The solar eclipse is a magnificent event and there are people who invest a lot of time and effort to chase this phenomenon around the world. Described in a very simple way, the eclipse occurs when an object passes in the shadow cone cast by another. Although most people are familiar with the solar eclipse, there is also a lunar eclipse and both are worth all the effort if you are a serious astronomer; no description and no photography can replace a live experience.
Steps
Part 1 of 3: Observe the Solar Eclipse
Step 1. Read up on the solar eclipse
It occurs when the Sun, Moon and Earth are aligned and the Moon blocks the sun's rays reaching our planet. It can be observed as a partial or total phenomenon, depending on your geographical position and whether or not it falls within the "shadow" cone (the small portion of the Earth hit by the shadow cast by the Moon) or "penumbra" (the peripheral portion of the shadow cone).
- The duration of the total eclipse varies from a few seconds to a maximum of seven and a half minutes, as the shadow moves along a "path of wholeness". There is also an "annular eclipse", which occurs when the Moon passes in front of the Sun without covering it entirely.
- Total eclipses are possible because the Sun is 400 times farther from the Earth than the Moon and 400 times larger than our satellite; consequently, the apparent dimensions of the two celestial bodies appear almost identical from our perspective.
Step 2. Be aware of the methods that should not be used to observe a solar eclipse
You must also be prepared to notify any other person you are responsible for to ensure their safety. You should not look at the phenomenon through binoculars, a telescope, any type of eyewear including sunglasses, smoked glass, polarized filter or already exposed film, as none of these tools are strong enough to protect the eyes.
Although the wavelengths of light visible to humans are blocked by these "filters", in reality it is the invisible ones that cause the damage; ultraviolet and infrared rays can overcome these barriers and cause more damage than visible light
Step 3. Make an observation device or darkroom
You can make them both without difficulty, they usually represent the simplest and safest way to see an eclipse, having to bear the cost of a thick cardboard or a cardboard, among other things. The downside to these devices is that they produce very small images, but they are ideal for kids and teens who can enjoy the darkroom building process and use it.
- Make a small hole in the center of a card using a pin or thumbtack. Put a second sheet of paper on the ground, which will act as a screen on which you will project the image of the eclipse.
- Turn your back to the sun and hold the card with the hole 60-90cm from the ground, over your shoulder or near your side. Make sure your head isn't covering the hole. You should hold the card in the direction of the sun while looking at the screen resting on the ground.
- When the projector is well aligned, you should see a perfect circle on the card held on the ground. If the circle has a faint outline, move the punched card back or forth to bring the image into focus.
- When the eclipse occurs, the circle will become small and take on the shape of a crescent, if it is a partial phenomenon. In the event of a total eclipse, the circle will become an "O" with a thin border.
- You can also use a pinhole camera to observe the eclipse.
Step 4. Use a solar filter to mount on the observation devices
If you choose to look at the Sun directly with your eyes (rather than projecting the image onto something), you must always interpose a solar filter between you and the eclipse. Although it is possible to look at a total solar eclipse only in the perfect superimposition phase, only an expert observer is able to accurately judge the exact moment and determine when the time comes to interpose the filter again, before the Sun reappears.
- Since most eclipses are partial and most observers are amateurs, it is much safer to always use a filter; even the slightest solar radiation can damage eyesight, so even the sun's coverage of 99.9% is dangerous. Sunscreens are available for all observation devices (camera, binoculars and telescope).
- When choosing the solar filter for a telescope or binoculars, it is essential that you purchase the one made specifically for the make and model of the device. If the filter does not fit properly or is used incorrectly, it can cause irreversible eye damage.
Step 5. Observe the eclipse indirectly by making a projector
This method, which you can use thanks to binoculars or a telescope, is just as safe to see the phenomenon. However, it is only really safe if you look at the eclipse indirectly and not through the optical device while performing the projection!
- Cover a binocular lens with a piece of cardboard or a special cap.
- Turn your back to the Sun and hold the binoculars with one hand pointing them towards the eclipse, so that the uncovered lens captures the image of the phenomenon. Use the shadow of the tool to help you align the lenses.
- See the image projected onto a screen, wall, or large sheet of white paper that you hold with your free hand. The screen should be approximately 30 cm from the eyepiece. Move the binoculars until the eclipse image appears on the card, wall or screen. The further you move the screen away from the eyepiece, the larger the projected image.
- When using this technique, try attaching the instrument to a stand, such as a tripod, or leaning it against a chair or table. The image quality is better if the instrument remains stationary.
- If you have decided to use this method to observe the Sun when there is no eclipse, protect the binoculars from the sun after one minute of exposure, to prevent it from overheating. Wait for the optics to cool down for a few minutes before starting over.
Step 6. Use welding goggles
Choose a model that complies with the UNI EN 169, UNI EN 175, UNI EN 379, UNI EN 16 standards; in this way, you are sure to use the most effective, widely available and inexpensive filter to look directly at the Sun. The glasses must completely cover the eyes during the whole observation period.
You can apply this type of filter in front of the binocular lenses. Again, remember that the lenses must be completely covered and, if you can only protect one lens, only use this by putting the cap on the other
Step 7. Use specific filters
These are special accessories that can be purchased and mounted directly in front of the telescope or binocular optics. Although they are quite expensive, there are cheaper versions that protect your eyes while still allowing you to see the sun. There are several important warnings you need to consider when buying and installing a sunscreen:
- You must be absolutely sure that it is a sunscreen, because normal photo ones Not they block dangerous rays.
- The accessory must perfectly fit the make and model of your optical device. Always contact a reputable dealer; if you have any doubts about the safety of the filter, do not use it and, if you need some advice, call your local planetarium or an astronomy association for expert advice.
- Check the filter surface for any damage before mounting it to the optics. Polyethylene terephthalate tears or tears easily and, when damaged, can no longer be used.
- Check that the filter is mounted securely; if you have to tape it to make sure it won't come off, don't hesitate to do so.
- Do not use accessories that screw into the eyepiece of the binoculars or telescope. The light focused by the eyepiece lens can burn or break the filter due to the intense heat being concentrated; even the smallest crack or opening on the filter can cause permanent eye damage. Use only accessories that attach to the lens.
Part 2 of 3: Observe the Lunar Eclipse
Step 1. Learn about lunar eclipses
They are less frequent phenomena than the total eclipses of the Sun, given that the partial ones occur twice a year, while the total lunar ones occur on average once every two or three years. They occur when the full Moon enters the shadow of the Earth and takes on the color of copper or dull red (the phenomenon is called "Red Moon").
- The total lunar eclipse lasts up to one hour and forty minutes, although it can reach six hours, if we take into account the phases in which the Moon passes into the penumbra region.
- Just as with solar phenomena, there are total and partial lunar eclipses, which depend on the alignment of the Earth with the Sun and the Moon.
Step 2. Be prepared to stay up late
A lunar eclipse occurs only during the full Moon and when this is perfectly aligned with the Sun and our planet that casts its shadow on the satellite. It is visible only late at night and over a period of a few hours as the Moon moves in and out of the shadow cone. If you want to observe the whole phenomenon, you have to stay up late.
The sky must be clear and practically cloudless for good observation
Step 3. Look at it with the naked eye or through a magnifying device, depending on your preference
The lunar eclipse is perfectly safe for the eyes and you can enjoy the show without using filters. You don't need any special tools, because you are not looking directly at the Sun, but at the projection of its light on the lunar surface. For this reason, there is no risk of retinal damage and no special equipment is required.
- To observe more exciting images of the eclipse, you can use binoculars or a telescope.
- If you want to photograph the phenomenon, read this article for more details.
Step 4. Dress appropriately
Since the eclipse is visible at night, the air could be cold, so wear warm clothes and bring a thermos with a hot drink to sip. Don't forget to bring something comfortable to sit on too, as the eclipse lasts more than an hour.
Part 3 of 3: Prepare for Eclipse Observation
Step 1. Find out when and where the eclipse will be visible
It is difficult to observe it when it is not there! The best way to know the eclipse calendar is to use the internet and follow the updates of reliable sites. Well-written journals and astronomy books publish the dates of impending eclipses. Some sites you can consult are:
- NASA's website (in English) for eclipses, available here: provides details of lunar and solar phenomena. Also, you can learn about the paths of eclipses up to 2020 and up to 2040.
- Some sites or blogs dedicated to astronomy and science publish the dates of the impending eclipses.
Step 2. Check the weather forecast for the day the phenomenon is expected
Sometimes, climatic conditions prevent good observation, for example when there are clouds or a storm. If the sky is clear, you are ready to enjoy the show! Use the weather information to dress appropriately; in the winter months you will need to cover up well to keep warm while watching the eclipse.
Step 3. Inspect the observation point in advance
If it is your garden, it is obviously familiar to you, but if you have to go to another place to enjoy the perfect view, check it before the fateful day. Check the conditions of the ground, where you can park your car, if there will be many people and so on. There are some fundamental factors you need to consider when choosing your viewing area.
- View: choose a place that allows you to see the horizon clearly, so that you can observe the approach and exit of the celestial body from the shadow cone.
- Convenience: are there bathrooms, refreshment points, shelters?
- Accessibility: can you reach it easily, can you park without problems, can you walk in the area?
- Familiarity: Could the area attract busloads of tourists? If it is easily accessible by buses, there is parking for these vehicles, the place is advertised on Facebook and Twitter, you should look for a less known and therefore less crowded place! If you know someone who lives on a farm, ask them for permission to enter their property to see the eclipse.
Advice
- If you can't watch the eclipse outdoors, you can see it on astronomy sites, including NASA's.
- Sun goggles for observing the Sun are not recommended, unless they are certified by the Ministry of Health and comply with European Community standards. If you can't be sure of their quality and level of protection, it's best not to use them.
Warnings
- In addition to the specific problems already covered regarding eye safety, when you look at an eclipse you must also think about your personal safety. Staring at the sky in rapture makes you vulnerable to the action of a robber or someone who wants to hurt you. If you are in a place known to be unsafe, stay alert and don't go to an observation point alone.
- Stay in the company of friends or people you know and always be aware of your surroundings during an eclipse. The other safety issues concern observation points out of the way in the countryside, the need to watch out for other people who are not focused on driving, lock the car and store valuables in a safe place if you go to an area. crowded or public observation.
- You should always monitor children during the eclipse and not leave them alone with an optical device!
- Don't leave your binoculars or unfiltered telescope unattended to watch the eclipse, in case some curious individual wants to use it without warning you. You should always keep all tools close to you, place an obvious warning sign or sign, and move them, in case you have to walk away for some time.
- Remember mom's warning: don't look at the sun or you'll go blind! It is absolutely true!
- The larger the telescope, the more likely it is to damage it with the projection method, especially during a prolonged observation of the Sun. The heat generated by the solar image is intense, so use a simple telescope, such as a (lens) refractor., or Newtonian (mirror) and avoids the more complex tools for projections.
- Beware of wildlife. During an eclipse, lunar or solar, animals feel confused and strange noises in the dark could generate some anxiety.
- If you are aphakic (you have had cataracts or have suffered a trauma that required the removal of the lens), you must use an adequate sunscreen to ensure eye protection while observing the eclipse.
