Should humans look into finding another planet besides Earth to live on?
Given enough time, humans might develop the technology to build long term containments on another planet, or an interstellar colony which might, one millennium, find a habitable world. But this would be for a small, select group of humans. The idea of moving everybody to another place is a pipe dream. So suppose they KNOW that some event is going to occur which will make this planet uninhabitable. Okay, send your mission out, but for the billions of others, the only escape is to die before it happens. The humane thing to do would be to have absolute birth control. We would simply stop having babies. The population would dwindle. Finally, there would be one person left. I have often thought about that one old person. He or she might look in the sky frequently and think about those humans out there, wishing them the best. The person would sit on a beach, with no one else but the other creatures of the planet, watching seagulls go about their blissfully ignorant business, knowing, "I am the last of my kind. What can I do of significance with what days I have left? Nothing. Nothing but enjoy and appreciate this marvelous world with all my might...for all of those who never had a chance to live." Oh, 2012? Psshh. It's a crock. Total BS. Don't worry about it.
How does Earth look from other planets?
When Voyager I reached 6 billion kilo meters Carl Sagan requested NASA to turn around its camera. And what we saw is the Pale Blue DotIts as he quoted was "all of human history has happened on that tiny pixel, which is our only home". So, it really doesn't matter how we look from outer space, because all we are to outer world is a pale blue dot. Thus, from any planet in the solar system earth looks like a blue planet. And from planet beyond the asteroid belt, its hardly visible with naked eyes. So, from Jupiter, Saturn, and others, Earth can be seen only with the help of powerful telescopes.Visibility is not the only criteria for searching the planet, if some intelligent life form is really searching for us. They can look for all the electromagnetic radiations we have been emanating lately, which is the certain proof of our existence in the universe.
Since other planets look like stars, does Earth look like a star from far away?
obviously...... Martians would see a very dim blue dot...in their red night sky...!!!.....people from other solar systems would not be able to see our planet in the light of the sun
Why are we looking for Earth-like conditions when searching for life on other planets?
Because that's the only one we are capable of identifying. There might be other species who might have evolved to breathe in say methane, drink benzene and eat gold or something and can withstand in harsh(according to us) conditionsSure, there could be. But what do we look for? Chemistry is not my strong point, so I'll just give an overall layman idea. We are a water-based, oxygen-based planet and our bio-signature, simply put, consists of water, oxygen, carbon dioxide, methane, nitrous oxide. The presence of water indicates a chance for habitation. The presence of oxygen/carbon dioxide might indicate the presence of at least primitive lifeforms. Bacteria give off nitrous oxide and methane. Of all the components, water is what is most practical to go with when searching for life. Water is a universally good solvent. It allows for easy motion of molecules within cells. It has the ability to remain liquid within a wide range of temperatures and has a high heat retention. I'm not entirely sure why, but its strong polarity helps too. That's why we are more interested in Mars (that has water-ice) and Europa (which has oceans below the surface). We are also interested in Titan, which has an earth-like water cycle system, but with Methane. However, we can't really tell how to proceed there. Additionally, water vapor is what causes climate regulation that helps sustain life. Here is an excellent answer about how that happens: Alex Guerra's answer to How does global warming work?So we know that if we find a planet that has all of the above (in addition to other things, but let's keep it basic), there is a higher chance of finding life or life-sustaining conditions on the planet. Now, you ask whether there could exist organisms that could be breathing in Methane. Chances are, there could. Who knows, maybe there could be some form of primitive algae life on Titan. However, what would the life form give out after consuming methane? Plants on Earth take in CO2 and give out O2. Animals do the opposite. But we don't know what a methane-based life form would give out. Researching about such systems that might survive on the gazillion compounds out there is far more expensive, highly impractical, and very prone to errors. Simply put, we look for Earth like conditions only because we don't know how to identify other conditions that could support life.
Do Flat Earth Supporters think that other planets (Mars, Venus, Jupiter, Saturn) are flat too?
There are three answers to this, at least what flat earthers have argued:There is no proof that other planets are spheres because we only see one side of them when we look. As in we see a 2D picture. NASA probe pictures are fake.Other planets are not even made of rock. They are clouds of shiney gas. There are some videos on YouTube of some uneducated fool zooming in with a digital camera on a twinkling light.I've heard this only once: just because other planets are spheres it doesn't mean earth is a sphere as well. This is the guys “logical” argument: there's a room full of women, a man walks in. Do we say he's a woman just because everyone else is?In case #1 those people have never looked thru a telescope. I've told a few of them to go look at Jupiter and see it spin.In case #2, well all you can tell them is use a telescope and not their point and shoot, or DSLR, to zoom in.In case #3 I simply pointed out that the logic of that argument is flawed. We look at the evidence and see he's a man so we call him a man. And with earth we see its a sphere from all the evidence (pictures, laws of physics) that it's a sphere.The flat earth argument is extremely flawed and has no basis in reality. It is only believed by those who have very low, or no, scientific understanding of how the world works. I mean some of them don't even believe in gravity lol