On Sunday evening, the moon will pass into the earth's shadow, appearing a rusty red and larger than usual. The total lunar eclipse, the last one until May 2021, will be a sight to see.

That is, if one can see it. The weather does not look promising.

What time is this happening?

The partial phases of the eclipse — when you start to notice something happening — will begin in Connecticut at about 10:33 p.m. on Sunday, explained Connecticut College physics professor Leslie Brown, who has taught astrophysics and astronomy courses. It will look like bites have been taken out of the moon.

The total lunar eclipse will last from about 11:41 p.m. to 12:43 a.m. Compared to solar eclipses, that's a long duration of totality; the longest ground duration of totality for the Aug. 21, 2017 solar eclipse was under three minutes.

The moon will then go back into partial phase, and viewers will see parts of the moon's surface reflecting sunlight again, Brown said. The partial phase will end at 1:50 a.m. Monday.

Why do I keep hearing the term "super blood wolf moon?"

This is a colloquial term, not an astronomical one, and the three adjectives refer to different characteristics of the moon, so let's break it down.

The path of the moon's orbit of the earth is an ellipse rather than a circle, meaning the distance of the moon from the earth varies. The moon therefore appears the largest at perigee, the point at which the moon is closest to the earth, and a "supermoon" occurs when a full moon coincides with perigee.

The term "blood moon" refers to the color, which is caused by Rayleigh scattering of light — the same phenomenon that makes the sky blue and sunsets orange.

"Wolf Moon" is the term used for a January full moon in the Farmers' Almanac, which has a name for every month. For example, a September full moon is a Harvest Moon, while one in November is a Beaver Moon.

"They each get a name sort of reminiscent of the time of year and the activities that are going on at that time, so this is a time of year when wolves are out prowling at night," Brown noted.

Do I need to go somewhere special to observe the eclipse?

The moon is going to be "pretty high in the sky, so you can actually observe it from anywhere; you just don't want to have a whole lot of trees," said Ronald Zincone, who teaches Introduction to astronomy for New London Adult & Continuing Education.

Noting that viewers don't have to worry about light pollution with a total eclipse, he said anywhere in Connecticut would be fine to view the event, though he'd recommend against major cities.

But Scott MacNeill, director of Frosty Drew Observatory in Charlestown, R.I., noted that unlike during a normal full moon, stars become visible during a lunar eclipse, and a remote location like Frosty Drew allows for better stargazing than a city.

Another benefit is "being in a spot with a lot of other people that are going to be excited about the eclipse," he said.

Frosty Drew is scheduled to be open from 8:30 p.m. to 3 a.m. There will be feeds of the event projected inside on the Sky Theatre and possibly on the outside wall, a few telescopes will be set up outside, and astronomers will be on hand to answer questions.

MacNeill plans to post on Frosty Drew's website and on social media early Sunday afternoon if the planned activities are still on, which will depend on visibility and if it will be safe for people to drive.

"We plan to remain optimistic to the point of zealotry that every possible negative attribute that's been applied to Sunday's weather will not happen during the eclipse," he said.

What's the weather forecast?

Gary Lessor, meteorologist at Western Connecticut State University, said it will probably still be too cloudy to see anything around 8 p.m., but that skies should start clearing around 10 p.m. in the Groton area and about a half-hour later in Charlestown.

Even if the skies clear, the downside will be the "bitterly cold" weather, Lessor said. He expects the temperature to be in the upper teens around midnight, with a wind chill that makes it feel like 1 degree.

e.moser@theday.com