Can anyone tell besides Venus being a terrestial planet and Miranda a icy satellite, what is the real diffrnce in their formation of Coronas on both surfaces. Where they both formed the same way like an upwelling of material from within or are they called coronas because both they are similar.

I hope this is clear

Thanks.

They are both called coronae because both types of features are shaped like ovals Seriously. The descriptor term in a feature name, be it patera, corona, or facula, are just that, descriptor terms, and may relate to different types of features on different bodies (and even features that formed in different ways on the same body). For example, some facula on Titan are formed as ejecta blankets around impact craters. Some are just hills poking up above the surrounding dark, sand dunes.

Hmm. That's an interesting point.

I guess it's like on Earth, where the term "mountain" can refer to any major topographic high, regardless of whether it was thrust up by tectonism, spouted up by extrusive vulcanism, or gradually exposed by preferential erosion of surrounding material.

Have scientists come any closer to answering the question as to explaining Miranda's jumbled up appearance? I mean, is the collision/re-formation idea still dominant or do they believe that there was another way (ie vie cryovolcanism/differentiation/mass tectonics)

Personally, given Miranda's tiny size, I can't see how those huge coronae were formed by cryovolcanism.

No, there's now an alternative theory, that they formed by upwelling. Do a Google search on pappalardo greeley miranda. Alternatively, join the Planetary Society (with the dollar so weak, it's a great deal for international members right now) and ask to be sent a copy of the March/April 2005 issue of The Planetary Report, in which Bob Pappalardo wrote a detailed article about the current thinking on Miranda.

--Emily

Emily, thanks a million for that. I'll take a look.