NASA just scored a double whammy: water is now confirmed for the first time ever on Mars and a liquid hydrocarbon lake, which is the only other place in the solar system that has liquid on its surface.
First Mars: For the past few days, the Phoenix Mars Lander has been having problems getting icy soil unstuck from its bucket scooper. And just four hours ago, NASA announced, on twitter, that the ice is chemically confirmed to be water. The robotic arm delivered the soil sample to an oven which then heated the soil and the water vapor observed. We've had evidence for water on Mars for a while now but this is the first confirmation by chemical "tasting".
The sample came from a frozen layer 2 inches deep under the Martian surface soil. The sticky soil was difficult to move into the oven and so the sample was exposed to the Martian air to get some of the water to evaporate and make it easier to handle. The oven is known as Thermal and Evolved-Gas Analyzer, or TEGA.
For more Pheonix updates, follow @MarsPhoenix on twitter and keep an eye on the Lander's home page on NASA's website.
The other news is of Cassini finding a liquid lake on Saturn's moon Titan. Before Cassini, scientists thought Titan would have global oceans of methane, ethane and other hydrocarbons. Now after more than 40 close flybys of Titan by Cassini, we have not seen any such oceans. Instead, hundreds of dark, lake-like features were seen but we weren't sure if they were made of dark material or really lakes.
The results came from a mapping instrument of lake Ontario Lacus, in Titan's south polar region, during a close Cassini flyby in December 2007. The lake is roughly 20,000 square kilometers (7,800 square miles) in area, slightly larger than North America's Lake Ontario, and now is known to be made of liquid ethane. The ethane is in a liquid solution with methane, other hydrocarbons and nitrogen. At Titan's surface temperatures, approximately 300 degrees Fahrenheit below zero, these substances can exist as both liquid and gas. Titan shows overwhelming evidence of evaporation, rain, and fluid-carved channels draining into what, in this case, is a liquid hydrocarbon lake.
Image credits: TOP: This partial view of a full-circle panorama shows NASA's Mars Phoenix Lander and the polygonal patterning of the ground at the landing area. The image is in approximately true color. Image credit: NASA/JPL-Caltech/University Arizona/Texas A&M University. BOTTOM: NASA/JPL/Space Science Institute.
A very interesting paper has just been published about aging in worms. The paper basically uncovers evidence that goes against the current thinking about how and why animals age and might in the future shed light on how and why humans age. Worms? Yes, because they are a good genetic model that is easy to grow and experiment on.
Some background: there are two theories that explain how cells and animals age:
Cells get damaged and the damage accumulates over time, which leads to cells malfunctioning and dying.
The control mechanisms inside the cell break over time leading to the cell's processes to stop functioning properly, something descriptively called antagonistic pleiotropy.
Cell damage can come from sources such as cellular stress, free radicals, and disease, and there is evidence to support this theory. The life span of worms can be extended by feeding them harmless bacteria and growing them in conditions that reduce cell damage. Some experimental strains of worms have longer lifespans because they have mutations that allow them to survive stress better. So there is evidence for this kind of thinking but it's not the whole story.
Today's paper uncovers 3 genes that are master control switches for many cellular processes - they control over 1200 genes in total! These genes, known as elt-3, elt-5, and elt-6, interact: elt-5 and elt-6 inhibit elt-3 late in life and lower levels of elt-3 mean that some processes are switched off. When the researchers knocked out elt-5 and elt-6 (i.e. removed their inhibitory effects), high levels of elt-3 were seen in older worms just like in younger worms, and not just that, the worms lived longer - about 25 days compared to 20 days.
So what does this mean? The evidence in this paper looks good and of course it needs to be repeated and validated. Furthermore, it may or may not apply to humans because humans live for decades as opposed to the days a worm lives which could mean that different aging mechanisms may be important in humans. Still, this research opens the door for further experimentation and gives us a handle on how to approach this age-old problem.
Two years ago, I blogged about how Einstein's E=mc2 was supported by experimental evidence. Well now an international group of astronomers have observed evidence that supports another prediction from Einstein's General Relativity from 1915.
The video below explains the experiment, so I'll give some background and a quick explanation. When massive stars die and explode as supernovae, they leave behind an ultradense object called pulsars. One such stellar ruin, affectionately known PSR J0737-3039A/B and lying about 1700 light years away from us, is the only known double pulsar, meaning there are two objects that orbit each other. Actually, they are so close to each other the whole system can fit inside our sun. As pulsars rotate, they emit very powerful radio waves which we can detect on Earth, and that's what allowed the astrophysicists to test Einstein's theory.
What Einstein's theory predicted is that in a system like a double pulsar, the two objects will affect each others motion. The change in motion is a slow one and called a "precession". You can see something similar at home: spin a top but make it spin slightly off-vertical. You'll see the axis of the top rotate slowly, like the image to the right. The question is: can we observe such precession in PSR J0737-3039A/B? Yes we do.
In animal brains, there is a gene called the brain-derived neurotrophic factor (BDNF) that is important for neurons in the hippocampus to grow and connect to each other, processes that are the basis of memory and learning. The gene produces a growth factor that makes neurons grow which plays a key role in the initial development of the brain: Mice born without BDNF have developmental deficits and die soon after birth. BDNF is also secreted by neurons in adult brains when synaptic junctions between neurons require strengthening (something called "synaptic plasticity") which again are processes that underly memory and learning. Just in case this is not enough, BDNF production has been linked to exercise and to treating depression.
(Quick recap of The Central Dogma of genetics as it's about to feature in our story: DNA stores the genetic material which is then transcribed into RNA that is then translated into proteins. This DNA->RNA->Protein is at the heart of genetics and molecular biology as it summarizes how genetic material is transmitted between generations (via DNA) and how the DNA controls the cell's processes via the RNA and proteins.)
There's been a weird twist in the BDNF story: when the BDNF gene is transcribed into RNA it makes two different types of RNA, a long one and a short one, differing in the tail length of the RNA that's produced. This is not uncommon in genetics as lots of genes produce more than one type of RNA that end up producing variants of the same protein product. The weird thing about BDNF is that both RNA types end up producing the exact same protein. The question is why does it do that? Why does BDNF need two types of RNA to produce the same exact product when only one would suffice?
The answer seems to be transportation. A paper recently published in the journal Cell shows that the long version of the BDNF RNA is transported down the long axons of nerve cells. Nerve cells can be quite long and the long BDNF RNA has anchors that transport proteins dock to and move the RNA towards the tips of the nerve cells. There, the same exact BDNF protein is made but it is at the tip of the nerve instead near the main body of the nerve cell. Neat!
A new study published recently is bound to get some serious attention. Spanish researchers looked at over 500 studies that documented the effects of asthma drugs called inhaled corticosteroids: 275 studies weer funded by pharmaceutical companies (they called this group the PF studies; PF stands for Pharmaceutical Funding) and 229 were funded by other sources, such as government agencies and non-profit organizations (they called this group NoPF).
What they found was that 65.1% of the NoPF group found adverse effects of the drugs under study compared to only 34.5% of the studies in the PF group. This is a significant difference that is very worrying.
So the researchers dug a little bit deeper and found that the real difference between the PF and NoPF studies was how the studies were designed. This means that PF-type studies were more able to discern adverse outcomes.
Still, this is a correlation and definitely not a causation at the moment. What this means in reality is that many studies need to be done to be sure of the true effects of a drug. And when you hear the results of a study, always double check who funded the study. The authors called for the strengthening of disclosure of conflicts of interest, which should help.
While many people continue to completely ignore the evidence that climate change is real, and continue to think that humans have nothing to do it with it, a lot of other people are working hard to fix it and minimize the damage us humans are doing to the environment. A survey of all the good work being done is impossible - there is simply a lot of activity. So in this post, I would like to pick out a few high profile and a few virtually unknown examples of what people are doing to fix and mitigate environmental damage.
The examples I've chosen are meant to be diverse, each attacking the problem in a different angle or fixing one small piece at a time. The idea here is to demonstrate to everyone just how amenable the problem is. There simply is no excuse not to minimize our damage. And by "our", I mean you and me, I mean companies, I mean governments and countries. And, perhaps surprsingly, a lot of these examples actually save a lot of money!
So in no particular order...
I want to start with Climate Care, an Oxford, UK based organization. Climate Care sells carbon offsets. Briefly, every human activity, from travel, to heating houses, to cooking, even food, requires energy, which in turn means everything we do generates carbon dioxide emissions; the emissions are called the carbon footprint of the activity. Some activities have a much larger carbon footprint than others and so it would be useful to be able to calculate the footprint accurately, reduce it as much as possible, and compensate for whatever footprint is left.
Calculating carbon footprints is a bit of an art and a bit of a science but there are ways to roughly gauge the footprint. The Climate Care website has several carbon footprint calculators that tell you what's the footprint of your activities. What Climate Care does is much more though: the website has guidance on how to lower you carbon footprint and also helps you compensate for whatever carbon impact you have that you cannot change. The compensation is called carbon offsetting and simply put, you pay Climate Care to fund projects that avoid, reduce, or absorb greenhouse gases like carbon dioxide. Projects range from simply planting more trees that absorb carbon dioxide to using alternative fuels that have a lower carbon footprint.
So how much does this cost? I recently did a return trip from London Heathrow to Boston, so I plugged this into the Climate Care flights calculator and it told me that the resulting emissions are 1.45 tonnes of CO2 and the cost to offset this will be £10.85. How much is that as a percentage of the ticket price? 3%. That's it.
Next up is an organization called Less Watts back by Intel Corp. Less Watts is a forum where Linux developers, end users, and IT managers talk and develop solutions to make Linux more power-friendly. What could an operating system do for the environment? A lot actually.
Think about a laptop you're using to type up a letter or a blog post. You really only need the screen, the keyboard, some processing power to run the software, and occasionally, internet access. What about all the other hardware? A clever operating system sends unused hardware to sleep, waking it up only when it's needed. Also, as the processor is idle, the operating system can wait in many ways, and some use more power than others. I mentioned laptops as they're easy to measure in terms of battery life: a clever system can maximize battery life by consuming less power. Scaled to all computer users world-wide, the power savings, and thus carbon footprint of computing, can be greatly reduced!
Next up are companies like Google and Microsoft. Granted Google has some very questionable practices, it, Microsoft, and many others are installing solar panels to power their campuses. At the time of writing, Google's solar initiative has generated over 500000 kW-hours while at the time of building Microsofts's was claimed to be the largest in Silicon Valley.
Why is this important? Internet data centers consume large amounts of electricity, and the more we depend on internet-based services, the more of a demand there'll be. It's good to see companies noting this fact and trying to work with it.
There is a startup company working on energy generation from vibrations called Perpetuum. Basically, these tiny generators convert vibrations into a little trickle of electricity. These so-called microgenerators can power measurement devices placed in very hard to reach places, like in monitoring machines in a factory or at the top of buildings, and allow these measurements to be relayed using a wireless connection. Very cool and frankly, this is the kind of creative thinking we need to tackle global warming.
Finally, I want to talk about Virgin Galactic, especially their proposed Spaceport America design. The architecture of the spaceport is an amazing marriage of design and function that works with its environment. Two things are worth noting here: the spaceport looks like it is part of the surrounding desert, so it's not like the eye-sores that we call airports today. Secondly, notice how the spaceport is heated and cooled (slide 4 in the second link) using the surrounding air. This mechanism will ensure that the energy spent to control the temperature of the spaceport will be minimal. This is called 'sustainable design' and it's a movement that's gaining a lot of traction these days. Watch this space (sorry for the pun ).
So as you can see, tackling global warming and minimizing the human impact on the environment is doable. It doesn't require some magic potion or divine intervention. It is simply a matter of everyone thinking more about how their actions affect the environment and how to minimize those effects. Easier said than done, yes, but it can be done.
A supernova is the explosion of a star at the end of its life. When this happens, huge amounts of matter and energy are released in the explosion, giving rise to a bright new object in the sky. This start remnant remains visible for a few weeks and then dies away.
Supernova 2005ap shown with four nearby galaxies (A, B, C, and D). The photo on the right was taken two and half months later than the one on the left.
Because they are explosions, you know astronomers will keep a league table of the most powerful explosions. And so it goes that a few days ago, the most powerful supernova explosion was detected. Called SN 2005ap, the paper describes the measurements that put the explosion's peak brightness at more than 100 billion times the brightness of the Sun and placing the supernova at 4.7 billion light-years away from us. To re-phrase the distance measurement, the explosion happened 4.7 billion years ago, but only now are we seeing it because light needs time to travel that distance.
I heard about the news from Bad Astronomy Blog, which also has a lot more details about the science behind supernova explosions and measurements.
The world is gasping after US researchers reported the hot news that the chemical that makes peppers hot is the key to targeted pain killing.
Image showing capsaicin and the new experimental pain killer QX-314.
To understand the significance of this report, we need to step back and understand what makes hot chili peppers hot. Chili pepper have a protein called capsaicin which makes them hot. The amount of capsaicin present is measured using the Scoville scale. Pure capsaicin scores about 15000000 on the Scoville scale while cayenne pepper scores a few tens of thousands. Capsaicin causes a burning sensation of pain by opening a molecular gate found in pain neurons. This gate, called TRPV1, is usually closed and only when it is open do molecules freely enter and leave the cell. Also, TRPV1 is found only in pain neurons and not other neurons, making it a very attractive target we can selectively open up.
Now that we can open a channel into pain neurons, we need the actual pain killer. Enter QX-314. On the face of it, QX-314 is a bad pain killer: add it to nerves and nothing happens. This is because it cannot enter the nerves on its own.
So now we have two nice pieces: we have a pain killer that needs help to enter pain nerves and numb them and we have a way to selectively open up pain nerves. Surely it's not that simple... is it?
Actually, it is! The paper talks about the experiments that demonstrated this. The first test was using isolated nerve cells grown in a dish. The researchers applied capsaicin and QX-314 (separately and in combination) to isolated pain-sensing and other neurons and measured how they responded. What they found was the combination of capsaicin and QX-314 selectively blocked the excitability of pain-sensing neurons, leaving the others unaffected.
Next, the researchers injected capsaicin and QX-314 into the paws of rats and measured their ability to sense pain by placing them on an uncomfortable heat source. With the combination injected, the rates tolerated much more heat than usual. Next, capsaicin and QX-314 were injected near the sciatic nerve of the rats, and a researched pricked their paws with stiff piece of nylon. The animals ignored the provocation. Although the rats seemed immune to pain, they continued to move normally and respond to other stimuli, indicating that QX-314 failed to penetrate their motor neurons.
This last observation is crucial. Pain killers these days are not specific causing general numbness since they affect all nerves. Having a very specific pain killer is very useful indeed!
So what's catch? Well, as we talked about above, capsaicin causes a burning sensation, so the formulation must not cause this kind of pain in humans, perhaps using something else than capsaicin. Also, research is still needed to figure out the best way to make the pain killing effects last as long as possible. Regardless, it's a great first step to a pain free world in a few years time.
We recently talked about Greenland melting in 2007. Along similar lines, the New York Times posted an article yesterday titled Arctic Melt Unnerves the Experts. It's well worth a read if you're into grim factoids about the environment, this time talking about the Arctic polar ice cap. There is also a neat time graphic showing the melting patterns in the past few years. In short: as far as anyone can remember, the Arctic's ice melted the most and is scaring the scientists who can't predict it reliably and who need to figure out the full implications.
The implications of losing this much ice are staggering. A few thoughts:
The Arctic ice sheet may not recover fully if it loses too much ice in a year.
Polar ice reflects sunlight and so helps the Earth stay cooler. What happens when it's lost is complex. An excellent introduction to the topic is on NASA's Earth Observatory website.
A receding ice cap opens up shipping lines. We can already do that during the summer, but the routes may become open for longer and starting earlier in the year in the future.
The receding ice sheet makes it easier to hunt for resources. Will we be seeing oil rigs at the North Pole in a couple of decades? Do we want to?
What about wildlife that depends on an icy environment?
As ever, a complex topic with bad news sprinkled in for fun.
Map of melting in Greenland published by NASA. Credit: NASA/Earth Observatory.
NASA is reporting of new data about the melting in Greenland in 2007. In short: areas at high altitudes (over 1.2 miles above sea level) are experiencing record melting, clocking in at a chilling 150% above average. At lower altitudes, the melting is 30% above average. To put this in perspective, the amount of snow that has melted this year over Greenland could cover the U.S. more than twice over.
The melting data came from satellite-based microwave imagery, which was then compared to the average snow melting from 1988-2006. The map on the left shows the melting difference between the past 19 years and this year: the redder it is, the more melting that occured in that area this year. All in all, this puts 2007 as the fifth highest in amount of melting. The top four are, in order: 2005, 2002, 1998 and 2004.
Needless to say, this is scary proof that global warming is really happening and that predicting and modelling how melting occurs is very difficult. And then we have to think about where this melted snow is going, i.e., to the seas, which brings up the thorny issue of rising sea levels. The image above is no longer pretty, is it?
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Image showing capsaicin and the new experimental pain killer QX-314.
Map of melting in Greenland published by NASA. Credit: NASA/Earth Observatory.