NASA's Cassini spacecraft will end its nearly two-decade space journey when it performs its "grand finale" and dives into Saturn's atmosphere on Sept. 15.

Here's a look at some of the best photos taken by Cassini during its mission.

Cassini Saturn

(NASA/JPL-Caltech)

Rings of ice

The photo below — taken on July 9, 2004, just over a week after entering Saturn's orbit — shows the planet's rings in ultraviolet.

According to NASA, the image indicates there is more ice in the outer part of the rings compared to the inner part, which could provide clues about their origins and evolution.

saturn a ring

(NASA/JPL/University of Colorado)

Dark side of Saturn

With Saturn blocking the glare of the sun, Cassini captured the planet suspended in darkness on Sept. 15. 2006.

The panoramic shot was created by combining 165 images taken in the span of nearly three hours. Colour was digitally added to resemble natural colour.

If you look closely to the left of Saturn, you can see a pale dot just inside one of the outer rings — that pale dot is Earth.

cassini saturn

(NASA/JPL-Caltech/Space Science Institute)

Lunar geysers

Plumes of water ice and organic particles are seen emanating from the south pole of Saturn's moon, Enceladus, in the image below, a mosaic created from two images captured by Cassini on Nov. 21, 2009.

The plumes come out from what scientists call "tiger stripes," fissures along the moon's icy surface. Scientists also believe there is an ocean of water underneath the surface of Enceladus and that the moon is a promising lead in the search for life outside of Earth.

Enceladus

(NASA/JPL/SSI)

Fab 5

Cassini captured a quintet of Saturn's moons on July 29, 2010.

From left are Janus, Pandora, Enceladus, Mimas and Rhea. Cassini was about 1.1 million kilometres away from Rhea and 1.8 million kilometres from Enceladus when it took the photo.

saturn moons

(NASA/JPL-Caltech/Space Science Institute)

Winter is coming

Titan, one of Saturn's moons that measures about 5,200 kilometres across and larger than the planet Mercury, is dwarfed by the planet in the first photo below taken on May 6, 2012.

The blue hue on Saturn's northern hemisphere is seen fading as the planet goes into spring, while the same azure haze gets darker in the southern hemisphere as it prepares for winter — the latter can be seen more clearly in the second photo below, taken on July 29, 2013. Both photos are natural colour or as human eyes would have seen Saturn.

Scientists believe the blue haze is caused by methane absorption and scattering by molecules and smaller particles in the atmosphere, which they say glows brighter when there is a reduction in ultraviolet light from the sun.

titan saturn winter

(NASA/JPL-Caltech/SSI)

saturn winter

(NASA/JPL-Caltech/Space Science Institute)

'The Day the Earth Smiled'

On July 19, 2013, Cassini captured Saturn, its rings, Earth and our moon all in one photo during a planetary eclipse of the sun — an event NASA dubbed "The Day the Earth Smiled."

Earth is seen off to the centre right in the photo below — taken about 1.44 billion kilometres away — with an arrow pointing to its location, the moon off to the right of Earth. See here for a closer look.

day the earth smiled

(NASA/JPL-Caltech/Space Science Institute)

Above and beyond

Cassini soared above Saturn on Oct. 10, 2013, and the natural colour mosaic image below was created from 36 of the photos taken.

Saturn's six-sided weather pattern, known as the hexagon, is visible on its north pole.

saturn

(NASA/JPL-Caltech/SSI/Cornell)

Distant second

Titan, Saturn's largest moon, is seen behind Rhea, the planet's second largest, in the Dec. 23, 2013, photo below.

The image is natural colour, taken about 1.8 million kilometres away from Rhea and 2.5 million kilometres from Titan.

titan rhea

(NASA/JPL-Caltech/Space Science Institute)

Knocked up

Saturn's moon, Epimetheus, is seen in the May 9, 2016, photo below — taken about 2,700 kilometres from Epimetheus and with Saturn in its background.

The moon had been blasted and pelted by debris over years, leaving it misshapen and full of craters.

Epimetheus

(NASA/JPL-Caltech/Space Science Institute)

Rise and shine

The night side of the Tethys moon is illuminated by sunlight reflecting off Saturn — a phenomenon known as Saturnshine — in the May 13, 2017, photo below.

The photo was taken about 1.2 million kilometres from Saturn and 1.5 million kilometres from Tethys.

Tethys

(NASA/JPL-Caltech/Space Science Institute)