Visualize an alien sunset

Dennis McClain-Furmanski, Dalworthington Gardens, Texas — Tue, 11 Dec 2007 22:41:09 GMT

According to the Drake equation (estimating stars with planets, planets on which life could arise, planets on which life did arise, planets on which intelligent life arose), the number of planets that could support life outnumber those capable of receiving radio signals by several orders of magnitude. And the latter would then know what, among all the possibilities (far more possibilities that our SETI people consider) to do with them. Scientists who scoff at people who buy lottery tickets would still send radio signals. Sending a probe is the only way to cover all the bases. And it may give us a reason to stick around so we can know the answer.

Visualize an alien sunset

steve smyth — Tue, 11 Dec 2007 23:43:46 GMT

I still can't understand how the light gets here with no obstructions...there can't possibly be a straight, unobstructed line between the Hubble and the planet under examination...it's not really a vacuum out there...there's lots of stuff in the way.
Any answer would be appreciated...one of those 'always wondered' things, eh?

Visualize an alien sunset

Serge, Atlanta, GA — Wed, 12 Dec 2007 03:57:13 GMT

In answer to Steve Smyth's question:
You raise an interesting point. As an astronomy doctoral student who studies nearby stars such as this one, I must often ask the same question you are asking. It turns out that indeed there is a lot of dust in interstellar space, and it is absolutely right to say that outer space is not a vacuum. However that dust only becomes a relevant obstacle to light when looking at objects much further away than HD 189733. A good analogy is to consider a smoggy day on Earth. Smog or dust can completely block our view of a distance skyline, but may have no effect on how we see nearby objects. It turns out that our view to things such as the center of the Milky Way galaxy, at a distance of about 26,000 light years, is completely obscured by dust! Astronomers who study more distant objects have clever ways of correcting for dust extinction. Because dust selectively obscures red light more than blue light, it is often possible to come up with a mathematical correction based on the excess of blue light, and recover the object's true colors. Another possibility is to carry out observations using infra-red light, where dust extinction is not as important.
As far as large clumps of matter obscuring the line of sight, that is very unlikely to happen. Interstellar distances are truely enormous when compared to the sizes of stars and planets, so the chances of two unrelated objects overallaping in the line of sight are next zero, especially when considering nearby stars such as this one.
I hope this answers your question. If not or if it raises more questions, drop me an email at dieterich@chara.gsu.edu

Visualize an alien sunset

Doug Graham, Coral Springs Florida — Wed, 12 Dec 2007 05:28:08 GMT

It’s amazing that we as a species have started seeking life and possibly a future home outside our own solar system. Unfortunately the day that we find out for sure is probably well past our life times.
My guess would be that by the time we start manned missions to mars we will find an extra solar planet the stands a highly probable chance of harboring life. However I don’t think that we will be able to confirm it until well after we mined many of the asteroids and colonized titan. In other words centuries into the future. I also think that the only feasible way to confirm the planets habitability will be to send some kind of colony ship. Mainly because even the closest star is over a light year away and if it doesn’t have an earthlike planet then we could spend generations traveling to one that dose. Not that we can’t handle the challenge.

In response to Steve,
You are correct to think that there is a lot of “stuff” out there but the ratio between the stuff and the massive amount of empty space is what allows for a strait view of other stars.
Just think about it, how often do you see a star blink out and then come back a second later.

Visualize an alien sunset

Richard, San Diego, CA — Wed, 12 Dec 2007 09:15:17 GMT

I wonder if explorers from earth will treat those on other planets (should they happen to find life there) like the European explorers treated the indigent peoples of the Americas? Hopefully they'll leave the booze on earth!

Visualize an alien sunset

Paul Donahue, St. Paul, Mn. — Wed, 12 Dec 2007 10:54:42 GMT

What kind of advanced TV shows should we send up to these planets? How about re-runs of Mr. Ed.

Visualize an alien sunset

Howard Small, Las Cruces, NM — Wed, 12 Dec 2007 11:01:32 GMT

The imagination is a wonderful thing. Ever since I first heard of planetary discovery outside our solar system I try to imagine what lies up there. I believe a probe is the most logical choice. he only problam is none of this will ever happen in our life times. Heck, we were supposed to have flying cars by the year 2000.

Visualize an alien sunset

steve smyth — Wed, 12 Dec 2007 12:20:44 GMT

thank you for the answers...but, I still ain't buyin' it...forget the dust/smog effect...is there any sort of map of interstellar space that could be developed to show imaginary straight lines from Hubble to the aforementioned planet?
I cannot believe that there is any unobstructed line, measured in light years, running anywhere through the 'void'...just doesn't seem possible...no matter what prevailing wisdom says...besides, the light is ancient by the time it gets here...one more opportunity for something...anything...to get in the line of sight...fascinating stuff, eh?
someone go to habitablezone and ask Raoul...he lives, eats, and breathes astronomy...I can't post there because of questions like this...disruptive influence...
Thanx, Al...

Visualize an alien sunset

Jason Clark, Portsmouth VA — Wed, 12 Dec 2007 13:40:00 GMT

I agree with Doug Graham's comment: It will be hundreds of years before we have the technology to reach speeds close to that of light. However, I think that long before we reach that point through our own science we will be given the technology by those that are visiting this planet.

Visualize an alien sunset

Jason Fontaine — Wed, 12 Dec 2007 13:58:51 GMT

Think of this....the circle is the most powerful tool to our existence. What exists without the cycle of the circle. Look at the properties of the magnet. The magnet will propel us eventually into the further reaches of space. Please study the properties more closely of the magnet. We will not reach the heavens on rockets of fire!

Simply think of it this way

Power comes from bend
Look at the line -
How the circle bends
This is power
To bend a line
Effortlessly through time

Now figure the riddle out, harness the powere of magnetism - and let's get out of this place!

Visualize an alien sunset

Larry, Burlington, VT — Wed, 12 Dec 2007 14:23:53 GMT

Serge, I like your angle on viewing objects in the skies. I have one point of contention, you mention that the center of our Milky Way is obscured by dust. How are we able to see other galaxies and not the center of our own then?

Just wondering.

Visualize an alien sunset

Karl Detrich, Chapman, KS — Wed, 12 Dec 2007 14:25:02 GMT

This looks like a good forum for me to ask a nagging question: If light can be completely stopped by sufficient gravity (the black hole effect), how can the speed of light be universally constant? Would the speed not be affected to some degree by the gravitational pull of EVERY object?

Visualize an alien sunset

Jordan, Lake Havasu City, AZ — Wed, 12 Dec 2007 15:52:04 GMT

I don't understand why we think that only planets like Earth will be able to harbor life, just because Earth does. The life on this planet was born out of and adapted to oxygen, water, and etc.

So who is to say that life on another planet can't grow out of and adapt to different elements?

Visualize an alien sunset

Robert M. Berry, Rochester NY — Wed, 12 Dec 2007 17:50:58 GMT

Yes. Think in terms of the solar system. Yes there are things such as asteroids and such floating around in between us and the outer planets, but it's obvious that we can still have an open view of every planet in the system. And cosmologically speaking, this is a pretty crowded space. Open up out the universe and you have vast expanses of "nothing".

That's always the hardest thing for the average person to grasp are the vast sizes and distances involved with the universe....

Visualize an alien sunset

Qon Russell , Landing, NJ — Wed, 12 Dec 2007 18:47:55 GMT

One thing to consider that if we do discover a life world we can live on and have the capability of humans to it, we would never be able to live there. First is that regulations would probably prohibit us living there for fear of contaminating the world with our bacteria and viruses. The other reason is that the planet's microbes and viruses could wipe out the colonists since we'd have no immunity to them. But on the optimistic side is that they'd be so alien that they can't infect us so I hope for the latter.

Visualize an alien sunset

Dave, Stillwater, OK — Wed, 12 Dec 2007 23:18:20 GMT

Steve, the planet HD 189733b passes in the direct line of sight between earth, or the Hubble, and its parent star. Each time it does so, it creates a measurable dip in the visible light coming from the star. Many particles pass through the space between, and each blocks some light, but the space between is not filled with enough matter to obscure all the light from this atar at once. Light is emanating from the star constantly. If an object large enough passed between earth and the star, it would completely obscure the star from view. The neat thing is that, although the are object between here and there that may be of such size, they are relatively few and far between, so they seldom obscure the view completely. Most of the matter between is just interstellar grains of dust that distorts the light spectrum, like when light shines through a haze. Seeing this star is just like seeing any other star. For example, we can normally see the sun, even though there are objects that transit the space between us and the sun (i.e., Venus, Mercury, the Moon, and some asteroids). We have solar eclipses occasionally, but the stream of light waves is never permantly obstructed because celestial bodies move in and out of the light's path.

Visualize an alien sunset

Serge, Atlanta, GA — Wed, 12 Dec 2007 23:52:53 GMT

Hi Larry and Karl
As far as why we can see other galaxies but cannot see the center of the Milky Way, it has to do with where the dust is concentrated. The Milky Way galaxy, as other spiral galaxies, is shaped into a disk with a bulge in the center. The vast majority of stars lie very close to the disk, either right above or right below it. So does the dust! If our line of sight takes us at an angle above or below the disk, there is very little dust and light can travel through intergalactic space essentially unaltered by dust. You mention that we can see other galaxies, but that is only true when we look away from the disk of the Milky Way. The fact that we cannot see other things that look like galaxies close to the disk was actually an argument in the early 20th century in favor of the fact that these "spiral nebulae" were in fact distant galaxies and were not part of our Milky Way. it is interesting that they were originally called "Island Universes".

About "stopping" light inside a black hole: The speed of light is indeed always the same no matter where the observer is an how he or she is moving. The theory of relativity explains that in order for this to be true, time must flow at different rates for different observers. Close to the massive gravitational field of a black hole time slows down (gravitational time dilation). The reason why light cannot escape a black hole is not because the speed of light there is different, but because time passes so slowly that it would take an infinite ammount of (our) time for that photon (a "bundle" of light) to escape and reach us. So when we talk about time flowing at different rates due to relativity, it is precisely because of the fact that the speed of light is invarient for all observers that time has to vary.
Black holes are so weird!

Visualize an alien sunset

Dan — Thu, 13 Dec 2007 00:19:13 GMT

Gravity does not change the speed of light but the direction it is travelling in. The path of light from distance sources is bent when it travels past massive bodies such as stars.

The speed of light is constant no matter what frame of reference you have. For instance, if you are in a car travelling at 99% the speed of light, the light from your headlamps will still be travelling away from you at the speed of light.

Visualize an alien sunset

Liza — Thu, 13 Dec 2007 01:06:24 GMT

Personally, I don't think we should have the right to live on another planet when we can't even take care of our own.

Visualize an alien sunset

Delmar Fairchild, Barron, WI — Thu, 13 Dec 2007 01:43:17 GMT

I would say that with the speed of light not being attainable, we would never reach "there", (what we see today) before it is long gone. All that we see through our telescopes is only the light of millions or billions of years gone by. A snap shot of "then". What we are looking at today may be different tomorrow. Maybe a little more dust in that picture.
I think the whole universe has the same building blocks as our galaxy, solar system and planets, therefore there is life as we know it based on our universal atomic structure. We are a minute but essential part of the universe. We have to be the same if we are in the same elemental pool. However, because of the ever expanding outward space and it's getting greater than even our comprehension, we can never get to "there". Our own galaxy may already be falling apart and we may not know it for another 2 billion years watching through a telescope. The bottom line's amazing truth is that we have the brain power to even think we can reach "there" or even have the capacity to see the snap shot. That is something special for humans as only one of Earth's inhabitants.
It probably isn't something special for the whole universe's inhabitants. It is probably common. Alas, we will probably never know that either.

Visualize an alien sunset

steve smyth — Thu, 13 Dec 2007 02:11:35 GMT

Dave...best yet, but I'm still having a hard time picturing the unobstructed view...I know that what you are saying is the best explanation of prevailing wisdom so far...but, prevailing wisdom's getting us nowhere...shake it up, eh?
maybe someone reads one of these comments and has the big epiphany...even if it's 'wow, we don't really know, or agree upon much...do we?'

Visualize an alien sunset

Dave, Stillwater, OK — Thu, 13 Dec 2007 17:40:48 GMT

Delmar, HD 189733b is only about 63 light-years away. What we are seeing through our telescopes when we look at it happened only 63 earth years ago. I am not certain that we have telescopes powerful enough to detect planets billions of light years away, though we may. As for whether we could reach the planet HD 189733b in any reasonable time frame, you are certainly right - we could not. It would take ages more than 63 years, since we cannot even travel at speeds remotely near the speed of light. Manned missions could only include colonists with no intention of ever returning to earth, and every intention of carrying on life as usual (procreation, etc.) in a very large space ship during the long, long trip. Since this particular planet is certainly incapable of supporting life like ours, there would likely be nowhere for the colonists to make a new home. It's all a very unlikely scenario.

Visualize an alien sunset

John Dorian — Thu, 13 Dec 2007 18:05:05 GMT

Steve,
I would like to know exactly what your alternative hypothesis is.

Here's my attempt at shaking it up, since prevailing wisdom is getting us nowhere. We can see the stars becasue they are much closer than the astronomers say. The sun, moon, stars, and planets are actually very small orbs of light suspended in a sheet of water that floats above the earth. The earth is absolutely still, and this sheet of water spins around every 24 hours. This view is one interpretation of Biblical Cosmology, and is probably not correct, but I suppose it is plausible, assuming there is a HUGE, global government cover-up to discourage us all from believing the truth. I certainly don't think this is what you beleive is going on. These are just my musings on the issue. So what do you think?

Visualize an alien sunset

Serge, Altanta, GA — Thu, 13 Dec 2007 23:13:20 GMT

Dave,
You make a good point of how nearby these exoplanet discoveries are. I checked in the catalogue (www.exoplanets.org), and the farthest one is at a distance of 200.0 parsecs, which is 652 light-years. The most powerful technique for detecting extra-solar planets as far as distance is concerned is the transiting technique which detects a reduction in the light from a star as the planet passes in front of it. This reduction is usually in the order of a few percent. So with large modern telescopes we could detects this anywhere where we can resolve an individual star. I belive the limit on the distance of the technique here is obscuration by dust. The Milky Way galaxy is about 100,000 light years in diameter. My feeling is using the most powerful telescopes available we could detect transits a radius of about 5 to 10 thousand light years from the Sun. That's already a lot of stars! In the order of hundreds of millions!
So this business of extra solar planets is really something that needs to be done on a somewhat local scale. When we talk about millions of light years, we are talking about the distance to other nearby galaxies. Billions of light years is truely a cosmological distance, where the large scale structure and expansion of the universe comes into play. There are many fascinationg things to study at these larger scales, but I think for the purpose of extra terrestrial life and detectable planets, we need to tone our talk down to a few hundred light years at most, and that will already give us enough to think about.
Unfotunately transiting is not a very productive technique because it requires a rather special geometrical arangement, only attainable in a few percent of planetary systems. The planet must cross our line of sight to the star and that is just not very likely to happen. The most productive technique, which is studying radial velocity perturbations to the parent star, is even more restrictive as far as distance goes.
(disclaimer: Any other astronomers here may wish to verify the accuracy of my extinction estimations. My work focuses within about 30 parsecs, where dust extinction is irrelevant!)

Visualize an alien sunset

steve smyth — Fri, 14 Dec 2007 00:23:44 GMT

it's all revolving, in some geostationary fashion, around us...everything co-ordinates perfectly...far away goes faster...closer goes slower...so everything appears as is...the stuff that's behind things will always remain behind things, and never be seen...bummer...
at least we agree on geocentricity...how's that?

Visualize an alien sunset

Lev, Knoxville, Tenn — Thu, 19 Jun 2008 13:19:51 GMT

Alright, say we decide to roll the dice with radio signals...
Firstly, is there any form of life there to receive/answer?
Second, if there is, do they possess the technology to send/receive radio waves?
Third, would they be able to understand the coding we're accustomed to, or would it be completely 'alien' to them?
Also, would they be capable of breaking said coding, or would it just confuse them to no end?

We could send a probe...but how would it get there?
A straight line?
What type of propulsion would be suitable/effective?
Hmm...perhaps if we found a way to slingshot it, sort of like the shuttle is slung from the Earth's orbit to the moon or what-not...but on a larger scale...
Is that even possible?
If so, what would be the requirement?
Surely, Earth's orbit is not a powerful enough momentum...so...the solar system?
The galaxy?

Hmm...

So, say we manage to succeed in finding/creating and executing a suitable/effective method of propulsion...
Now we have to hope that the straight stretch would be unobscured...
I understand the colossal distance scaling between cosmic objects, but it never hurts to think of as many x-factors as possible...
(Wow, this is beginning to feel like a wild tangent... XD)
That said, maneuverability has to be included.
A wrong time, wrong place scenario plays out, a planet/star/asteroid/etc is between probe and destination, dangerously close, evasive maneuvers come into play.
So...thrust vectoring?
Individual jets located at various points around the probe?

Bahhhhh, anyway, I'm going into the big nowhere fast.
Sleep deprivation...the perfect time to come across grand subject matter, only to lose brain cells at a rapid rate whilst attempting to analyze... *sigh*

SO, as I was saying, hopefully the probe makes its course there and back, and in the mean time, would it send a continuous stream of information?
Perhaps a series of still images?

We could learn some amazing things from the trip alone, long before the destination is actually reached...
Amazing how many possibilities open up just by considering this subject matter...

Alright, I'm not sure what else to put on the probe matter...

So, on to the final idea...a colony spacecraft...
It would have to be huge, obviously...
Room for the initial colonials as well as offspring, as well as supplies...

Hmm...we'd need to figure out how to make sustenance from nearly nothing, huh? XD
Aaanyway, so off they go...back to the propulsion angle...
Would the propulsion that may have worked for a probe be safe for a colony ship?
Probably not...hmm...
Still, it would have to be suitable for both space travel and landing, right?
Hmm...perhaps landing craft instead...

This craft would probably cost more than the National Debt to build lol.
Not to mention, it would have to be assembled in space, unless we find a means to get it there in one piece by the time it's ready to go...

Alright, anyway...someone said that there might not be a return course...
I think that not only will contact be possible from ship to Earth the entire way (save for anomalies that distort radio broadcast), but also a return trip would be possible...if at all necessary.

Say we find the perfect planet...who would WANT to return?
If radio broadcast is possible, send it, wait 126 years for a response, etc.

Still...by the time we have the technology for a craft of such magnitude...life on Earth may be all but nil.
By the time we reach the planet, it may be gone...
So, at least we'll have a new planet to start the human race anew...and we'll already be far ahead of our ancestors (theoretically) with space-aged technology...the hop to the next planet would be far sooner achieved...

I always feel like I've left something out...
Ehhh, well, I'm tired, so sue me.
Aaanyway, now that you eyes are as worn as mine just from reading my ramblings, I'd love to see what you think about any and all of it.
I look forward to getting back to you...

~Lev