What Is a Solar Eclipse and Lunar Eclipse?
Have you ever seen an eclipse? The astronomical event is famous and is frequently used in music and literature in a metaphorical way. Some say that the phenomenon is nothing more than the movement of the celestial bodies, others prefer to believe that the event has something more mystical to it than just the celestial movements. Read this article and find out what really is a solar eclipse and lunar eclipse and why they happen in the solar system.
Going back in time, it was common to consider the phenomenon as an omen of something evil. During his epic poem “Odyssey”, Homer described a solar eclipse saying that “an evil mist” has been on Earth while the suiters tried to win hero Odisseus’ wife’s heart. In fact, the first recorded eclipse occurred around 760 years B.C.E. in the Assyrian civilization.
The word “eclipse” has its origins in Greek and means “the abandonment”, “the downfall” or “the darkening of the heavenly body”. Generally speaking, the term can be used when a celestial body obscures another. However, while the phenomenon occurs in every planet, the eclipses we see more commonly are the solar eclipse and the lunar eclipse. But, what’s the difference between them?
A solar eclipse (also called sun eclipse) happens when the moon is between the Earth and the Sun, blocking the sunlight from arriving on our planet. The phenomenon can only happen during a New Moon when the natural satellite’s orbit is tilted by 5 degrees in relation to Earth’s orbit. The event is quite rare and can be of 4 types: total solar eclipse, annular eclipse, hybrid eclipse (the rarest one) and partial eclipse.
In order to understand the difference between these 4 kinds of eclipses, let us remember that the Moon moves around the Earth in an elliptical orbit. Have you ever noticed that the size of the moon seems different on different days? In fact, the appearance differs by 13%, according to the distance between the moon and our planet – which can go from a minimum of 221 thousand miles from a maximum of 252 thousand miles.
That distance is the key to recognizing the differences between the 4 kinds of solar eclipses. If the Moon’s orbit is at the minimum distance, the celestial body will appear to be bigger than the Sun. When the phenomenon happens, we are presented with a total solar eclipse.
On the other hand, when the moon is closer to its maximum distance from Earth’s orbit and placed between our planet and the Sun, what we’ll see is a much smaller shadow and thus an annular eclipse. Both eclipses have a short duration, not surpassing 10 minutes.
The hybrid eclipse is extremely rare, occurring almost every 160 years, and happens when a total eclipse morphs into annular eclipse or vice versa. The phenomenon occurs due to the Earth’s Curvature.
At last, we shall speak about the partial eclipse. As the name suggests, the event happens when the moon is not able to launch a shadow that covers the entire sun from Earth’s perspective but is large enough to cover part of the star.
A lunar eclipse is not as magnificent as the solar one. The event occurs when the sunlight is not able to reach the moon because Earth comes in between and the shadow doesn’t allow it. In order to happen, the three celestial bodies need to join in the same plane of orbit with Earth in the center. In fact, the event only happens during full moons.
In contrast to the solar eclipse, the lunar eclipse can last for more than 1 hour. According to the amount of darkness of the shadow that falls on the moon, we can define 3 types of lunar eclipses: total lunar eclipse, partial lunar eclipse and penumbral lunar eclipse.
Like the expression reveals, a total lunar eclipse occurs when the Earth’s penumbra (type of shadow) totally covers the moon and prevents the fall of sunlight on it. A partial lunar eclipse can be seen when only a part of the Moon is visible. A penumbral lunar eclipse is a combination of both phenomena and happens when the rotation of the moon makes a movement that changes the eclipse from partial to total, or vice-versa.
When is the solar eclipse and lunar eclipse?
Eclipses are extremely rare. There are a lot of websites that shows live eclipses online around the World. You can enter on NASA Eclipse Web Site, University of Arizona’s SkyCenter – or the community observatory Slooh.
If you don’t want to miss any solar eclipse and lunar eclipse in 2015, then put the following dates in your calendar and don’t miss the next opportunity.
20th March, 2015: The Total Eclipse of the Sun can be watched by people in Europe, North Africa and northwestern Asia.
4th April, 2015: The Total Eclipse of the Moon can be observed in North America.
13th September, 2015: The Partial Eclipse of the Sun will be seen in southern Africa and in the countries of the Indian Ocean.
27th September 27, 2015: Once again, the Total Lunar Eclipse will be seen in North America.