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"Dragonfly" Titan explorer drone, NASA funds Johns Hopkins University Applied Physics Laboratory (APL)
Daniele_bianchin...
post Jan 3 2018, 07:07 PM
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iL kraken sea extends to 56 north. I think small lakes can be on 50 north.
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scalbers
post Jan 3 2018, 11:25 PM
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How about some twilight lake watching?

https://www.space.com/36609-twilight-outshi...moon-titan.html

Although the paper mentioned in this article is mainly referring to the total disk brightness as seen from space, it is a reminder that a reasonable amount of scattered light is available at the surface during twilight (e.g. in near-polar winter).


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Habukaz
post Jan 4 2018, 04:20 PM
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QUOTE (Explorer1 @ Jan 2 2018, 09:49 PM) *
Ontario Lacus is in the southern hemisphere, but it is much smaller and shallower than its northern counterparts. Other more equatorial lakes have been theorized but not yet confirmed


Polaznik Macula, Sionascaig Lacus and Urmia Lacus on Google Maps

This mission seems like an excellent opportunity to test the lake hypotheses for these two features. wink.gif

Also of note:

QUOTE
However, Stofan et al. (2007) and Tan et al. (2013) state that liquid methane is thermodynamically stable anywhere on the surface of Titan.


So, maybe there could be smaller pools of liquid, or even smaller lakes too small to have been resolved yet, even closer to the equator.





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JRehling
post Jan 6 2018, 08:15 AM
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From half of Titan's surface, Saturn will be visible almost all the time. That seems like it'd be very useful for navigation, even more so than the Sun, because the Sun will vanish for ~192 hours at a time.

Going a lot farther down the magnitude scale, a really interesting possibility would be if you could see Betelgeuse, Antares, Aldebaran, and possibly some other stars like Arcturus. The former are red giants that are bright in infrared, which, as we know, penetrates Titan's haze pretty well. You'd never see them in the daytime sky, but at night they'd be brighter in the IR band than they are in visible light from Earth. Seems like navigating by the stars could cover your nights on Titan and the combination of the Sun and Saturn would handle the daytime. And an IR sensor could be pretty sensitive operating at 94K.

In addition, the radio link with Earth would give you greater precision longitude checks twice per sol.
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vjkane
post Jan 6 2018, 06:26 PM
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QUOTE (JRehling @ Jan 6 2018, 12:15 AM) *
Going a lot farther down the magnitude scale, a really interesting possibility would be if you could see Betelgeuse, Antares, Aldebaran, and possibly some other stars like Arcturus. The former are red giants that are bright in infrared, which, as we know, penetrates Titan's haze pretty well. You'd never see them in the daytime sky, but at night they'd be brighter in the IR band than they are in visible light from Earth. Seems like navigating by the stars could cover your nights on Titan and the combination of the Sun and Saturn would handle the daytime. And an IR sensor could be pretty sensitive operating at 94K.

The descriptions so far don't mention an IR sensor, although it could be considered an engineering instrument. The highest frequency atmospheric window is 0.93 microns. The Mastcam Z cameras goes to 0.88 microns. I don't know if the sensor itself goes to 0.93 microns and the Mastcam Z limit is based on the scientific value of that band and not the sensor.


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vjkane
post Jan 7 2018, 03:31 AM
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QUOTE (vjkane @ Jan 6 2018, 10:26 AM) *
The descriptions so far don't mention an IR sensor, although it could be considered an engineering instrument. The highest frequency atmospheric window is 0.93 microns. The Mastcam Z cameras goes to 0.88 microns. I don't know if the sensor itself goes to 0.93 microns and the Mastcam Z limit is based on the scientific value of that band and not the sensor.

I'll correct my last post after finding a better paper. The MastCam Z sensor goes out to a full micron, so if Dragonfly uses a similar sensor, it could image through the 0.93 band. If nothing else, it could take great tourist pictures of the surface with Saturn in the sky (although it would be a monochrome image).


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scalbers
post Jan 7 2018, 10:28 PM
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At around 0.93 microns these images would be interesting, though still a bit hazy since the aerosol optical depth at this wavelength is about 3 at the zenith. Thus looking at Saturn and stars would be a bit like the view through medium-thin cirrus clouds on Earth. Some details are in figure 12.18 from this paper: http://ciclops.org/media/sp/2010/6514_15623_0.pdf. Saturn may look best during twilight and it should be high in the sky. A wide angle lens (or a mosaic) would help with showing the terrain at the same time.


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