Podcaster: Richard Drumm
Title: Space Scoop: Countdown to Cassini’s Grand Finale
Organization:365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1711/
Description: Space scoop, news for children
Our understanding of Saturn’s rings is still evolving. A team of researchers using observations made in 2008 have managed to measure the brightness and temperature of Saturn’s rings in more detail than ever. More detail in mid-infrared images from the ground, that is.
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Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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Transcript:
This is the 365 Days of Astronomy Podcast. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
Countdown to Cassini’s Grand Finale
After spending nearly 13 years orbiting Saturn, the Cassini–Huygens mission will soon be over.
The Cassini spacecraft was launched from Earth in 1997. It then spent seven years traveling across the Solar System before arriving at Saturn.
A few months later the Cassini “mothership” released the Huygens probe onto Saturn’s mysterious moon Titan. This was humanity’s first landing in the outer Solar System!
We’ve done landings on Venus, the Moon and Mars before, but nothing this far out!
During its time on Titan, Huygens revealed several things which that moon has in common with Earth. It has a thick atmosphere and weather. On Titan it rains liquid methane instead of water, and has lakes of methane too.
However, it’s much colder than Earth, with a surface temperature of -180°C, or -292°F, which is twice as cold as our South Pole.
When Cassini left Huygens behind on Titan, it continued to explore Saturn, its rings, and its family of moons. The spacecraft spotted saltwater geysers spraying into space from the moon Enceladus.
This revealed an ocean hidden just a few kilometers beneath its icy surface. Using Cassini’s Ion Neutral Mass Spectrometer, or INMS, the scientists also detected hydrogen gas in the geysers.
This suggests that there’s a rocky seafloor that’s having a chemical reaction with the warm saltwater. These conditions indicate that Enceladus could very possibly be a home for alien life.
Now don’t get your hopes up! There won’t be any underwater cities or anything. Microbes or some sort of slime would by far be more likely.
But, after years of hard work, Cassini is now running low on fuel. Too bad it couldn’t scoop up some of that nice methane fuel on Titan, eh? You’d still need an oxidizer, though. Oh well.
Scientists have decided to end Cassini’s journey by plunging it into Saturn’s atmosphere on September 15th. This will eliminate any possibility of it accidentally crashing into any of Saturn’s moons, keeping them uncontaminated for future study.
To do this the mission planners had the spacecraft do one last fly-by of Titan. The precise trajectory they took meant that after leaving Titan the spacecraft would head over the North pole of Saturn and would dive down inside the innermost or D ring of the planet.
There isn’t even close to enough fuel aboard Cassini to make the maneuver on its thruster power alone. It needed Titan’s gravity to do the job.
Cassini will spend its final months performing a series of 22 daring dives between the planet and its famous rings. This is an area that’s never been explored before.
As of the time of this recording, it’s already done 2 of these ring-dives. So 20 are left to do!
Cassini has taken the first detailed photos of the rings closest to Saturn and the planet’s clouds. It also took close-up images of the edge of the polar hexagon to study how the hexagon formed.
It will also measure Saturn’s gravity to help scientists work out what the inside of the planet is like and how fast the winds are.
They will also be able to tell how massive the rings are for the first time, with the rings in one direction and the planet in another.
The Cosmic Dust Analyzer instrument will sample any ring dust particles it encounters and the INMS instrument will sample any molecules or atoms that are escaping from the planet’s atmosphere.
There’s also a chance that water vapor from the rings can be detected by INMS during the ring-plane crossings.
Cassini’s magnetometer will also probe Saturn’s surprisingly weak magnetic field better than it has before.
So, even in its final days Cassini is helping us to better understand our giant cosmic neighbor, the second prettiest planet!
You’re live on the prettiest, by the way. Just so ya know.
Hey, Here’s A Cool Fact:
Saturn is a gas giant, meaning it doesn’t have a solid surface. With the final dive, Cassini will sink down into its atmosphere and break apart. The deeper it sinks, the more heat and pressure it will feel, until it’s eventually crushed and roasted.
Then it will become part of Saturn and stay there forever.
Ooh! That’s a long time!
End of podcast:
365 Days of Astronomy
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The 365 Days of Astronomy Podcast is produced by Astrosphere New Media. Audio post-production by Richard Drumm. Bandwidth donated by libsyn.com and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. This year we will celebrate more discoveries and stories from the universe. Join us and share your story. Until tomorrow! Goodbye!