Searching the remnant of the Northern Electrostatic Disturbance

Rings A-B-C-D, Cassini Division, Enke Minima, Ringlets visible (see below) 

These images are the reward of going to bed a bit later than usual. Taken on March 17th between half two to quarter to three local time, they show Saturn past its transit time from my observation point. This year Saturn reaches opposition on Monday 16 April. This is when Saturn is at its closest to the Earth, and therefore easiest to locate in the night sky, and of course slightly bigger and brighter. 

Another interesting feature in this set of images is Saturn's belts and zones. The North polar region is very evident as a dark greenish band while the Northern hemisphere has an overall reddish hue. The NNTZ is also very evident (light blue, narrow belt) in which the Northern Electrostatic Disturbance is still observed (http://saturn.cstoneind.com/). 

At this point in time, the planet's surface is rather dim for a 200mm SCT even if you set the Gain setting to maximum. Saturn's rings C and D are therefore still quite a challenge to capture through a 200mm SCT. However, Rings A and B, Cassini's Division as well as ringlets in Rings A and  B were observed (following some image processing of a section of the rings) as shown below. The Encke Minima are barely visible on both sides of the rings. 

Cloud-banded Venus at 16.8" diameter

False colour & grayscale of (R) to highlight cloud contrast

2012/02/17 17:48:04 (UT)
CM1 111.0deg CM2 322.7deg
Nexstar 8SE NEQ-6 Pro
DMK21AU04 IR807-R-IR807
Seeing 8/10 Trans 8/10

Similar results were obtained by
Javier Beltran (Spain) and Camilo Ucha (Spain) 
http://alpo-j.asahikawa-med.ac.jp/kk12/v120217z.htm

Image has IR(R)_R(R)_IR(B) colour combination to highlight clouds


ALPO Report - Venus, 17 February 2012:

Banded dusky markings visible
No South Cusp-Cap visible
North and South Cusp-Bands not visible

Limb band not visible
Terminator geometrically regular
Terminator shading visible

High Mars definition at 13.7"

This is my second Mars observation session this month, taking the opportunity of a good clear night.

During this session I used a slightly higher gain to improve the image contrast. This resulted in a considerably improved final R(IR)GB composite. In addition I replaced the R channel with the IR channel, since the latter  always gives a better image definition and contrast than the normal R image.

Regional structure

The RGB composite shows a very interesting albedo composition. Syrtis major is seen as dark blue compared to the neighbouring Iapygia region, which has a reddish-brown hue. Hellas region is brighter and bluish in colour. The complex structure of Syrtis major together with the small protuberance of Moeris Lacus is very impressive. The indentation pattern of Sinus Sabaeus is very prominent especially at Sinus Meridiani.

The isolated Alcyonius Nodus next to S. major tip is very prominent. On the opposite site of S. major is Utopia which is lighter than S. major region. Ismenius lacus is subtle but visible.

Clouds

A bluish haze is seen over Chrysae and Elysium region. Aeria region is very bright, although slight processing of the Blue channel gives a light blue signal between 0 degrees and +20 degrees in latitude, and stretching from Chrysae to Elysium region.

The thin blue-green border could be an imaging artifact, but certainly not related to the final RGB overlapping, since this feature is seen in the green channel.

This effects is seen in other images taken by other planetary imagers such as Christophe Pellier.


Polar cap

An interesting surface feature is visible almost cutting the polar cap in half, which is possibly due to retreating ice sheets. This feature is most visible in the Green channel.

Comments on this blog are welcome.