Wednesday, 24 October 2012

Birds of East Kent: Purple Sandpiper

The second in an occasional series of posts discussing the different birds that can be found in East Kent and how easy (or not) it is to get a decent picture of them.

Purple Sandpiper
Viking Bay, Broadstairs, November 2011

According to the RSPB website, Purple Sandpipers are supposed to be scarce south of Yorkshire, which perhaps explains why some local photographers have been known to risk life and limb (and their camera gear) clambering over wet rocks just to get a photo of one of these birds. However, despite what official sources say, Purple Sandpipers can in fact be found along the Thanet coastline every winter, with the stretch between Stone Bay and Dumpton Gap being a good area to get close-up shots of them. The photo above was taken from the relative comfort (and safety) of Broadstairs jetty.

Often described as "dumpy little waders" in the guidebooks, Purple Sandpipers are slightly smaller and not as bold as the more plentiful Turnstones with whom they share their winter haunts. Their propensity for skulking under the jetty, or creeping furtively along the seawall while picking at the seaweed-covered stone makes them easy to overlook unless you're actively seeking them out.

Distinctive features include a downcurved beak and mustard-coloured legs. The purple sheen that gives them their name is less obvious, but if the light hits them at the right angle, it shows up quite well:

Purple Sandpipers
Broadstairs, February 2010

Don't dismiss these "dumpy" birds; under the right conditions, they can be very photogenic.

See also:
More of my Purple Sandpiper photos on Flickr
Purple Sandpiper (RSPB)
Purple Sandpiper (Birdforum)

Tuesday, 9 October 2012

Ocean of Storms

Oceanus Procellarum

At first glance Oceanus Procellarum (the Ocean of Storms) appears to be one of the less interesting regions of the Moon, presenting to the casual observer nothing more than a vast, monotonous plain of dark grey lava, dotted with the occasional impact crater. But look closer and you'll find evidence of ancient volcanism on a huge scale, unlike anywhere else on the lunar surface.

Here's a 100% crop showing the Aristarchus plateau - an diamond-shaped block of uplifted terrain dominated by the dazzling crater Aristarchus and the 160 km-long Schröter's Valley:

Easily visible in a small telescope, the valley is the largest and perhaps most dramatic example of a lunar rille, a sinuous channel cut (a very long time ago) by fast-flowing lava.

Follow the terminator south and you come to the Marius Hills, a complex of some 300 volcanic domes and hills that - through a small telescope - look like pimples on the lunar surface:

Lunar Orbiter 2 photographed the complex from an oblique angle, giving an idea of the relative height of the domes, and a few decades later the Japanese SELENE/Kaguya mission discovered an intriguing dark pit in the area (shown here in a high-resolution image taken by the Lunar Reconnaissance Orbiter).

Incidentally, if you move your mouse over the cropped images you can compare the finished versions with one of the original photos, illustrating the dramatic improvement that image-stacking can make to lunar photography.

See also:
Procellarum: The Biggest Basin?
Shooting the Moon: Lunar Photography with a DSLR and a Small Refractor