THE SOUTHWORTH PLANETARIUM

70 Falmouth Street Portland, Maine 04103

43.6667° N 70.2667° W Altitude: 10 feet below sea level Founded January 1970

2021-2022: CXXIV

"If Abraham Lincoln were alive today, he'd roll over in his grave." -attributed to an anonymous politician.

THE DAILY ASTRONOMER Friday, May 13, 2022

Quiz # 28: Lunar Eclipse T or F

I suspect you're not surprised to discover that today's quiz focuses on lunar eclipses. After all, we're now slightly less than sixty hours away from the next total lunar eclipse. And, since there is no such thing as a half-hearted obsession, we thought it best to focus on lunar eclipses for one more day.

Best of luck!

1. Lunar eclipses can only occur when the moon is new.

2. A lunar eclipse is either followed or preceded by a solar eclipse two weeks later or earlier.

3. Due to the moon's slow recession from Earth, lunar eclipses will stop after 1.3 billion years.

4. A lunar eclipse with a Danjon rating of 0 exudes a bright orangish hue instead of red.

5. Lunar eclipses don't happen each month because the moon's orbit is inclined nine degrees relative to Earth's orbit.

6. Sunday's lunar eclipse is part of Saros Cycle 131.

7. The next lunar eclipse in the same Saros Cycle as Sunday's eclipse will occur on May 26, 2040.

8. One must use welder's glass with a rating of at least 12 when observing a lunar eclipse.

9. Totality refers to the time when the eclipsed moon is fully immersed in Earth's penumbra.

10. Earth's shadow cone extends two million miles out into space.

ANSWERS

1. Lunar eclipses can only occur when the moon is new.

FALSE!

Lunar eclipses can only occur when the moon is full, or at opposition. Only when the moon is full will it be able to enter Earth's shadow.

2. A lunar eclipse is either followed or preceded by a solar eclipse two weeks later or earlier.

TRUE!

The solar eclipse associated with Sunday's lunar eclipse was a partial eclipse which occurred on April 30, 2022.

It was only visible in the southern hemisphere.

3. Due to the moon's slow recession from Earth, lunar eclipses will stop after 1.3 billion years.

FALSE!

Lunar eclipses won't end until the Sun perishes more than six billion years from now.

4. A lunar eclipse with a Danjon rating of 0 exudes a bright orangish hue instead of red.

FALSE!

A lunar eclipse with a Danjon rating of 0 appears so dark as to be almost invisible.

5. Lunar eclipses don't happen each month because the moon's orbit is inclined nine degrees relative to Earth's orbit.

FALSE

Lunar eclipses don't happen each month because the moon's orbit is inclined five degrees relative to Earth's orbit.

6. Sunday's lunar eclipse is part of Saros Cycle 131.

TRUE

7. The next lunar eclipse in the same Saros Cycle as Sunday's eclipse will occur on May 26, 2040.

TRUE

Eighteen years, 11 days and 8 hours separate successive eclipses within the same Saros Cycle.

8. One must use welder's glass with a rating of at least 12 when observing a lunar eclipse. FALSE!

No eye protection is necessary to observe a lunar eclipse.

9. Totality refers to the time when the eclipsed moon is fully immersed in Earth's penumbra.

FALSE!

Totality refers to the time when the eclipsed moon is fully immersed in Earth's umbra, or inner shadow.

10. Earth's shadow cone extends two million miles out into space.

FALSE Earth's shadow cone extends about 840,000 miles out into space. Because the moon's distance from Earth will never even reach half this distance, lunar eclipses will continue to occur throughout the rest of the Sun's life.

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