Titan's topography, strange.... Options

[Juramike]

Recent article in Science by Zebker et al.:

Zebker et al. Science in press, "Size and Shape of Saturn's Moon Titan". doi: 10.1126/science.1168905
(published online April 2, 2009)

Link to abstract (pay-for article): http://www.sciencemag.org/cgi/content/abstract/1168905

Article on spaceref discusses this paper: http://www.spaceref.com/news/viewpr.html?pid=27912

Figure 3 from the Science article is a global elevation map relative to barycenter.

Key points of article:

• Poles are squished - might explain why lakes are up there
• "Mountains" aren't necessarily elevated - they might've sunk down into the crust to form "a basin of their own creation".
• (quote from spaceref. article)
• Large scale features do not appear correlated with elevation
• Xanadu and Tseghi are BASINS! (ca. -600 m to barycenter)
• Adiri is higher than Xanadu (by almost 1 km)
• Dilmun is also pretty elevated (+ 400 m relative to barycenter)
• highest elevated terrain on Titan seems to be region around "Adiri junior" in the S Senkyo "basin" at ca. + 600 m above barycenter
• Shangri-La "basin" is elevated +400-800 m ABOVE Xanadu (using barycenter elevations in Fig. 3)

"Xanadu seems to be systematically lower than other parts of the equatorial belt, and not uplifted like most mountainous areas on Earth." (quote from Fig. 3 caption in article)

-Mike

[elakdawalla]

To elaborate, we use crater counts to establish relative age dates of surfaces. Tying those to absolute age dates is fraught with peril. (See this post about lunar chronology for more on that.) Estimating ages of individual craters really isn't possible without sample return. You can say they're relatively fresh or relatively degraded from their morphology, but that doesn't necessarily even tell you their relative age, because as ngunn points out different parts of the world may experience more or less rapid degradation.