The Square Kilometer Array

EyesWideOpen writes "A very ambitious project to build the world's largest radio telescope, named the Square Kilometer Array or SKA, is in its early design stages. As its name suggests the SKA will be one square kilometer in size if it gets built. The SKA consortium (consisting of Cal Tech, Cornell, SETI, the Max Planck Institute and Beijing Astronomical Observatory to name a few) hopes to build the telescope by 2010. "If they succeed the SKA will be so big and precise it will jump the world's current best, the American Very Large Array in New Mexico, by a factor of 100, both in sensitivity and resolution." It's interesting to note that the project is based on technology that will only exist in three, five or seven years -- to account for data rates of tens to hundreds of terabytes per second and storage in the petabytes -- so they're counting on Moore's law to hold true."

Comments

Talking about SETI....

[Howzer]

This baby would actually make it possible.

Instead of relying on super-powerful transmissions from the aliens, as we do now, we could detect, for the first time, signals at the same strength as our own and "listen" to most of our own galaxy for them.

This is truly new, and means a SETI "hit" comes into the realm of the probable, IMO. The link is to the "SETI" page on the SKA site. It's down a couple of levels and jargonized, so I don't think I deserve a redundant mod... but you're the boss!

Re:Talking about SETI....

[Angry Toad]

Sure, you can come up with as many scenerios on why someone wouldn't do it as you want.

I think this is the part that I'm uncomfortable with - the argument seems to rest on the idea that if someone doesn't do it the way we think they should, then they probably don't exist. I accept provisionally that with a "reasonable degree of certainty" we see no evidence that they have ever been here, and thus must assume that either (a) they don't exist, as per the paradox, or (b) something is wrong with the model under which a paradox arises.

You can make up all kinds of conspiracy scenerios

I recognize that my argument treads dangerously close to loony ground. For the record let me state that I'm no UFO nut. All the same, the detritus of tinfoil hats and Von Daniken spoor all around us should not dissuade us from having a look around the territory. We cannot currently say anything conclusive about the frequency of extraterrestrial civilizations even nearby to our own solar system - we don't have the technology. The only thing we can eliminate with certainty is the presence of any nearby high-power directed beacons. Once we have the technology to detect earth-level RF from other solar systems, then we'll be able to say that we are not surrounded by civilizations. Until then, the Fermi Paradox must rest upon the absence of evidence for visitation within our own solar system.

I accept the conclusions of the paradox, but only provisionally. We are still speculating in a sea of unknowns, and I'm uncomfortable with charting out a single string of minimal-assumption hypotheses and then taking the results with anything but a grain of salt.

FWIW, my own personal suspicion is that technological life is incredibly rare, but that simple, bacterial-level life might be common. This is just based upon the one piece of evidence we have - the history of life on Earth. It's only a single data point, but all the same it is an absolute and undeniable example of life evolving in a solar system. Over 4.5 billion years of Earth's history, nearly 3 billion of those were spent as a stable bacterial world. In all that time, only one successfull association of bacteria managed to develop the information capacity of eucaryotic life. That's really bad odds.

Why bigger is better

[Space cowboy]

The reason radio telescopes have to be so much larger than their optical counterparts is due to the wavelengths they are looking for. For a given observation aperture, there's a simple rule-of-thumb which goes:

Voltage gain ~= circumference / wavelength.

... with the power gain (the "magnification") being the voltage gain squared.

Given that the wavelength of 'visible' light is approximately half a million times shorter than radio wave wavelengths, the collecting area has to be much larger to get the same antennae gain.

An interesting corollary of this is that the naked eye is (very roughly) as powerful (at visible light wavelengths) as Arecibo is (at radio wavelengths). See the The seti league pages for more info...

Simon.

Re:Moore's Law

[Detritus]

Moore's Law is about the density of transistors in integrated circuits, not their speed or cost.

Resolution

[FlemLion]

" If they succeed the SKA will be so big and precise it will jump the world's current best, the American Very Large Array in New Mexico, by a factor of 100, both in sensitivity and resolution."

Fortunately it's only compared to the VLA in regards of resolution. Single radiotelescopes have no chance in hell to get to extreme resolutions. Resolution is all in the diameter, or baseline. Nothing you can do about, it's just basic physics. Fortunately you can have big holes in your telescope, or inversely just a few parts of the surface. Excactly the principle of the VLA and VLBI in radio frequencies and the VLTI for light. You can even find a simulation applet here

In fact the earth itself is getting too small to get more resolution. Going into space is indeed being looked into, but not in the sense of a satellite like the Hubble orbiting the earth. That would hardly be worth the effort where radio astronomy is concerned. Having a baseline as long as the distance between the earth and the moon, now that would be an improvement. Plus, if it's built on the side that's always turned away from the earth, the telescope will be shielded from all the annoying interference created by all the radiochatter on earth, while it's still possible to look at the same piece of sky as an earth based telescope.

In the visual spectrum, Darwin from ESA looks set to become the next record holder . A first technology demonstration/development flight in the form of SMART-2 is currently under development.

Built by 2010...?

[blakespot]

I think the square kilometer array, to be completed in 2010 would be an excellent tool to augment our search for extraterrestrial life. I hope that the funding, so critical to such an endeavor, is made available and that we can cooperatively, as a planet, make use of this in harmony. An intersting thing about such a large arr -g@@! #$ 01001 #3t245@

ALL THESE WORLDS ARE YOURS--EXCEPT EUROPA.

ATTEMPT NO LANDINGS THERE.

blakespot