
New neighbours ahoy!
'ALIEN EARTH with a RED SUN discovered 470 light-years away'
I wonder if they'll mind if we pop round to borrow some sugar...'
The discovery of new planets likely to be able to support life along Earthly lines has been announced, with one of the most promising candidates for alien and/or human habitability located just 470 light-years away. The new exoplanets have been discovered by analysis of data from the Kepler space telescope, and bear the tags …
That's always been an interesting concept. But if we assume that life started an progressed on both planets at the same time, then they're about 400 years behind us at a least as far as the radio signals getting here. And vice versa. A bit of time lag..
Solve the time lag and the sensitivity for artificial radio waves then the searches can begin in earnest.
There's some speculation as to how long a civilisation actually outputs identifiable radio signals.
Our early signals are all pretty easy to decode(plain AM or FM, or even Morse)
Add the TV signals and it gets a bit moe dificult. Not impossible, just takes a bit of trial and error as soon as they see a pattern.
Now, imagine today's digital radio, or the signal being sent to a satellite for broadcast.
Our strongest transmitters today are probably those used to talk to assorted probes in space, and they're highly directional.
How long will we even continue using Radio waves?
Maybe there's only a short (less than a 1000 year) window when civilisations use radio?
Get a life. Exactly. Stop doing what you love and satisfying your own desire to know things just because it's there to be known. Fuck all that shit. Just do what you're told like johnnymotel. Drink what you're told to drink, aspire to copy those you're told are "cool", be attracted to the people the media tells you are atractive. Interested in exoplanets? What a loser. You've been told so many times you're meant to enjoy getting drunk and watching some kind of sport, so do it. Get a dull job like you see on the soap operas you're supposed to watch. That's a proper life.
The reference to 1000 planets in the original NASA press release is that these are the 1000th confirmed planets from the Kepler mission. I guess this means the 837 other planets on your app must have been detected by other means.
When I first heard of the Kepler mission I thought that in the long run it would be the most important single mission that NASA has ever undertaken, and likely to be the most important one of the 21st century. I am thinking I was right. It's nice to know that at least some tiny fraction of my tax money was not squandered on buying bleeding-heart votes for some congresscritter.
In order for planets to form you need a stable(ish) solar system and lots of time (think: in the millions of years). Now, usually the planets start to form from discs of material, dust etc... surrounding their start shortly after the star's birth. Close enough that you start the "millions of years" clock from star birth.
It's reasonable to assume, then, that these planets have orbited that star since about 3-10 million years after its birth. A Red Dwarf star burns longer the smaller it is and these stars (according to the article) are smaller than our sun meaning they could go on for more than 15, 20 billion years. I can't find info on the mass of Kepler 442, the star Kepler 442b orbits so will have to leave the guess as to its age in the billions of years.
This means the planets have been around for likely billions of years and, at least up until 470 years ago, in a stable system.
So the chances of them undergoing some catastrophic event that has destroyed them is 470 divided by those billions of years. Sufficiently small for us to conclude they're so overwhelmingly likely to still be there now that it's not statistically credible to propose that they are not.
Good question, though!
...470 light years ago, the planet existed...
You mean 470 YEARS ago the planet existed. The year is a unit of time, the light year is a unit of distance.
But as the previous poster said, planets are pretty permanent and it's not very likely anything so catastrophic as to destroy it would happen to one in the space of a few hundred years!
how do we know it is still there?
That's either an unsolvable question in epistemology, or a very easy one in physics.
The physics one has been answered: based on the data available to us, and the best explanatory models we've developed for that data, we calculate a high probability the planets "still" exist.1 A Bayesian reasoner concludes that the assumption the planets still exist is the most useful one to operate under (while remembering the converse still has a non-zero probability, of course).
The epistemological one is unsolvable because we can't say how we know anything "for certain". We have to trust our mental facilities; then we have to trust the evidence of our senses (in this case, for the sensory impressions we receive from our technologies); then we have to trust that our technologies do not suffer defects that cause them to report erroneous results; and so on.
Of course, in a case like this, we ultimately have to trust that no cataclysm has destroyed the planets, because we won't know about it until it catches up with us. False vacuum collapse, for example, propagates at C or very slightly less, which means we'll find out about it right as it's destroying us. In fact, we'll probably never know, because it would propagate as fast as (or very nearly so) any of its effects, so our brains wouldn't even have time to recognize the signs. We'd be here and then we wouldn't be. And nothing else would be, either, in this universe. Ever.
Since there's nothing to be done about that possibility, it's safe to assume it hasn't happened, and never will. If you're wrong, there won't be anyone around to laugh.
1"Still" is problematic in itself, since it assumes some absolute frame of reference for time. But we'll pretend simultaneity has meaning across large distances for the sake of discussion.
Fed up with all this "Kepler nnnn-X" malarky. About time we started using names, there are plenty from Sci-Fi, vaguely fitted with the relevant story's description.
E.g. this one could be Naboo? Or Romulus?
What would be amusing is if the residents then get wind of this name calling, take offence, and launch an attack....
What would be amazing is if these planets didn't end up like the earth, of whom very likely was struck by a mars or smaller size orbiting companion planet - which means we might actually be BEHIND this newly discovered planet by about 4.5 BEEELLION years! HA!
I welcome our new overlords! 3:)
The Earth and Moon get exactly the same amount of solar energy, yet the maximum temperature on the Moon is 200C hotter than maximum on Earth. The minimum temperature on Earth is 75C warmer than the minimum on the Moon. There are three major factors in this difference, atmosphere, oceans and Earth's internal fission heating. Read "Greenhouse Gas Ptolemaic Model" at Faux Science Slayer for details. Earth is unique in a hundred ways that allow self replicating, conscious life forms which take an eternity to develop. Even after years in school, some life forms are still unconscious.
How can any article include the phrase 'just' when referring to many light years?
'It's a good bit further off, at 1,100 light-years.'
I know the English have a penchant for understatement and this is an example. Light from this star left the star before William the Conqueror did his thing but it's 'a good bit further off'. Makes it sound like you'd have to go all the way to the next town over to get there. No, these are vast distances and the language should, in my opinion, reflect the (literally) astronomical distances involved.
In the scheme of things, 1100 light years is still in our close neighbourhood. Our galaxy is over 100,000 light years across. The closest proper galaxy to our own is over 2,000,000 light years away. The most distant are thousands of times further than that! Such phrases used in this article and others like it are, in my opinion, fine.
And its distances are totally incomprehensible to the regular human being.
Consider that astronomers are regularly talking about our "galactic neighborhood" - meaning the group of galaxies that are closest to us.
This has nothing to do with understatement, and everything to do with you not being used to the distances and concepts. Not a slur on your knowledge or intelligence, far from, but when one's job is to look at data coming from the nearest galaxies who happen to be up to a trillion light-years away, I guess that one does end up considering them in a different light and talking about them in such a way.
So, considering that a group of stellar systems less than 2000 light-years away are in "our neighborhood" seems perfectly reasonable, when you realize that that distance is less than 1.7% the diameter of our galaxy.