Astronomy 101. Phases of the Moon, Lunar Eclipse, Solar Eclipse, and More. Earth, Sun, and Moon.
An amazing and rewarding hobby.
Ever since I was very young, I have always loved astronomy. I stayed up late with my parents to find constellations in the sky and observe the moon through a telescope. I soaked up all of the information about the solar system and stars when I was in school, and I took a few astronomy classes in college, always staying after class to use the university's telescope with my professor.
If you are a seasoned sky watcher, you know how eerie and amazing it can be to see something larger than yourself in the sky. This could be a comet, a shooting star, the rings of Saturn, or the moons of Jupiter.
If you're just getting interested in viewing stars and planets, you will find it to be a wonderful hobby. This short hub will cover a few basics for you, including the phases of the moon, solar and lunar eclipses, and some very elementary astronomy terms.
The Phases of the Moon
The following illustration shows the position of the moon relative to the Earth and Sun, and what "phase" this appears to us as.
The sun shines from the right, leaving half of the moon in darkness at all times. It takes about a month for the moon to revolve around the Earth. So, when we see a full moon, the moon is on the opposite side of the Earth than the sun.
When is the best time to look at the moon through a telescope?
This one is tricky! Its actually not during a full moon. When the moon is full, there is so much sunlight that all you really see through a telescope is white.
The best time to look at the moon through a telescope is during a half-moon. The shadow-effect created allows you to see all of the craters and pock-marks.
What about a SOLAR ECLIPSE?
The following image shows how a solar eclipse occurs. The moon comes between the sun and the Earth, blocking the sun's light.
How to safely view a solar eclipse.
According to NASA, it is only safe to view a solar eclipse through the proper filter. These can include shade # 14 welder's glass goggles, or aluminized mylar, which is manufactured specifically for viewing a solar eclipse. Some people use CD's, but you need to be careful. Some CDs do not offer the proper protection, and the quality of the image is compromised.
Of course, once the sun is completely covered, you may view it with the naked eye! This is a wonderful experience, a true beauty to witness.
I have this book-- it has great information on the sun and how to safely observe it during the day.
And a lunar eclipse...
A lunar eclipse occurs when the Earth's shadow becomes visible on the moon. The Earth comes between the moon and the sun, and we see the eclipse on the moon at night. The following image illustrates this event:
The beauty of a lunar eclipse.
Last winter, I stayed up all night and bundled up tight to watch the lunar eclipse. It is a truly beautiful and humbling experience, one that I highly recommend to anyone whenever they have the opportunity. Part of what makes it so special is the fact that it is quite rare to actually be able to see a total lunar eclipse.
During a lunar eclipse, which lasts several hours, the moon slowly takes on a copper-reddish hue. When it is completely covered, all you see is a faint circle in the sky.
A Few Basic Astronomy Terms and Meanings
Light year (ly)- The distance light travels in 1 year.
Astronomical unit (au)- The average distance from the sun to the earth, used to measure distance within the solar system.
Ecliptic- The apparent path of the sun in the sky.
Rotation- Spins around an internal axis (think of a wheel spinning).
Revolution- Spinns around an external axis (think of a kid on a merry-go-round, spinning around the center).
Lunar eclipse- Moon passes into the Earth’s shadow. We see the Earth's shadow across the moon.
Solar eclipse- Light from the sun is blocked by the moon. We see the moon moving across the sun.
Celestial sphere- Imaginary sphere of stars surrounding earth