The not-planets

Filed under Enceladus, Dione, Tethys, Titan, Rhea, Iapetus, Dawn, Saturn's moons, Mimas, Jupiter's moons, Io, Pluto, Europa, scale comparisons, Ganymede, amateur image processing, Charon, Callisto, the Moon, asteroid 4 Vesta, New Horizons, Cassini, Galileo, asteroid 1 Ceres, pretty pictures, Triton, Neptune's moons, Uranus' moons

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The solar system contains dozens of objects that are large enough for self-gravity to make them round, and yet are not considered planets. They include the major moons of the planets, one asteroid, and many worlds in the Kuiper belt. The ones that we have visited with spacecraft are shown here to scale with each other. A couple of items on here are not quite round, illustrating the transition to smaller, lumpier objects.

Montage by Emily Lakdawalla. The Moon: Gari Arrillaga. Other data: NASA/JPL/JHUAPL/SwRI/UCLA/MPS/IDA. Processing by Ted Stryk, Gordan Ugarkovic, Emily Lakdawalla, and Jason Perry.

Here is a version without text.

Montage by Emily Lakdawalla. The Moon: Gari Arrillaga. Other data: NASA/JPL/JHUAPL/SwRI/UCLA/MPS/IDA. Processing by Ted Stryk, Gordan Ugarkovic, Emily Lakdawalla, and Jason Perry.

The not-planets (without text)

Original image data dated on or about July 13, 2015.

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. For uses not allowed by that license, contact us to request publication permission from the copyright holder: Emily Lakdawalla : Gordan Ugarkovic : Jason Perry : Ted Stryk

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Comments:

Steve williams: 07/14/2015 02:42 CDT

There is a line cutting through Iapetus. It looks like an error in the processing to go into the montage, because it is perfectly horizontal. P.S. I'm highly tempted to make a poster-sized printout for the Science Museum/observatory where I volunteer.

storysinthesoil: 07/15/2015 01:51 CDT

Regardless, reaching Pluto is a momentous achievement. We should be humble and honor the hard work that it took to get their. We may have bigger problems yes, but to step back and stand in aww of our insignificance can be good for the soul. We all do our best to be our best but to think about what exists beyond us is often compromised so it is nice to step back and just envision the universe beyond us. let's be grateful and proud of how long we have come and instill our hope for the future generations of humanity.

Albanius: 07/18/2015 11:20 CDT

Very nice, but why does Titan look larger than Ganymede? Does its atmosphere increase the apparent diameter?