Cassini's Swoop over Enceladus: First Morsels of Science Coming Back Now

Bonnie J. BurattiBonnie J. Buratti,
Cassini scientist on the Visual and Infrared Mapping Spectrometer Team

Phew! We made it through the deepest swoop yet down into the plume of Enceladus, the encounter we call “E7” because it’s the seventh targeted flyby of Enceladus.

But now we have our work cut out for the next few weeks as we pore over the data, painstakingly analyzing every signal to understand the composition of the plume and its structure.

So far, we know the Visual and Infrared Mapping Spectrometer (VIMS) was able to get images and data in a variety of wavelengths of light and saw that the plume extends out to at least 1,000 kilometers (600 miles).

We also have striking images of the moon crowned by its glorious plume, which Cassini captured right before its plunge. The images illustrate well that the spectacular plume spewing from the south polar region is composed of many much smaller jets.
Raw image of Cassini's Nov. 2, 2009 flyby of Enceladus
The images and VIMS data both show that as the moon becomes less and less illuminated by the sun (similar to when our moon approaches the phase known as “new moon”), the plume gets much brighter. These data will be valuable for understanding the detailed structure of the plume and where it connects to the surface.

We have also learned that the density of the plume appears to be less than half of that predicted. Still, the heart of the plume measured on this flyby was about three times denser than the sparser parts of the plume we flew through previously.

There is more good news. We will be able to do the Enceladus flyby on April 28, 2010, on the spacecraft’s reaction wheels. This means we will be able to perform the Radio Science Subsystem experiment with Cassini’s main antenna to understand the interior of Enceladus under the hot south polar region.

During this experiment, antennas from the Deep Space Network (DSN) on Earth will be tracking the spacecraft to see how much Enceladus tugs on it.  By measuring this tug, scientists will be able to answer such questions as: How much is the shape of the moon deformed by tidal forces from Saturn?  Is there an unusually dense mass under the south pole? (The higher the mass, the larger the tug?)

We know that heating by tidal forces is what drives the plumes, but we’re not sure exactly how. In addition to a possible liquid subsurface ocean, Enceladus may be harboring a dense mass underneath its surface that helped to start and maintain the moon’s current activity.

Just wanted to share our excitement about the reams of data we’re combing through. Now, back to work!

8 thoughts on “Cassini's Swoop over Enceladus: First Morsels of Science Coming Back Now”

  1. greetings

    dark energy, dark matter. I thought it was a force of its own.I Cameron bailey lives in the universe. in physics theres are two forces the force applied on the wall by my hand and the wall pushing back on the my hand. Exactly so with dark matter and dark energy, this is the universe. Does dark energy and dark matter exist in places of voids they dont. the unverse has a bouncy exact with its own mass. Its improbable to have a place without a galaxy without the elements in the universe for dark energy and dark matter to exist. Ive read, heard and insisted that it was just to hard to accept that this force moved through a place where the force of weight was not a tidal force. the odds of this being true are very extreme. its like two sheets of paper side by side but understand the overview as a body of water wich in any direction the planets may move in a place where there is a rotational force. from this universe the body of water the galaxy will move and drag the plains of the universe interplacing them causing great cataclismic crashes .

  2. hi..Good luck for your team. I must say you did right thing.
    Your post is amazing. your way of telling things is great.I would like to read more from you.
    Thanks for sharing information.

  3. The density of the plume appears to be less than half of that predicted.Predictions always not true.

  4. The Visual and Infrared Mapping Spectrometer (VIMS) on-board the Cassini spacecraft is made up of two cameras in one:one is used to measure visible wavelengths, the other infrared.Combined, the two cameras gather a lot of information on the composition of moon surfaces, the rings, and the atmospheres of Saturn and Titan.Our instrument measures the characteristic colors of the many materials that make up planetary surfaces and atmospheres: rocks, ices — such as water, ammonia, methane — and organic compounds,” says Dr. Bonnie J.Buratti, VIMS Investigation Scientist.

  5. Hello Dr. Buratti,
    I am a sixth grader in United States, and i have visions of becoming a NASA space scientist when i grow up. Ever since i was very young i always adored space and astronomy. Now i daily visit the NASA website and check up on the latest news, and missions. I just read your article on Cassini, and I thought it was extremely interesting. I really LOVE the Cassini spacecraft, I came up with my email address using it, and i just wanted to comment on your article because i thought it was very interesting. Have a great day!

Comments are closed.