Tuesday, September 15, 2009

Sublimity before sunrise

kw: observations, astronomy, photographs

I went out before breakfast to get the newspaper and saw Venus and the Moon in the dawn sky. There was a bit of Earthshine visible on the moon also. Sublime! I particularly like it when Venus is the Morning Star (3 years out of 8).

By the time I got my camera, the Earthshine was almost swamped by the dawn light, so in this image and the next, it is very hard to see. For that matter, it takes a moment to find Venus, near mid-image and to the left. This image is cropped from a horizontal one shot at 26mm f.l. (DX; equivalent to 42mm), f/4, 1/25 Sec, ISO 800. The cropping makes it about 40mm (64mm equiv).

Before Venus got swamped out also, I looked with binoculars, and could see its crescent shape, quite a bit narrower than the Moon's crescent. Some sharp-eyed people in pre-telescope times wrote that Venus seemed to have 'horns', but once even a 5x telescope became available, anyone could see the planet's phases, which convinced some (not all!) that Venus is closer to the Sun than Earth is.

This image was taken at 55mm (88mm equiv.), f/5.6, 1/15 sec, handheld, and cropped just a little. I tried setting the shutter to 1/60 sec, but could not get an image that shows Venus. The Earthshine is still barely visible.

An hour later when I left for work I looked for Venus, hoping with the Moon to guide me I could see Venus as a daylight object. But a very thin layer of cirrus clouds had moved in, a precursor to tomorrow's overcast (and expected rain). I've seen it before, but not this time. I could barely make out the Moon.

Both these images are resized to 600x800, which you can see if you click on either one.

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