The Elusive "Wow!"

The Elusive "Wow!" - What We Do | The Planetary Society
The Quest for the "WOW!" - One Man's search for SETI's Most Promising Signal

Review of Robert H. Gray, The Elusive Wow: Searching for Extraterrestrial intelligence (Chicago: Palmer Square Press, 2011). A Radio SETI update by Amir Alexander. January 27, 2012.

<http://www.planetary.org/programs/projects/seti_radio_searches/20120127.html>

SETI Home needs your help.

December 2011

Dear SETI@home Volunteer: We need your help to continue the search for extraterrestrial intelligence! For the last eleven years, SETI@home has brought the search for extraterrestrial intelligence to millions of households around the world. SETI@home is the longest operating SETI search. We use the largest and most sensitive telescopes on earth to scan the skies for the faint whispers of another technology. Your tax-deductible donation will help enable us to continue the SETI@home and Astropulse projects at Arecibo Observatory, as well as pursue ambitious new experiments all over the world. SETI@home is primarily funded by the financial support of its participants. Your contribution is vital to sustaining our search for intelligent life on other worlds. During the last year, we have laid the groundwork for expanding SETI@home into new portions of the radio spectrum and new regions of the sky. We have performed observations of Kepler exoplanets with the Green Bank Telescope in West Virginia, USA, and we are very close to releasing these data to SETI@home and Astropulse volunteers. These observations will allow us to conduct the most sensitive search for intelligent life on these new worlds ever performed. We are also working with our colleagues at observatories all over the planet to install additional SETI@home data recorders to operate in piggy-back mode. In addition to conducting SETI experiments, the SETI@home group actively trains the next generation of SETI scientists, working with students from high school through doctoral studies. Your contribution directly affects our ability to support additional students working with our group. Engaging the next generation of astronomers and engineers in SETI is absolutely crucial to ensuring its future. Please consider a donation to SETI@home this holiday season. Any amount you can contribute would be an immense help in sustaining and growing the SETI@home search for extraterrestrial intelligent life. To contribute click here. Thank you for your support and continuing dedication to SETI@home. Sincerely, Andrew Siemion, Project Scientist P.S.: We are now able to accept PayPal donations! Andrew Siemion is an astrophysics Ph.D. candidate at the University of California, Berkeley. His research activities focus on designing instruments and experiments to detect rare and novel radio phenomena.

SETI's telescopes to go back online, resuming hunt for alien life

SETI's telescopes to go back online, resuming hunt for alien life

This week the SETI (Search for Extraterrestrial Intelligence) Institute announced that it had raised more than $200,000 from a crowd-sourced fundraising effort that launched earlier this spring. The money, which came from just over 2,000 people who want to keep the search for alien life alive, will help the institute put its Allen Telescope Array back online.

Why the Silence from E.T.?

Humorous, but as in all good humor, a kernel of truth? I was thinking on this very thought for awhile - would advanced, especially postbiologic, beings either destroy themselves or get so wrapped up in virtual reality technology that they turn inwards and not actively care about technologically primitive aliens (not care enough to contact them)?



Reference:
Weiner, Zac. Saturday Morning Breakfast Cereal. 18 Sept. 2010. Web. 19 Sept. 2010.

Interview with Jill Tarter, Director of the Center for SETI Research

Jill Tarter, Director of the Center for SETI Research, is trying to find an answer to a question people have asked forever: is there life on other planets?

Earth Speaks? - SETI Research Project Wants Your Input!

Earth Speaks is a SETI Institute research project where they pose the two part question:

“If we discover intelligent life beyond Earth, should we reply, and if so, what should we say?”

As I have addressed in many previous blog posts on alien contact, this is an important question.

The Earth Speaks project would like your response to that question. Should we reply? Why or why not?  If we should reply, what do you think we should say? How do you think should we present ourselves? How do we address the issues of the differences between our and the alien's philosophies, theologies, and customs as well as language idioms and means of communicating? 

Join Earth Speaks (it's free) and add your response to that enduring question.

Earth Speaks project home page:
<http://earthspeaks.seti.org/>

Earth Speaks on Twitter:
<http://twitter.com/SETiEarthSpeaks>


Image credit: 1. Lynette Cook.

Music to an Alien's Ears?

Interstellar Message Composition

The SETI Institute has an interesting (but not unexpected if you think about it) department: Interstellar Message Composition. Is Director, presently Dr. Douglas Vakoch, a psychologist, is charged with figuring out how to create a message that would communicate, inform, aliens about Earth and humanity. It is a most challenging task. To help him with this task, he is gathering mathematicians, scientists, and artists.

Mathematically Speaking?

Mathematics is considered, at least by mathematicians, to be a universal language. After all, it seems logical that all higher order intelligent sentient species would need to devellop an understanding of mathematics if they are to explore and apply the physical laws of the universe. If physical laws are constant in the universe, or at least in our region, then the mathematics would be the same as well.

Of course, there are some limitations to communication via mathematics. Sure, we can establish that we are both burdened with trying to solve differential equations. We can show each other that we all know the Fibonacci sequence (though the aliens will, undoubtedly, call it by a different name), but how do we use mathematics to communicate a smell of coffee in the morning, the beauty of a butterfly fluttering between flowers, or the incredible delicious taste of Mochi cream (the best Japanese sweet ever made).

Making Sense With Different Senses

There is a connection between music and mathematics. As explained in the Exploratorium article on the SETI mission to craft a message to the stars

Music is largely rooted in math, a quality that makes it a good candidate as a form of interstellar communication. Aesthetically, humans seem to seek patterns, and many of the melodies we find pleasing often contain some sort of mathematical pattern.

I grant you that music is largely rooted in math. Bach's music, which I love, is very mathematical. Humans are pattern seekers, and it could be argued that most intelligent sentient beings would be likewise. Also, I understand that since a love for music is inherent in humans, generally speaking, informing aliens about music is helping to inform them of what it is to be human. However, what is music to our ears, may be just a strange mish-mash of mathematical patterns to an alien's. To them, at best it could be a strange noise.

What if  the aliens communicate with each other through light - changing colors as well as intensity, or, if they have several light producing organs, via changing the number of lights visible as well as pulse lengths. The mathematical patterns for what passes as music to them - a light symphony - could be very different from the mathematical patterns produced by human musical instruments, or the human voice.  These human produced sounds may not translate well, and have the aliens pondering the meaning behind the weird signal they were receiving. Would they think to convert the radio pulses into light pulses? But how to convert? Which radio frequency or pulse should be three lights blinking twice, and which should be two lights blinking three times and changing color? It would be a meaningless message - a failed message.

And what of the possibility that some aliens may communicate through their version of a sense of smell? As some languages have a limited syllabary which still yields a large number of meaningful words created from combining different syllables in different orders, so could a olfactory language be made up of a limited "syllabary" of orders or chemical signals. Such signals would be difficult to overlap, and so there would be no equivalent for chords, or harmonies. How would our music translate to them? Would they have anything equivalent to music, something they could see our music as an analogy to of theirs, or would our music leave them utterly confused?

Lost in Translation

If there is difficulty in translating between two Earth languages, how much more so would there be between an Earth language and an alien language? Different Earth languages have different rhythms, different patterns, and different idioms. It is difficult enough to translate technical manual (as comedians like to poke fun at from time to time), but to translate poetry can sometimes be nearly impossible. It may very well be the same with sending music out as a way to communicate the Earth and humanity to the aliens. They may find what we send the mathematical equivalent of a babbling fool, or dismiss what they "hear" as mysterious noise that may, or may not, have an artificial origin.

And then there is cultural differences. What if music is only used as a means of communicating aggression, or to mate, or to mark territory? They may see the mathematical roots, and realize it is a message sent by another sentient species, but they may have quite a different interpretation of what it means.

Pardon My Alien Faux Pas.

Maybe that is why aliens have been silent. If some of the reports of UFO are authentic, and there are aliens observing us, they have been rather quiet and evidence has been fleeting - maybe it is because there are such differences between them and us that observation of culture is first needed - so that dangerous faux pas are avoided. Alien cultures can be, and most likely are, extremely different from ours. If communication problems have caused painful faux pas between Earth cultures then it is highly likely that communication problems between us and aliens would be astronomically more difficult and fraught with faux pas.

The desire to communicate with aliens is understandable. It is in our nature to explore. And any aliens venturing out into the stars will be explorers themselves. The thirst for knowledge is hard to resist. However, communicating with aliens is something we should approach with much caution and patience.

Freshman Interstellar Message Composition 101

But if we could communicate, what new and exciting classes would be taught at college!

Interesting stuff, this.


Reference:

"Douglas Vakoch and Interstellar Message-Making." Origins: Astrobiology: The Search for Life.n.d. Web. 23 Sept. 2009. <http://www.exploratorium.edu/origins/arecibo/tools/vakoch.html> Exploratorium.

Image credits: 1. Lynette Cook.  2. Animation Factory

The Sun's Twin? (and does that mean another Earth as well?)

Another Sol?

An article by Bob Berman in this month's (Oct 2009) issue of Astronomy mentions that

of the 1,000 nearest stars within 3 dozen light-years, only one matches our Sun's temperature, size, and luminosity and has the same precise spectral class of G2V (a main sequence star with a surface temperature of about 9980 degrees Fahrenheit...).

In addition, that twin star is similar in age, though a bit older: the Sun is 4.6 billion years old, while this twin star is 5 to 6 billion years old.

One in a Thousand

That twin star? Alpha Centauri A. As Bob Berman points out - of all those 1,000 stars the only one that is the Sun's close twin is also the nearest naked-eye star (4.35 light-years away). An amazing coincidence. 

Hopefully the new generation telescopes, especially the whose main tasks are to search for exoplanets, will aim their sights on the Centauri trinary system. It would almost be criminal not to take a closer look. If there is a terrestrial planet circling Alpha Centauri A, the new generation telescopes should be able to find it. With Alpha Centauri A a bit older than the Sun, unless life evolved on Earth quicker than usual, a terrestrial planet in a habitable zone around Alpha Centauri A would have had plenty of time for sentient life to arise.

Long Distance Relationship

Of course, maybe sentient life does not survive its early years of sentience and there is no longer any sentient life to discover... But let us be optimistic for a moment and say that it survives. 4.35 light-years away would allow for communication via radio waves or laser. Sure, it would take 8.7 years for each message to be answered (4.35 years for it to travel there, and 4.35 years for the answer to travel back), but it still could be done.

But should we try to communicate with them? The wonders are tempting, but there is the possibility of danger...


References

"Alpha Centauri - A Candidate for Terrestrial Planets And Intelligent Life." Smoot Group Cosmology. The Smoot Group. 15 Oct. 1997. Web. 30 Aug. 2009. <http://aether.lbl.gov/www/classes/p139/speed/Alpha-Centauri.html>

Berman, Bob. "A dozen cool facts." Strange Universe. Astronomy. Oct 2009: 16. Print.


Image Credit: The Smoot Group.

Updates polls, links

Finally back from my vacation and ready to jump back into this blog. I've updated the exoplanet links and replaced the old poll with a new one. You can go to Polls to see the archived results of past polls.

The results of the last poll was interesting - at least to me. As much as I am deeply interested in the search for exoplanets and the discovery of alien life, I am conservative when it comes to the matter of contacting any alien civilization. Should we purposefully beam messages to the stars? For me there is a hesitation as there are possible risks involved that need to be kept in mind. But 85% of those responding to the poll said they thought we should purposefully beam messages to the stars. I would love to hear why you all believe we should.

Blog in Space III: The Beatles' "Across the Universe"

© NASA/JPL

"Nothing's going to change my world..."

Beatles in Space

At 7 pm on 4 February 2008, NASA beamed the Beatles' song "Across the Universe" toward Polaris (the North Star) 431 light years away via NASA's Deep Space Network. This was done to celebrate several anniversaries that occurred in the first week of February 2008:

• 5oth anniversary of the founding of NASA
• 50th anniversary of the founding of the Beatles
• 50th anniversary of the launch of the first U.S. satellite, Explorer I
• 45th anniversary of the founding of the Deep Space Network
• 40th anniversary of the production of the first version of the Beatles "Across the Universe" by George Martin.
  

For NASA to pick "Across the Universe" to beam makes sense, from the shared anniversaries, to the title of the song itself. However, for NASA to beam the song in the first place may not make as much sense.

A Moot Question?

As mentioned in an earlier post, on one hand the question whether we should or should not send a message into space for aliens to detect may be a moot point as we've been leaking radio and TV signals into space for over 60 years now. And the amount of signals we're leaking out into space has increased. However, weakly leaking out man-made radiation isn't the same as purposely beaming out a strong focused signal into deep space.

© Lynette Cook

The chance that there is, or will be by the time the signal reaches it, a technologically advanced sentient alien race who are not only able to detect the signal and understand that it is artificially produced, but who also just happen to be listening with their electronic ears pointed toward our region of space at the right moment to pick up our one "Across the Universe" transmission is rather minute.

Possibly decreasing the chances even further is the nature of Polaris. It is a Cepheid variable star in a triple-star system. A Cepheid variable is a star 5 - 20 times the mass of the Sun that regularly cycles between expanding and contracting in size. This may impact the stability of the habitable zone for the star system.

Finally, the chance of an alien space probe (not necessarily from Polaris) happening across our transmission beam, or for another sentient race around a star beyond Polaris detecting the beam is also rather minute (even astronomically minute).

The Problem of Blasting Music toward Your Neighbors 

So what's the problem with introducing the Beatles to the Polarians, and whoever else may hear it after them?

We do not know the nature of the Polarians, or of any alien that may intercept our message. We do not know how they will react to it. Too often on Earth, when a technologically advanced civilization meets (or "discovers") a less advanced civilization, it usually ends up disastrously for the less advanced one. This does not mean that the aliens would behave the same way, but it does point to the distinct possibility that they could. If we can, others can - I seriously doubt that there is a universal natural law that only one arrogantly aggressive sentient race can exist in a galaxy.

The aliens may be xenophobic because they were invaded once themselves by an alien race, and their leader(s) decide that it is better to do preemptive strikes. Or maybe their world leader is a megalomaniac who isn't satisfied with ruling just one planet. Is it impossible for someone to want to try to rule the galaxy, even if that is a deluded desire? Or the aliens may have a religious reason to attack, one that we can not fathom. The aliens may misinterpret our message as one of aggression or of grave insult to their faith, leader, or way of life.

Or they may want to come and "help us" - parent us. They may feel it is their inherent right to do so. Some imperialistic nations in Earth's history had that philosophy - they conquered other nations to help them. They may see us as uneducated, lost heathens who need to be shown the light, and they know, from experience with other planets or their own history, that heathens won't listen unless you use "tough love" on them.

Technological advances do not always come with the appropriate advances in culture or society. A technologically advanced alien race does not have to be morally advanced as well (though one sentient species morality may not be the same as another's).

Yes, there is also the chance that the aliens that happen to hear our transmission will respect our sovereignty in all aspects of our world. They may be merely knowledge seekers, explorers, curious to learn more about us, and nothing more.

Or the aliens may even be rather indifferent to us, like the aliens in Dan Abnett's short story "Point of Contact" (found in The Solaris Book of New Science Fiction, Volume Two, edited by George Mann).

We just do not know. Is it worth the risk to announce ourselves?

Ah, but, you may say, at 431 light years away are we not safe?

Vast Distances, Like Fences, Good Neighbors Make?

It would be if the speed of light is the fastest any one can travel, and the aliens are short lived as we are and are adversed to multi-generational space journeys. Recent research over the last 15 years shows that "warp drives" may be possible one day after all. A more technologically advanced civilization than ours may have figured out warp drives.

© Animation Factory

Such an advance in spaceflight technology could make moot another related barrier - long interstellar distances can, with sub light spaceships, take many generations to traverse. This, of course, assumes that an alien race has short life spans like ours. With great medical advances, and their own different biology that may allow longer life spans to begin with, it is not inconceivable that an alien race could live long enough to make the trip to Earth and back in one generation or less. Of course they would have to be able to deal with being cooped up in the small (compared to the open air or water of their home planet) spaceship, as well as be able to produce enough sustenance and breathable atmosphere. But again, faster than light travel would take care of most of those problems.

Another barrier to traveling interstellar distances is the danger of cosmic radiation. It is difficult to shield from it. Our atmosphere is thick enough (60 miles) to protect us, but out in space, travelers just have the skin of their spacecraft. Though researchers are looking into creating magnetic bubbles around spacecraft to protect the humans within it from cosmic radiation. So that is probably not a problem for a more technologically advanced space faring civilization.

They, Robot

However, even if an alien race is too far away to send some of their own out to travel to Earth, they could send robots in their place. Sending robots solves many problems - no need to grow food, maintain a breathable atmosphere, or worry about the trip taking generations. Robots would also be able to explore a greater variety of planets as they would be able to tolerate a far wider range of physical environments as well as be essentially immune to any alien virus or bacteria. They could even be more resistant to attack from many biological creatures. This is one reason why some ufologists believe that the aliens known as "Grays" are actually advanced robots.

The robots would need to have sufficiently sophisticated AI (Artificial Intelligence) though, so that they can operate mostly on their own due to a 862 year round trip for any communications - unless the aliens are able to develop something akin to subspace communications like in Star Trek (would such robots be sentient?). Of course, if their mission is simple, like "observe from a distance, take notes and report" or "destroy all humans," there wouldn't be a great need for two way communication. Just sending reports updating on their progress (either to the home planet, or to a second wave of robots coming after them so that they can adjust their game plan if need be before arriving at Earth).

"Nothing's going to change my world..."

Outro

The irony of it is, the song could change our entire world by its being beamed into space by a radio telescope. Yes, I know that what John Lennon means is that when you achieve a pristine state of consciousness, you are in a mental and spiritual state where you are free of worldly distractions: "Nothing's going to change my world..." However, if, and it is a big if, the song does get the attention of aliens, most of us will find our worlds changing as most of us haven't reached the mental and spiritual state sung about in the song.

What do you think about this?



Some additional information about the Polaris star system

© NASA

Like most triple star systems, the Polaris system contains a close binary with a more distant star circling the binary.

In the Polaris system, the central binary pair is made up of Polaris A, the giant Cepheid (somewhere between 4.3 to 5.4 times the mass of the Sun), and Polaris Ab, a dwarf star (1.4 solar mass).

Polaris A is the brightest Cepheid as seen from Earth. Polaris Ab circles Polaris A in a highly eccentric orbit, with the distance between it and Polaris A varying from 27 AU to 6.7 AU, taking over 29 years to orbit Polaris A (about the time it takes Saturn to orbit the Sun).

Comparing those distances to our solar system, Pluto's closest approach to the Sun is 29.7 AU, and Jupiter's furthest distance from the Sun is 5.5 AU. By the way, recall that while Pluto is further away than Neptune, on average, it has a much more eccentric orbit than Neptune and thus actually can be closer to the Sun than Neptune.

The third companion, Polaris B, is a main sequence Sun-like star (1.1 to 1.25 solar masses) which orbits some 2400 AUs from the center binary pair, or 60.8 times the distance from our Sun to Pluto (at its furthest point in its orbit). It takes Polaris B 29,000 years to orbit Polaris A.



References:

"About the Deep Space Network." Deep Space Network Home Page. NASA's Jet Propulsion Laboratory. 20 Mar. 2008. Web. 11 Aug. 2008. <http://deepspace.jpl.nasa.gov/dsn/>.

Borland, John. "Physicists Do the Math on Warp Drive Science." Wired Science. Wired News. 14 Dec. 2007. Web. 11 Aug. 2008. <http://blog.wired.com/wiredscience/2007/12/physicists-do-t.html>.

"Cepheid Variables - Introduction." Imagine The Universe! NASA Goddard Space Flight Center. Web. 11 Aug. 2008. <http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/cepheid.html>.

Kaler, Jim. "Polaris." Stars. University of Illinois. Web. 11 Aug. 2008. <http://www.astro.uiuc.edu/~kaler/sow/polaris.html>.

Knight, Will. "Repelling cosmic rays with magnetic bubbles." New Scientist.com news service. 19 Nov. 2004. Web. 11 Aug. 2008. <http://www.newscientist.com/article.ns?id=dn6694>.

"NASA Beams Beatles' 'Across the Universe' Into Space." NASA. 5 Feb. 2008. Web. 11 Aug. 2008. <http://www.nasa.gov/topics/universe/features/across_universe.html>.

Nave, Carl R. "Solar System Data." HyperPhysics. Georgia State University. 2006. Web. 11 Aug. 2008. <http://hyperphysics.phy-astr.gsu.edu/hbase/solar/soldata2.html>.

Tytell, David. "Probing Polaris." News from Sky and Telescope. Sky and Telescope. 10 Jan. 2006. Web. 11 Aug. 2008. <http://www.skyandtelescope.com/news/3311001.html>.

"Warp Drive, When?" NASA. 17 Mar. 2006. Web 11 Aug. 2008. <http://www.nasa.gov/centers/glenn/research/warp/warp.html>.

Blog in Space IIb: Receiving difficulties addendum - the Wow! Signal

© The Big Ear Observatory

Before I move on to Blog in Space III: Across the Universe, I want to briefly touch upon the Wow! Signal. The Wow! Signal is the most famous signal in the history of the SETI program - a still unexplained signal that appears to be a non-terrestrial (non Earth) artificial signal received for 72 seconds on 15 August 1977.

However, it was a one time event - no radio telescope has ever been able to pick up the signal again. Some feel that indicates it is not a signal from an alien sentient race after all.

But why can't an alien signal sometimes be a one time transmission?

There is one good terrestrial example I will discuss in the upcoming Blog in Space III post: the one time transmission of the Beatles song "Across the Universe" into space. This transmission was aimed at Polaris - it was not a omni directional transmission, nor was it a continuous transmission. Any listener on Polaris over 43o years from now will have a small window of opportunity to catch the signal. If the Polarians tried to pick up the signal again, they'll be out of luck, scratching their heads, or whatever it is Polarians scratch when they are puzzled - if they scratch when puzzle, as they debate the signal's nature.

The Wow! Signal could be a one time signal sent out by a sentient race, their "hello, we are here" signal. Why don't they keep sending out their hello? Why didn't we keep sending "Across the Universe"? Their own SETI program could be nascent like ours, with their radio telescopes mostly tied up with other scientific research, not leaving much time for broadcasting signals into deep space.

The Wow! Signal could also be an errant communication transmission to a moving target - say, oh, I don't know, an interplanetary or interstellar space ship or deep space probe. Such communication transmissions would most likely not be a continuous stream. They could be repeated at regular intervals, but since we don't know what the intervals are, and since we do not have radio telescopes constantly trained on the Wow! Locale (the area of the sky the Wow! Signal came from), it would be a great stroke of luck to hear another signal from the Wow! Locale on one of the short sporadic times we are listening for it.

The Wow! Signal could be a transmission from aliens to one of their deep space probes - a signal that is sent out very infrequently, only when needed for course corrections, turning on or off a science instrument or experiment, or to transmit program updates to fix a problem the probe developed.

Another thing to consider is if this was an alien transmission that was not aimed at us but at a moving space craft or space probe, the likelihood that the space craft or probe is on a direct line between the aliens and our solar system is rather minute. Most likely the space craft or probe is moving at an angle to us, especially for a craft or probe within their own system. The probe may flyby other planets to get a gravity assist to help boost its velocity, or the probe may flyby other planets as part of its long term mission. The chances for the alien's probe to happen to line up between the aliens and Earth right when they are transmitting a signal to the probe (or, conversely, for the alien's planet to line up between the Earth and the probe which is transmitting a signal to the alien's planet) are minute at best.

But wait, there's more! Another complication is that our planet is circling our sun which is itself moving through space while the alien's planet is circling a star which is also moving through space. Think about a probe circling Mars. As Mars travels in its orbit, and we in ours, the angle of the transmission beam between the Earth and Mars changes, due to the fact that each planet's orbit is different in size and each planet travels at a different speed around the Sun. Sometimes the Earth and Mars are on the same side of the Sun, and other times on opposite sides of the Sun. Because of this, the background stars change as well.

And even if the alien's space craft or probe was sent toward our Sun, because of their planet's orbit, the transmission signals sent to the craft would be sent from varying angles. This would be, of course, most pronounced early in the craft's journey to our Sun as the angular distance would be the greatest. Only occasionally would the alien planet, their space craft, and the Earth line up. As the craft nears the Sun, the angular distance would decrease (compare how the distance between the rails of a train track appear close up to the distance between the rails appear at the horizon). In that case, we would actually be in some luck (unless the craft is an invading alien army) - as the craft gets closer, our chances of relocating their transmission signals increases.

Don't count the Wow! Signal out as an alien signal just because we detected it only once.

References:

Alexander, Amir. "The "Wow!" Signal Still Eludes Detection." Planetary News: SETI. 17 January, 2001. Web. 10 August 2008. <http://www.planetary.org/news/2001/0117_The_Wow_Signal_Still_Eludes.html>.

"A Gravity Assist Primer." Jet Propulsion Laboratory. Web. 10 August 2008. <http://www2.jpl.nasa.gov/basics/grav/primer.html>.

Kawa, Barry. "The Wow! Signal." Big Ear Radio Observatory. 6 September 2006. Web. 10 August 2008. <http://www.bigear.org/wow.htm>. Reprinted from the Cleveland Plain Dealer Sunday Magazine section, 18 September 1994.

Blog in Space II: Receiving difficulties

© Animation Factory

The question of whether we should be announcing ourselves to the Universe may be a moot point to an extent. We've been leaking man-made electromagnetic radiation for quite some time now. So the "cat's out of the bag," any way, right?

Well, not so fast.

Every planet have a vast night sky in which to search for signals. The further away they are from our solar system, the harder it will be for them to pick up a signal; not only will most have to have their finely tuned directional electronic ears pointed right at us, but their equipment will need to be able to receive the frequencies that we are radiating out into space with as well as be free from possible local interference. It is possible the aliens could dismiss, at first, our signals as noise.

The aliens will only have a small window to detect the signal as their planet rotates on its axis (unless they have space based radio telescopes). Interstellar dust could attenuate some, or all, of the signals. And finally, if they pointed their radio telescope to the Earth a couple of hundred years ago they would've not heard anything and may take some time to come back and listen again; or they may discover artificial (unnatural) signals from one or more other star systems and that may be enough to preoccupy them, delaying them from continuing their search, or from their going over previous searched sections of the sky. So even if the cat is out of the bag, we may have time to put it back in.

So, we need an alien race close enough to pick up the signals we've been leaking, with the technology to pick up the signals and to recognize them as non-local artificial signals, and the will to take the time to dedicate equipment for meticulous searches of the vast sky looking for alien signals.

Even if they did find our signals, they would have to then figure out what they are. Radio and television signals are not simple signals - they are signals which are modulated onto carrier signals. They will need a receiver that is capable of distinguishing signals from each other, able to remove the carrier to retrieve the information being sent, and then process it so that it can be used by a speaker, or TV screen. However, the original signals are meant for human ears and eyes, not an aliens', which could further complicate their ability to receive, and perceive, the signals.

If they are able to figure out the signals, and are able to get the information out in audible and/or visual form by adapting it to their own hearing and/or visual range, they would still need to interpret what they are seeing. Being that our culture and theirs will be very alien to each other, it may be profoundly difficult for them to make sense of what they hear or see. They may not perceive music as we do. They may not even be able to hear, communicating instead through scents (like ants), or touch, or light. How would such aliens make sense out of a audio broadcast? Will they have a sense of humor or be able to understand ours? Will they mistaken a TV show as a historical document (like the Thermians in Galaxy Quest)? Will they be offended by what they see either because of cultural differences or because of misinterpretation. It's hard to interpret a truly foreign language, especially the context, thousands of light-years away.

(I have to pause for another humorous aside, this one from Futurama - will they become addicted like Lrrr, the ruler of Omicron Persei 8, to a 1,000 year old TV series and demand the last episode be shown or the Earth is destroyed?)

But it may be enough that they detect the signal, and realize it is artificial - they would be able to figure out where they came from. If the speed of light is the ultimate speed limit, and there are no "tricks" to get around it (warp engines, worm holes), there's not much to worry about - physically (theologically and psychologically we may have something to worry about, as mentioned in earlier posts on alien contact).

Anyway, while the amount of signals we're leaking out into space has increased (cellphones, space probes, GPS, for example), weakly leaking out man-made radiation isn't the same as beaming out a strong focused signal on purpose for aliens to... oh, wait, we've done that. Ooops. it looks like we not only let that cat out, but we sent it running, meowing all the way.

More on that in the next post.

Reference:

"Character bios: Lrrr." Can't get enough Futurama. 6 August 2008. <www.gotfuturama.com/Information/CharacterBios/lrrr.dhtml>.

"Galaxy Quest (1999)." Internet Movie Database. 6 August 2008. <www.imdb.com/title/tt0177789/>

Blog In Space I: Introduction

© Animation Factory

There is a blog, "Blog In Space" (by PayPerPost.com), which will beam your blog into space because, according to their unsupported (at least as far as I know!) claim, "Aliens Love Blogs Too!"

If aliens did get your blog, they would have to know how to figure how to translate correctly the electronic signal so that they can see and hear your text, images, sound files, and/or video in the proper format (do aliens have the same HTML, CSS, and image standards?). Then they would need to understand your language (including the nuances only known by understanding the cultural context of the language).

But maybe they don't need to understand anything beyond the fact that some fool sentient species is purposely broadcasting their presence into outer space. Someone - or something - may indeed hear you. But it may not a welcomed guest...

More tomorrow.

Save Arecibo

From an 18 July 2008 email from Seti@home:

Arecibo Observatory, the world's largest radio telescope and the source for the SETI@home data that your computer analyzes, faces massive budget cuts that will END its ability to continue the search for life beyond Earth. The decision to ensure full funding currently rests upon votes in Congress on Senate Bill S. 2862 and House Resolution H.R. 3737. These bills desperately need more support.

Please take a moment to help us SAVE ARECIBO.

Clicking the link below will direct you to a web page that allows you to print out letters prepared for your Senators and Congressional Representative urging them to support Arecibo. Printing and mailing the letters is really easy, too! You will also have the chance to add a few personal thoughts, if you wish, to let your Senators and Representative know why this funding is important to you! And if you're really feeling passionate about saving Arecibo, please use these
letters as the basis for letters you write yourself, urging your congressmen and women to vote to save Arecibo.

Because our representatives in Congress rarely give much attention to all the email they receive, printing out and MAILING these letters via standard U.S. Postal mail remains our best option for contacting them and our best hope for saving Arecibo (The second best option is to call your representatives). Your 42 cent stamps on these letters could help us get the millions of dollars
needed to save Arecibo.

Our search cannot continue without the necessary support. Your work, as SETI@home participants, represents an indispensable resource for conducting the search. Now, we need your help to ensure that our other most valuable resource - our eyes and ears to the cosmos - can continue to probe the universe as we seek to answer the question: Is there anybody out there?

http://setiathome.berkeley.edu/arecibo_letter.php

Thank you for your help,

The SETI@home Team

Related information:

• As the largest radio telescope in the world, the Arecibo Observatory is an important asset to America's scientific and technological communities. No other radio telescope comes close to the sensitivity that the Arecibo telescope has.
• Not until the year 2020 will any other telescope even have a chance to surpass Arecibo. If the Square Kilometer Array (to be located in South Africa or Australia) gets all of its funding on time, a decade-long gap without the use of Arecibo (or any comparable telescope) will still plague astronomic, planetary, and atmospheric research.
• Only Arecibo's planetary radar can image and determine exact trajectories of potentially threatening asteroids. This makes Arecibo the best tool for investigating Near Earth Objects and warning the world about possible asteroid threats.
• Radio technologies developed for the Arecibo telescope strengthen the U.S. competitive edge in the global marketplace. Ionospheric radio wave propagation studies conducted at Arecibo form an important component of space technologies, from communications satellites to the Global Positioning System (GPS).
• Arecibo benefits education. Many of our next generation of scientists and engineers receive training at the Arecibo Observatory.
• Arecibo captures the public imagination. Over 120,000 people per year visit this technical wonder while millions more contribute to scientific projects conducted with this telescope. Over 5 million participants have contributed to SETI@home -- the world's largest public participation science project.
• The citizens of the United States, especially those in Puerto Rico, and the scientific community look at Arecibo with pride. The Observatory represents a commitment to the Commonwealth of Puerto Rico and a major asset to the world scientific community.

Reference:

"Save Arecibo: Write to Congress." Press Release. UC Berkley News. 3 July 2008. 21 July 2008. <http://setiathome.berkeley.edu/arecibo_letter.php>

SETI@home looking for more volunteers

SETI@home looking for more volunteers

By Robert Sanders, Media Relations | 02 January 2008

BERKELEY – The longest-running search for radio signals from alien civilizations is getting a burst of new data from an upgraded Arecibo telescope, which means the SETI@home project needs more desktop computers to help crunch the data.

Since SETI@home launched eight years ago, the project based at the University of California, Berkeley's Space Sciences Laboratory has signed up more than 5 million interested volunteers and boasts the largest community of dedicated users of any Internet computing project: 170,000 devotees on 320,000 computers.

Yet, new and more sensitive receivers on the world's largest radio telescope in Arecibo, Puerto Rico, and better frequency coverage are generating 500 times more data for the project than before. The SETI@home software has been upgraded to deal with this new data as the search for extraterrestrial intelligence (SETI) enters a new era and offers a new opportunity for those who want to help find other civilizations in the universe.

"The next generation SETI@home is 500 times more powerful then anything anyone has done before," said project chief scientist Dan Werthimer. "That means we are 500 times more likely to find ET than with the original SETI@home."

According to project scientist Eric Korpela, the new data amounts to 300 gigabytes per day, or 100 terabytes (100,000 gigabytes) per year, about the amount of data stored in the U.S. Library of Congress. "That's why we need all the volunteers," he said. "Everyone has a chance to be part of the largest public participation science project in history."

The 1,000-foot diameter Arecibo dish, which fills a valley in Puerto Rico, is part of the National Astronomy and Ionosphere Center operated by Cornell University with funds from the National Science Foundation. Since 1992, Werthimer and his team have piggybacked on radio astronomy observations at Arecibo to record signals from space and analyze them for patterns that could indicate they were transmitted by an intelligent civilization.

When the team's incoming data overwhelmed its ability to analyze it, the scientists conceived a distributed computing project to harness many computers into one big supercomputer to do the analysis. Since SETI@home was launched, other distributed computing projects have arisen, from folding@home to predict the three-dimensional tangle of a protein to the newly-launched cosmology@home to model possible universes. Most are now on a platform called BOINC (Berkeley Open Infrastructure for Network Computing), which was developed by SETI@home's director David Anderson so that the various projects could share resources.

"There are now 42 projects on BOINC, and, until now, there has been enough computing power to go around," Werthimer said.

What triggered the new flow of data was the addition of seven new receivers at Arecibo, which now allow the telescope to record radio signals from seven regions of the sky simultaneously instead of just one. With greater sensitivity and the ability to detect the polarization of the radio signals, plus 40 times more frequency coverage, Arecibo is set to survey the sky for new radio sources.

These improvements also prime the telescope for an improved search for intelligent signals from space.

"The multiple receivers help us weed out interference better and make us less susceptible to thinking that things terrestrial are extraterrestrial,"
Werthimer said.

Werthimer noted that, despite the fact that UC Berkeley has been analyzing radio signals from space since 1978 on various telescopes, no telltale signals from an intelligent civilization have yet been found.

"Earthlings are just getting started looking at the frequencies in the sky; we're looking only at the cosmically brightest sources, hoping we are scanning the right radio channels," he said. "The good news is, we're entering an era when we will be able to scan billions of channels. Arecibo is now optimized for this kind of search, so if there are signals out there, we or our volunteers will find them."

SETI@home has been funded by various organizations over the years, including the Planetary Society and Sun Microsystems, and continues to be supported by individual donations from its volunteers.

Further information:

SETI@home Web site (<http://setiathome.berkeley.edu/>)

Reference:

Sanders, Robert. " SETI@home looking for more volunteers." Press Release. UC Berkley News. 2 January 2008. 17 January 2008. <http://www.berkeley.edu/news/media/releases/2008/01/02_setiahome.shtml>

Introduction to The Drake Equation

The Drake Equation

I really shouldn't go on without at least an introductory mention of the famous (and controversial) Drake Equation created by Dr. Frank Drake in 1960.

Dr. Drake's equation is a tool for estimating the number of intelligent advanced civilizations presently in the Milky Way galaxy that we would theoretically be able to communicate with.

The Drake Equation is

N=(R)(fp)(ne)(fl)(fi)(fc)(L)

where N is the number of civilizations we can communicate with at this time in the galaxy, and where:

• R = average star formation rate (10/yr)
  
• fp = percent of those with planetary systems (50%)
  
• ne = average number of planets that can potentially support life per star with planetary systems(2)
  
• fl = percent of the above planets where life actually begins - life started on Earth very quickly, water and the complex organic building blocks for life are common in the universe (100%)
  
• fi = percent of habited planets where intelligent life evolves (1%)
  
• fc = percent of intelligent life that develop communication technology capable of transmitting into space(1%)
  
• L = lifetime of all such civilizations on a particular planet - civilizations may collapse and rise again, or nearly wipe themselves out and the survivors rebuild (10,000 years)

The values in the parentheses are Dr. Drake's estimations. Using Dr. Drake's original values we arrive at N=10. As new data rolls with increasing frequency, these values tend to change. For more discussion see below. 

Assumptions

• Liquid water is required for life, 
• type M stars are too cool, 
• type O and B stars are too short lived, 
• life will develop if given a chance, 
• developing intelligence gives a survival edge, 
• and technologically advanced civilizations do not consistently prematurely destroy themselves because of their technological advances (global atomic war, for instance).

R, fi, and ne Discussion

As mentioned above, as new data rolls with increasing frequency, these values tend to change. Presently, the value for R is thought to be 6 per year. And, as mentioned a few times before in other postings in this blog, we are increasingly discovering certain intelligent traits first thought to be reserved just for humans cropping up in other animals: birds that make and keep tools, ferrets purposefully lying, and dogs mapping language to mention just a few. This indicate that the first estimation for fi (a mere 1%) may be too low.

If, however, sentient, intelligent life is so rare that we are the only one in the galaxy, or even the universe, then the vale for fi may be infinitesimally small. But, if we are the average result of habitable planetary system, and if life is found to have once existed on Mars, and to exist on Europa, then the value for fi becomes 33% (and ne becomes 3). That life formed quickly on Earth, a wet rock orbiting an average star in a nondescript part of the galaxy, then maybe, just maybe, it can form in extrasolar systems as well.

Calculate N for Yourself

See the Drake Equation Calculator on the right. Type in your own values for the variables in the Drake Equation to calculate N.

Habitable Zones and Habitable "Hot Spots"

Personally, I believe the habitable zone estimates are a bit conservative. For instance, Jupiter's moon Europa, despite being outside of our solar system's Habitable Zone, may have liquid water beneath its icy surface, and many scientists feel that Europa could support life. Thus, Habitable Zones could actually be larger, or a system could have Habitable "Hot Spots" (which includes not only planets, but large moons as well) in addition to its Habitable Zone . Maybe even an occasional type M stars could have habitable planet (see Color of Life for some discussion about life in a M class star system).

In addition, the equation does not take into account life that is spread to other planets by advanced civilizations (whether unintentionally from exploration or purposefully from terraforming). And finally, life is constantly surprising us with its great diversity here on Earth - our definition of what is life may need to be expanded.

Additional Drake Equation Posts.


Reference:

Schilling, Govert and Alan. M. MacRobert. "The Chance of Finding Aliens." SETI: Searching for Life. Sky and Telescope Magazine. 15 January 2008. <http://www.skyandtelescope.com/resources/seti/3304541.html>


Image credit: © Lynette Cook

Alien Technology - 1. Biology/Physiology - Part II

"Enclosure" © DigitalBlasphemy.com

An article I recently read about "stereo noses" of certain insects got me to thinking about how some technological advances/abilities may be rather common because of a common need for communication in space and the universal nature of space: while different beings may communicate on their planet in a number of very different ways - by light, sound, touch, or smell for instance - because of the near vacuum of space, communication is somewhat limited. One cannot communicate by touch, sound, or smell through the vacuum of space; however, one can communicate by light, or rather by the electromagnetic spectrum (radio waves, x-rays, light, and so forth). So no matter how a species communicates amongst its members on their home planet, they are rather restricted to how they can communicate in space.

Thus, many feel we may fairly confidently look to the electromagnetic spectrum as the most likely means for communicating with most alien species, it may not be the best way to search for indications of intelligent life on other worlds. Most assume that intelligent life will, at some point eventually, if they survive long enough, develop technology that will include some forms of electromagnetic communication / transmission of information which would either "leak" out into space and/or would purposefully used for space communications. These signals would eventually be detectable by sensitive radio telescopes (by those who believe that such intelligent life would use mostly the radio band) or by optical telescopes (for those believe some advance civilizations would use lasers to communicate, at least for communication in outer space).

However, not all species may use the electromagnetic spectrum to communicate with each other on their home planet, and thus not leak out any evidence of their presence or of their advanced civilization into space and, eventually, if we are fortunate enough, be detected here on Earth by our telescopes.

Take, for an extreme example to make my point, a water world where the intelligent species has developed wholly as an underwater organism. Smell, light, and radio waves are not the most effective or efficient means of communication in water, due to the properties of water. But sound is a different matter - sound is a very effective means, which is why whales and dolphins, among others, are able to communicate over long distances (sometimes thousands of miles) via sound alone. Using electricity would be difficult, and so development in that area could be very slow.

As mentioned in a previous post, such a species may also be slow to leave the planet - a creature that needs to be immersed in water has a much heavier load to launch into space than a creature that needs to be immersed in air. Water is dense and very heavy, launching from under water and breaking free from the planet's gravity (especially if the gravity is even heavier than Earth's), carrying enough water to fully immerse one or more creatures, not to mention the mechanisms to not only oxygenate the water and remove waste air (and other wastes) which would be more complicated than those to care for a terrestrial creature, all would add up to a much much more difficult endeavor than it is to launch from the surface, in air, with air breathing terrestrial passengers.

However, it could be argued that such a species would tend, then, to rely wholly on robotic space probes (after they tackle the problem of creating such probes with electricity in a underwater environment from scratch - though one could suppose a heavy reliance on pneumatics, which while adding weight to the craft, would add far less than a water immersed passenger). In which case, they would need a means for communicating with the probes, and thus reveal themselves to other planets.

Although, let us pick, for a another extreme example, an intelligent species that deaf or nearly deaf with rudimentary vision and which communicates mainly by smell and touch. Such a species would not feel the need to develop TV or radio, though they may develop something akin to the teletype where they can, by touch, feel what is being transmitted. Such a device could easily be updated where the information is transmitted through the air via radio waves, which get converted by a braille type mechanism or even a pulsating mechanism which while producing sound as a by-product, it is the variations in the vibrations that can be felt by sensitive appendages which is how the message is deciphered. Thus, such a species would use a means of communicating over distances that would leak out into outer space and which could be eventually detected by radio telescopes on, or orbiting around the Earth.

Finally, someone once mentioned, in a discussion about the Drake Equation, that some species may be paranoid about broadcasting, even inadvertently, their presence to the universe and may restrict/shield and otherwise block signals from leaving their planet - there may be more advanced civilizations out there that we can not detect by our SETI or OSETI telescopes.

Such beings may be paranoid because their physiology causes them to be especially xenophobic, or because of their theology makes them so, or because their ruler is. Or it may be because of a negative experience they had with another alien species. Or it just may be they logically thought about it and saw how violent their own people can be toward each other over differences and how more technologically advanced civilizations tend to easily conquer less advanced civilizations and figure they should play it safe (there are those here on Earth that present this very argument against our having SETI programs which purposefully try to make contact with other worlds).

We've had many examples on Earth of cultures closing their borders to avoid contact from other countries because of the paranoia of the leaders - mostly to limit the influence of "subversive" ideas from other cultures that may cause the people to reject the leader, or the paranoia of a people in reaction to a negative experience with outsiders. And so it could also happen with at least some other alien worlds.

References:

"Optical SETI - OSETI." Life in the Universe. 8 August 2001. 13 January 2008. <http://www.lifeinuniverse.org/noflash/OpticalSETI-07-01-03.html>

Rockefeller University. "Two 'Noses' Are Necessary For Flies To Navigate Well." ScienceDaily. 29 December 2007. 13 January 2008. http://www.sciencedaily.com/releases/2007/12/071226230117.htm>

Introduction

© Lynette Cook

The Blog's Focus
 

This blog focuses on extrasolar planetary discussions from scientific research to speculations on extrasolar (alien) biology, communication and linguistics, psychology, society, technology, and theology. This includes commentary on pertinent science articles, reviews of both relevant science and science fiction books and movies, and speculation that they inspire.

Why?

Why such discourses? As we move further into the 21rst century, these are topics will gain in importance as we continue to detect more exoplanets, to discover how widespread the building blocks of life are in the universe, and to expand the definition of life. The chances of our detecting life on another planet outside our solar system increase as our technology and techniques increase in sophistication (for example, the ability to analyze the atmosphere of a planet light years away).

Thus, the questions of whether life exists outside of the Earth take on new impetus. For with new life comes the possibility of new sentient life. What would that extrasolar sentient life be like? Pondering this question is not a mater of mere idle speculation. It goes beyond grown up fairy tales. Just as the examination of other planets in our solar system help us to understand our own planet, the examination of life on other planets may help us to understand ourselves. This meditation on other life affects meditation upon our own life.

As T.S. Eliot wrote in his poem "Little Gidding":

And the end of all our exploring
Will be to arrive where we started
And know the place for the first time.

We need to explore, to learn.

Additionally, such contemplations can help us prepare for when we discover alien biologies, psychologies, societies, technologies and theologies.

Brief Background to the Issues

It seems that every few weeks there is another discovery of an exoplanet. As of October 2007 over 200 have been found. As more new telescopes, both on the ground and in space, having greater viewing power than the Hubble Space telescope come on line, the discoveries have not only begun to pick up speed, but ever smaller planets are being discovered as well.

In 2006 the ESA launched the COROT space telescope, designed to detect planets not much larger than the Earth. It began searching in Feb 2007 and has already found additional planets. In 2009 NASA plans to launch the Kepler space telescope, also designed to search for extrasolar planets. The James Webb Space Telescope, with a possible launch date of 2013, will be the replacement for Hubble, with greater observing powers than its predecessor. DARWIN, an European Space Agency proposed space telescope with a possible launch date of 2015, will be able to detect directly an earth sized extrasolar planet - with enough detail that we may even be able to determine if there is carbon-based life on it. In 2005, Dr. Webster Cash of the Univ of Colorado at Boulder, had his New Worlds Imager project funded by the NASA Institute for Advanced Concepts (NIAC). The project plans to build a large pinhole camera in Earth orbit capable of detecting Earth sized extrasolar planets up to 32 light years away. So far there is no proposed launch date. Even more extrasolar planet mission exist or are planned: for more information visit the Jet Propulsion Laboratory's "Planet Quest: Missions" page.

From a different angle, the newly powered up Allen Telescope Array, a SETI project, will increase the chances of detecting signals from extrasolar civilizations (those who have advanced to a technological level).

The next logical question, though, is how many extrasolar planets can harbor life? First, the building blocks of life, from simple chemicals like Carbon and water to more complex amino acids, are found throughout space in interstellar clouds, planetary disks, meteors and comets, and the atmosphere of exoplanets, as being expelled into space by dying stars. Some even theorize that is how life began on Earth - it was seeded from the heavens. Second, planets are being found (whole or forming) within the "habitable zones" of their parent stars (basically, the zone around a star where liquid water can exist) - a recent one is the fifth planet to be discovered around 55 Cancri.

Around the sun, the Habitable Zone is 0.95 to 1.37 A.U. However, life could possibly exist beyond this zone: scientists are now contemplating the possibility of life existing on Europa (there is a thin atmosphere of oxygen and quite possible a liquid ocean underneath the planet covering ice sheet). And finally, as we keep finding on Earth, life is tenacious - we are finding life everywhere on this planet, under an increasing range of conditions, including extreme conditions of no oxygen, boiling water, and frozen ice.

Because life can thrive under a wide range of conditions, it is most likely that alien life does not need a Earth duplicate on which to form and thrive, and thus it will be an astronomically minute chance that alien life will be duplicates of Earth life. There is a vast range of variables that can affect the direction alien biology takes, which in turn can affect the alien's psychology, society, technology, and theologies.

Closing Remarks

I don't want this blog to be one-sided. Please feel free to leave comments, whether to challenge or to support a speculation, or to suggest other references and resources. It is my hope this blog can be beneficial to its readers, including amateur philosophers, students looking for essay topics, and science fiction writers looking for ideas to stimulate writing, as well as for space science and/or science fiction fans.

© DigitalBlasphemy.com

Return to Alien Realities' home page.


References:

"ATA." SETI Institute. 2007. Web. 30 October 2007. <http://www.seti.org/seti/projects/ata/>.

"Europa, a Continuing Story of Discovery." Project Galileo. NASA. Web. 30 October 2007. <http://www2.jpl.nasa.gov/galileo/europa/>.

"Extrasolar planet." Wikipedia, The Free Encyclopedia. 4 Nov 2007, 07:02 UTC. Wikimedia Foundation, Inc. Web. 4 Nov 2007. <http://en.wikipedia.org/w/index.php?title=Extrasolar_planet&oldid=169111401>.

Jet Propulsion Laboratory. "Planet Quest: Missions." NASA. Web. 30 October 2007. <http://planetquest.jpl.nasa.gov/missions/missions_index.cfm>.

Johns Hopkins University. "Earth-like Planet Forming In Nearby Star System, Astronomers Believe." ScienceDaily. 4 October 2007. Web. 30 October 2007. <http://www.sciencedaily.com/releases/2007/10/071003130744.htm>.

NASA Goddard Space Flight Center. "Cornucopia Of Earth-sized Planets Modeled By NASA." ScienceDaily. 25 September 2007. 30 October 2007. <http://www.sciencedaily.com­/releases/2007/09/070924132510.htm>.

NASA/Marshall Space Flight Center. "NASA Scientist Discovers New Species Of Organism In Mars-like Environment." ScienceDaily. 31 July 2003. Web. 30 October 2007 <http://www.sciencedaily.com/releases/2003/07/030731081613.htm>.

"Notes for star 55 Cnr [55 Cancri]" Extrasolar Planets Encyclopedia. Web. 4 November 2007. <http://exoplanet.eu/star.php?st=55+Cnc>.

University of California, Los Angeles. "Polluted Dead Star Indicates Planets Like Earth May Have Formed Around Other Stars." ScienceDaily. 17 August 2007. Web. 30 October 2007 <http://www.sciencedaily.com/releases/2007/08/070816214820.htm>.

University of Liège. "Astronomers Detect Shadow Of Water World In Front Of Nearby Star." ScienceDaily 16 May 2007. Web. 30. October 2007 <http://www.sciencedaily.com­/releases/2007/05/070516151053.htm>.