It’s practically here, a rarer and exciting phenomenon is coming to our location. For me, after two two years of wait, this coming eclipse is right around the corner for all of us, living in the… US! Yes, we will have a big spectacle practically for everybody living in the United States and beyond its borders; this coming August 21st, we will witness a total solar eclipse that will cross all continental US from West to East, starting in Oregon, and ending in South Carolina. And yes, I will say it again, we’re one month away from this event, and let me tell you, the furor is in crescendo!
Solar eclipses, as well as Luna eclipses, are somewhat uncommon phenomena that occur when certain conditions are met regarding the location and alignment of the Sun, the Moon and of course Earth. But, why these events are considered rare? and how come it seems we experience more Lunar eclipses than Solar eclipses? And, how many kinds of eclipses are there? Well, let’s have a brief explanation of this phenomena.
Eclipses 101
So, why do eclipses occur? well, there are several factors involved. First, although the Sun and Moon have different sizes, there’s an interesting relation, the Moon is approximately 400 times smaller than the Sun; but at the same time, the sun is 400 times farther from Earth than the Moon, and as a result of this ratio the apparent disk size of the Sun and Moon seeing from Earth, visually are practically the same; they have a slight variation due the Earth’s elliptic orbit around the Sun, having a difference in distance of approximately 3.3% when the earth is the closest to the Sun (perihelion), and farther from it (aphelion). The same situation happens with the Moon, having a variation of approximately 10% between the nearest point to Earth (Perigee, when we have the so called Supermoon), and the farthest (Apogee, when we have the less known Micromoon).
Ecliptic (www.astronomy.ohio-state.edu)
Probably the most important factor in eclipses is the Earth and Moon’s movement and alignment with the Sun. In general, all planets, including Earth, move in the same plane around the Sun, this plane is called Ecliptic. Is interesting to mention that Earth isn’t positioned perpendicularly with the ecliptic plane, so it’s Equator (the imaginary line that divides the North and South hemisphere) has an inclination angle of 23.5 degrees with respect to the ecliptic, being this the reason for the Earth’s seasons, by the way. In the Moon’s case, its orbit around Earth is a plane with 5 degrees of inclination in respect to the ecliptic plane; and is due this combination of differences that most of the Moon’s orbits around the Earth don’t interfere with the Sun; but twice a year the Moon’s movement around earth will cross the Ecliptic in the right moment and position. Is on these few occasions, when literally the “Astros align themselves”, having the possibility of an eclipse, either lunar, when the Earth is between the Sun and Moon; or Solar when the Moon is between the Sun and Earth.
Umbra & Penumbra (scienceblogs.com)
And there’s more, the eclipse zones. Due to the light optics, an eclipse has two distinguished zones, the penumbra, which for a Solar eclipse is where the Sun is covered partially; and the umbra, where the sun is covered in totality. Due to these conditions, in the case of the Moon can have three distinct eclipse types depending on where it is located; it can be penumbral, with the Moon in Earth’s Penumbra, partial eclipse with the Moon partially on the umbra, and total eclipse with the Moon fully covered by the Umbra.
Annular eclipse (apod.nasa.gov)
For the Sun, there are two kinds of eclipses, due to the mentioned Earth and Moon’s elliptic orbits, in some eclipse, the Moon’s umbra ends before reaching Earth’s surface and we get an Annular Eclipse, where the Sun is covered but an outer rim is still visible. And for cases like the eclipse we will have in August, the umbra touches the Earth’s surface during its trajectory and is in these areas where a total solar eclipse is experienced.
Safety first!
It is important to consider that even when the Sun looks dimmer during a partial eclipse it is still dangerous to look at it directly, as it can cause irreversible sight damage. So, please use appropriate eye protection, there are special glasses that allow you to safely see and enjoy the eclipse. You can get these online and are very affordable. Please notice that Regular sun glasses or some other means to filter the light aren’t safe. Also, cameras, telescopes or Binoculars should have a proper solar filter to consider them safe to use during an Eclipse. But also notice that for those in the path of totality, during the totality phase don’t lose the opportunity to see it directly; during this period it is totally safe to watch it without filtering and observe it in all its splendor.
Where and What to see?
The partial eclipse will be visible from Northern Canada to Centro America and marginally in parts of south America too. But the best sight will definitely be in the continental US, where it will be visible in the south with approximately 60% partiality (percentage of the Sun that will be covered by the Moon), to 75% – 90% in the North depending on the location. And of course, the mentioned totality path in the middle of the country. To know the places where the eclipse will be total you can use NASA’s interactive eclipse map, To find your preferred location in the totality path and experience the different events during an eclipse, mainly starting with the second contact right before totality, the solar corona during the total eclipse, and the famous “diamond ring”, right after the third contact when the totality ends. (the first and fourth contacts are when the partial eclipse starts and ends).
The site http://www.eclipse2017.org, has also excellent information, including general information about it, maps, weather information (critical for good sight), safety, news, etc. Also, the site www.greatamericaneclipse.com offers excellent information. And as we’re getting closer to this event’s date, more and more information is being presented in media and surely, additional resources will be at reach.
But in case you’re not prepared for this event, don’t worry, nature’s got you covered. For people in Mexico, and the US, you will be able to see a total solar eclipse event on April 8th, 2024, when a total solar eclipse will sweep the Northern region of Mexico, all US and Canada from Southwest to Northeast with maximum Eclipse and Maximum duration in the Mexican state of Durango; you can see the path for this eclipse in the same Nasa’s map site.
For me; well I can’t say I’m close to the totality for this eclipse, Pennsylvania region will experience probably 80% partiality, but I can’t let go this opportunity to see this event in all its magnificence; so, Kentucky, save my spot in the “Greatest Eclipse” location, one of the best spots to see it. and to experience my second (yes second), total solar eclipse.
So, get ready, and enjoy this coming eclipse on August 21, fingers crossed for good weather!
Regards, Alex-ScienceKindle.
