|Why are eclipses limited to solar & lunar names? Is galactic the meaning of solar? So what other 2 celestial bodies would be in a solar eclipse with us; hence the power of three rule, cosmic clouds, a universe, a sun, a comet. My question is why we can not sense life outside planet Earth & guessed one possibility is we're all eclipsing each other right now?|
|Question Date: 2019-10-19|
An eclipse is an event when an astronomical object in space is obscured (hidden), either because it passed into the shadow of another object, or another astronomical object came between it and the viewer.
On Earth, we witness two major eclipses, the solar eclipse and the lunar eclipse. In a solar eclipse, the moon comes between the Earth and the sun, blocking the sun from our view on Earth. Solar means "of the sun", so a solar eclipse blocks the sun from view. In a lunar eclipse, the shadow of the Earth covers the moon, so that we cannot see it. Lunar means "of the moon", so a lunar eclipse blocks the moon from view.
We only have solar and lunar eclipses on Earth because the moon is the only object close enough to the Earth to totally block out the sun, and the Earth is the only object close enough to the moon to totally shadow the moon. Other astronomical bodies do come between us and the sun, though. Comets and the two inner planets (Mercury and Venus) pass between the Earth and the sun, but they are too small and too far away to block all of the sun's light. When these pass between the Earth and the sun, they look like a little black dot on the sun!
We could think of other examples of the sun or the moon blocking our view of other astronomical objects. The moon moves around in the night sky, and sometimes it blocks other stars or galaxies from our view. We could also call these eclipse events. It happens so often, though, that we usually don't name these eclipses like we name the solar and the lunar eclipses.
We have not yet sensed life outside of our solar system yet, for many reasons! One of them is that planets in other solar systems far away do get eclipsed by their own suns. Sometimes, the planets "go behind" their suns from our perspective, so we cannot see them or sense that they are there. The biggest reason that it is hard to detect life outside of our solar system is that the universe is huge! Even our solar system is huge. If we were to send a phone call from Earth to the sun, it would take eight minutes for our call to get there! The universe is much, much larger than the distance from the Earth to the sun. If we were to send a phone call to the star closest to the sun (Alpha Centauri A), it would take 4.2 years for the phone call to get there. Additionally, we would have to have a very powerful phone to send the call out that far.
If another civilization in the universe wanted to contact us, they would have to send us a very powerful signal for it to reach us. There is a large worldwide effort to look for life outside our solar system called SETI, the Search for Extraterrestrial Intelligence. They use many different tools to look at the universe and search for life!
These are interesting questions. When we talk about an eclipse, we mean that there is a shadow cast on a celestial body that we can normally see (the sun or the moon, for instance). These shadows are cast when our sun, Earth, and moon line up. For a solar eclipse, the moon gets in between the sun and Earth, blocking the light of the sun from reaching Earth. During a lunar eclipse, on the other hand, the Earth gets between the sun and moon, casting a shadow on the moon so we can't see it. So when we say "solar" or "lunar," we are referring to the celestial body we are not able to see. We can't see the sun during a solar eclipse, and we can't see the moon during a lunar eclipse.
When we use the word "galactic," on the other hand, we are talking about things in relation to galaxies, rather than specific objects like the sun or the moon.
Looking for life on exoplanets, or planets that exist outside of our solar system, is an ongoing effort by many scientists! Some scientists are trying to do this by detecting certain chemicals that we associate with life as we know it. It is very difficult to do this though, because such planets are very far away and there are many of them to analyze.
I hope this helps you and that you continue to be curious about science!
Great questions! An eclipse happens when a celestial body blocks our sight. On Earth they're limited to solar and lunar because they're the closest celestial bodies in space. No other celestial bodies largely block our sight. The reason we cannot sense life outside planet Earth is space is HUGE. There are at least 25 billion places where life could exist, orbiting 100 million stars. Your guess is smart and we could be not seeing life because celestial bodies block our sight. For example, a nebula is dense may be hiding other planets!
No - life on other planets is hard to find, because we only know about the kind of life on Earth, so we might not recognize other kinds of life. Also, we can see so little of other planets, because they're so far away. Eclipses come and go quickly, so they don't cause problems with finding life on other planets.
A solar eclipse is when the moon gets between the Earth and the sun and casts a shadow on the Earth. We call it a solar eclipse because we can't see the sun (because the moon is in the way).
A lunar eclipse is when the Earth gets between the sun and the moon and casts a shadow on the moon. We call it a lunar eclipse because we can't see the moon (because the moon doesn't emit light, and isn't reflecting sunlight because the Earth is in the way).
The word "galactic" refers to the galaxy, which our solar system is part of, but is hundreds of billions of times larger than our solar system. Solar and lunar eclipses have nothing to do with the galaxy outside of our solar system. If the rest of the galaxy were to vanish, or the sun were to be expelled from the galaxy, solar and lunar eclipses would still happen the same way they do now.
Solar and lunar eclipses involve exactly three bodies: the sun, the Earth, and the moon. Other planets have their own eclipses, but we can't see them from Earth. Jupiter, for example, has four large moons, and each one can cause an eclipse if you viewed it from a balloon in Jupiter's atmosphere (Jupiter has no surface that you can stand on, hence why you would need the balloon).
There is no power of three rule. Cosmic clouds have nothing to do with eclipses. Comets have nothing to do with eclipses.
We don't know of any life outside of Earth, but that's probably because we haven't explored far enough, not because of anything involving eclipses (in fact, it's hard to see how an eclipse could prevent us from discovering life on another world).
The word, "eclipse" means to block from view. It is important to remember that the view depends on the viewer. So when we talk about a solar eclipse, we mean that something is blocking the sun from our view here on Earth. It is the moon that blocks our view of the sun, because even though the moon is much smaller than the sun, it is much closer to us, and so it appears large enough to block the light of the sun. So during a solar eclipse, the moon passes between the sun and the earth such that when you look at the sun, your straight line of sight hits the moon first.
Try to draw the positions of the sun, moon, and Earth on a piece of paper. Now imagine that at the same moment you see a solar eclipse, another life form could be looking at the sun from a spaceship, but the sun would not appear blocked to them, because their view and their line of sight is different. A lunar eclipse is when the earth passes between the sun and the moon, so that the shadow of the earth appears on the moon and it looks darker than usual. Partial lunar eclipses are what cause the phases of the moon -- when it looks like a crescent, a half circle, and a full circle every month.
A galactic definition for the word eclipse would need to include the specific entity which is light (like the sun, another star, or a cluster of stars) and the specific entity observing the light (usually people on Earth because this is where most of us spend our entire lives). The entity doing the blocking of the light -- between the light and the observer -- could be anything from a moon to a comet to another planet.
You asked if the reason we cannot detect other life is because we are eclipsing it. That's a good guess, but not exactly. In fact, eclipses help us to detect other planets like our earth, where there could be other life forms. Let's think about that quickly. We don't know what another life form will look like, whether they will need air to breathe and water to drink and food to eat. But if they don't,what DO they need? This is anyone's guess. Sowhat we currently do, is to look for life forms that might be something like us. This way we have a better chance of recognizing them when we see them. We usually say that if the other life form is like us, it needs water to drink. And if it lives on a planet that is too far away from a star (like our sun that keeps us warm), the water is frozen and the life form cannot survive. Therefore, we want to find a planet at a certain distance from a star, and look there for signs of life.
When we look at the sky, it is much easier to see far-off stars, than it is to see planets. This is because the stars give off more light. But if we watch some stars carefully, we find that the amount of light they emit, decreases by a little bit for a short amount of time, and then goes back to normal. This happens on a regular basis; with some stars, it happens every week, and with others, it happens every month. What is happening? Why is the star's light fading for a moment? It is because something is passing in front of it and blocking some of that light. Something is eclipsing it.
Many times, that something is a planet revolving around the star, just like the earth revolves around the sun. And it is places like these, where there are eclipses because a planet orbits a star, that we are searching every day for signs of life.
Eclipses, like you said, involve three bodies: one providing the light, one obstructing the light's path, and one that is no longer receiving the light.
On earth, the sun and the moon are the main visible celestial bodies so that is why we usually only talk about these types of eclipses. Other types of eclipses are possible as long as the light from some celestial body is blocked by another body, preventing it from reaching Earth. There are also specific size ratios between the light producing body and the blocking one that are necessary for an eclipse to happen. Most other light-producing bodies are rather far away from us so we don't really see their light unless we are looking through telescopes. When you add that to the specific ratio requirements, getting an eclipse to happen becomes very very very difficult and unlikely.
Galactic and solar are not the same: galactic means that you are talking about something in reference to a galaxy while solar is more in reference to a sun.
As for looking for other life forms, we usually go about doing this in two ways: (1) listening for any weird signs of communication and (2) by looking for other planets with conditions that resemble those on Earth. It is possible that signs of communication could be getting blocked from reaching Earth by celestial bodies (similar to an eclipse). However, it is also not easy to distinguish these signals from general "cosmic noise" which is constant all around us and the result of a number of different cosmic events (like supernova explosions). It is also not easy to analyze the compositions of planets too. These difficulties together mean it is really hard to discover life on other planets.
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