C/2013 A1 Siding Spring

Closest to Earth on 5 September 2014 at 0.85AU
Closest to Sun on 25 October 2014 at 1.40AU
Closest to Mars on 19 October 2014 at 0.00088AU or 132,000kms!!

Maximum magnitude 9 in September 2014

8 hours before closest approach.
Taken remotely from Siding Spring Observatory.
Spikes from the very bright planet Mars are caused by internal reflections in the telescope.

Never in recorded history has a comet this large passed so close to an inner solar system planet.
Mars passed through the coma of the comet and was pelted by dust particles travelling at a speed of 56km/s.
Prior to this major event, comet Siding Spring was well situated in southern hemisphere circumpolar skies during September,
shining at magnitude 9.0 and visible all night.

An early image of the comet

C/2013 A1 Siding Spring.
2013 Jan 4.56UT. C11 telescope and Starlight express MX7c CCD camera. 10x20second exposure.

August 2014 finder chart

As August began, the magnitude 10 comet was situated in Eridanus, 2 degrees to the south of galaxy NGC 1316, best observed in the morning.
It was within 1 degree of galaxy NGC 1269 on Aug 3-4.
Moonlight interfered from the 10th but from the 14th, the comet was then observable in southern evening skies in the constellation of Horologium.

C/2013 A1 Siding Spring.
2014 Aug 25.5 UT: Canon 60Da camera and Sigma 70-200mm f2.8 lens cropped. 6x30sec stack.
Visual magnitude m1=9.8, Coma Diameter=4', DC=5...25x100mm binoculars
Note the short dust fan tail.

A fantastic event occurred around midnight of August 28, when the comet transited across the core of globular cluster NGC 362.

C/2013 A1 Siding Spring encounter with Globular Star cluster NGC 362.
A bit of processing to show the stars in globular cluster NGC 362.
Time approx 15:17UT Aug 28.
Celestron C11 and MX7c CCD camera. 1 minute exposure

C/2013 A1 Siding Spring: 214 Aug 28 at 09:45UT.
Encounter with the Small Magellanic Cloud, 47 Tuc (at right) and NGC 362 at top left.
Canon 60Da, Sigma 70-200mm f2.8 at 150mm. 10x30sec exposures. Cropped

A couple of nights later, it was a degree to the south of 47 Tuc (NCG 104)

September 2014 finder chart

As September began, comet Siding-Spring was situated on the Octans-Tucana border, near the SMC.
It was closest to Earth on Sep 5 at 0.89AU.
Moonlight interferee with evening viewing until Sep 11, with the comet now situated in Pavo.
A few great deep sky rendezvous events occurred this month.
On the 13th, It was a degree west of face-on spiral galaxy NGC 6744 as seen below.

Comet situated near and galaxies IC 4720/21 on Sep 16th

On the 20th, a degree SW of globular cluster NGC 6584 in Telescopium
On the 26th, a degree SW of globular cluster NGC 6496 in Scorpius below.

October 2014 finder chart

As October began, the magnitude 9.5 comet was situated near the stinger of the Scorpion in the evening sky. 
Moonlight interfered with viewing until the 10th. 
On Oct 8-9, the comet was within a degree of the butterfly star cluster M6 as seen below.

On Sunday evening Oct 19th, the now magnitude 10.0 comet and magnitude 0.9 Mars were separated by less than 20 arc minutes. 
From Adelaide, the altitude was 38 degrees at 9pm, reducing to 3 degrees by midnight.
Mars passed the comet's orbital plane some 100 minutes after closest approach, which resulted in a barrage of meteors.
All spacecraft in Mars orbit survived the passage.

9 hours before closest approach. Field of view 0.5 degrees wide.
Photo taken in twilight. Unfortunately cloud interrupted the view here in Swan Hill, Victoria.

32 hours before closest approach. Very hazy conditions.