The Allen Telescope Array.When I first began to work on Quest's SETI: The Search for ET segment, I have to admit that my initial reaction was "are we still looking for ET?" Of course, humans have been gazing up to the heavens for millennia, asking ourselves that interminable question "are we alone?" And of course, there's been a long line of increasingly sophisticated radio telescopes searching the skies for cosmic signs of intelligence. But hey, don't we at some point have to call it a day? Though I think most of us don't actually believe we're alone, the universe is really, really big. What chance do we have of finding ET?

Well, it turns out our chances are much better than I thought. Grote Reber began conducting sky surveys in the radio frequencies with his newly invented radio telescope in 1937, and detected the first signals from outer space in 1938. In the seven decades since then, we've seen a multitude of radio telescope designs pop up all over the world, but we still haven't gotten signals from any little green men. What I didn't understand, until I spoke to Jill Tarter and Seth Shostak at the SETI Institute, is that in all that time, we've hardly looked at any space at all.

Since SETI's first experiment in 1960 by Dr. Frank Drake, and until very recently, they've only looked at a thousand stars out of about 400 billion stars in our galaxy, and there are 100 billion other galaxies to look at! There are two reasons for this: 1) The radio telescopes they've been using can only look at narrow swaths of the sky, and 2) they've had to RENT time on other people's telescopes, which constrains their search and budget. Now, the new Allen Telescope Array is being built just for them, and with it they'll be able to capture millions of frequencies from multiple star systems simultaneously. It will be the biggest and fastest tool in the world for seeking signs of ET!

To learn why scientists use radio frequencies in the hunt for intelligent life, and to learn more about the history & future of the search, watch our story SETI: The Search for ET. You can also watch our extended interview with Astronomer Jill Tarter. And hey folks, the SETI Institute is a non-profit organization, so if you'd like to help them out with the search, consider adopting a scientist like Jill Tarter or Seth Shostak. Go to Adopt-a-Scientist, or join Jill's team and become a TeamSETI member at Join TeamSETI.
Also, check out U.C. Berkeley’s SETI@home page and turn your home computer into a tool that downloads and analyzes radio telescope data.

Watch SETI: The New Search for ET story online, as well as find additional links and resources.
Joan Johnson is an Associate Producer for QUEST on KQED Television.

Julien Guy: supernova cosmologistI'm sitting in the airport right now, passing time as I wait for my flight back to SFO. Looking at the clock now, I see that my jet lag future does not bode well. I awoke at 5:00 AM here and nearly 11 hours later feel like the day is over, yet it is only 7:50 AM in CA.

I spent the last week at a conference in the Italian Alps with about 200 skier/cosmologists. Mornings were spent in the conference hall watching 15 or 25 minute presentations. Afternoons were for the slopes. Evenings were back in the conference hall.

The conference started with supernova talks – I was fourth on the list. Being in the field, I had heard most of the results that were presented in the other talks. Ditto the other attendees' perspectives on my talk. However, there were some new and very promising results from the Supernova Factory.

The supernova factory is a LBNL-based research group that focuses on "nearby supernovae". By nearby, I mean only a few hundred million light years away. These supernovae occur in galaxies that are distant enough to be free of the gravity of the Milky Way and our neighboring galaxies but close enough to observe with smaller telescopes.

The supernovae observed by the SN factory are very bright compared to the supernovae I observe with the Hubble Space Telescope. The supernovae are bright enough to make very precise measurements at each wavelength of the supernova spectrum. Just like my earlier post on spectroscopy, the supernova light is imaged after passing through a prism. These images provide very detailed information about the molecules and atoms that are present in the supernova explosion.

The spectroscopic observations also tell us how one supernova may differ from another. The small variations in type Ia supernovae have been a mystery for quite some time. If we can learn the causes of these variations, these supernovae could be come even more useful for measuring distances in space.

There are several models and theories to explain the differences, but none has been extensively tested. A large number of bright nearby supernovae is required to test these models. Hopefully, a project like the supernova factory will provide that sample. In this conference, they only showed a handful of supernovae. All but one of these supernovae was well-behaved, fitting our current models. The last one differed enormously from the others, but the detailed spectroscopic observations lent evidence as to why this may be the case. The data is still being examined, but I am encouraged by the progress necessary if supernovae are to be used to explain the cosmology of our universe.

The presentations over the next five days covered a very large range of topics. Some conference attendees presented ideas that had never occurred to me. One that I found very interesting was an experiment to model the orbital paths of stars around the black hole at the center of the Milky Way. For those patient enough to watch these stars for 15 years, it should be possible to measure the properties of gravity and the black hole itself by looking for deviations in the stars orbits from our current models.

While the talks were very interesting and well-attended, I can't help but comment on the other important side of this conference. That would of course be the skiing. The Europeans really have it right – they chose the site and the schedule with the perfect balance for leisure time. We were only ten miles from the tallest mountain in Europe, within site of the Matterhorn, had perfect snow all week, and had just enough time to enjoy it. I even had a chance to practice my amateur photography on the slopes. Now the next challenge will be to organize a conference in Tahiti!

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

A single email on Sunday afternoon brought my weekend to a screeching halt. Some collaborators made a very exciting discovery and needed to confirm if it was real. This would be the last time we'd have for almost another year on the 10 meter Keck Telescope so I jumped at the chance and scheduled it into our observing run Monday night.

I spent the rest of Sunday studying similar projects and forming my observing strategy. Early Monday morning, with only two hours before the final deadline, I finally got the images I needed from the collaborators. I quickly examined these images and identified the interesting galaxies for our observations.

I chose the galaxies which looked to be the most distant. We were hoping to find a cluster of galaxies some 10-12 billion light years away. Confirming so many distant galaxies is only possible with a large telescope like Keck.

For the first two hours of the night we observed these galaxies using spectroscopy. This technique is essentially inspired by the rainbows at the end of a thunderstorm. Just like the raindrops that create a rainbow, the spectrograph has a prism that separates light into its fundamental colors. The difference in my observations is the light comes from distant galaxies instead of the sun.

Because there are so many galaxies and stars in the sky, the important galaxies have to be singled out and shielded from the not-so-important galaxies–sometimes I wonder if some astronomer in the Andromeda galaxy is flagging our Milky Way as one of those not-so-important galaxies.

All of the distractions on the sky are blocked from view with a slitmask. A long and narrow slit is milled into a sheet of aluminum for each object you are studying. The slitmask is aligned to match the positions of the objects that are being targeted. If you were to peek at the sky through the slitmask and telescope, you would only see the handful of galaxies that were hand-selected. Everything else would be blocked by the mask.

In spectroscopy, the light from a galaxy passes through the slit, then through the prism and into the camera. In an observation of a sun-like star using color film, the resulting image would look a lot like a rainbow. In this case I was not observing a star and I was not using color film. The image loses the fancy colors but still carries the same amount of information.

Believe it or not, a rainbow can be just as beautiful in black and white as it is in color. The black and white rainbow tells you how much light is at every wavelength. From this information you can infer the properties and the redshift of the galaxy.

So what happened in last night's observations? We haven't finished the analysis, but I did take a quick look at the data before calling it a night. Skimming through the spectra of all the galaxies in the slitmask, I didn’t find the features I was hoping for. I'll look more carefully at the final processed data, but I have a bad feeling that we didn't confirm this new discovery. Maybe we'll have better luck next year.

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

latitude: 19.5228, longitude: -155.152