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Probing the Martian Pole

May 9th, 2008 by Ben Burress

Mockup of Phoenix (top) and ‘Robinson Crusoe on Mars’
(bottom)—both set in Death Valley National Park…
Credit: NASA (top), Paramount Pictures (bottom)
It’s that time of the Martian year again: when a flying saucer from Earth appears in the skies of Mars. Imagine if there actually were Martians up there: what’s science fiction here on Earth would pass for reality on the Red Planet—and a routine occurrence at that!

This time the flavor of the day is the Phoenix Lander, courtesy of NASA, scheduled to land on May 25th at about 4:38 PM PDT. We’ll be watching live NASA coverage of the landing at Chabot Space & Science Center that afternoon, if you’d care to join us…

Following somewhat in the footsteps of the Viking landers of the 1970s, Phoenix’s primary mission is to look for evidence of life, or at least the chemical conditions that might be suitable for life to exist. The two Viking landers carried small chemical laboratories that analyzed soil samples scooped up from the surface, as does Phoenix.

While its mission parallels that of Viking, one big difference from Phoenix is its destination: the Northern Polar Ice Cap of Mars. The Vikings landed much farther south in the mid latitudes. Phoenix is targeting the ices of Mars’ arctic region.

Growing up, one of my favorite sci-fi films was Robinson Crusoe on Mars. Made in 1964, the same year that Mariner 4, the first space probe to Mars, was launched, RCOM made a descent stab at imagining what it was like. So what if the main character walked around in apparent t-shirt weather and with sufficient atmospheric pressure to keep his blood from boilin–he still wore a respirator that doled out oxygen from an ever-dwindling supply tank, a nod to Mars’ thin atmosphere.

A couple of other things our astronaut Robinson Crusoe found on that fictional Mars that we are now looking for on the real one: liquid water and life…Our hero found small caches of water (with the help of a monkey) in grottos between the rocks, and, lo and behold, living in that water was a vine-like life form with edible fruit or tubers. He even took a foot-trek, along with his guy Friday, to the polar ice cap…

(I also loved the film because some of its “Martian terrain” scenes were shot in my favorite spot on Earth, Death Valley…)

Though evidence of past liquid water action seems to be all about the planet, Phoenix certainly won’t find any brooks or pools or grottos of spring water, owing at least in part to the frigid arctic region it will set feet on–an arctic zone on a world where the warmest temperatures in the tropics might reach levels of the coldest climates on Earth. What’s important about landing on Mars’ ice cap is that Phoenix is almost certain to dig up some water–albeit frozen.

And it is the chemical compounds either locked up in that ice or preserved by its proximity that Phoenix is interested in. (Similarly, climatologists on Earth study ice cores from Antarctica to analyze the trapped and preserved gases of Earth’s atmosphere of past millennia.)

We wish Phoenix a happy landing, and look forward to the first images and discoveries from the Martian North Pole. And I’m fairly confident the epic polar adventure ahead won’t resemble in the least another “great” film of 1964: Santa Claus Conquers the Martians….

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.



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Mountain-top telescopes and stars that don’t twinkle

May 5th, 2008 by Kyle S. Dawson

Infrared image of a zebra from the London Zoo.
Credit: Steve Lowe

Right now I am very excited about the possibility of working on a new small telescope in southern Utah. This telescope was funded by a private donation and will be run by the University of Utah. We even found a mountain top in the middle of nowhere that this telescope will call home.

Why this particular mountain? There are essentially three reasons:

It’s dark
It’s clear
It doesn’t make the stars twinkle

The first two reasons are so obvious that I am almost embarrassed. The last reason is not quite so intuitive. What makes a star twinkle and why do we care? This goes back to a post I made a few months ago.

The basic idea here is that the churning atmosphere blurs your astronomical image. Local geography and weather patterns can either mitigate or exaggerate this effect. It is difficult to predict and many measurements need to be done to determine what is actually happening. Cameras were placed all around southern Utah on various mountain tops to observe the North Star over the course of the year. The mountain top that produced the highest resolution image of the star won the competition. That was Frisco Peak.

The telescope that will be placed on Frisco Peak was built by a very specialized company. This is quite rare–more typical are either large custom-made telescopes or small amateur telescopes. This telescope falls in the middle. It is bought off the shelf but is far superior to the commercially made amateur telescopes.

We are now discussing plans for this telescope, like the type of cameras that should be used. There is a strong interest in building an infrared camera. This allows us to see through large clouds of dust and allows us to see very distant galaxies.

Like most people, I am much more experienced with cameras in the visible spectrum. I work on CCDs in Berkeley and have barely used anything in the infrared. CCDs are made of silicon which is sensitive to light that can be seen with the naked eye (plus a little more red than what can be seen).

However, there is a lot of information in the sky that is too red to be seen with the naked eye and too red to be detected with a silicon detector. New materials are required for detectors in this wavelength range. One of the major new materials for infrared detectors is a blend of mercury, cadmium and telluride, usually called Mer-Cad-Tell in the astro community. The wavelength range of the detector can be tuned by changing the amount of mercury in the blend.

Clearly, a lot of the legwork has been done for this new telescope. We have the funding, we have a vendor, and we have a location. Now all that’s left is to prioritize our science goals and to figure out how to get our hands on some mer-cad-tell.

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.



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Producer's Notes: Amateur Astronomers

April 29th, 2008 by Sheraz Sadiq

In 1968, John Dobson started the San Francisco Sidewalk Astronomers with the help of two boys who loved astronomy but couldn’t join an amateur astronomy club in the city because they were too young. So the trio created their own club, carting two homemade telescopes onto Jackson and Broderick Streets and inviting curious passersby to take a look at the craters of the moon, the rings of Saturn, the banded clouds of Jupiter.

Forty years later, the San Francisco Sidewalk Astronomers is still going strong, boasting a web site replete with a monthly star chart, specific for San Francisco, a calendar of monthly amateur astronomy events, a helpful “cheat sheet” of astronomical facts and answers to questions that routinely come up if you set up a telescope on your neighborhood sidewalk, and where to go if you want to borrow, build or donate a telescope.

Another great resource for the budding SF amateur astronomer is the Randall Museum, which hosts star parties, lectures by amateur and professional astronomers and classes for making your own Dobsonian telescope from scratch. The free public lectures at the Randall Museum take place on the third Wednesday of each month, sponsored by the San Francisco Amateur Astronomers.

Since 1952, the San Francisco Amateur Astronomers have been an invaluable resource for stargazers to learn about the choicest observing sites throughout the Bay Area, monthly star parties and make contact with a community of like-minded folks. Be sure to also check out their astrophotography web page, where they have uploaded photos and even videos shot with their telescopes of galaxies, comets, moons, planets and nebulae.

If you can’t get enough of amateur astronomy clubs in the Bay Area, check out the Astronomical Society of the Pacific and the Astronomical Association of Northern California. The Astronomical Society of the Pacific, founded in the 19th century, has members from 70 countries and claims to be the largest astronomy society in the world. It also boasts educational outreach programs, such as Astronomy from the Ground Up, a National Science Foundation-funded program that helps informal science educators such as docents and volunteers by giving them the tools and training to more effectively communicate astronomy information to the public.

If you should need to buy equipment or talk with some very knowledgeable folks about the right telescope, accessories or CCD digital camera to begin your foray into astrophotography, check out Scope City, a retailer in San Francisco specializing in telescopes and binoculars.

Watch the “Amateur Astonomers” TV Story online, as well as find additional links and resources.


Sheraz Sadiq is an Associate Producer for QUEST on KQED Television.



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Cassini Martini: Add Water, Ammonia, Methane; Mix Well

April 25th, 2008 by Ben Burress

Artist concept of a geyser erupting on Enceladus.
Credit: David Seal.
Back when I was young…okay, a previous generation might have ended that sentence with, “…I’d walk forty miles through the snow to get to school…” But I’m not exaggerating when I say, when I was young we knew next to nothing about faraway places in the Solar System…such as the moons of Saturn.

A layer of the veil around Saturn’s moons was removed when Pioneer 11 and Voyagers 1 and 2 made flybys of Saturn in the ’70s and ’80s. The Saturnian moons, it appeared, were not the lumps of rock and dust that Earth’s own Moon is made of, but objects containing no small amount of water ice. Not terribly surprising, considering the low temperatures of the outer solar system where ice-rich comets roam.

Visions of frozen alien landscapes, replete with icicles and ice cliffs and ice fields and ice ice ice! were conjured in my imagination, and in artist depictions of majestic ringed Saturn seen from moons like Rhea or Dione or Enceladus.

Four years ago, Saturn’s first permanent visitor from Earth–the Cassini spacecraft–arrived there, and since has been making extreme closeup examinations of Saturn, its rings, and its increasingly wondrous and beautiful moons. Cassini is almost literally ripping apart veil after veil of our ignorance of these little worlds.

Far from a contingent of enormous but simple snow cone balls, Cassini has shown us that some of Saturn’s moons are apparently alive with liquid motion. First, there were the surface “lakes” and “seas” on Titan, probably made of extremely cold liquid hydrocarbons like methane and ethane–the stuff that spouts out of the gas range in your kitchen. Lakes and seas and rolling waves of liquid natural gas are fine and dandy for an imagined shoreline scene–but take a dip in those “waters” and an actual water-based creature like you would freeze solid in seconds. Scenic, but not inviting for a swim…

But recent observations by Cassini have shown that Titan’s frigid unearthly lakes and Enceladus’ snowball exterior may just be additional veils that are now being lifted.

In March, Cassini flew within 30 miles of the surface of Enceladus and right through a plume of material venting into space from the moon’s interior—an enormous “geyser.” Earlier observations had sensed the presence of water in the plume, giving rise to speculation that liquid water in some form might exist beneath Enceladus’ surface—perhaps chambers of liquid heated by tidal stressing of the interior.

When Cassini flew through the plume, its chemical sensors “sniffed” more than just water in the stream, but a good deal of organic molecules as well…not unlike material found in comets, stuff left over from the formation of the Solar System that may have been the building blocks of life on Earth.

The other “water find” was that of a possible liquid ocean under the crust of Titan–similar perhaps to the deep liquid water ocean believed to exist under the surface of Jupiter’s moon Europa. Unexpected “drift” in the locations of landmarks on Titan’s surface is what suggests a liquid ocean–water with perhaps some ammonia–that the frozen crust may be floating on.

With all the liquid water and organic chemistry being revealed in the Saturn system (and elsewhere in the outer solar system), our imaginations can shift from the older standards of envisioning otherworldly landscapes of sculpted ice or even seascapes of liquid hydrocarbon lapping on shores of water ice sand, to something a little more, shall we say, “lively…”?

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.



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Pixels are so 20th century - say hello to ’spaxels’

April 23rd, 2008 by Kyle S. Dawson

Making Every Photon Count

Last week I went to a talk given by the leader of the Supernova Factory collaboration at LBNL. What is SN factory? This is an ambitious project to study supernovae like never before. I mentioned this project briefly in a previous post , now that they are so close to releasing their results I want to discuss it a bit more.

The main idea of this project is to study several hundred nearby supernovae using an instrument known as the Supernova Integral Field Spectrograph, or SNIFS. This type of instrument is essentially a blend between a traditional imaging camera and a spectrograph.

The resolution in an integral field spectrograph is defined in spaxels instead of the pixels that have become all too familiar with the advent of digital cameras. A spaxel is quite similar to a pixel, there aren’t nearly as many and each one carries at least a 1000 times as much information.

In your digital camera, the light passes through the lens and directly onto the CCD. Each pixel on the CCD counts the number of photons in the red, the blue, and the green. Typically, there are millions of pixels, each counting photons from a slightly different region of the subject of your photograph.

Now imagine that instead of just counting red, green, and blue, that each pixel counts the entire rainbow of light from your subject. Now you have a spaxel. In an intregral field unit, the light passes through an array of microlenses and prisms before landing on the detector. We would call each set of microlenses and prisms a spaxel. The resulting image carries information about every wavelength of light from every region of your target.

Spectrum of the first SN observed with SNIFSThe advantage to an integral field spectrograph like SNIFS is that you gain a lot more information than either an imager or spectrograph alone. With an integral field spectrograph you can basically identify and organize every photon that reaches the telescope.

Specifically designed to observe supernovae, SNIFS is being operated at the 88-inch telescope on Mauna Kea. Spaxels are quite expensive - this particular instrument has only 225. However, this is more than enough to observe the entirety of a galaxy, a supernova, and the background.

The members of the SN Factory have now observed over 100 SNe using this new camera. Last Thursday, I saw the data from the first 25 well-calibrated supernovae and was very impressed. The data showed the evolution of each supernova and the properties of the host galaxy in great detail. I’m sure the supernova community will be equally impressed when they first see these new results.


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.


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The Last Hoorah for Solar Cycle 23?

April 11th, 2008 by Ben Burress

Magnetic activity on March 27th; white indicates N
magnetic poles, black S. Credit: ESA/SOHO/NASA.

A few blogs back I wrote about the 11-year cycle of ups and downs in solar activity–the Solar Cycle –and how over the last year or so the baton was supposedly passed from Cycle 23 to Cycle 24. But there has been an occurrence on the Sun that suggests we may be in somewhat of a gray zone….

For the past two or three years, the Sun has been downright boring. We set up our Sunspotter telescopes for visitors and try very hard to make what we see seem interesting–”See that perfectly blank circle of light? That’s the Sun! Really it is!”

About a week ago, the tedium was suddenly broken by a train of sunspots that rotated into view on Sun’s disk. Five–count’em– five sunspots! Finally, something to actually look at! And in the eyepiece of our Coronado Hydrogen-Alpha filter telescope there were filaments and plage! What are filaments and plage? Exactly! People wanted to know….

Then came the weird part: these were not Cycle 24 sunspots (I am not the Dread Pirate Roberts…); they were refugees from the supposedly defunct Cycle 23. While the distinction may be a fine point that doesn’t worry most of our visitors, it can still be a good talking point.

So, why were these five sunspots fingered as old solar trekkers rather than members of the next generation? It all comes back to what a solar cycle is–and sunspots, flares, prominences, and plage are merely details: manifestations of the Sun’s magnetic convulsions. The Sun, like the Earth, generates an enveloping magnetic field–a big donut with a north and a south magnetic pole. On smaller scales there are plenty of twists and swirls and knots in the field caused by local “hot spots” of magnetic activity–which are what produce features like sunspots in the first place.

At solar maximum–the peak of activity of a solar cycle–the Sun’s magnetic poles flip over, or reverse. In fact, it’s this reversal that really lets us know when a solar maximum has arrived. (Earth’s magnetic field also reverses polarity periodically–although this only happens every 200,000 years, on average.)

At the beginning of a solar cycle, new sunspot activity can be found at high solar latitudes, and as the cycle progresses, activity migrates toward the equator. On a finer nuance, the magnetic polarity of sunspots–which can be N or S, and are usually paired up, like the two ends of a bar magnet –are typically oriented east-to-west on the Sun’s surface, one leading to the other as the Sun rotates. Which type of pole (N or S) leads and which trails depends on the overall magnetic “flip” state of the Sun’s magnetic field.

To round out this report, the five surprise sunspots of yesterweek were lined up close to the Sun’s equator, and the orientation of their magnetic poles bespoke their affiliation with the outgoing magnetic administration (Cycle 23). So far, only a single, high-latitude, reverse-polarity sunspot observed last January has signaled Cycle 24 .

Who knows? Maybe the magnetic candidates of Cycle 24 are still holding primaries, caucuses, and debates and have yet to begin some serious campaigning…

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.



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Supernova Legacy

April 8th, 2008 by Kyle S. Dawson

Last night we completed our observations for the Supernova Legacy Survey. This was a five year program to study supernovae using a 4-meter telescope in Hawaii in combination with several of the largest optical telescopes in the world.

The project was headed by a group at a university in Toronto and a group at a university in Paris. Canada and France sponsor the 4-meter telescope that is used to discover and observe the supernovae from the point of explosion to the final days when the supernova fades from view. We call this the imaging part of the program. This data constrains the apparent brightness and life cycle of the supernova, and eventually the absolute distance to the supernova.

Our contribution to the project was primarily through our affiliation with Keck Observatory. We were typically awarded four nights a year to observe recently discovered supernovae spectroscopically. The data is used to determine the redshift and the kind of supernova explosion.

The supernovae are used to study the rate of expansion of the universe. It was this type of experiment that was first used to discover that the universe is actually dominated by dark energy.

No one really suspected the presence of dark energy for almost the entirety of the 20th century. Now, we not only know it exists but are actually trying to understand it in the same way we understand gravity, protons, and electrons. That is where projects like the Supernova Legacy Survey come in. With projects like this, we work to collect enormous samples of well-studied supernovae that can improve our understanding of dark energy.

We use a certain type of supernova as yardsticks to measure distances in the universe. We then model the affects of dark energy on the expansion history of the universe by comparing distances and rates of expansion. This comparison is typically represented in a Hubble Diagram.

The Supernova Legacy Survey has been very successful in its attempts thus far. On the right, I show the Hubble Diagram from the first year of data. This is less than 20% of the full sample. The dotted line outlines the expectations of the 1990’s cosmology crowd. The solid line shows the prediction from the more sophisticated cosmologists of the 21st century. As you can see, the original expectations were pretty far off the mark - the supernovae just don’t lie on top of the dotted line.

Now that this program is finishing up, we should be seeing similar figures that are teeming with supernovae. Future programs should do an even better job of making these measurements. Someday we may actually understand this dark energy thing, it may turn out to be something else completely new and unexpected!

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.


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Producer's Notes - SETI: The New Search for ET

April 1st, 2008 by Joan Johnson

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.


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Living in the Sun's Atmosphere

March 28th, 2008 by Ben Burress

Illustration of a blast of solar wind impacting
Earth’s protective magnetic field. Credit: NASA
Breathe in, exhale. Feel the air in your mouth, windpipe, and lungs. That’s a sample of Earth’s atmosphere: the thin layer of gases enveloping our planet.

Did you know that the Sun also has an atmosphere, and that the Earth is inside it? In fact, the Sun’s envelope of gases extends well beyond the orbit of Pluto, out to the regions of the solar system where the 3-decade-old Voyager spacecraft are only now reaching.

Space weather” refers to the conditions in space caused by the outflow of electrically charged gases (plasma) coming from the Sun—what we call the “solar wind.” The term “space weather” may conjure images of cosmic tornadoes, astral lightning bursts, and some Star Trek version of a galactic hurricane– but actual space weather is nothing so Earthly and familiar.

First of all, the “air” in space is nothing like the atmosphere we draw our breath from. Earth air, at the surface, is made of nitrogen, oxygen, argon, carbon dioxide, water vapor, and other trace elements, and is relatively dense. “Space air” is mostly hydrogen– ionized hydrogen at that (meaning stripped of its electrons and so electrically charged; the separated electrons are also blowing along in the solar wind).

Second, the gases of the solar wind are extremely rarified. Despite the talk of a solar atmosphere, solar wind, and space weather, space within the solar system is still almost a complete vacuum. At Earth’s distance from the Sun, the average density of the solar wind is somewhere between 6 and 9 atoms (mostly hydrogen) per cubic centimeter. If you spread out the gas contained in an ordinary party balloon to this same thinness, it would fill a volume of space over 10 miles across!

Third, the solar wind, for all its sparseness, blows fast! Depending on conditions of space weather, the flow of solar wind past the Earth can speed along anywhere from 200 to 900 kilometers per second! Earth’s fastest winds slug along at only a few hundred kilometers per HOUR.

So how does space weather—the changing conditions of the solar wind—affect us on Earth? How might you, personally, have experienced, directly or indirectly, the effects of the Sun’s gentle breeze?

The most familiar phenomenon caused by space weather is Earth’s beautiful auroras —the northern and southern lights. Interactions between the solar wind and Earth’s magnetic field and electrically charged particles trapped in it excite atoms in the upper atmosphere to emit light. And it’s not just a softly glowing night light: the most powerful auroras can generate up to a trillion Watts of power!

Solar wind “storms” can not only produce more active auroras, but can cause fluctuations in Earth’s magnetic field whose effects can be felt on the ground. These “geomagnetic storms” usually pass unnoticed, perhaps causing a tiny change in the direction that compass needles point– but have also been known to overload electrical power grids and cause blackouts.

In the space around Earth, solar storms have been known to damage or disable satellites, and can put unprotected astronauts at risk. Space walks on the International Space Station are scheduled for times when space weather is - so to speak -”sunny and calm.”

Thinking about space weather on Earth might seem like worrying over Atlantic hurricanes here in the Bay Area—but with more and more human activity taking place beyond the confines of our atmosphere, this is a very real and vital concern, and is taken very seriously.

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.


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Excellent conditions for skiing and supernovae

March 24th, 2008 by Kyle S. Dawson

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.


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