by TIFFANY LIU
Plunging into its final year observing Saturn, the National Aeronautics and Space Administration’s Cassini spacecraft has contributed valuable information to the field of space science since its launch from Cape Canaveral in 1997.
“The initial goal was to return to Saturn. The planet was visited by the Voyager probes in the beginning of the 80s and once we flew by Saturn, a bunch of the scientists got together and said ‘this is an interesting place, we should go back and spend some time there and see what we could learn about this!’”, said Dr. Scott G. Edgington, Cassini deputy project scientist.
According to saturn.jpl.nasa.gov, Cassini has taken over 379,300 images, allowing scientists to view Saturn from different perspectives. The spacecraft has also found 10 new moons and provided many close-ups of the planet’s hurricane-like storms.
“So your cellphone has a camera on it and it is probably 16 megapixels, maybe 20 now. Cassini’s camera is 1 megapixel, and when you have a lot less pixels, you are going to get pictures that look like more squares rather than pictures. So you have to be up close and personal to these moons and rings in order to get a good picture,” said Edgington.
Despite its lack of advanced technology, the spacecraft has revealed some unusual information about Titan, Saturn’s largest and possibly most famous moon. With the help of the Huygens probe, named after astronomer Christian Huygens who was known for discovering Titan, scientists were able to discover ice dunes on the moon.
“On the surface of Titan, it is cold enough that the gas can be a liquid and we actually have measurements to show that it is methane that flows in the rivers and oceans and lakes,” said Edgington, “The geology is similar to that on Earth; you can imagine a river carving its way through rock, maybe forming a grand canyon so to speak. The same thing is happening on Titan, just with methane instead.”
Currently all of Cassini’s orbits have been outside of the rings of Saturn. However, starting Nov. 30, the team will begin pulling the spacecraft inward so that the orbits will be just outside of the rings. Then, after orbiting the outer edge of the rings 20 times, Titan will give the spacecraft a gravitational boost that will send it on a trajectory between the planet and the rings.
“If you look at Saturn, you can see the gap between the planet and the rings. We’re going to fly through that gap 22 times. So imagine a rollercoaster ride and you can go through that gap at 35km/sec.” said Edgington, “At this speed, it will take about an hour from the poles of Saturn, so we’re really going fast.”
After those 22 times, Cassini will receive another gravity boost from Titan and that will send it right into the planet. During this process, the radio antenna will be pointed towards the Earth, with the instruments on, in order to project as much information as it can.
“At some point, the atmosphere will cause the spacecraft to basically turn, and we will lose radio signal. Then the spacecraft will keep plummeting into Saturn’s atmosphere and things will start melting, breaking off, and eventually…there will be no more spacecraft,” said Edgington.
Over the years, data from Cassini has influenced scientists’ views on where life might exist. Although living organisms have not yet been discovered, conditions that would be favorable for life—such as water—have been detected.
Click at the link attached to look at a Q&A with Dr. Scott G. Edgington: https://wordpress.com/post/schurrscroll.com/5094