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Messages from Mercury

 

Ben Burress by Ben Burress  July 30th, 2008
37.7631, -122.409

A limb shot of Mercury's horizon taken by the
MESSENGER spacecraft on January 14, 2008.
Photo Credit "NASA/MESSENGER"

If you can take a name like "Mercury Surface, Space Environment, Geochemistry and Ranging" and craft it into a neat acronym like MESSENGER, then you may have a future working with NASA….

And no, this blog isn't about NASA acronymizations, but rather the heat-resistant robot behind one of them. MESSENGER is the space probe that NASA sent to Mercury to give the Solar System's innermost planet the first up-close look since 1975, when Mariner 10 flew by.

Though MESSENGER's main mission will begin in earnest when it returns to Mercury and finally settles into an orbit around the planet, on March 18th 2011, we were given a tantalizing peak last January 14th when the probe made its initial flyby.

What did this quick, on the fly snapshot tell us that we didn't know before? Well-a lot, considering Mercury has been one of the least understood planets in the Solar System, and was for a long time thought to be similar in character to our own Moon. Mercury is shaping up to be a lot less like Earth's Moon than its gray, cratered, airless appearance would mislead.

One key difference: density-how much material is packed into the planet; or how heavy a standard sized chunk of it would be. Our Moon is a lightweight on this score, with an average density of only 3.4 grams per cubic centimeter, while Mercury weighs in at a hefty 5.427 g/cc-almost as dense as Earth.

Another key difference: magnetic field. Planets like Earth and the Gas Giant worlds (Jupiter et al) generate respectable magnetic force fields, useful for everything from deflecting plasma flowing from the Sun (the "solar wind") to properly directing magnetic compass needles. Venus, Mars, and our Moon do not possess magnetic fields worth mentioning, as it turns out.

Mercury, on the other hand, does. Planetary magnetic fields are believed to be generated by currents in a planet's liquid outer core-like how the electric current in the wire coil of an electromagnet generates a magnetic field. Mercury's magnetic field suggests it still has some activity in its core-molten metals circulating in currents as the core slowly cools off. And speaking of Mercury's core, it appears to comprise 60% of the planet's mass-about twice what is "typical" for Terrestrial (solid) planets.

I've often imagined Mercury to be a cosmic goldmine, with its apparent richness in metals and its density. I wonder if an astronaut could just walk along and pick up chunks of gold from its surface….

Another interesting find by MESSENGER is that some of the flat plains on Mercury may have been formed by volcanoes, long ago. In particular, MESSENGER imaged a number of volcanoes along the edge of the Caloris Basin, a large impact basin-one of the largest in the Solar System, at 1550 kilometers across.

The news coming out of the innermost region of the Solar System makes me giddy. Too bad I have to wait until 2011 for my next look at Mercury. These things take time.

Producer's Notes: How Edison Got His Groove Back

 

Josh Rosen by Josh Rosen  July 29th, 2008
37.865903, -122.258285

As the Series Producer for QUEST, I get to read through a lot of amazing science story ideas, but when I first read about the work that Carl Haber, Vitaliy Fadeyev and Earl Cornell were doing at Lawrence Berkeley National Labs, I knew it was a story I wanted to do. OK, I admit that part of the reason is that I love music and sound, and have been interested in audio technology since I was a kid (back when we listened to records). But for me, a big part of the story's "coolness" is how this team – and Carl Haber in particular – came up with the idea. I love the idea that he was just listening to the radio one day and heard that the Library of Congress was failing in its struggle to preserve a significant portion of our nation's music and sound heritage. Haber basically thought, "well, as a designer of instrumentation for particle physics, I think I can help." And that's what he did. He felt passionate about solving a problem, and he changed the world.

I had heard of Edison-style wax cylinders, but I had never seen one, and I had no idea how much audio history (musical as well as cultural) had been recorded in the format. One of the best parts of the shoot (we shot on two different days), was our visit with Victoria Bradshaw at the Phoebe A. Hearst Museum of Anthropology. Walking through the floor-to-ceiling shelving and stepping up to literally hundreds of carefully-packed wax cylinders was a revelation. Holding one in my hands (gloved hands) was an amazing feeling. And to see the wax cylinders upon which Alfred Kroeber had actually recorded Ishi speaking – hard to put into words. I couldn't help but imagine Kroeber himself, with a box of blank cylinders and a recorder strapped to a mule, fording a river on his way to meet an Indian who "spoke a language nobody can understand." Suddenly it was clear to me how important it is to save these recordings before they disintegrate.

And for a science-head, visiting Haber's lab was amazing. Far from antiseptic, the whole place was filled with hacked parts of microscopes, old record and cylinder players, computers running custom software, circuit boards, wires hanging everywhere. It was a great reminder that real science is a permanent work-in-progress. And when it's all said and done – and the Library of Congress is already using Haber's flat-record technology – we'll all be better off. Thanks to Haber's team, soon we'll have pristine, permanent copies of many of these endangered recordings. And as these collections are migrated to the web, that's great news, not just for museums and archives, but for all of us.

And one last quick thing: If you’re interested in learning more about our wax cylinder legacy, check out this UC Santa Barbara site. It has great information on the history of the format, and it offers hundreds of wax cylinders that you can listen stream right off the net!


Watch the "How Edison Got His Groove Back" TV Story online, as well as find additional links and resources. Also, check out our online photo set for images from this story.

Producer's Notes: Science Flexes its Muscles

 

Sheraz Sadiq by Sheraz Sadiq  July 29th, 2008
37.348596, -121.882954

Our QUEST story on the science of anabolic steroids, how they affect the body, and the super-smart sleuths who are using science to catch the cheaters who abuse them, turned up some interesting information. For one thing, I was surprised to learn that according to the National Institute on Drug Abuse's fact sheet about anabolic-androgenic steroids, nearly 2 percent of 10th graders (both boys and girls) admitted to using steroids at some point. Now that may not seem like much, but when you think about the devastating consequences that steroids can have on the body, such as jaundice, kidney failure, and infertility, that's pretty alarming. One could even argue that there's a trickle-down effect when high-school athletes hear allegations of steroid abuse amongst professional athletes and see the athletes continue to pull down multimillion dollar contracts while winning accolades and national titles.

It's nice to know that there are scientists like Terry Sheehan and other high-tech chemists who have the high-tech tools like liquid chromatography and gas chromatography to identify the cheaters in the elite sporting competitions, like the upcoming Beijing Olympics and Tour de France. Clearly the temptation to cheat is great but as the case of Marion Jones has illustrated recently, the fall from grace if you're caught is swift and unremitting. At the end of June, Floyd Landis lost his last appeal to try and hang onto his 2006 Tour de France title. At the time, he vehemently denied that he used testosterone, instead claiming that he naturally has high levels of testosterone. This year's Tour de France has also been riven by positive doping results for several cyclists who tested positive for EPO, a banned substance that is naturally produced by the kidneys and stimulates the production of red blood cells in the bone marrow.

The other thing that I discovered when researching this QUEST story was how prevalent the use of steroids and other performance-enhancing illicit substances are amongst "average" people and amateur/semi-pro athletes. Granted, I can only speak anecdotally but there were quite a few personal trainers in the Bay Area with whom I spoke who mentioned how easily available anabolic steroids and increasingly, Human Growth Hormone (HGH), is in the gym-going and semi-pro cage-fighting and weightlifting community. Nowadays, it's not even necessarily the lure of big bucks or stardom that is enticing people to risk their health by abusing steroids, EPO, HGH or other substances. It seems that the quest for a youthful, fit appearance is enough of a motivator to make some people do so.


Watch the "Science Flexes Its Muscles" TV Story online, as well as find additional links and resources.

Producer's Notes: Why I Do Science

 

Jenny Oh by Jenny Oh  July 29th, 2008
37.7697, -122.466

I had the pleasure of briefly meeting Dr. Robert Drewes, the esteemed Curator and Chairman of the Department of Herpetology at the California Academy of Sciences, upon his return from the Gulf of Guinea where he has been leading research teams over the past decade to study the unique flora and fauna of the islands.

He was still tired from his travels, but his exuberant personality and lively sense of humor were still intact despite his jet-lag. He supplied me a DVD of photos that illustrated his adventurous exploits over the years – such as grappling a giant python snake and mucking about in swamps at night in search of specimens – and proof that he certainly had a lot of fun in the field throughout the course of his long and productive career.

Learn more about Dr. Drewes and his passion for Africa and frogs in the "Why I Do Science" profile, and be sure to check out our story "Disappearing Frogs" about Bay Area researchers investigating the decline of frog populations.

Reporter's Notes: Disappearing Plants

 

David Gorn by David Gorn  July 25th, 2008
37.404946, -122.244593

Pacific Madrone

Marin will look Baja. Berkeley like Bakersfield.

That's the projection of climatologists for the end of this century, if global warming continues on its current path.

But in trying to determine what California's plant life will look like based on those projections, studies and computer models only go so far. Despite the dire warning raised by this recent plant-loss study, biologists say the reality probably will be a lot worse.

In trying to get your mind around the idea that two-thirds of California's endemic plant species will lose 80 percent of their range by the end of the century, there are two ways to look at it.

The first is that, well, plants will just be different. It's not as if we're going to have barren soil where plants are now. As climate changes and warms, plants will most likely shift to the north. If we're talking an 8.3 degree Celsius shift in the summers, that means a rise of about 15 degrees Fahrenheit during the summer. Desert plants would move into Bakersfield and the Central Valley, for example. And in the Bay Area, the climate would be more similar to Southern California.

So, one way to think about it is: Plants will migrate or shift to cooler climates, so our endemic plants wouldn't necessarily disappear – they would just shift north.

But there were many factors that were NOT included in the plant-loss projection. And, as study author David Ackerly says, they are sobering.

If plants migrate, where will they go, and how will they get there? They need a certain type of soil, a certain amount of water. Many times, they interact with and need the plants or animals around them to survive; for instance, the gooseberry might need an animal that likes its berries so that its seed can be spread. And they don't just get up and walk north. It's a long, laborious process that can easily be derailed.

During the last Ice Age, plants migrated a thousand miles, Ackerly says, over about a thousand years. So why can't plants here move a hundred miles in a hundred years? Let us count the ways.

So IF the soils are compatible, IF the entire ecosystem of plants and animals can successfully travel north, IF such sites as vernal pools can somehow be created in the north, IF those ecosystems can somehow leapfrog over cities, farms, reservoirs, roads, ranches and other developments and find a compatible area that doesn't already have a robust ecosystem, IF the slow-growing plants can somehow travel a mile a year for the next hundred years, then yes, you'll successfully have a new habitat in a different place farther north.

Biologists suspect that most endemic plant species in California will die, if climate change continues at the same pace. For instance, redwood trees could still be growing in California by the end of the century, because the adults are hardy – but scientists say it will be a forest of the "living dead," meaning that, if no seedlings can make it, those adults will be the last redwoods on earth.

And the plants that come in to replace California plants, they say, will be invasive species – more commonly known as weeds – the fast-growing Mediterranean-climate plants with light, airborne seeds that will take over a barren area.

That's different plant life, true. But it's unlikely, they say, that our madrone or bay ecosystems will actually be re-created a hundred miles away, unless we move them up there ourselves.


View a slideshow of the"Disappearing Plants" Radio Report online, as well as find additional links and resources.

Hiking Through Jasper Ridge Biological Preserve

 

Shuka Kalantari by Shuka Kalantari  July 25th, 2008
37.404946, -122.244593

Jasper Ridge Biological Preserve

Jasper Ridge Biological Preserve can easily be missed: just off Highway 280 in the city of Woodside, the entrance is blocked by a rusted metal gate with a small sign that reads 'No Tresspassing, Area Patrolled.'

But some of the folks at QUEST – including yours truly – got a special tour of the preserve. I joined reporter David Gorn and biologist Scott Loarie on a three hour hike around Jasper Ridge's Searsville Lake.

I learned that plant-life on the preserve, and most endemic California plant-life, are in trouble.

At least, that's what Loarie and his team at Stanford predict. "If plants can't adapt to the climate changes," says Loarie, "Then by the end of the century two-thirds of California plants face an 80 percent reduction."

So which plants are most likely to go as the global climate changes, well, the plants that have a hard time with seed dispersion. Plants like Bay Laurel, the California Buckeye, Madrone and the Western Burning Bush have seeds that aren't easily dispersed. This gives them a very concentrated zone for growth. If the climate shifts slightly in that particular region, then the these California natives could all die out.

Bay Laurel

The plants that do have an easier time are those with a wide seed dispersion – like the beautiful but dangerous Poison Oak, the Coyote Bush, Clarkia, Virgin's Bower and Box Elder Maple. These plants all have small seeds that are easily dispersed by the wind, or by birds. By dispersing their seeds to various climates, these plants will have a better chance of surviving.

Virgin's Bower

So which California plants will survive a century from now? It's hard to say. But what is definite is that preserves like Jasper Ridge are crucial for monitoring and protecting California's unique plant life.


View a slideshow of the"Disappearing Plants" Radio Report online, as well as find additional links and resources.

Producer's Notes: Dark Energy

 

Gabriela Quirós by Gabriela Quirós  July 23rd, 2008
37.872222, -122.268403

Sitting in a small, non-descript room in the basement of the Lawrence Berkeley National Lab in Berkeley, physics graduate student Hannah Swift and physicist Saul Perlmutter are searching for supernovae, stars destroyed in huge explosions millions or billions of years ago. (They're looking for ones that exploded billions of years ago). Through a computer hooked up to Hawaii's Keck 2 telescope -– one of the largest in the world –- they are able to follow along as UC Berkeley post-doc Rahman Amanullah, a team member who had traveled to Hawaii a few days earlier, supervises the night's observation.

Their goal is to use a device called a spectrograph to get a spectra of five to eight supernovae. This spectrum is a "photograph" of the light emitted by the supernova and it allows scientists to determine whether they are the type Ia supernovae that are useful for their research. By figuring out how far away these type Ia supernovae are (or "were," since by the time their light reaches us, they have long since vanished) and observing how much the light traveling towards the Earth has shifted towards red wavelengths, they can determine how long ago the star exploded. With this information, they're building a history of the expansion of the universe. The weather in Hawaii is good, and the researchers are forecasting a good "seeing."

It's encouraging and moving to see how young these researchers are. Swift is a twenty-something from Kansas. She's so young that she has always understood the universe to be accelerating, that is, expanding faster and faster. She has never thought that the universe is decelerating, which is what the scientific community believed before 1998, when Perlmutter's team at Lawrence Berkeley National Lab and another team simultaneously reported their findings that the universe is accelerating. When this announcement was made, Swift was in the 8th grade. Perlmutter himself is only in his 40s. When he started his post-doc, he and his colleagues had to beg for time on the big telescopes. That wasn't that long ago: our understanding of the universe has shifted very fast.

A few days later, Swift invites us back to the lab to show us some of the data the researchers gathered during the observation. They obtained spectra for five supernovae – a good night's work. Swift is now in the process of figuring out which of the supernovae are type Ia's. To do this, she's comparing their spectrograms to the spectra of a standard type Ia. Light is a very useful tool because different elements emit light of different wavelengths. Swift shows me the spectrogram for a standard type Ia. It has telltale peaks and valleys that reveal what exploding type Ia supernovae eject when they explode – silicon and cobalt, among other elements.

I wonder what big changes in the way we understand our universe will be commonplace when my one-year-old niece is in her 20s. What new discoveries will we use as points of reference in the coming decades? (Assuming we're hip enough to use astronomical discoveries as points of reference!) Will scientists know by then the nature of dark energy, the now-mysterious "something" that is making the universe accelerate, pushing its fabric apart? Will I be able to preface a comment to my niece with, "When you were little, before we knew what dark energy is…"? And will she be able to reply, "Aunt Gabi, you're so ooold!" I suspect she'll do the latter no matter what.

Watch the "Dark Energy" TV Story online, as well as find additional links and resources. Also don't miss our online photo set.

Watching the Water

 

Cat by Cat  July 23rd, 2008
37.7697, -122.466

On July 16th, my Mom and I left San Francisco by boat to tour the Southeast coastal islands of Alaska. I have been hearing stories about the untamed Alaska since I was a small child. My mom lived in Kodiak as a girl. Her father and my grandfather had his last tour of Naval duty on Kodiak. His assignment was to survey the numbers of Kodiak bears for the sake of conservation. So I was more than eager to see the wildness and wildlife of Alaska.

While at sea, I've seen common Alaskan wildlife. Humpbacks have spouted and breached, raven and eagles have dived at the water for a dinner of spawning salmon. But I keep looking at the water, hoping to glimpse Orcas. The next opportunity to do so will be tomorrow coming out of the port of Victoria, British Columbia. Orcas, or killer whales as they are commonly known, are not whales at all. They are the largest species of the dolphin family and they are prominent along the Southeast islands of Alaska. They have captured the spirit of natives in these lands. They are alive in their legends and are carved into totem poles that are being preserved in the towns and museums along the coast. Both the native people here and Orcas form matriarchal societies and many native people believe that members of their tribe are reincarnated as killer whales.

Resident Orcas are just one type of Killer Whale. Three groups of Orcas have been found to be genetically separate on the nuclear and mitochondrial DNA level here. Resident Orcas stay close to the shore of the Alaskan islands in herds of up to 200. They have strongly bonded familial ties and are the fisherman of the Orcas, as their diet consists only of fish. Transient Orcas, on the other hand, live also in groups of up to 200 but will split off for the sake of the hunt. They hunt small marine mammals and migrate a great deal more, going where they can find food. While residents have a small and predictable migration route, transients are harder to research because of an unpredictable migration route. Researchers in Alaska have been able to collect more data on resident pods because of their predictability. They identify each individual by their Saddle-patch, or the white markings adjacent to the dorsal fin. It is like a fingerprint, identifying individual Orcas. The third group of Orcas is even more elusive than the transient pods. They are known as the Offshore Orcas. They are known as the rogue of the species and have been very difficult to research because of their unpredictability and often solo migration.

I am most interested in Orcas because of the question of Orca culture. They are seen as very intelligent animals by Native tribes as well as researchers. There is a controversy in the scientific field if Orcas have culture. Traits of fishing or hunting seem to be passed down to offspring denoting learning and hence culture. However, the science community is still split on learning behavior. One story I heard while here paints them as creatures of learning and remorse. One sick Orca was found in a pod. Fisherman noticed the other pod-mates line up and the sick Orca went through the line giving attention to each pod member and then left the pod after what looked like "saying his goodbyes". Was this a goodbye ritual for sending off a dying pod-mate? Whether is was or not, such unusual behavior is well worth more research. Hopefully, I will be able to see some of their behavior myself before returning to San Francisco.

Producer's Notes: Tracking Raindrops

 

Amy Miller by Amy Miller  July 22nd, 2008
39.730422, -123.644708

Riding to work on BART, about a week before I was to begin shooting this story, I ran into a former colleague of mine whom I had not seen since 2001. He and I had worked together for something like 9 years at KUSF, a non-commercial community radio station in San Francisco. The station -and this particular guy- have always had a reputation for being fairly progressive. OK, that might be an understatement: he's a militant vegan, Critical-Mass-bicycle-riding, anti-automobile, bleeding heart liberal who played a lot of 60's Psychedelia and Prog Rock like the Fugs, the 13th Floor Elevators and Frank Zappa on his radio shows.

After explaining to him that I was working on a story about the impact that global warming is having on the Earth’s supply of fresh water, I was shocked to find myself arguing with him about the very existence of climate change. He claimed that it was all a bunch of sensationalism and that the Earth's climate has always had dramatic changes and that what we are experiencing now is anecdotal and has nothing to do with humans. He said that even if it is happening, longer growing seasons in northerly regions would be beneficial to world food supply and that an increase in carbon dioxide in the atmosphere would cause plants to grow even better. Sure, I’ve heard these types of arguments before but usually not in San Francisco. It was definitely a timely reminder to me about why the media should cover the kind of scientific work that’s being done on this issue.

Given my conversation with BART guy, one of the reasons the Keck Hydrowatch Project is so interesting to me is that Inez Fung, Todd Dawson and the rest of the team aren’t actually setting out to prove the existence of climate change. The researchers are embarking from the position that without question, global climate change is happening and what we are experiencing today is just the tip of the rapidly melting iceberg. And you know what? I believe them. So, they are dedicating the next four years of their lives to understanding how these changes will affect the availability of fresh water for use by humans, plants and land animals. So far, their predictions are "rather grim", as Fung says in the story. It will rain but because we've cut down so many forests, altering the natural landscape that allows the water to cycle back into the atmosphere, much of it will fall in the middle of the ocean where we can't access it. This will result in widespread drought and famine in the not so distant future. Yikes. Being an environmental reporter in this day and age can be a bit disheartening.

So, I was curious how scientists like Fung and Dawson, whose research leads to predictions of widespread climatic chaos and environmental meltdown, are able to cope with their frequently depressing findings. And what do they hope to do with their results? Well, according to Todd Dawson and others on the Keck Hydrowatch team, this project can serve as a model for understanding water movement throughout the globe in order to more fairly allocate water for future human use in a dryer world. But also, and perhaps most importantly, this research can drive home the point that because climate change is largely the result of human activities, its solutions also reside with us.

Watch the "Tracking Raindrops" TV Story online, as well as find additional links and resources.

Surviving Chromosomal Rearrangements

 

Dr. Barry Starr by Dr. Barry Starr  July 21st, 2008
37.332, -121.903

Mole voles do fine with one X and no Y
chromosome.

Last blog I talked about the Transcaucasian mole vole. This little burrowing mammal has lost its Y chromosome over time. Now both males and females have only a single X.

I focused on how scientists can't yet figure out how there are any male mole voles running around. This week, I want to focus on what this means from an evolutionary perspective.

These little animals show that massive changes in chromosome structure can be tolerated and the species can do quite well. Even when the chromosomal change results in a significant increase in miscarriages.

About half of a mole vole's fertilized eggs don't survive to term. Why not? Because these embryos have either no or two copies of the X chromosome.

Most mammals have two copies of each of their chromosomes– one from mom and one from dad. At the end of meiosis, each chromosome copy ends up in a different sperm or egg. This is so that when an egg and a sperm combine, the new mammal has the right number of chromosomes.

Mole voles end up with half of their sperm or eggs with one X chromosome and the other half with no X chromosome. There is a 1 in 4 chance that a sperm without an X chromosome will fertilize an egg without an X chromosome. Since mammals need an X chromosome to survive, these fertilized eggs don’t make it to term.

There is also a 1 in 4 chance that a sperm with an X chromosome will fertilize an egg with an X chromosome. In most mammals, this would be OK– the fertilized egg would go on to become a female.

But this is fatal for mole voles. Most likely this is because these animals have a defective Xist gene. This gene's job is to keep only one X chromosome on in any cell.

Whatever the reason, these mole voles deal fine with the fact that half their fertilized eggs do not make it to term. This means that chromosomal rearrangements and changes that affect fertility can be tolerated. At least in the mole vole.

This is important because one of the key differences between a chimpanzee and a human at the chromosome level is that humans have 46 chromosomes and chimpanzees have 48. Looking at the DNA we see that human chromosome 2 looks just like chimpanzee chromosomes 12 and 13 fused together.

Some people argue that this sort of rearrangement wouldn't be successful because at an early transition stage from 48 to 46 chromosomes, half the fertilized eggs would not make it to term. These fertilized eggs would either be missing or have an extra chromosome. Just like the mole vole.

Here we have a mammalian example where this isn't an issue. This little mole vole is doing quite fine thank you very much. As our ancestors most likely did too.

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