Quote:

---

Nasa... Have they really taken pics of everything they can past our boundaries of cold?

I was thinking. They say its to cold past pluto and everything. Well, the suns a star, and there are tons of stars in the sky. Why didnt they try to travel from star to star, atleast with satilites? Chances are if the universe is unlimited, there is an unlimited number of chance life started elsewhere.

I dont know if its vastness is endless or not, but has nasa done everything like my above mentioned suggestion to find life? (The satilite chain taking pictures and sending data back to earth.

Edit: 360 degrees times 360 degrees is something around 170k angles they would need to try before saying we cant go further. Atleast 25% of those angles. My guess is they tried from one to three angles. (Angles from the sun, the earth, wherever)

---

Quote:

---

But keep in mind, that not all stars have the intensity of the Sun, but who am I to say that, because nobody else has been close enough to another star to actually test whether the heat and intensity is the same or close enough to the sun.

---

Quote:

---

To my knowledge, NASA doesn't claim to have examined every inch of sky for extrasolar planets.  If they did, the astronomical community would laugh at them.    Deep-sky telescopes can only look at a tiny, tiny slice of sky at a time.  Not all slices are likely to have planet-friendly stars visible (e.g. some areas are occupied by interstellar dust clouds and the like).  NASA and other programs target their searches very carefully, probably finding suitable candidate stars on a chart long before booking telescope time.  Of course, the search is far from over.  IIRC, they need more precision before they can locate Earth-like planets, but they're getting there.  

Besides, the astronomers aren't only looking for Earth-like planets for life.  Those are the most exciting, but it's also interesting to find planets completely unlike those in our system.  Odd and new types of planets give clues into how planets form and develop in general.  They also give us an idea of the sheer diversity of planets which the universe is capable of creating.

Titanium Alloy is right: Travelling from star to star is not practical.  Even if it were technologically possible, even with robots, it would be unbelievably expensive and take lifetimes upon lifetimes to do.  It's much more efficient to sit at home and find extrasolar planets by looking at stars through telescopes and other instruments.  

@william:

Quote:

---

But keep in mind, that not all stars have the intensity of the Sun, but who am I to say that, because nobody else has been close enough to another star to actually test whether the heat and intensity is the same or close enough to the sun.

---

You don't have to be too close to a star to figure out its temperature.  Temperature is indicated by the star's color.  Here's the common chart that's used to classify stars by temperature/color and absolute magnitude.

(Temperature kelvin is equal to temperature Celsius plus 273 degrees.)    The sun is in the yellow-white section of the main-sequence.  It's classified as a G2 star, so to find other stars like our sun, they should look for main-sequence G2s.  

Stellar mass, which determines absolute magnitude (= "intensity" as you put it ), is trickier.  However, most stars have partners -- our sun is somewhat unusual as a loner -- so astronomers can calculate the stars' masses by watching them orbit around each other.  There are some other methods, but I'm forgetting what they are.  Age also affects absolute magnitude.

By the way, intensity is important for more reasons than just the obvious "don't fry the planet."  Stars with a high mass, and therefore a high intensity, live fast and die young.    They use up all the the fuel at their core in several million years or so.  Then they age, die, and go supernova.  They're going to toast any life nearby, and they may not have enough time for planets to grow life anyway.  Humans arrived when our star & planet were already 4.5 billion years old.  We don't know for sure how long it takes life to "catch" on a given planet, nor how fast it might evolve under alien conditions.  We've only got one example.  If it always takes this long, that's another reason to omit the crazy big blue stars like Rigel and Beta Centauri on that H-R chart.  And crazy big red stars (which were once big blue) like Betelgeuse are highly unstable.  Their size and magnitude go up and down, sometimes unpredictably.  There's very little chance life could tolerate that sort of nonsense.  

On the other side, red dwarves have the lifespan necessary for life...they can chug along for trillions of years.  But they also have a nasty habit of spitting enormous stellar flares proportionally much bigger than anything our sun does.  Any life sitting around a red dwarf might be subject to the occasional radiation bath.    Think of what sunburn does to us, even with our planet's protective magnetosphere, and you can see how this might be a problem.  Again, with only one example to work with, we don't know how much radiation life can adapt to.

That being said, there are several hundred billion stars in the Milky Way galaxy alone (140 billion stars is a low estimate).  So even if we have a lengthy "Don't Bother" list, there are still a lot of stars out there that might host life-bearing planets.

We'll never be able to measure the universe with a measuring tape, and star-hopping to see the different stars up close is still in the realm of sci-fi.  But that doesn't mean we live completely deprived of information on our beautiful, fascinating universe.  

[/random astronomy rambling ]

---

Quote:

---

But wouldn't certain things like other stars temperatures, effect the reading that we get if we are trying to figure out a certain star's temperature?
Maybe other thing's could affect that reading or whatever.
Just a thought.

---

Quote:

---

Quote:

---

But wouldn't certain things like other stars temperatures, effect the reading that we get if we are trying to figure out a certain star's temperature?
Maybe other thing's could affect that reading or whatever.
Just a thought.

---

Hmm, yes.  If there are two stars very close together, like a binary system, it would be hard to collect the light from one star and not the other.  My guess: Astronomers analyze starlight using a spectroscope, which separates the light into a spectrum (colors/radiation/heat).  Elements in the stars cause dark lines to appear on these readings.  There are specific, known patterns which the scientists look for.  If they get multiple spectra, they're looking at multiple stars.

Wikipedia: "Binary Star" talks about Dopplar shifts in order to ID binary systems.

---
For fun:  Neighborhood Stars is an illustration of all known stars within 12 light-years of our sun.  (Our current travel technology can't handle one light-year yet, let alone twelve, but we can dream. )  It shows their relative sizes and colors.  Picture is from The Universe and Beyond: Third Edition by Terence Dickinson.  This book was published in 1999; since then they may have found a few more red dwarfs and maybe some exoplanets.

---

Quote:

---

360 degrees times 360 degrees is something around 170k angles

---

Quote:

---

I think why bother exploring that part of universe
i think that it just too big,to complicted,to us,humens to understand.
If we can kill each other,i think,then other creatures already did,i think where the last remaining life form,others already killed thmselfs,over and over again.

---

Quote:

---

i wonder if even there "alien virson of HC" would have an alien virson of "black in denyal-modartor"

---