Look for total lunar eclipse in Sisters

The glare of a full moon will be temporarily darkened when earth's shadow falls upon the face of our only natural satellite on Sunday evening, January 20.

The celestial event is a total lunar eclipse - a super blood moon one at that - to be conveniently staged in the evening hours here in Sisters Country.

Because the moon's orbit is tilted at about five degrees with respect to the orbit of the earth around the sun, we enter an "eclipse season" approximately every six months, and during this time there will be two or three solar or lunar eclipses visible at some places on the earth. Right now we are in one of those seasons. Last week there was a partial eclipse of the sun visible in parts of northeastern Asia and barely visible from southwestern Alaska.

On Sunday night, January 20, a total eclipse of the moon will occur that will be visible over more than half the earth, and Central Oregon will have as good a view of this event as any part of the world.

Though the eclipse starts as a barely noticeable penumbral eclipse at 6:36 p.m. local time, we will start to notice a bit of darkening of the moon on its lower left side by about 7:20 p.m. when the moon will be due east of us and at an elevation, or angle above the horizon, of 25 degrees. It will be about one-half dark at about 8:20 p.m. and will show the famous red (blood red) color over part of its surface. The still-bright half will tend to overwhelm the darker and redder side for most viewers.

The maximum eclipse will occur at about 9:10 p.m. when the moon will be at about 45 degrees elevation and just east of southeast. As the moon begins to emerge from the earth's shadow it will be about half lit again by 10 p.m. and by 10:30 p.m. the partial phase of the eclipse will be over. The penumbral eclipse will end at about 11:50 p.m., but during the last hour the casual observer may not even notice any darkening of the moon.

This particular eclipse is sometimes referred to as a super blood moon eclipse; super because the moon is near perigee in its orbit, placing it closer to the earth than it normally gets, and blood because the blue wavelengths of light are scattered by earth's atmosphere, allowing the red end of the spectrum to fall upon the moon.

Because this lunar eclipse occurs in our winter, we will have a view of it with the moon very high in the sky and the opportunity for photography will be better than for a summer lunar eclipse at our latitude.

As the moon progresses through the partial phases, exposure settings will need to vary tremendously.

For instance, at the start of the penumbral phase, the moon is about as bright as a normal full moon.

You can get a decent image of the early phases of the eclipse with manual camera settings such as: ISO 400, f/8, 1/200 sec.

Put your camera on a tripod for the longer exposures.

During the partial phases, you will need to increase the exposure time to about 1/3 to 1/2 second.

The bright part of the moon will be overexposed for these shots.

For the total phase, you will need to have the camera on a tripod and shoot at something like: ISO 400, f/4, 2 sec.

A telephoto lens or zoom lens with a focal length of 150 to 500 mm will give you a better image of the moon.

Remember to spend some time just viewing the eclipse with your naked eyes or through binoculars.

For information about Richard Lighthill's observatory and to view a time lapse video of a previous lunar eclipse, visit https://tinyurl.com/ycovp4zf. To be alerted about astronomical events check the Sisters Astronomy Club Facebook page: www.facebook.com/sistersastronomy.