QUEST Community Science Blog

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.

Why do Moon Bears need you to knit?

Once upon a time in the far away land of Hong Kong, a woman named Jill Robinson discovered that beautiful moon bears where being held captive in tiny cages in China and farmed (through their bellies) as a living source for bear bile, which is used in traditional medicines. She decided to do something heroic about the issue and founded the Animals Asia Foundation. Animals Asia became a thriving organization, dedicated to ending cruelty and restoring respect for all animals in Asia.

For many moon bears, their stories have a happy ending. Jill and the AAF crew have rescued 500 bears, releasing them into their idyllic sanctuary in Chengdu China. Newly rescued moon bears tentatively step on fresh grass, slowly learn to climb, socialize, scamper through bamboo, wrestle and eat honey, finally becoming a real bear.

Of course, the bears can’t go from cages to sanctuary directly; they must endure urgent veterinary care and often surgery to remove the bile equipment from their bodies. Bears must be anaesthetized to receive this care and it is important that they stay warm and comfortable during the process. Just as with humans, the bears’ extremities are the first things to get cold and that is where knitters on the West Coast of the United States, worlds away, come in. They must knit giant bear mittens!

The Oakland Zoo is hoping to have some mittens knitted in order to hand them directly to Jill Robinson on May 21, when she speaks at the Oakland Zoo. We will have a knitting party at the zoo on Friday, May 9, from 1pm-3pm. However, mittens can be turned in to the Oakland Zoo at anytime and mailed to China in the hopes that the thousands of moon bears still in captivity will need them soon.

The mitten pattern allows for several weights of yarn and includes instructions for knitting in the round with one circular, two circulars, double-pointed needles, or knitting flat. Finished mittens are about 7″ wide (14″ circumference) with a 12″ foot and 6″ cuff. The pattern is intended to be beginner level, but if you have any questions about the techniques mentioned, you might find the website knittinghelp.com helpful.

Click here for the pattern and try it yourself:

bearbooties.pdf

The Oakland Zoo will be working with Article Pract in Oakland on more mittens for bears.

Find out more about Moon Bears and their plight, and meet Jill Robinson on Wednesday, May 21 at 6:30 for the lecture entitle, “From Prison to Paradise: Rescuing the Endangered Asian Moon Bear. Bring the family to Bear Day at the Oakland Zoo on Saturday, May 17.

Some of this information is thanks to Twisted, the Knit Shop in Oregon who is helping the Oregon zoo knit mittens.


Amy Gotliffe is Conservation Manager at The Oakland Zoo.

Unless our sewage happens to end up in the Bay and in the headlines, most of us probably never give a second thought to where our wastewater is headed each time we run the tap or flush the toilet.

To learn more about the travels of sewage, I took a tour of the Las Gallinas Valley Sanitary District treatment plant led by Plant Manager Matt Pierce. The plant has been in operation for about 50 years and serves over 30,000 residents in north San Rafael.

After leaving sinks and showers throughout the District, wastewater travels through a network of pipes and pump stations. Once the sewage arrives at Las Gallinas, it passes through an inlet screen and a grit chamber, which together remove much of the dense, inorganic material-”like diamond rings,” Matt jokes.

A lot of what happens at the plant is not that different from what happens in your compost pile: “It’s basically bacteria at work,” Matt points out. (The much bigger challenge for sanitation districts these days are all the unnatural things we’re putting down the drain: household chemicals, personal care products, pharmaceuticals.)

From the grit chamber the sewage heads into a series of clarifiers, where gravity causes the organic solids to settle out. The biosolids pass through a thickener and then an anaerobic digester-the most, ahem, aromatic stop on our tour. After further thickening in storage ponds, the sludge is injected into a disposal field.

Meanwhile, the liquid from the clarifiers travels through two biofilters, where rotating arms spray the water over rock beds. The organic matter in the wastewater is a feast for microbial slime living on the rocks. In the nitrification tower, more microorganisms break down the ammonia in the water. In the final stages of treatment, the wastewater is chlorinated to kill any remaining bacteria, then dechlorinated since the chlorine is toxic to many aquatic species. Finally, the treated water is sprayed onto District fields or discharged into Miller Creek where it flows to San Pablo Bay.

The District has done a lot to minimize the environmental impacts of its operations. The plant is powered by a field of solar panels. The methane released in the sludge treatment process is captured and used to generate power and heat the digester. Some of the treated wastewater supports acres of fresh and saltwater wetlands-in fact the District’s land is a favorite local gem for walkers and birders. And in a partnership with the Marin Municipal Water District, more than a million gallons of treated wastewater are recycled daily for landscape irrigation and other projects.

There are plans to make even fuller use of the reclaimed water. The Bay Institute-in partnership with the Sonoma County Water Agency, Las Gallinas, and three other North Bay sanitation agencies-has developed a plan to use recycled water for wetland and creek restoration and for agricultural irrigation. Legislation sponsored by Congressman Mike Thompson to establish the program passed the House late last year; Senator Dianne Feinstein has introduced similar legislation that we are hopeful will pass this year.

With California’s growing demands for water, such creative means to conserve and recycle are critical to helping prevent this precious resource from just going “down the drain.”


Ann Dickinson is Communications Manager for The Bay Institute (www.bay.org), a nonprofit research, education, and advocacy organization dedicated to protecting and restoring San Francisco Bay and its watershed, “from the Sierra to the sea.”

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.

Your house may not be your biggest contributer to global
warming. Credit: Jim Gunshinan.

My focus in this blog had been on green homes, but there are other areas of our lives that account for our total carbon footprint–how much carbon we are responsible for adding to the atmosphere–a measure of our contribution to global warming. Our houses and apartments, but also our cars, air travel, and the food we eat all contribute.

Don Fugler, who does research for the Canada Housing and Mortgage Corporation, estimated the amount each area of our lives contributes to our carbon footprint. He used a hypothetical family of four (two adults, two kids) in Ottawa, with a medium-sized house (2,400 square feet), and two cars (Ford Explorer and Honda Fit) to do the calculations. Both parents work and travel about 20 miles roundtrip to work each weekday. The kids travel a few miles each day back and forth to school. Both parents make a total of five trips to Toronto and five trips to other places each year for business, and the family goes on a yearly ski trip to Whistler by air travel, and back and forth by car to visit relatives in Nova Scotia once a year.

For us Californians, replace Ottawa with Oakland, Whistler with Lake Tahoe, add a trip to Hawaii, and subtract most of the energy used for heating a house, and I think we come close to the Canadian example.

The folks who brought us the movie also gave us a nifty
carbon calculator. Use it to measure the size of your carbon
footprint (go to www.climatecrisis.net/takeaction).
Credit: www.climatecrisis.net

Our hypothetical family, according to Don’s calculations, emits about 13 tons of CO2 from their house, about 14 tons because of air travel, about 10 tons from their cars, and about 5 tons from the food they eat (including growing, shipping, and waste disposal). Notice that the highest amount is from air travel!

The folks who brought us the movie An Inconvenient Truth also provide an online calculator so that you can more accurately calculate your contribution to global warming–the site also gives good information on how to reduce your carbon footprint. Don recommends that we conduct more and more of our business using the Internet instead of traveling far from our homes, live close to our jobs in dense urban areas with good public transportation, ride our bikes a lot, and all become vegetarians.


Jim Gunshinan is Managing Editor of Home Energy Magazine. He holds an M.S. in Bioengineering from Pennsylvania State University, State College, Pennsylvania, and a Master of Divinity (MDiv) degree from University of Notre Dame.

A “penguin suit” doesn’t just refer to a tuxedo anymore.

Why does Pierre, the Academy’s 25-year-old penguin
need a wetsuit?Thanks to an innovative treatment at the California Academy of Sciences. Pierre, the Academy’s 25-year-old penguin was recently fitted with a wetsuit! Pierre’s feathers were thinning and not growing back. Because penguins rely on their feathers for warmth, Pierre was often shivering and uncomfortable without the protection of his feathers. When medical tests concluded there was no medical reason for the feather loss and more conventional treatments proved unsuccessful, senior aquatic biologist & penguin handler, Pam Schaller came up with a more creative approach to keep Pierre warm.

Pam was very familiar with the warmth of wetsuits. She then mused why couldn’t a wetsuit be designed for a penguin? She approached Academy veterinarian, Freeland Dunker with her left field idea. At first, he was dubious but after talking with Pam, he agreed it was worth a try as long as the wetsuit was fitted to insure it did more good than harm. In other words, as long as the wetsuit was fitted not to impede movement or cause rashes, it was worth a shot. Pam knew the best person to design a custom wetsuit would be Celeste Argel, the Early Childhood Specialist at the Academy, who is an excellent and creative seamstress. Celeste was asked to collaborate with Pam to develop and fit a wetsuit just Pierre’s size.

But how do you go about designing a penguin wetsuit? The answer seems to be trial and error. Celeste sat down with me and went over the details about the unusual experience. The process from idea to creation required a great deal of patience and re-fitting.

Celeste, Pam and Pierre met several times in order to customize dimensions. The first fitting consisted of Pam restraining Pierre in order for Celeste to take measurements. From the start, Celeste marveled at the strength of Pierre. “From far away,” she commented, “penguins just look so cute and cuddly but being up close gave me an appreciation for just how strong penguins really are.” With measurements in hand, Celeste drafted up a pattern for the wetsuit and created the first prototype from white cotton bed linens.

On the second fitting, Celeste was faced with a new challenge - getting Pierre’s flippers through the armhole. Pam wanted to keep the armholes as small as possible to maximize warmth. In doing so, Pierre’s flippers had to be bent at the joint and folded in upon themselves in order to thread them though the armholes. While Pam again restrained Pierre, Celeste applied pressure at the joint to fold his wings. “It was amazing and scary to fold up Pierre’s flipper. I wanted to make sure I wasn’t hurting him but to fold his flipper required a bit of pressure at the joint,” Celeste related. With the prototype on, Celeste was able to use a marker and note where the suit had to be taken in or taken out to make Pierre more comfortable. And then again, it was back to the drawing board.

A few more fittings took place to streamline the suit and to ensure that Pierre’s flippers had full mobility. Then Velcro was added to the back of the suit. Pierre was let loose in the penguin enclosure to see how he moved. Both Celeste and Pam sat down to watch his movements and observed where the fabric was bunching. Pierre seemed to be adjusting to his suit quite well but the other penguins, new to a mostly white Pierre, started poking and prodding to investigate the newly adorned bird. Because of the interest from the other birds, the session in the suit only lasted a few minutes. Celeste changed the color of the prototype to a dark brown to see if the other penguins would respond differently and they did. They accepted Pierre with a dark physique. More sessions in the new prototype followed and when Pierre jumped into the water and swam around with the suit on, Celeste and Pam knew it was time for the neoprene fitting.

Celeste conducted research to see how neoprene would act differently than cotton. From her research, she concluded that the whole suit would have to be taken in at least an inch because of the give of the material. However, Celeste didn’t have a machine to sew neoprene effectively so Pam asked Oceanic Worldwide, who supplied wetsuits to the human staff at the Academy, to manufacture a neoprene suit. Pam delivered the working prototype and the patterns to Oceanic who agreed to donate their time and materials. “We were really excited to do it,” said Teo Tertel, company marketing specialist. “We heard most of these penguins only live to 20, and our little buddy there was already 25. Anything we could do to help them, we were all for it.”

When the suit from Worldwide was delivered, it still wasn’t quite ready. The neoprene suit fit differently than expected and had to be re-fitted all over again. However neoprene can be glued instead of sewn so it was a matter of trying the suit on Pierre, marking where it didn’t fit snugly and adjusting. “I would walk behind him and look at where there were any gaps, and cut and refit and cut and refit until it looked like it was extremely streamlined,” Pam remarked on the final alterations. There were hiccups with a penguin being in a wetsuit for the first time and being curious about the Velcro and tabs. So nothing was left unaltered for Pierre’s comfort and mobility.

With all the alterations finally done, a final set of patterns was delivered to Oceanic Worldwide and they again donated their time to manufacture the final wetsuit for Pierre. All the hard work paid off for all involved when Pierre became warm again. It was a huge bonus when he also started to gain weight and his feathers began to grow back. The goal of designing the wetsuit for Pierre was to keep him comfortable and warm and the custom suit worked much better than expected. Having Pierre happy and healthy without the further need of the wetsuit was a perfect outcome for a very unusual treatment.

Cat Aboudara is the Special Projects Manager at California Academy of Sciences and works in the public programs division. The Academy is a wonderful fit for her because of her curiosity about the natural world and her experience in working with native California wildlife.

These fish can tell us a lot about ourselves.

Species often end up a different color when their environment changes. And humans are no exception.

When people moved out of Africa tens of thousands of years ago, they were dark-skinned. Now when we look around Northern Europe or parts of Asia, we see much lighter people. What happened?

A common explanation has to do with sunlight and vitamin D. When people moved north, they got less sun. Less sun means less vitamin D and awful diseases like rickets.

Anyone who moved north and had lighter skin ended up getting more vitamin D and did better than their darker neighbors. After awhile, most of the population had light skin.

This is all well and good, but what happened at the gene level to cause this transformation? One way scientists are learning about how humans ended up with lighter skin is by studying fish. For example, the zebrafish has taught us a lot about why Europeans are often so pale.

The zebrafish is an important model system that scientists use to study vertebrate development, human disease, and lots of other things. A common mutant fish that scientists use in these studies is called “golden.” These fish have lighter, yellowish stripes instead of black ones.

Scientists discovered that these mutant fish had yellow stripes because of a single DNA difference (or SNP*) in their SLC24A5 gene. When fish have this DNA difference, they have yellow stripes.

These scientists next looked for this gene in people. What they found was that most of the people they looked at had two copies of the “black stripe” version of the gene. Except for Europeans. They tended to share a common SNP in their SLC24A5 gene that the scientists went on to show is a big part of why many Europeans have lighter skin.

Another group of researchers decided to dig a bit deeper and find out when this transformation happened. By looking at the DNA around SLC24A5, they found that lighter skin came to dominate Europe around 6,000-12,000 years ago. At first this result is a bit confusing because humans moved into Europe around 40,000 years ago. Why did it take so long for lighter skin to become the norm?

Scientists can’t know for sure but one idea is diet. Around this time, Europeans started to grow their own food. And a farmer’s diet has less vitamin D than does a hunter-gatherer’s diet. Maybe the lack of sun only started to affect Europeans after they started growing their own food. Then, after a relatively brief time, most Europeans ended up fair-skinned to get enough vitamin D.

This gene doesn’t explain all of skin color. For example, it doesn’t explain the difference in color between Northern and Southern Europeans. Or why some Asians have fair skin. But it does explain a good deal of European coloration. Thanks, zebrafish!

*SNP=single nucleotide polymorphism

Dr. Barry Starr is a Geneticist-in-Residence at The Tech Museum of Innovation in San Jose, CA.

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.

And live in an aquarium in my living room?

A fish tank calms my nerves. A fish tank connects me to the sea. A fish tank brings peacefulness into my hectic world. These are the words of marine aquarium owners. The lure of a tropical fish tank is clear: they are mesmerizing and colorful, they are relaxing to gaze at and they bring real sea creatures right into one’s home. In fact, between 1.5 and 2 million people worldwide feel this way, and keep marine aquariums, including 800,000 households in the United States alone.1,471 species of fish are traded worldwide, with global trade ranging between 20 and 24 million individual fish annually.

Unfortunately, not enough aficionados of tropical fish know how these beautiful beings got to their local tropical fish store. Fewer than 10% of the fish are captive-bred, meaning most are collected from their coral reef habitats off of places such as Indonesia.

Most collectors are men from small villages, who make mere pennies on their catches. Though they sometimes use nets and their own hands, often they employ squirt bottles full of cyanide. As a result of cyanide use, mortality rates of captured fish are between 5% and 75% within hours of collection, with 20% to 50% of survivors dying soon thereafter. Of those that survive the collection process, another 30% on average die prior to export. Collection using cyanide results in an overall survival rate of less than 1 in 10 fish, at best, and often produces 100% mortality.

For those that make it out of their country of origin and onto a plane, eight out of ten will die en route from lack of oxygen, stale water and trauma. For U.S. export, most of these bagged fish are sent to “fish row” in Los Angeles where they are distributed to fish supply stores all over the country.

The good news is that once tropical fish collectors know more, they tend to act. More and more collectors are asking suppliers about their collection techniques and making informed decisions. Reef Project International is a project of Earth Island Institute (and the supplier of most of this information). They have created a Reef Fish Guide for the aquamarine hobbyist that lets them know if a particular fish falls under “Take it Home” or “Keep it Wild”. The guide is available at (www.reefprotect.org). The hope is that when consumers demand sustainable and humane tropical fish, suppliers will respond, and fish and their habitats will benefit.

By the way, Clownfish, like Nemo, are one of the few species that can be captive-bred.

Amy Gotliffe is Conservation Manager at The Oakland Zoo.

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.