring the planet and its satellites. Cassini is the fourth space probe to visit Saturn and the first to position itself in the planet's orbit.

Recently, on August 17 of this year, the spacecraft completed its last close flyby of Dione, during which it came as close as 295 miles (474 kilometers) to the orb and snapped close-ups of landscapes on its surface.

Mission scientists over at NASA say the Cassini probe will now move on to repeatedly dive through the space between the giant planet and its iconic rings.

Then, sometime in 2017, the spacecraft will run out of fuel and so will no longer be able to maintain its orbit around Saturn. When this happens, mission scientists will send it crashing into the planet.

The reason the probe will be instructed to plunge to its doom and collide with Saturn is that researchers want to make sure it won't impact one of the planet's moons and contaminate it if left to its own devices.

“If we plan to one day explore the surface of these moons, which may have some evidence of past or present extraterrestrial life on their surfaces, such a collision would contaminate said moon and possibly give us incorrect data,” NASA scientists explain.

Cassini has been studying Saturn and its moons since 2004 (8 Images)

Artist's rendering of NASA's Cassini probe at Saturn
Dione seen crossing the face of SaturnClose-up view of Dione
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