Wednesday, September 23, 2009

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

Saturday, September 19, 2009

You Can Help Find Exo-Earths

From The Planetary Society, a way that laypersons can get involved in the search for terrestrial exoplanets:

FINDS Exo-Earths

A thrilling new hunt for Earth-like planets orbiting distant stars is starting...

The Planetary Society is teaming up with planet hunters Geoff Marcy of the University of California at Berkeley and Debra Fischer of San Francisco State University to help with the quest to find other "Earths," other worlds like our own, elsewhere in our galaxy.

The project is called FINDS Exo-Earths (which stands for Fiber-optic Improved Next generation Doppler Search for Exo-Earths).

This new high-end optical system will be installed on the 3-meter telescope at the Lick Observatory, dramatically increasing discoveries of smaller exoplanets and playing a crucial role in verifying Earth-sized planet candidates from the Kepler planet-hunter mission.

This is exactly the kind of project the Society has always excelled at. It's a small, vital effort, overlooked and under-valued by the space community's "Powers That Be." And we can see that it offers an incredible cost-benefit ratio.

Imagine: a way to specifically hunt for and discover Earth-sized planets orbiting far distant suns. This could truly revolutionize exoplanet exploration. It will, at the very least, massively expand our scientific knowledge; at best, it could eventually prove a major step forward in the dream of finding life native to another world. It will also provide valuable backing to NASA's Kepler mission, a vital goal all in itself.

How Does FINDS Exo-Earths Work?

When planet hunters train their telescopes on the stars, they usually aren't looking for an actual visual image of any planets. The distances are simply too vast. Rather, they seek evidence of those distant planets based on the behavior of the light from the stars themselves.

The most common method is called the "radial velocity technique," which relies on measuring minute Doppler effect changes in the star's light. The starlight changes because orbiting planets "tug" on their stars; so, as they circle, a minute Doppler effect occurs in the starlight. This tug either pulls the light waves slightly apart, or pushes them slightly together, changing their frequency. (It's the same effect that occurs to sound waves when a train rushes by you, with the sound of its whistle suddenly dropping in pitch.)

You can imagine how small these changes are, and how hard to detect. Modern technologies make it possible, but there are limits. For example, the terrific 3-meter telescope at the Lick Observatory can detect Doppler velocities of about 5 meters per second. That's good enough to spot enormous Jupiter-sized planets.

But to identify smaller worlds -- the ones more likely to have life -- a telescope must be able to detect Doppler velocities of 1 meter per second. To detect a planet the size and density of Earth, the precision would have to be under 0.5 meters per second.

The Marcy-Fischer team has tackled this problem by devising not one, but two optical systems to be used in tandem. The first is a fiber optics array that will make the cone of light entering the telescope's spectrometer "uniform," and therefore resilient to naturally occurring changes that foul up Doppler measurements.

The second part is an adaptive optics system that will keep the maximum amount of light flowing through the system -- that is, providing a better "signal-to-noise ratio."

Altogether, this bundle of new technology is referred to as Fiber-optic Improved Next generation Doppler Search for Exo-Earths, or FINDS. At Lick, it could improve detection to the 1-meter range, enabling additional discovery of many Neptune-sized planets and larger. If Marcy-Fischer can do all that with our help, then it will be on to the Keck Telescope, where 0.5 meter precision (and Earth-size planet discoveries) can happen.

And, once our instrument is adapted for the Keck Telescope, FINDS Exo-Earths will provide crucial follow-up for planets found by the Kepler mission. Specifically, the Keck Telescope -- equipped with FINDS -- will rule out false positive detections of Earth-sized worlds.

We're on the brink of discovering Earth-like planets around other stars -- worlds that may support life. You can play a key role in the hunt!
To make a secure tax-deductible donation to the FINDS Exo-Earths project, visit the Project's donation Web page at <https://planetary.org/join/donate/0903exow/>. The Planetary Society's FINDS Exo-Earths Project main Web page is at <http://planetary.org/programs/projects/finds/>.


Reference:

"Projects: FINDS Exo-Earths." What We Do. The Planetary Society. n.d. Web. 19 September 2009. <http://planetary.org/programs/projects/finds/>

Image credit: Ryan Bliss, DigitalBlasphemy

Wednesday, September 16, 2009

First Solid Evidence for a Rocky Exoplanet!

The following is a breaking news release from the European Space Organization:

ESO 33/09 - Science Release

16 September 2009
For immediate release

First Solid Evidence for a Rocky Exoplanet

Mass and density of smallest exoplanet finally measured

The longest set of HARPS measurements ever made has firmly established the nature of the smallest and fastest-orbiting exoplanet known, CoRoT-7b, revealing its mass as five times that of Earth's. Combined with CoRoT-7b's known radius, which is less than twice that of our terrestrial home, this tells us that the exoplanet's density is quite similar to the Earth's, suggesting a solid, rocky world. The extensive dataset also reveals the presence of another so-called super-Earth in this alien solar system.
"This is science at its thrilling and amazing best," says Didier Queloz, leader of the team that made the observations. "We did everything we could to learn what the object discovered by the CoRoT satellite looks like and we found a unique system."

In February 2009, the discovery by the CoRoT satellite [1] of a small exoplanet around a rather unremarkable star named TYC 4799-1733-1 was announced one year after its detection and after several months of painstaking measurements with many telescopes on the ground, including several from ESO. The star, now known as CoRoT-7, is located towards the constellation of Monoceros (the Unicorn) at a distance of about 500 light-years. Slightly smaller and cooler than our Sun, CoRoT-7 is also thought to be younger, with an age of about 1.5 billion years.

Every 20.4 hours, the planet eclipses a small fraction of the light of the star for a little over one hour by one part in 3000 [2]. This planet, designated CoRoT-7b, is only 2.5 million kilometres away from its host star, or 23 times closer than Mercury is to the Sun. It has a radius that is about 80% greater than the Earth's.

The initial set of measurements, however, could not provide the mass of the exoplanet. Such a result requires extremely precise measurements of the velocity of the star, which is pulled a tiny amount by the gravitational tug of the orbiting exoplanet. The problem with CoRoT-7b is that these tiny signals are blurred by stellar activity in the form of "starspots" (just like sunspots on our Sun), which are cooler regions on the surface of the star. Therefore, the main signal is linked to the rotation of the star, with makes one complete revolution in about 23 days.

To get an answer, astronomers had to call upon the best exoplanet-hunting device in the world, the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph attached to the ESO 3.6-metre telescope at the La Silla Observatory in Chile.

"Even though HARPS is certainly unbeaten when it comes to detecting small exoplanets, the measurements of CoRoT-7b proved to be so demanding that we had to gather 70 hours of observations on the star," says co-author François Bouchy.

HARPS delivered, allowing the astronomers to tease out the 20.4-hour signal in the data. This figure led them to infer that CoRoT-7b has a mass of about five Earth masses, placing it in rare company as one of the lightest exoplanets yet found.

"Since the planet's orbit is aligned so that we see it crossing the face of its parent star — it is said to be transiting — we can actually measure, and not simply infer, the mass of the exoplanet, which is the smallest that has been precisely measured for an exoplanet [3]," says team member Claire Moutou. "Moreover, as we have both the radius and the mass, we can determine the density and get a better idea of the internal structure of this planet."

With a mass much closer to that of Earth than, for example, ice giant Neptune's 17 Earth masses, CoRoT-7b belongs to the category of "super-Earth" exoplanets. About a dozen of these bodies have been detected, though in the case of CoRoT-7b, this is the first time that the density has been measured for such a small exoplanet. The calculated density is close to Earth's, suggesting that the planet's composition is similarly rocky.

"CoRoT-7b resulted in a 'tour de force' of astronomical measurements. The superb light curves of the space telescope CoRoT gave us the best radius measurement, and HARPS the best mass measurement for an exoplanet. Both were needed to discover a rocky planet with the same density as the Earth," says co-author Artie Hatzes.

CoRoT-7b earns another distinction as the closest known exoplanet to its host star, which also makes it the fastest — it orbits its star at a speed of more than 750 000 kilometres per hour, more than seven times faster than the Earth's motion around the Sun. "In fact, CoRoT-7b is so close that the place may well look like Dante's Inferno, with a probable temperature on its 'day-face' above 2000 degrees and minus 200 degrees on its night face. Theoretical models suggest that the planet may have lava or boiling oceans on its surface. With such extreme conditions this planet is definitively not a place for life to develop," says Queloz.

As a further testament to HARPS' sublime precision, the astronomers found from their dataset that CoRoT-7 hosts another exoplanet slightly further away than CoRoT-7b. Designated CoRoT-7c, it circles its host star in 3 days and 17 hours and has a mass about eight times that of Earth, so it too is classified as a super-Earth. Unlike CoRoT-7b, this sister world does not pass in front of its star as seen from Earth, so astronomers cannot measure its radius and thus its density.

Given these findings, CoRoT-7 stands as the first star known to have a planetary system made of two short period super-Earths with one that transits its host.

Notes

[1] The CoRoT mission is a cooperation between France and its international partners: ESA, Austria, Belgium, Brazil, Germany and Spain.

[2] We see exactly the same effect in our Solar System when Mercury or Venus transits the solar disc, as Venus did on 8 June 2004 (ESO PR 03/04). In the past centuries such events were used to estimate the Sun-Earth distance, with extremely useful implications for astrophysics and celestial mechanics.

[3] Gliese 581e, also discovered with HARPS, has a minimum mass about twice the Earth's mass (see ESO 15/09), but the exact geometry of the orbit is undefined, making its real mass unknown. In the case of CoRoT-7b, as the planet is transiting, the geometry is well defined, allowing the astronomers to measure the mass of the planet precisely.

More Information

This research was presented in a paper to appear in a special issue of the Astronomy and Astrophysics journal on CoRoT, volume 506-1, 22 October 2009: "The CoRoT-7 planetary system: two orbiting Super-Earths", by D. Queloz et al.

The team is composed of D. Queloz, R. Alonso, C. Lovis, M. Mayor, F. Pepe, D. Segransan, and S. Udry (Observatoire de Genève, Switzerland), F. Bouchy, F. and G. Hébrard, G. (IAP, Paris, France), C. Moutou, M. Barbieri, P. Barge, M. Deleuil, L. Jorda, and A. Llebaria (Laboratoire d'Astrophysique de Marseille, France), A. Hatzes, D. Gandolfi, E. Guenther, M. Hartmann, and G. Wuchterl (Thüringer Landessternwarte Tautenburg, Germany), M. Auvergne, A. Baglin, D. Rouan, and J. Schneider (LESIA, CNRS, Observatoire de Paris, France), W. Benz (University of Bern, Switzerland), P. Bordé, A. Léger, and M. Ollivier (IAS, UMR 8617 CNRS, Université Paris-Sud, France), H. Deeg (Instituto de Astrofísica de Canarias, Spain), R. Dvorak (University of Vienna, Austria), A. Erikson and H. Rauer (DLR, Berlin, Germany), S. Ferraz Mello (IAG-Universidade de Sao Paulo, Brazil), M. Fridlund (European Space Agency, ESTEC, The Netherlands), M. Gillon and P. Magain (Université de Liège, Belgium), T. Guillot (Observatoire de la Côte d'Azur, CNRS UMR 6202, Nice France), H. Lammer (Austrian Academy of Sciences), T. Mazeh (Tel Aviv University, Israel), and M. Pätzold (Köln University, Germany).

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Links

Contacts
Didier Queloz
Geneva Observatory, Switzerland
Phone: +41 22 379 2477
E-mail: didier.queloz (at) unige.ch

François Bouchy
IAP, Paris and OHP, St Michel l'Observatoire, France
Phone: 33 4 92 70 64 94
E-mail: bouchy (at) iap.fr

Claire Moutou
Laboratoire d'Astrophysique de Marseille, France
Phone: +33 4 91 05 59 66
E-mail: Claire.Moutou (at) oamp.fr

Artie Hatzes
Thüringer Landessternwarte Tautenburg, Germany
Phone: +49 36 42 78 63 55
Mobile: +49 (0)163 69 13 863
E-mail: artie (at) tls-tautenburg.de

ESO La Silla - Paranal - ELT Press Officer: Henri Boffin - +49 89 3200 6222 - hbofin@eso.org
ESO Press Officer in Chile: Valeria Foncea - +56 2 463 3123 - vfoncea@eso.org
National contacts for the media: http://www.eso.org/public/outreach/eson/

Dante's Inferno

Maybe we should call this planet Dante, it sure is one hellava planet as it shows how detection methods are advancing rapidly and that our galaxy, if not the universe, will be found to be abundantly populated with planets - from gas giants to smaller terrestrials. So while this first confirmed rocky planet is a blast furnace, it is just the first to be found. Improved planet hunting devices are in development which will increase our ability to discover terrestrials. We are still just at the beginning of an exiting search.

Reference:

"First Solid Evidence for a Rocky Exoplanet." Press Releases 2009. ESO for the Public. ESO. 16 Sept. 2009. Web. 16 Sept. 2009. <http://www.eso.org/public/outreach/press-rel/pr-2009/pr-33-09.html>


Image credit: ESO

Tuesday, September 8, 2009

Pathways Towards Habitable Planets

Conference

I knew it had to happen - a conference centered on the search for habitable planets. Pathways Towards Habitable Planets is being held at Barcelona, Spain, 14-18 September. Short notice, I know - I have signed up for their distribution list so that next year I will be able to give a decent heads up.

From their Web site:

The aim of this conference is to help integrate the prospective efforts in Europe and in the US, build a community around this theme, and bring together several pathways towards that final goal.
Conference Offerings

It should prove to be a very interesting conference. Looking over their program, there does not appear to be one talk I would pass up. Though if I could only attend two presentations:
  1. first, I would have to say Dr. David Kipping's presentation, "The Detectability of Habitable Exomoons," is not to be missed. As I have mentioned before, I strongly believe that we should not only look for life on habitable planets, but on large moons as well. Planet moons like Star Wars' Endor may not be just in the realm of science fiction (and will likely prove to be more interesting and exciting than what has been so far imagined).
  2. Second, I would have to attend J. Scheider's "'Are We Alone?' in different cultures" presentation. Dr. Scheider - I believe you have a book concept there: an exploration of how different culture's answer that enduring question: "are we alone?
Why It Matters

This is exiting stuff. One long running theme for the human race has been exploration: climbing a mountain to peer over the horizon, sailing across forbidding seas in small, fragile craft, spreading out across the globe until no continent was left. We are meant to explore. It is our nature.

There are still areas on the Earth that remain largely unknown. We have the depths of the oceans where many mysterious life forms swim in the dark, waiting to be seen for the first time by wonder-filled eyes of undersea explorers. But as incredible as the diversity of life is on our mother Earth, much of which is yet to be discovered and studied, out across the vast space-ocean lie islands of life to be discovered that will expand even more our understanding of the diversity of life. And we will find yet again that T.S. Eliot was right, as he 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.

Conference Blogger (Tweeter)?

But alas, I have classes to teach, and the conference falls at the beginning of the Fall quarter - it would be difficult to miss the first week of classes. Someone needs to blog from that conference. If anyone attending the Pathways Towards Habitable Planets conference is planing on blogging (or tweeting) about their conference experience, please let me know, I will be more than happy to link to your blog.

Reference:

Pathways Towards Habitable Planets. n.d. Web. 8 Sept. 2009. <http://www.pathways2009.net/>

Wednesday, September 2, 2009

Comet Contains Building Block for Life


Recently NASA scientists discovered glycine, a fundamental building block for life, in samples of Comet Wild 2 collected by the Stardust spacecraft:

"Glycine is an amino acid used by living organisms to make proteins, and this is the first time an amino acid has been found in a comet," said Jamie Elsila of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Our discovery supports the theory that some of life's ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts."
This find adds to the growing body of evidence that the building blocks for life are common in the universe.

Reference

"Life's Building Block Discovered in a Comet." News. Astronomy. 18 Aug. 2009. Web. 2 Sept. 2009. <http://www.astronomy.com/asy/default.aspx?c=a&id=8562>

Image credit: NASA