[X] My Assistant

[Guest_Max Power_*]

Will Cassini ever do a radar survey of Saturn proper?

Due to declining fuel and RTG power, the ability to do so decreases with time.

It is my understanding that in the Equinox orbits that there is a possibility for up to 3 close approaches of the dark side with RADAR in its lower resolution modes.

It is also my understanding that not that much reprogramming would be needed -- as the radar system has been fully mastered.

The risks of doing a radar swath would not increase substantially, versus any other close moon approach.


ADMIN - Thread title changed for clarity.

[rlorenz]

Will Cassini ever do a radar survey of Saturn proper?
ADMIN - Thread title changed for clarity.

We only do SAR within about 4000km of an object - we don't get that close to Saturn except
right at the end of the mission, and in any case Saturn is a gas giant -no surface to observe!
Ammonia opacity is significant at our wavelength, so radiometry (as other posters have noted)
is somewhat useful, but must compete both with other Cassini observations at Saturn, and for
our own manpower (which is concentrated towards Titan) to plan and execute the observations,
calibrate and archive the data.

[Den]

We only do SAR within about 4000km of an object - we don't get that close to Saturn except
right at the end of the mission, and in any case Saturn is a gas giant -no surface to observe!
Ammonia opacity is significant at our wavelength, so radiometry (as other posters have noted)
is somewhat useful, but must compete both with other Cassini observations at Saturn, and for
our own manpower (which is concentrated towards Titan) to plan and execute the observations,
calibrate and archive the data.

There may be a chance of serendipitous discovery of something.
I'm not saying you'll spot flying mountains , but maybe
anomalous radio reflectance of the Saturn atmosphere?

If you never try, you won't know.

[rlorenz]

There may be a chance of serendipitous discovery of something.
I'm not saying you'll spot flying mountains , but maybe
anomalous radio reflectance of the Saturn atmosphere?

A saturn rainstorm, perhaps, might have detectable backscatter. But not
detectable except during the rare and oversubscribed close flybys as
discussed before, and ammonia absorption I think prevents Ku-band
radiation from getting down more than a bar or two.

There are flying mountains, but most people call them 'ring particles'.

You can do interesting science with the rings (there was an Arecibo
observation some years back, published by Nicholson et al. in Icarus in 2005)
because the frequency-domain doppler information resolves structures.
But even for the rings, Cassini has to be close to get a useful echo, and
when we are close, the geometry changes rapidly so it is hard to 'stare
and integrate' (remember the rings are spread out in space and velocity
- not like an icy satellite).

Trying a ring observation is on our wish list, but Titan observations come first.
The question isnt whether something is interesting or not, but how to manage
oversubscribed geometrical opportunities with limited planning manpower.