Full Moon Fever

Free Public Viewing of a Total Lunar Eclipse
Offered by The Albuquerque Astronomical Society (TAAS)
Followed by our Monthly Meeting

Saturday, November 8th 2003, 5pm
At the Lodestar Astronomy Center

Join the Amateur Astronomers of the Albuquerque Astronomical Society for an up-close view of one of the most beautiful sights in nature, a total lunar eclipse.  The Eclipse Viewing begins at sunset - 5pm

After the Eclipse, join us for our regular Monthly meeting at 7pm, held at Lodestar's Honeywell auditorium, as noted astronomer and telescope builder Barry Spletzer presents "How Did the Moon Get in My Telescope", a basic talk about how telescopes work.  It's all free, and great for the family.

• Info and Map to the Lodestar Astronomy Center
• Eclipse Time Table
• Exposures for Lunar Eclipses

What is a lunar eclipse?

A lunar eclipse happens when the Moon passes through the Earth's shadow. Earth always has a shadow, which is created by the Sun. On those rare occasions when the Moon, Earth and the Sun are all lined up just right, the Moon passes through this shadow.

Why does the moon turn red?

When the Moon is in the darkest area of the Earth's shadow, which is called the "Umbra", there is still some light on the Moon's surface. Sunlight diffusing through the Earth's atmosphere bathes the Moon in a dull reddish glow that reduces it to about 1/10,000th of the normal brightness of a full Moon.

Is it safe to watch a lunar eclipse?

Unlike a solar eclipse, which involves looking directly at the sun, viewing a lunar eclipse is safe because you are simply observing the moon at night.  It's just more colorful than normal.

When will this lunar eclipse occur?

Saturday, November 8, 2003
(Mountain Time)
Moon Enters Umbra 4:32pm
Local Moonrise 5:02pm
Local Sunset 5:05pm
Totality Begins 6:06pm
Mid-Eclipse 6:19pm
Totality Ends  6:31pm
Moon Leaves Umbra 8:04pm
Moon Leaves Penumbra 9:22am

Where can I learn more?

NASA / Goddard Space Flight Center - Eclipse Page
http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html

Sky News Eclipse Page
http://www.skynewsmagazine.com/pages/lunareclipse.html

Sky and Telescope - Observing and Photographing Lunar Eclipses
http://skyandtelescope.com/observing/objects/eclipses/article_89_1.asp

 

Exposures for Lunar Eclipses
[adapted from "Astrophotography" by Barry Gordon, Willmann-Bell, 1983]
Find the Row with Film's ISO.  
Staying in that Row, Select the Column with Lens Aperture.

Film ISO 

  

Lens Aperture

1600   2000   2500

-

-

-

-

-

-

f/22

f/16

f/11

f/8

f/5.6

f/4

f/2.8

800   1000   1250

-

-

-

-

-

f/22

f/16

f/11

f/8

f/5.6

f/4

f/2.8

-

400    500    640

-

-

-

-

f/22

f/16

f/11

f/8

f/5.6

f/4

f/2.8

-

-

200    250    320

-

-

-

f/22

f/16

f/11

f/8

f/5.6

f/4

f/2.8

-

-

-

100    125    160

-

-

 f/22

f/16

f/11

f/8

f/5.6

f/4

f/2.8

-

-

-

-

50     64     80

-

f/22

f/16

f/11

f/8

f/5.6

f/4

f/2.8

-

-

-

-

-
25     32     40

f/22

f/16

f/11

f/8

f/5.6

f/4

f/2.8

-

-

-

-

-

-

Subject

 Use Exposure Duration [in Seconds] in Selected Column of Subject Row below.

Normal Full Moon

 1/8 1/15 1/30 1/60 1/125 1/250 1/500 1/1000

-

-

-

-

-

Moon Wholly Within Penumbra

Just Within

 1/8 1/15 1/30 1/60 1/125 1/250 1/500

1/1000

-

-

-

-

-

Deep Within

1/4

1/8

 1/15

1/30

1/60

1/125

1/250

 1/500 1/1000

-

-

-

-

Moon Straddling
Penumbra and Umbra

Part in Penumbra

2

1

1/2

1/4

1/8

1/15

1/30

1/60

1/125

1/250

1/500

1/1000

-

Part in Umbra

60

30

15

8

4

2

1

1/2

1/4

1/8

1/15

1/30

1/60

Moon Wholly Within
Umbra

Just Within

-

-

60

30

15

8

4

2

1

1/2

1/4

1/8

1/15

Well Within

-

-

-

60

30

15

8

4

2

1

1/2

1/4

1/8

at the Center

-

-

-

-

60

30

15

8

4

2

1

1/2

1/4
For example:  Using Kodachrome 200 at an f/8 telescope's prime focus, the exposure for a normal Full Moon (and the Moon just wholly within the Penumbra) would be 1/500 of a second. 
For the Moon deep within the Penumbra, the exposure would be 1/250 of a second, and so on.

Exposure Limitations to Avoid Trailing

[adapted from "Astrophotography" by Barry Gordon, Willmann-Bell, 1983]

A stationary camera with a lens of  (f) x (mm focal length) will produce acceptably sharp images with exposures of 500/f seconds or shorter.  For example, a stationary camera with a 500 mm lens will produce acceptably sharp images with exposures of 1 second or less, but exposures for a stationary 1000 mm lens should be kept to 1/2 second or less.

(For a telescope or camera tracking at Sidereal Rate, rather than Lunar, the difference is negligible for exposures of 13600/f seconds or less.)