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for June, 2010.
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Well, it was a close race between the medical and animal files this week in the “Most Bulging” category, but the animals won so off we go for yet another look at the wonderful animals that share (or have shared) our planet with us. It turns out that this week we’re concentrating on animal lifestyles. Of course, you may not want to look at our first animals. They may not win the “Ugliest Animal” contest, but they certainly are contenders!
THEY MAY BE NAKED BUT . . . .
Small rodents called naked mole rats are not only contenders for the ugliest animals, they rank right up there for “Weirdest Mammalian Life Style”. Apparently, they have forgotten they’re mammals and think they’re insects.
They’re found in the wild only in the Horn of Africa and they live underground in large colonies with tunnels that can stretch for miles. And the bee or wasp analogy doesn’t stop there; mole rats have a complicated social structure that includes a queen, her breeding males and two kinds of workers. Sound familiar? The workers are sterile and come in two sizes. The smaller ones find food and the larger ones defend the colony against attack.
They’re well adapted to life underground; they’re virtually blind and they’re hairless (saves combing the dirt out of the fur!). They also have really ugly rodent front teeth that they don’t bother to hide. So, why should we be interested in something this weird and this ugly?
Well, your common field or house mouse and most other small rodents typically live around two or three years but these bad boys have an average life span of about thirty years which is exceptionally long for a small rodent. There’s been a great deal of scientific interest in them because of their bizarre social structures and there are mole rat colonies in several major animal research centers.
And here’s what else they’ve discovered. Despite the large numbers of naked mole rats under observation, there has never been a single recorded case of a mole rat contracting cancer. And if that weren’t strange enough, mole rats appear to age very little until the very end of their lives.
Biologists at the University of Rochester think they may have discovered why naked mole rats don’t get cancer. They have a gene called p16 that makes their cells "claustrophobic." It stops the cells from reproducing when too many of them crowd together and this, of course cuts off runaway growth before it can start. The effect of p16 is so pronounced that when researchers mutated the cells to induce a tumor, the cells’ growth barely changed, whereas regular mouse cells became fully cancerous.
Vera Gorbunova, associate professor of biology at the University of Rochester and lead investigator on the discovery says, "It’s very early to speculate about the implications, but if the effect of p16 can be simulated in humans we might have a way to halt cancer before it starts."
When Gorbunova and her team began to investigate mole rat cells, they were surprised at how difficult it was to grow them in the lab for study. The cells simply refused to replicate once a certain number of them occupied a space. Other cells, such as human cells, also stop reproducing when their populations become too dense, but the mole rat cells were reaching their limit much earlier than the cells of other animals.
"Since cancer is basically runaway cell replication, we realized that whatever was doing this was probably the same thing that prevented cancer from ever getting started in the mole rats," says Gorbunova.
Gorbunova and her research team are now planning to delve deeper into the mole rat’s genetics to see if their cancer resistance might be applicable to humans.
A face only a mother could love but they may be the key to winning the battle against cancer. (Credit: Image courtesy of University of Rochester)
And continuing our investigation into animals with strange and wonderful lifestyles, let’s leave the mammal that thinks it’s a social insect and move on to some real social insects.
GO STUDY THE ANT
I’ve actually been rather surprised during this prolonged dry season that my house hasn’t become the local oasis for every water-seeking ant in my neighborhood as was the case in years past. Ants are fascinating and there are many different kinds. There are the ones that I call ‘crazy blacks’ because they’re black and they run around all over the place and act crazy. When I lived in Thailand there were ants everywhere. I remember leaving the house one day and seeing a huge solid disc of ants on my outside wall. They were all going around in a circle and the disc was about two feet across.
There was also a colony that lived upstairs that kept repletes. Repletes are specialized ants that are carried to a water ring on your table by the other ants. Then, they drink the water until their abdomen swells to about a quarter inch across. Then the other ants carry them back to the colony and use them as water fountains.
Of course, the best Thailand ant story involves the three or four I found in my house that were well over an inch long. Apparently, they’re the world’s largest ant and I was quite happy that they only appeared one at a time.
You’ve probably noticed that there are ants that smell funny when you crush them, sort of like moldy fruit. They are called odorous ants (no surprise there) and researchers from Purdue University have recently discovered some strange things about them.
Odorous ants are small ants that are typically forest dwellers but the scientists have discovered that odorous house ant colonies become larger and much more complex when they move from forest to city. The ants live about 50 to a colony with one queen in forest settings but explode into supercolonies with more than 6 million workers and 50,000 queens in urban areas.
Odorous ants are native to the US but they are acting like an invasive species when they move to the big city. One researcher said "Native ants are not supposed to become invasive. We don’t know of any other native ants that are outcompeting other species of native ants like these."
In semi-natural areas that are a cross between forest and urban areas, like a park, they’ve observed colonies of about 500 workers with a single queen. They believe that as the ants get closer to urban areas they have easier access to food, shelter and other resources.
The ants have been observed in three different settings on and around the Purdue campus and you might expect if odorous house ants can multiply into complex colonies, other ants would do the same.
But the researchers found no evidence that other ants had adapted to new environments and evolved into larger groups as the odorous house ants have. It’s possible that odorous house ants are better adapted to city environments than other ant species or that they had somehow outcompeted or dominated other species.
The researchers would like to know the answers because they have implications on the mechanisms that allow other invasive species to prosper. Future studies on odorous house ants will include studying the ant’s genetics and trying to understand the effects of urbanization of odorous house ants.
Grzegorz Buczkowski discovered odorous house ants living in supercolonies, creating complex networks entomologists have never seen with the species before now. (Credit: Purdue Agricultural Communication photo/Tom Campbell)
And now we’ll segue into a tale about some animals in our own back yard. They aren’t generally considered social, but researchers have recently observed a behavior that will change how you look at them forever just like our recent tale of the ‘ride ‘em cowboy’ germ-fighting cell and its rope.
REAL ESTATE MADNESS
Everybody wants to live in the nicest possible house, right? And when you outgrow your house, you’d like a bigger one, right? Well, consider the dilemma of our old familiar friend, the hermit crab. He routinely outgrows his house and a recent study by biologists at Tufts University and the New England Aquarium shows us that hermit crabs have a bizarre and wonderful way to deal with the housing crisis. They shop together.
With their soft abdomens, hermit crabs that aren’t in some kind of shelter are food for somebody very quickly. We’ve all seen them dragging around cans and baby bottles and all sorts of weird and unsuitable ‘homes’ because there weren’t enough suitable shells to go around.
So, how do hermit crabs win this life-or-death shell game? By doing some overnight observing, the researchers discovered some really cool behaviors. They placed vacant shells on the beach and watched to see what would happen.
They discovered that when a hermit crab discovers an empty but oversized shell, it waits nearby instead of simply walking away. Once a small group of crabs gathers, they begin to ‘piggyback’ by holding onto the shell of a larger crab and riding along. These waiting and piggybacking behaviors seem to increase the chances that something truly wonderful will happen.
Scientists call it a synchronous vacancy chain. What it means is that when a new large shell becomes available, the hermit crabs gather around it and form a line from the largest to the smallest. What happens next is really good.
Once the largest crab moves into the new vacant shell, each crab in the line sheds its old shell and immediately plops into the newly vacated shell right in front of it. As a result, a single vacant shell kicks off an entire chain of shell vacancies that ultimately leads to everybody in the line getting new, larger and generally improved housing.
So, the next time you’re at the beach, watch the hermit crabs for a while and then imagine what happens when they go house-hunting tonight!
A hermit crab investigating a potential new shell house. Hermit crabs may locate new and improved housing using previously unknown social networking skills. (Credit: Image courtesy of Tufts University)
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Well, an examination of The Files shows that there are papers flying out of the one labeled ‘Medicine’ so let’s go have a look at what ails us. And as often happens here at The Deep, we’ve got good news, bad news and weird news. Let’s start with the bad news.
Tennis shoes, sneakers, trainers, running shoes. Whatever you call them, virtually everybody wears them because they’re so comfortable and good for your feet. Right? Read on!
TRAINERS GONE BAD?
In a recent study, researchers compared the effects on knee, hip and ankle joints of running barefoot versus running in modern running shoes. They concluded that running shoes exerted more stress on these joints compared to running barefoot or walking in high-heeled shoes (my italics).
Sixty-eight healthy young adult runners (37 women), who run in typical, currently available running shoes, were selected from the general population. None had any history of musculoskeletal injury and each ran at least 15 miles per week. A running shoe, selected for its neutral classification and design characteristics typical of most running footwear, was provided to all runners. Using a treadmill and a motion analysis system, each subject was observed running barefoot and with shoes. Data were collected at each runner’s comfortable running pace after a warm-up period.
The researchers observed increased joint torques at the hip, knee and ankle with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.
These findings confirm that while the typical construction of modern-day running shoes provides good support and protection of the foot itself, one negative effect is the increased stress on each of the 3 lower extremity joints. These increases are likely caused in large part by an elevated heel and increased material under the medial arch, both characteristics of today’s running shoes.
The effect of running shoes on knee joint torques during running (36%-38% increase) is even greater than the effect that was reported earlier of high-heeled shoes during walking (20%-26% increase).
This increased wear on the joints of the knees and hips is bound to increase the incidence of arthritis of the knee, which accounts for more disability in the elderly than any other disease. The authors of the study urge footwear manufacturers to redesign their shoes to reduce the joint torques to barefoot levels. Are you listening, Nike and Adidas?
So even though our footwear may be causing us problems, there’s something new coming down the pike in the clothing line that will be good for us. Are you ready for smart clothes?
MY BLOUSE SAYS I’M RUNNING A FEVER
A team of European researchers is designing something to get you out of the hospital sooner and make your life more comfortable. They’re getting ready to manufacture smart clothes that monitor the wearer’s heart, breathing and body temperature. This could revolutionize healthcare by reducing the length and number of hospital visits and allow patients to lead more active lives.
Unlike current remote health monitoring systems that rely on sensors strapped to users’ arms or chests that are connected by wires to bulky equipment, these scientists have embedded sensing devices directly into cloth, creating garments that are not only smart but also comfortable and practical to wear. Data from the biosignals collected by the clothes is then sent via a mobile connection to caregivers, allowing doctors to check up on their patients and warning if health problems develop.
“Remote monitoring is ideally suited to patients suffering from chronic diseases or recovering from an incident, such as a heart attack, who would otherwise have to spend longer in hospital or visit their doctor more frequently for checkups,” explains Theodore Vontetsianos, the head of the e-Health Unit at Sotiria General Chest Diseases Hospital in Athens, Greece.
Vontetsianos helped oversee the EU-funded HealthWear project in which a series of clinical trials were carried out to validate the remote health monitoring technology, which was developed by a consortium of smart fabric manufacturers, software developers, telecommunications providers and healthcare professionals.
By embedding the sensors in a vest that patients feel comfortable wearing, and requiring only a cell phone-sized device to gather and transmit the information, the system allows patients to be more active and independent while letting caregivers check on them at anytime or in any place as necessary.
Whereas other remote monitoring systems require different sensors linked to different transmission devices, the HealthWear system collects all the information from the sensors into a single device called a Portable Patient Unit (PPU).
The embedded sensors include an electrocardiograph (EKG), and sensors that monitor respiration, pulse rate and skin temperature. There is also a monitor that measures blood oxygen saturation and a 3D accelerometer inside the unit that gauges body position (Is the patient lying down or standing up?). The data are transmitted via a secure GPS mobile connection to a central server. This also establishes the patient’s exact location.
The information is stored on the patient’s electronic health record and can be accessed via an Internet connection by doctors and caregivers, in either near real-time or off-line.
The technology is very simple to use for both patients and healthcare professionals. Patients only have to wear the vest and keep the attached PPU’s batteries charged, just as they would recharge their mobile phone. In fact, in the future, the HealthWear team plans to replace the specialized PPU with a standard cell phone.
Caregivers, meanwhile, can easily access patients’ data, allowing them to monitor the patients’ progress accurately over time and in real time. This feature allows doctors to perform remote checkups by speaking with the patient via a videophone and instructing them to perform different exercises while they monitor their smart clothes readings. This one-on-one contact allows interaction between doctor and patient and is much more convenient than having to make a trip to the doctor’s office or hospital.
Thanks to the HealthWear system, a group of 24 people suffering from chronic obstructive pulmonary disease were discharged from the hospital after an average of just 3.6 days compared with 6.8 days for a control group. Just one patient using the HealthWear system had to be readmitted, compared to three from the control group, and, most significantly, patients using the smart clothes made just two outpatient visits compared with 32 from the control group. For healthcare providers, fewer visits and less hospitalization time should translate into substantial efficiency gains and significant cost savings.
According to the researchers, the costs of implementing the HealthWear system are high if it is done on a small scale, but the system and its components could readily be mass produced and widely deployed. That would bring down the implementation costs substantially and result in considerable savings for private and public health providers. With that goal in mind, the project partners are actively seeking investors and business partners to roll out a commercial version of the system.
And it couldn’t come a moment too soon! Here’s hoping this happens very quickly! So, we’ve had our bad medical news and our good medical news and now it’s time for our weird medical news. Are you ready for . . . .
THE BUNGEE OF DEATH
There are many ‘battlefield’ analogies that are applied to the human body. I think we all visualize our immune systems and more specifically our white blood cells as little soldiers that are in constant battle with the hoards of bad germs that seek to make us sick.
Now as for the specifics of how the battle is waged, I remember a lot of eating. My heroic immune cells surround those nasty germs and engulf them. I mean, hey, they don’t call them ‘phages’ for nothin’! (phage is the Latin root that means “to eat”).
But apparently this simple scenario doesn’t really describe what goes on in some instances. Are you ready for Cowboy Bob chasing down the bad old germ cells with his lariat?
Researchers in London have recently found that some immune cells chase down dangerous cells on the run and ensnare them with a bungee-like nanotube. These cells are a type of white blood cell called lymphocytes, but they are also called (I kid you not!) natural killer (NK) cells because they don’t need the release of chemical signatures to go after the bad guys, they just do it!
NK cells are our first line of defense against dangerous cells, such as tumor cells and cells infected with bacteria and viruses. Researchers want to know how NK cells work because they help the body to fight infection and stop tumors from growing.
We already knew that NK cells kill those nasty germs by attaching to them. They then form a connection called an immune synapse, which they use to inject the germs with toxic molecules. But sometimes the target cells move away from the NK cells to escape being killed.
This study shows that NK cells can maintain attachment to their target cells by snaring them with a bungee-like tube, called a membrane nanotube. The NK cells then either pull in the rope so the target cells come back into direct contact to be killed, or kill them from a distance.
The next step for the researchers will be to find out exactly how the bungee tubes help the immune cells to kill their target cells. The researchers hope that a better understanding of the process may help others in the future to develop drugs to improve the function of NK cells.
The researchers looked at the membrane nanotubes by staining cells with a dye that reveals membranes in microscope images. They found membrane nanotubes connecting NK cells with other NK cells, tumor cells, cells infected with viruses and cancer cells.
The researchers also took video footage of the cells that shows the target cells moving away and being pulled back towards the NK cells. When a target cell moves away from an NK cell, it normally moves ‘head’ first, at around eight micrometers per minute. However, this research shows that when the NK cell pulls its target cell back using the nanotube bungee it moves much faster, at around 14 micrometers per minute, and the cell is pulled backwards.
So, how’s THAT for a lovely load of imagery? From now on, when I get a ‘hot spot’ around a small wound, I’ll just imagine Killer Cowboy Bob riding to the rescue and going after those nasty germy villains with his trusty bungee lariat. “Com’ere, boy! I’ve got a bullet with YOUR name on it!”
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Well, since ecology and environmental issues are much in the forefront in today’s news I figure it was time to discuss the oil spill. No, not THAT one; the other one!
IT’S IN THE WATER
Scientists in Alaska have discovered that oil from the 1989 Exxon Valdez spill is still being ingested by wildlife more than 20 years after the disaster. The research, published in Environmental Toxicology and Chemistry, uses biomarkers to reveal long-term exposure to oil in harlequin ducks and demonstrates how the consequences of oil spills are measured in decades rather than years.
The Exxon Valdez tanker ran aground on the Prince William Sound on March 24, 1989, spilling 10.8 million gallons of crude oil into the sea, covering 1,300 square miles. It is still regarded as one of the most devastating human-caused contamination events, and the effects on wildlife populations and communities have been debated by biologists, ecologists, and the oil industry ever since.
Now, using the biomarker CYP1A, which is induced when an animal is exposed to crude oil, an international team led by Daniel Esler, from the Centre for Wildlife Ecology, Simon Fraser University, British Columbia, has measured prolonged exposure to oil in local wildlife populations.
"One of the more remarkable and unanticipated findings of recent research is the length of time over which animals were exposed to residual oil," said Esler. "Our research has shown that oil remaining in the area, particularly in inter-tidal areas, was encountered and ingested by some near-shore animals."
The team focused their research on harlequin ducks as an example of such a species. Harlequins are marine birds that live in inter-tidal and shallow sub-tidal areas. Between 1990 and 2005 there were approximately 14,500 ducks in the Prince William Sound area.
"In addition to the higher likelihood of exposure due to their habitat, harlequin ducks have a number of characteristics that makes them particularly sensitive to oil pollution," said Esler. "Their diet consists of invertebrates that live in this area and have a limited ability to metabolize residual oil. Also, harlequin ducks have a life history strategy based on high survival rates, as well as a small body size when compared to other sea ducks."
"We found CYP1A levels were unequivocally higher in areas oiled by the Exxon Valdez spill than in nearby areas, a conclusion supported by multiple samples and two independent laboratories. We believe this shows harlequin ducks continued to be exposed to residual oil from the spill through at least 2009, twenty years after the event," concluded Esler. "We believe it is important to recognize that the duration of presence of residual oil and its associated effects are not limited to a few years after spills, but for some vulnerable species may occur over decades."
Now, let’s see. The Exxon Valdez spill was around 11 million gallons. The British Petroleum spill (notice that I know what ‘BP’ means even though the media seems to have forgotten) in the Gulf of Mexico has been spewing a MILLION GALLONS A DAY into the Gulf since it blew up on 20 April. That’s over 50 MILLION GALLONS since it started.
Of course, volume estimates vary with BP saying it’s ‘only’ 840,000 gallons per day and independent sources saying that it’s more like 1.7 million gallons per day, but the bottom line is that the Exxon Valdez spill was literally a drop in the bucket compared with what’s going on in the Gulf and there’s no end in sight.
So if we’re still dealing with the effects of the Exxon Valdez spill 20 years later, how much longer will it take for the effects of the Gulf oil spill to disappear? Fifty years? A hundred years?
The BP oil spill and the subsequent inability to stop it was an inevitable nightmare. The oil companies have always known that it was virtually impossible to stop a deep blow-out but they kept right on drilling anyway because we keep right on buying oil. It’s called “You’ve made your bed, now you get to lie in it.” And I’m just as guilty as you are!
So, let’s talk about something else and find someone else to blame. Have you noticed that sometimes here on Guam the air looks smoky or hazy? I’ve seen days here when it looked like Los Angeles smog. We have no heavy industry here and most all of our ‘air pollution’ produced mainly by the power plants, blows out to sea in the west. So where is all that ‘smog’ coming from? Short answer? China.
IT’S IN THE AIR
Scientists at the National Center for Atmospheric Research recently published a paper that says that pollutants from Asia are being blown into the stratosphere during monsoon season. The paper also gives additional evidence of the global nature of air pollution and its effects far above Earth’s surface.
Using satellite observations and computer models, the research team determined that vigorous summertime circulation patterns associated with the Asian monsoon rapidly transport air upward from the Earth’s surface. Those vertical movements provide a pathway for black carbon, sulfur dioxide, nitrogen oxides, and other pollutants to ascend into the stratosphere, about 20-25 miles above the Earth’s surface. Once in the stratosphere, the pollutants circulate around the globe for several years. Some eventually descend back into the lower atmosphere, while others break apart.
The study suggests that the impact of Asian pollutants on the stratosphere may increase in coming decades because of the growing industrial activity in China and other rapidly developing nations. In addition, climate change could alter the Asian monsoon, although it remains uncertain whether the result would be to strengthen or weaken vertical movements of air that transport pollutants into the stratosphere.
When sulfur rises into the stratosphere, it can lead to the creation of small particles called aerosols that are known to influence the ozone layer. The monsoon transport pathway may also have effects on other gases in the stratosphere, such as water vapor, that affect global climate by influencing the amount of solar heat that reaches Earth.
Scientists have long known that air over the tropics moves upward between the lower atmosphere and the stratosphere, part of a large-scale pattern known as the Brewer-Dobson circulation. But the monsoon might also transport air into the stratosphere during the Northern Hemisphere’s summer months. This could explain satellite measurements showing anomalous levels of stratospheric ozone, water vapor, and other chemicals over Asia during summer.
To isolate the role of the monsoon on the stratosphere, the researchers focused on hydrogen cyanide, which is produced largely as a result of the burning of trees and other vegetation. The parcels of air over the tropical ocean that are lifted to the stratosphere by the Brewer-Dobson circulation contain low amounts of hydrogen cyanide, which breaks up over the ocean. But air over land that gets lifted up by the monsoon contains high levels of the chemical, especially during times of year when Asia has widespread fires, many set to clear land for agriculture.
When they examined satellite measurements, the researchers detected significant amounts of hydrogen cyanide throughout the lower atmosphere and up into the stratosphere over the monsoon region. Furthermore, satellite records from 2004 to 2009 showed a pattern of increases in the chemical’s presence in the stratosphere each summer, correlating with the timing of the monsoon. The observations also showed hydrogen cyanide, which can last in the atmosphere for several years before breaking up, moving over the tropics with other pollutants and then circulating globally.
The researchers then used computer modeling to simulate the movement of hydrogen cyanide and pollutants from other sources, including industrial activity. The model indicated that emissions of pollutants over a broad region of Asia, from India to China and Indonesia, were becoming entrained in the monsoon circulation and transported into the lower stratosphere.
Factories line the shores of the lower Yangtze River in China. Heavy pollution tied to China’s rapid industrial growth has produced poor visibility and health effects. (Credit: Copyright UCAR, Photo by William Bradford)
We actually get some of our Chinese pollution in a far more direct manner. Sometime you can see clouds of the stuff on the satellite map blowing down from the northwest. It really is one big planet, ladies and gentlemen and what goes around comes around!
So are you thoroughly depressed yet? Let’s leave pollution behind and do a follow-up story on one of our recently discussed creepy animals.
THEY’RE IN THE BONES?
You may remember my story a couple of weeks ago about boneworms, bizarre animals that spend their entire lives in and feasting on the bones of dead whales. In that story, I reported that scientists were uncertain about how long boneworms had been around.
Well, the definitive answer isn’t in yet, but an international team of scientists has found the first fossil boreholes of the worm Osedax that consumes whale bones on the deep-sea floor and they conclude that "boneworms" are at least 30 million years old. To get accurate images of the fossil boreholes, the scientists did CT scans on the bones.
The fossils belong to ancestors of modern baleen whales and their age coincides with the time when whales began to inhabit the open ocean. When they died they sank to the deep-sea floor where they served as food for the boneworms.
Finding that boneworms existed that long ago may also solve a paleontological mystery. Fossil whales are relatively rare in the fossil record and the fact that Osedax has been around that long, just could be the reason!
This 30 million year old rib fragment of a whale shows the circular boreholes (diameter: 0,5 mm) made by Osedax. (Credit: Copyright Uni Kiel)
Pollution, pollution and boneworms. Here’s hoping all this pollution doesn’t eliminate US from the fossil record!
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Greetings all. Well, it’s time to return to the roots and get spacey. There’s been some interesting space news recently that may have gotten lost in all this oily business so let’s escape the cares of Old Mama Terra and travel out into the solar system for some news about life and robots.
Our first stop is close to home, our moon, Luna. You know all about the Moon landings and how they changed humanity forever, but remember it was all a part of the Great Space Race with the Soviet Union. It turns out that we were never told what THEY were up to and they were up to some interesting things.
ROBOTS ON THE MOON
We know all about the Mars rovers, but most of us don’t realize that Sojourner, Spirit and Opportunity are not the first roving robots on another world. The Soviets landed several rovers on the Moon.
Now Phil Stooke, a researcher from The University of Western Ontario has solved a 37-year old space mystery using lunar images from the Lunar Reconnaissance Orbiter released in March by NASA and maps from his own atlas of the moon.
Using his atlas and the NASA images, Stooke pinpointed the exact location of the Russian rover Lunokhod 2. He pinpointed it by discovering tracks left by the robot 37 years ago. It covered over 20 miles, the longest distance any robotic rover has ever been driven on another celestial body.
"The tracks were visible at once," says Stooke. "Knowing the history of the mission, it’s possible to trace the rover’s activities in fine detail. We can see where it measured the magnetic field, driving back and forth over the same route to improve the data. And we can also see where it drove into a small crater, and accidentally covered its heat radiator with soil as it struggled to get out again. That ultimately caused it to overheat and stop working. And the rover itself shows up as a dark spot right where it stopped."
Location of the Russian rover Lunokhod 2, showing tracks left by the lunar sampler 37 years ago. (Credit: NASA)
But that’s not the end of the story. Now that the robot has been discovered, after almost 40 years of silence, researchers are putting it back to work again.
An LRO photo of the Luna 17 lander. Note the Lunokhod 1 tracks circling its mothership.
Researchers at the University of San Diego have beamed pulses of laser light from the 3.5 meter telescope at the Apache Point Observatory in New Mexico, zeroing in on the target coordinates provided by Lunar Reconnaissance Orbiter. A laser retro-reflector on Lunokhod 1 intercepted the pulses and sent a clear signal back to Earth.
Back in the late 1960s and early 1970s, Apollo astronauts placed three other retro-flectors on the Moon to allow laser ranging of the Moon’s orbit. Assisted by a fourth reflector on Lunokhod 2, a twin of Lunokhod 1 that landed in 1973, these mirrors constitute the only Apollo science experiment still operating.
Eric Silverman, now retired from the University of Texas, was in charge of the lunar laser ranging activities at the McDonald Observatory from 1969 until 1982. "During that time," he recalls, "we successfully ranged all three of the Apollo corner reflectors and the Lunakhod 2 reflector. We also tried to range on the first lunar rover but had only one possible (but not definite) detection on Dec 31, 1970. Our lack of knowledge of the location of the rover and the pressures of keeping up with the Apollo program caused us eventually to lose interest in Lunakhod 1."
The researchers were amazed at the strong signals returned from the lost rover. They expected the rover’s reflector to be degraded and dulled after forty years but the signal was so strong they have been able to get measurements in lunar daylight, the first time that’s happened.
The scientists are puzzled by the much stronger signals from Lunakhod 1, but they aren’t complaining. With Lunokhod 1 back in the fold, the laser ranging study can get up to full throttle for the first time.
The scientists are using laser ranging to push hard on Einstein’s gravity theory. Their telescope shoots out laser pulses that travel from Earth to the Moon and ping the reflectors. Because these are all ‘corner-cube reflectors,’ they send the pulse straight back where it came from and the scientists retrieve as many of the returning photons as possible.
The round-trip travel time exactly pinpoints the distance from the Earth to the Moon. With repeated measurements, over months and years, the scientists can trace the Moon’s orbit with millimeter precision.
Einstein’s theory of gravity (the Theory of General Relativity) holds that the mass and energy in massive objects like the sun make space curve, and this curving tells objects around the massive body how to move. The curvature actually makes the Earth and Moon fall around the Sun (and the Moon fall around the Earth).
By measuring the Moon’s fall through curved spacetime, the Apache Point Observatory Lunar Laser-ranging Operation–APOLLO for short–may yet find a crack in Einstein’s great edifice of General Relativity. That’s how science moves forward.
So far, the lunar ranging results support Einstein. But a funny looking old rover may shine, or at least reflect, new light on the subject.
It looks like a creature from science fiction, but Lunokhod 1 is real. Photo Credit: Lavochkin Association
Boy, talk about steampunk! That rover looks like something not out of the 60’s but out of Jules Verne! And now for some news about another extraterrestrial rover.
TAKING NEW OPPORTUNITIES
Opportunity, one of two functional rovers on Mars is now in its seventh year on the red planet and it’s still working just fine. As a matter of fact, it’s getting better. NASA scientists have uploaded new software to Opportunity, which allows it to make some of its own explorational choices such as whether to make additional observations of rocks that it spots on arrival at a new location. This allows NASA researchers to use Opportunity’s unexpected longevity (it was originally budgeted for 90 days, not 7 years!) to test advances made in robotic autonomy for future missions.
Now, Opportunity’s computer can examine images that the rover takes with its wide-angle navigation camera after a drive, and recognize rocks that meet specified criteria, such as rounded shape or light color. It can then center its narrower-angle panoramic camera on the chosen target and take multiple images through color filters.
The new system is called Autonomous Exploration for Gathering Increased Science, or AEGIS. Without it, follow-up observations depended on transmitting camera images to Earth for ground operators to check for targets of interest to examine on a later day.
The first images taken by the newly independent Opportunity show a rock about the size of a football, tan in color and layered in texture. It appears to be one of the rocks tossed outward onto the surface when an impact dug a nearby crater. Opportunity pointed its panoramic camera at this unnamed rock after analyzing a wider-angle photo taken by the rover’s navigation camera at the end of a drive on March 4. Opportunity decided that this particular rock, out of more than 50 in the navigation camera photo, best met the criteria that researchers had set for a target of interest: large and dark.
"It found exactly the target we would want it to find," said Tara Estlin, one of Opportunity’s drivers. "This checkout went just as we had planned, thanks to many people’s work, but it’s still amazing to see Opportunity performing a new autonomous activity after more than six years on Mars."
Opportunity can use the new software at stopping points along a single day’s drive or at the end of the day’s drive. This enables it to identify and examine targets of interest that might otherwise be missed.
NASA’s Mars Exploration Rover Opportunity took this image in preparation for the first autonomous selection of an observation target by a spacecraft on Mars. (Credit: NASA/JPL-Caltech)
And now, let’s journey a little farther afield for a visit to a great white whale.
THAR SHE BLOWS?
New pictures provided by another solar system workhorse robot have shown us that moons come in all shapes and sizes. Mars has a moon shaped like a baked potato and new pictures from Cassini, the orbiter that circles Saturn have shown that its moon Prometheus looks a whole lot like, well, Moby Dick, the great white whale.
The new image (which is available in 3-D on the Internet at http://www.nasa.gov/cassini) shows the irregular shape and circular surface scars on Prometheus that point to a violent history. These craters are the remains of many, many impacts.
Prometheus is one of Saturn’s innermost moons. It orbits the gas-giant at a distance of about 85,000 miles (Luna is about 250,000 miles from Earth) and is about 90 miles long and 30 miles wide. The icy little world was originally discovered in images taken by NASA’s Voyager 1 spacecraft back in 1980.
Saturn’s Prometheus does a white whale imitation in this close-up from Cassini. (Credit: NASA/JPL/Space Science Institute)
And of course, there’s BIG news from one of the white whale’s neighbors. Cassini researchers think they’ve discovered what could be evidence for life on Titan, Saturn’s largest moon. That’s the marvelous thing about science. It changes every day. Don’t miss a single column!
Jim is, above all, a passionate eco-humanitarian who has developed his own science talk-radio show to inform The DEEP’s listeners about such newsy topics as global warming, shark-finning and reef protection as well as to explore earth’s many underwater and space mysteries.
sailing 12,000 miles and visiting five countries Jim is back here, ready to explore the depths of the ocean to the deepest frontier, space MORE>>
Lady Pam Eastlick is an expert in both the stars
and seas as a graduate of the University of Guam Marine
Lab and the Director of the UOG Planetarium.