Thin Crescent Moons for 2009

This year we have several opportunities to view some really challenging thin moons from the Houston area. I’ve compiled a table below of the most interesting of the thin crescents. Some will be extremely difficult and may require travel to a drier location. All will need very good horizon views. The April and July crescents present opposing times under 38 hours – chances to see thin moons on consecutive days.

Can you see the thin crescent in the photo below? You can click on the image to see a full size view.

This is a detail from the photo above; the thin crescent is in the center of this photo.

Notes about the table: The date and time is when the Sun is nearest 4 degrees below the horizon since from the experience of many, that is the best time to spot thin and difficult crescents. The sky has darkened enough and the Moon is still high enough in most cases to avoid severe atmospheric extinction. I would recommend setting up before moonrise for morning moons and before sunset in the case of evening crescents. Those times can be found at the US Navy website. Or, download freeware Meridian to run locally. Altitude, Azimuth, Separation, (all in degrees) and Age (hours from new moon) were derived using MoonCalc 6.0. When using a magnetic compass, subtract 4 degrees in the Houston area. Starry Night Pro 5 was used as a graphical and sanity check on the locations of crescent moons.

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