Great Image: The Solar System's Smaller Worlds

The image above recently posted by The Planetary Society is labeled "Every round object in the solar system under 10,000 kilometers in diameter, to scale." This impressive collection represents 2 planets, 18 or 19 moons, 1 or 2 asteroids, and 87 "trans-Neptunian" objects. 

You can see how the moons Ganymede and Titan outside Mercury, and our own Moon exceeds the size of Pluto.

The image below shows the objects we have already visited, including the recently explored Ceres and Pluto. We are making great progress in our explorations of the solar system. 

Image Credit: Montage by Emily Lakdawalla. Data from NASA / JPL, JHUAPL/SwRI, SSI, and UCLA / MPS / DLR / IDA, processed by Gordan Ugarkovic, Ted Stryk, Bjorn Jonsson, Roman Tkachenko, and Emily Lakdawalla.

First Helicopters Exploring Planets, And Now Submarines!

Recently I wrote about plans to use a helicopter on Mars to assist the rover.  Well, NASA is thinking beyond land and air, and it is now considering the seas.  The proposed target would be the methane seas of Saturn's moon Titan.  Here is a video from earlier this month showing how it would work.  It appears that the video captured the media's attention, though NASA was talking about this new approach in June of last year, stating:

We propose to develop a conceptual design of a submersible autonomous vehicle (submarine) to explore extraterrestrial seas. Specifically, to send a submarine to Titan’s largest northern sea, Kraken Mare. This craft will autonomously carry out detailed scientific investigations under the surface of Kraken Mare, providing unprecedented knowledge of an extraterrestrial sea and expanding NASA’s existing capabilities in planetary exploration to include in situ nautical operations. Sprawling over some 1000 km, with depths estimated at 300 m, Kraken Mare is comparable in size to the Great Lakes and represents an opportunity for an unprecedented planetary exploration mission.

The approach makes perfect sense given the destination in mind. And as with helicopters, it adds a fascinating dimension to our robotic travels.  I wonder what else NASA has up its sleeves. 

Great Image: Titan's Shining Seas

While exoplanets are the interest du jour, our own solar system continues to fascinate. Take Titan, Saturn's moon and the subject of numerous Cassini spacecraft observations as well as investigation by the Huygens probe 10 years ago.  The image above shows an artificially colors view of the moon's methane seas taken last summer (our summer, that is).  One more intriguing feature in the far reaches of our solar system that Cassini continues to monitor for our behalf.

Here is NASA's story concerning the image:

Why would the surface of Titan light up with a blinding flash? The reason: a sunglint from liquid seas. Saturn's moon Titan has numerous smooth lakes of methane that numerous passes of our Solar System's most mysterious moon, Cassini has revealed Titan to be a world with active weather -- including times when it rains a liquefied version of natural gas.

Image Credit: VIMS Team, Univerity of Arizona, ESA, NASA

Great Image: Titan and Saturn's Rings

With other things happening around the solar system, we can forget about the ongoing mission of NASA's Cassini spacecraft as it orbits Saturn.  After 10 years, we are still getting valuable information and images from this distant aircraft.  Here is NASA's story for this image:

When orbiting Saturn, be sure to watch for breathtaking superpositions of moons and rings. One such picturesque vista was visible recently to the robot Cassini spacecraft now orbiting Saturn. In 2006 April, Cassini captured Saturn's A and F rings stretching in front of cloud-shrouded Titan. Near the rings and appearing just above Titan was Epimetheus, a moon which orbits just outside the F ring. The dark space in the A ring is called the Encke Gap, although several thin knotted ringlets and even the small moon Pan orbit there.

Cassini celebrated its 10th year in orbit back in June, when NASA highlighted some of its discoveries over this period:

-- The Huygens probe makes first landing on a moon in the outer solar system (Titan)
-- Discovery of active, icy plumes on the Saturnian moon Enceladus
-- Saturn's rings revealed as active and dynamic -- a laboratory for how planets form
-- Titan revealed as an Earth-like world with rain, rivers, lakes and seas
-- Studies of Saturn's great northern storm of 2010-2011
-- Studies reveal radio-wave patterns are not tied to Saturn's interior rotation, as previously thought
-- Vertical structures in the rings imaged for the first time
-- Study of prebiotic chemistry on Titan
-- Mystery of the dual, bright-dark surface of the moon Iapetus solved
-- First complete view of the north polar hexagon and discovery of giant hurricanes at both of Saturn's poles

Visit the Cassini mission site for more on the spacecraft as well as additional images.

Top Image Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA