Monitoring Titan’s Northern Lakes and Seas

Credit: NASA / JPL / edited by Val Klavans
Credit: NASA / JPL / edited by Val Klavans

Cassini’s 94th flyby is another encounter with Titan! Feel free to follow along with the latest information and images from the flyby on my Facebook event page: Titan (T-93) Flyby(Why is it the 94th flyby and not the 93rdHere’s why.)

Quick Facts:

  • Name Titan (T-93) Flyby
  • Date July 26, 2013 [SCET]
  • Altitude 870 miles (1,400 kilometers)
  • Speed 13,000 mph (5.8 km/sec)
  • Goal To monitor Titan’s nothern lakes and seas

What will we be able to see?

Cassini’s camera system, also known as the Imaging Science Subsystem (ISS) instrument onboard the Cassini spacecraft, will concentrate on imaging Titan’s north polar region and its southern hemisphere during this flyby.

As Cassini approaches Titan, ISS will image Ganesa Macula and the terrain to its northeast as well as the lakes Feia Lacus and Abaya Lacus. Ganesa Macula is a dark, circular feature on Titan, 180 kilometers (110 miles) wide. It crudely resembles steep-sided volcanic domes on Venus. It was therefore hypothesized initially to be a cryovolcanic feature. Read more about Ganesa Macula here.

The circle shows the location of Ganesa Macula Credit: NASA / JPL / ASI
The circle shows the location of Ganesa Macula
Credit: NASA / JPL / ASI
This shows the location of Titan's lakes Feia Lacus and Abaya Lacus Credit: NASA / JPL / USGS / edited by Val Klavans
This shows the location of Titan’s lakes Feia Lacus and Abaya Lacus
Credit: NASA / JPL / USGS / edited by Val Klavans

ISS will also take high-resolution images of Ontario Lacus, Titan’s ”footprint” lake near its south pole, as the Sun sets for southern winter.

Titan's "Footprint": Ontario Lacus Credit: NASA / JPL-Caltech / ASI
Titan’s “Footprint”: Ontario Lacus
Credit: NASA / JPL-Caltech / ASI

What science will be coming out of this flyby?

Cassini’s Visible and Infrared Mapping Spectrometer (VIMS) instrument will be imaging Titan’s north polar lakes and seas: Punga Mare, Ligeia Mare, and the lakes and playas to the south and east of Ligeia Mare, like Uvs Lacus. (Punga Mare and Ligeia Mare are the second and third largest known bodies of liquid on Titan, respectively.) Are Titan’s lakes and seas evaporating and getting smaller, staying the same, or getting larger? From this flyby, we may find more insight into how Titan’s bodies of liquid evolve as a result of seasonal change.

Close up of Titan’s North Polar Lakes and Seas Credit: NASA/JPL/USGS
Close up of Titan’s North Polar Lakes and Seas
Credit: NASA/JPL/USGS

VIMS will also image across the equatorial Belet dune field, covering a series of faculae (bright regions within Titan’s dune fields). Belet, also known as Titan’s “sand sea” is made of vast hydrocarbon dunes. Belet’s dunes have even been compared to Earth’s Oman dunes in Yemen and Saudi Arabia. (Read more about that here.) This imaging will include areas affected by the Arrow Storm in September and October 2010, though from previous ISS and VIMS imaging, the region has returned to the way it looked before the storm.

"Belet Below the Haze" Credit: NASA / JPL / SSI / edited by Val Klavans
“Belet Below the Haze”
Credit: NASA / JPL / SSI / edited by Val Klavans
Titan's Arrow-Shaped Storm Credit: NASA / JPL / SSI
Titan’s Arrow-Shaped Storm
Credit: NASA / JPL / SSI

Cassini’s Composite Infrared Spectrometer (CIRS) instrument will also be checking in on Titan during this flyby. CIRS will stare at Titan in order to acquire mid-infrared spectral and temperature information about Titan’s atmosphere.

Images

Now that all of the images have come in from the flyby, let’s take a look!

Here’s a view of Titan’s haze layers in true color, imaged by the ISS. Titan’s upper haze layers appear blue, while its main atmospheric haze appear orange in this view. The difference in color is most likely due to particle size rather than composition. The blue haze probably consists of smaller particles than the orange haze. Find out more about this image here.

Titan's haze layers Credit: NASA / JPL / SSI
Titan’s haze layers
Credit: NASA / JPL / SSI / composite by Val Klavans

This view from the ISS gives us a feeling as if we are staring down on Titan’s north pole along with Cassini. That large circle is Titan’s north polar hood, a cap centered on the north pole made of dense gaseous hydrocarbon haze. The hood has been changing its appearance with Titan’s change in seasons. Read more about that here.

Staring down on Titan's north polar hood Credit: NASA / JPL / SSI / composite by Val Klavans
Staring down on Titan’s north polar hood
Credit: NASA / JPL / SSI / composite by Val Klavans

The ISS used its infrared filter to reach down below the haze to Titan’s surface to image its lakes and seas. These images below show Titan in the infrared. If you look towards the north pole, you will see Titan’s north polar lakes and seas. (The “N” shows the direction of north on Titan.)

Three images of Titan in the infrared Credit: NASA / JPL / SSI / edited by Val Klavans
Three images of Titan in the infrared
Credit: NASA / JPL / SSI / edited by Val Klavans

The ISS also imaged a close up of a section of Ligeia Mare, Titan’s second largest sea. Below is a comparison of that close up taken during the flyby with the Cassini’s RADAR image of Ligeia taken nearly 6 years prior.

Left: A section of Ligeia Mare (imaged by ISS) during this flyby Right: All of Ligeia Mare (imaged by RADAR) in 2007 Credit: NASA / JPL / SSI /
Left A section of Ligeia Mare (imaged by ISS) during this flyby
Right All of Ligeia Mare (imaged by RADAR) in 2007
Credit: NASA / JPL / SSI / USGS / montage by Val Klavans

If you’d like to see more images from the flyby, check out my Facebook event page.

Sources

Want to know even more about this flyby? Check out Cassini Imaging Central Laboratory for Operations’ (CICLOPS) website with information on Cassini’s activities every day: Rev195: Jul 15 – Aug 5 ’13 and a quick overview of this flyby from Cassini’s main website: Titan Flyby (T-93): Monitoring the Lakes. (All of my information from this post, unless otherwise specified, comes from these sources.)

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