Cassini probe skims Saturn's atmosphere as it prepares for final 'death dive' phase of its mission
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NASA's Cassini probe has executed the first of five dives into the atmosphere of Saturn as it enters the final phase of its historic mission .
Before being deliberately crashed into the giant planet early next month, NASA is attempting to capture as much information about Saturn's atmosphere as possible.
This dive brought the craft down to 1,600km (1,000 miles) above Saturn's clouds, allowing the space agency to gather data on the chemical makeup of the atmosphere.
The team hopes that the next four dives will be even lower, providing Cassini can manage the buffeting effects of entering and exiting the atmosphere.
(Image: Rex Features)
"Thanks to our past experience, the team is confident that we understand how the spacecraft will behave at the atmospheric densities our models predict," explained Earl Maize, Cassini project manager at NASA's Jet Propulsion Laboratory (JPL).
Experts currently believe Saturn's upper-atmosphere is about 75% hydrogen. The rest is made up of helium with trace amounts of other gases.
Cassini will send back the results from this first dive on Tuesday.
"As it makes these five dips into Saturn, followed by its final plunge, Cassini will become the first Saturn atmospheric probe," said Linda Spilker, a Cassini project scientist at JPL.
"It's long been a goal in planetary exploration to send a dedicated probe into the atmosphere of Saturn, and we're laying the groundwork for future exploration with this first foray."
(Image: NASA)
Cassini has been orbiting Saturn for over a decade and is set to make its final "death dive" into the planet on September 15. NASA is deliberately crashing Cassini into Saturn so it can capture data on its final plunge.
The space agency is also keen to avoid any potential contamination of Saturn's moons, Titan and Enceladus, as they could harbour life.
What's the story of Cassini?
Following the launch in 1997, Cassini spent seven years flying through the Solar System to get to Saturn. During this time it conducted two flybys of Earth, one of Venus and one of Jupiter.
The craft also released a small probe, Huygens, that landed on Saturn's moon Titan on January 14, 2005. It's the first time humans have landed a craft in the outer solar system.
(Image: NASA/Wikipedia)
Saturn's moons Enceladus and Titan are believed to be geologically active - and could even support life thanks to vast subsurface oceans. That's part of the reason that NASA wants to avoid crashing Cassini into either of them.
Since arriving at Saturn (it travels at 2,040m/s), the 6.8-metre high spacecraft has collected huge amounts of data and snapped many pictures of one of the most fascinating planets in the solar system.
What has Cassini discovered?
In 2013, Cassini captured high resolution images of Saturn lit up by the sun.
The images are the first to show Saturn's moons and rings, Earth, Venus and Mars all in one shot, with others showing just a few.
It was created by merging 141 shots to give a "natural-colour view" and it sweeps 404,880 miles across Saturn's system.
(Image: NASA)
One of the most interesting discoveries was made when Cassini confirmed that hydrogen gas exists on Saturn's moon Enceladus.
Plunging the craft down over Saturn's moon Enceladus , NASA was able to capture samples of water plumes erupting from the surface.
Analysis of the samples collected revealed that there was hydrogen gas present in the water that exists under the icy surface.
The presence of hydrogen in the moon's ocean means that microbes (if any exist there) could use it to obtain energy by combining the hydrogen with carbon dioxide dissolved in the water.
This chemical reaction, known as "methanogenesis" because it produces methane as a byproduct, is at the root of the tree of life on Earth, and could even have been critical to the origin of life on our planet.
(Image: NASA)
It's not conclusive proof of alien life - but the discovery is helping evolve our understanding of Enceladus.
"This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate at Headquarters in Washington.
"These results demonstrate the interconnected nature of NASA's science missions that are getting us closer to answering whether we are indeed alone or not."