Finding a similar planet to earth.?

Question

This may be niave of me but if we see all of the bodies of space as they were in the past ( the amount of time relative to the distance) then if we were to find evidence of a planet similar to earth in each way and planets such as this came to an end then could it not be possible that by the time we reach or even find out out about this planet in reality it could no longer exist. If this is blatantly wrong excuse me I am an ignorant 15 yr old

Please note that of the recent discoveries of planets though most have been gasious (can't spell today) and closely orbiting there was on foun with three gasious planets orbiing round an ursula major star that were at further distances similar to those of Jupiter and Saturn around our own sun. This is where my question comes from

Answer 1

No, pretty smart for an ignorant 15 year old. Basically yea, if we were to somehow find out about a planet like ours in which we could inhabit then that'd be nice. But, by the time we reach it.. it could be inhabitable for whatever reason. The key is to travel fast enough (possibly the speed of light, if we ever attain the technology) to reach it. Because if we travel the speed of light then reaching the exoplanet would seem instantanous.
I may be wrong too, I'm not a genius either.
Some people in here are though, and they'll give you a more detailed explanation and probably give me a thumbs down... but that's ok. Thumbs down away.

Answer 2

I think the problem will be to find a planet that is truly similar. Until a few years ago we (and that includes most any scientist in the field, I bet) were rather limited in our imagination of what "most" planets look like. We thought about our solar system as being a rather typical, run of the mill kind of place.

The recent discoveries of gas giants larger than Jupiter orbiting their host stars in orbits much closer than our planet Mercury have thrown that naive picture out the window. So now we are looking at a host of new discoveries which indicate that "we" might not be that typical, after all.

From that I would conclude right now that the universe is a rather diverse place and that diversity cuts down on the chances to find something that looks and smells and works like Earth quite a bit. I find this thought absolutely amazing (I like my world colorful and diverse), but it kind of puts a damper on nearby sister worlds.

And as you mention, "nearby" is an important word. Even with the best imaginable technology, travel to even the nearest stars and their planets will take decades, maybe centuries. It is not so much the lifetime of planets which measures billions of years that puts a limit on. It is our own lifetime which makes interstellar travel a bit of a drag. I certainly would not want to commit my whole life (and possibly the lives of my children, grandchildren and grand-grandchildren) to a single one way trip.

Answer 3

The Earth has been in existence with life on it for about a billion years. A billion lightyears is a truly gigantic distance, and includes literally billions of galaxies. Our own galaxy is only 60,000 lightyears across, and we will probably visit many of the planets within it in the next million years. So they won't be gone.

Answer 4

it would in all probability be extra interesting if it has no existence because of the fact then technological understanding could ought to alter a number of its books. besides the undeniable fact that if it does have existence that is going to in all probability basically effect interior the start of a million new religions a tactics worse then something we've seen till now imo.

Answer 5

Don't knock yourself, all the best questions get asked by young people.

Those are actually EXCELLENT questions.

There are two surveys going on right now, where there is an explicit search for terrestrial planets. So far over 160 different star-systems have been detected and are being cataloged.

Among these there are some "sweet spot" star systems.

Among them are Upsilon Andromeda, Episilon Eridani and Gliese 876, these star systems, not only have primary stars VERY similar to our star, but also have planets in about the right position for life.

You can see some of them (as imagined) here,

http://www.extrasolar.net/starlisttour.asp?StarcatID=normal

Your question is actually two questions, if I understand correctly,

1. You are correct that we are seeing very distant planets are as they were thousands or millions of years ago, over time, we will discover most of the star-systems (but probably not all) in the the volume within about 50 light years of our star, and have discovered many systems both inside and outside of that volume.

We are just now discovering what the "typical" star system looks like, over time, we will be able to accumulate statistics about what star systems look like or group them into categories. Each category will have different "lifecycles" whereby we expect certain things to happen over millions or billions of years.

We have a pretty good idea that our star-system is very stable, with planets in orbits that are not decaying rapidly or anything.

Some moons are in better shape than others, Demios (of Mars) and Io and some other moons (of Jupiter) and many moons of Uranus, are not in long-term good stable orbits, and will eventually either crash into their primary planets or be crushed by gravity and turned into ring systems which again - will crash into the primary.

Your other question is good, lets presume that humanity get's "off world" and starts to colonize the solar system, eventually, we will want to build starships to go to some of these other planetary systems.

First things first, we will send small fast robot probes to each star system in range of any planned starships, like Voyager or Cassini, these probes will help us in more broad detail map each star system - determining how many planets are likely in each system, whether there is life and are any moons or planets which we could colonize.

Excellent discussion and fiction surrounding this topic is available at Orion's Arm, based entirely on "Hard Science" , that is not engaging in any BS speculation, but working off
of what physics and already known science tells us is possible.

http://www.orionsarm.com/intro/what_is_OA.html

After we had figured out which star systems had planets which looked good for colonization, we might send a second fleet of probes to actually go to the planet in the candidate star-system, once we figured out whether it was actually devoid of dangerous life, we would probably send back signals to the Sol system.

Then the fun begins, a set of starships would be created, each capable of going about 0.05 or 0.1 C or about 10% the speed of light, this would allow a colony ship to make it to say Alpha Centauri inside of about 40-50 years.

These ships would be massive, taking decades to assemble and prepare for launch, as big a planetary/solar economy investment (at first) as the first colony ships to America or to Mars were/will be.

Eventually shipyards for starships would exist around the Asteroid belt (for resources and proximity to Mars) and Jupiter (for hydrogen fuel).

We would then send a "seedship", these seedships will either have very small "prep" crews most probably either in some sort of deep sleep stasis like in Aliens or 2001/2010 or they would be totally "automated", with smart robots, like friendly robots like those in "I, Robot" , which would prepare the colony world for humans, planting forests, finding and starting to develop mines and identify and build areas for cities, and bringing animals and such for food and to start an human-friendly ecosystem, this prep colony would be send decades (perhaps) in advance of the main colony ship.

These machines would have started building the colony in advance of the colonists who may have been launched in a slower, larger "colony" ship, which would contain the colonists and maybe some additional tools and materials needed to adjust/expand the new colony.

However, any number of things could happen, a comet could strike the planet, the climate might not be right for us in some critical way, (lacking or having too much sulfur or potassium or iron or some element which we need only very small amounts of).

Answer 6

The galaxy's are so far apart it is doubtful if we will be able to communicate with them.

Answer 7

Thats entirely possible!