NASA struggles to contact lost Mars probe

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NASA last heard from the Mars Global Surveyor spacecraft on 5 November. Mission managers are not sure what went wrong, but communication problems began shortly after an attempt to move one of its solar arrays (Illustration: NASA/Corby Waste)

An unexpected break in communications has NASA struggling to restore contact with its Mars Global Surveyor (MGS) spacecraft. If communication cannot be restored soon, NASA may try to diagnose the problem by having another spacecraft, the Mars Reconnaissance Orbiter, take pictures of MGS.

MGS recently had its 10-year anniversary in space (see the New Scientist Space blog Mars probe's birthday blues). It was launched on 7 November 1996 and has been orbiting Mars since September 1997. It has far outlasted its original mission, which ended in 2000. NASA has repeatedly extended its mission since then.

On 2 November, MGS's managers sent routine commands to adjust the position of one of the spacecraft's solar power arrays.

The spacecraft sent back data indicating a problem with the motor that moves the array. The spacecraft software responded as expected, by switching to backup control circuitry for the motor.

Then the spacecraft went behind Mars, and when it came back into view, its radio signal was very weak. "It was down by about 42 decibels, which is a huge drop," says MGS manager Thomas Thorpe of NASA's Jet Propulsion Lab in Pasadena, California, US.

Safe mode

During the next two days, on 3 and 4 November, no signal was received from the spacecraft. Another very weak signal was received on 5 November, indicating that the spacecraft had switched to a waiting mode, pending further instructions from Earth. But the signal cut out again later that day and nothing has been heard from the spacecraft since.

One possibility is that a problem with the solar array has caused a loss of power, Thorpe says. If the power is too low, the spacecraft would not be able to send signals from its high gain antenna, which it normally uses to communicate with Earth.

If the solar panel is stuck, the spacecraft is programmed to go into a 'safe mode', rotating so the panel points at the Sun. As a result, the high gain antenna would end up pointed in the wrong direction.

But in this case, the spacecraft's low gain antenna should still have maintained contact with Earth. Yet no signal has been heard from it, Thorpe says, so the problem might lie elsewhere.

Micrometeorite hit

Alternatively, the high gain antenna may be pointed in the wrong direction for a reason unrelated to the solar panels. A micrometeorite hit could jolt the spacecraft and misalign the antenna, Thorpe says. A so-called 'mispointing' could also result from an error in tracking the stars, which the spacecraft does to figure out its orientation, he says.

If the spacecraft does not receive commands from Earth for seven days in a row, it is programmed to stop whatever it is doing and try to transmit a signal to Earth using its high gain antenna. This could happen at about 0014 GMT on Friday (1614 PST on Thursday), so NASA will be listening for a signal from MGS's high gain antenna at that time.

Even if the spacecraft cannot transmit a high gain antenna signal to Earth, it might still be able to listen to commands. So NASA will send a command to have the spacecraft point its low gain antenna at Earth as a fallback.

If no signal is heard on Thursday, NASA will listen again on Saturday, since it already tried to upload commands to the spacecraft on 4 November.

Neighbourhood watch

If no signal is heard on either day, NASA may call on the Mars Reconnaissance Orbiter (MRO) to take pictures of MGS early next week. The two spacecraft pass within about 100 kilometres of each other several times each week.

MRO's camera is easily powerful enough to determine the orientation of the spacecraft and its solar arrays. This would reveal whether the spacecraft has gone into safe mode or not.

Although the team is still hoping to be able to contact the spacecraft, there is a possibility that it could be lost forever, Thorpe says.

Right now, NASA is using its 70-metre radio dishes to try to contact MGS, but in time, pressure will build to stop the search so that other missions can use the dishes.

"When you don't hear from the spacecraft as time goes on, people become pessimistic as to whether the spacecraft can ever be recovered," Thorpe told New Scientist. "Other people need them for other things and after all, we're a spacecraft in its fourth extended mission. There are other missions out there doing good science too."

Mars’s north polar cap is surrounded by clouds in this image acquired by MGS on 15 October, about three weeks before communication with the spacecraft was lost (Image: NASA/JPL/Malin Space Science Systems)

Did Life Begin In Space?

Interstellar clouds of gas are impregnated with organic molecules, the chemical ingredients of life. In just two years of work with the Robert C. Byrd Green Bank Telescope, astronomers have discovered eight new organic molecules near the center of the Milky Way, bolstering theories that key chemical precursors of life were first forged in deep space.

All eight of the new carbon-containing molecules are relatively large, composed of 6 to 11 atoms each. One of the molecules, acetamide, is particularly exciting because it contains a peptide bond, the essential bond for connections between amino acids. "No one has ever found an amino acid in space," says Jan M. Hollis of NASA's Goddard Space Flight Center. "I've actually written several papers about not finding them."

The Robert C. Byrd Green Bank Telescope in West Virginia is tuning in to faint radio emissions from organic molecules in the far reaches of our galaxy. (Courtesy of NRAO/AUI and Harry Morton)

The new finds join a list of about 125 smaller carbon-based molecules identified in space so far. All of them tend to form by simple chemical reactions between smaller components or through the activity of radicals and neutral molecules on the surface of floating dust grains. Eventually, energy from nearby protostars causes the molecules to evaporate off the dust and fly end over end through space, where astronomers can trace their radiation frequencies, since each molecule radiates in a distinctive way.

In the famous Miller-Urey experiment of the 1950s, researchers produced a rich soup of amino acids by running an electric current through flasks containing elements of a primitive Earth, thus showing how precursor chemicals could have formed here. But the discovery of biologically significant molecules in interstellar clouds of gas and dust could push life's history much, much farther back in time and out into space. "When you look at these clouds, it's almost like looking back into history," Hollis says. Molecules like these, traveling on interplanetary dust, meteorites, or comets, "could give life a jump-start on an early planet."

Cheap, Superefficient Solar

A worker arranges wafers that will be fabricated into superefficient solar cells. These cells could help dramatically reduce the cost of generating electricity from solar energy. (Credit: The Boeing Company)

Technologies collectively known as concentrating photovoltaics are starting to enjoy their day in the sun, thanks to advances in solar cells, which absorb light and convert it into electricity, and the mirror- or lens-based concentrator systems that focus light on them. The technology could soon make solar power as cheap as electricity from the grid.

The idea of concentrating sunlight to reduce the size of solar cells--and therefore to cut costs--has been around for decades. But interest in the technology has picked up in the past year. Last month, Japanese electronics giant Sharp Corporation showed off its new system for focusing sunlight with a fresnel lens (like the one used in lighthouses) onto superefficient solar cells, which are about twice as efficient as conventional silicon cells. Other companies, such as SolFocus, based in Palo Alto, CA, and Energy Innovations, based in Pasadena, CA, are rolling out new concentrators. And the company that supplied the long-lived photovoltaic cells for the Mars rovers, Boeing subsidiary Spectrolab, based in Sylmar, CA, is supplying more than a million cells for concentrator projects, including one in Australia that will generate enough power for 3,500 homes.

The thinking behind concentrated solar power is simple. Because energy from the sun, although abundant, is diffuse, generating one gigawatt of power (the size of a typical utility-scale plant) using traditional photovoltaics requires a four-square-mile area of silicon, says Jerry Olson, a research scientist at the National Renewable Energy Laboratory, in Golden, CO. A concentrator system, he says, would replace most of the silicon with plastic or glass lenses or metal reflectors, requiring only as much semiconductor material as it would take to cover an area the size of a typical backyard. And because decreasing the amount of semiconductor needed makes it affordable to use much more efficient types of solar cells, the total footprint of the plant, including the reflectors or lenses, would be only two to two-and-a-half square miles. (This approach is distinct from concentrated thermal solar power, which concentrates the heat from the sun to power turbines or sterling engines.)

"I'd much rather make a few square miles of plastic lenses--it would cost me less--than a few square miles of silicon solar cells," Olson says. Today solar power is still more expensive than electricity from the grid, but concentrator technology has the potential to change this. Indeed, if manufacturers can meet the challenges of ramping up production and selling, distributing, and installing the systems, their prices could easily meet prices for electricity from the grid, says solar-industry analyst Michael Rogol, managing director of Photon Consulting, in Aachen, Germany.

But the approach has been difficult to implement. "It has not delivered on the promise, mostly because of the complexity of the systems," Rogol says. The goal is to engineer a concentrating system that focuses sunlight, that tracks the movement of the sun to keep the light on the small solar cell, and that can accommodate the high heat caused by concentrating the sun's power by 500 to700 times--and to make such a system easy to manufacture.

In the face of this complexity, many have decided to focus their research efforts on cutting the cost of traditional "flat-plate" systems. This is done through making them thinner, to decrease the amount of semiconductor needed, or through turning to cheaper, though less efficient, organic materials. But now several companies claim to have developed reliable systems that can be manufactured on a large scale. For example, SolFocus is making a system that combines the concentrators and cells in one sealed package by employing manufacturing techniques similar to those used to make automobile headlamps. This way they can easily be created in large quantities, according to the company's CEO, Gary Conley.

As for the use of superefficient solar cells, critics originally said that although the cells worked well in the lab, it would be unlikely that their high efficiencies could be maintained in large-scale manufacturing. Unlike conventional solar cells, which use only one type of semiconductor (silicon), these more efficient cells, called multijunction cells, are made from layers of three types of semiconductor. This approach is meant to overcome a major limitation of silicon: although it can absorb photons from most of the spectrum in sunlight, it does so inefficiently, converting into heat, rather than into electricity, most of the energy in high-energy photons from the blue and ultraviolet parts of the spectrum. The multijunction cells use three materials designed to efficiently convert light from different parts of the spectrum, the result being that much less is converted into heat and much more into electricity.

All of the materials must be carefully engineered to work with the other materials, and they have to be assembled under very clean, well-controlled conditions. So in the 1990s, when this type of cell was still experimental, people called it "a laboratory curiosity that could never be manufactured in large volume," Olson says. "Now Spectrolab on their production floor does better than we do in the lab. So it basically blew that myth out of the water."

Other factors that have limited the use of concentrated solar, such as aesthetic objections to mounting concentrator systems on suburban rooftops, may largely restrict applications to commercial buildings or arrays in the desert.

But the advances that have come about, along with growing demand for solar and a shortage of silicon feedstock, have made concentrated solar photovoltaics attractive.

"There's a lot of uncertainty in this area, where historically there's been a lot of hype that just hasn't been delivered," Rogol says. "The biggest news for me is that serious solar people, over the course of the last year, have made notable commitments to concentrators."

Tips on Speeding Up Your Torrents

Many people out there suffer from slow downloads through the torrent network.Often times they do not realize that there are ways to improve those slow speeds.Simple tweaks can be done to optimize your current speeds.

If you are on a dialup line wishing to download using Bittorrents,then you’re simply out of luck.Here I will provide some of the many tricks out there to optimize your download speed.

»Cap your Upload Speed

Although Bittorrent protocal is designed to perform efficiently when all users upload to their maxium output,while they are downloading.The truth is that you should not upload to your maxiumum bandwidth because it effects your download speed significantly.You should set your upload to be somewhat of 75-80 percent of your actual maximum upload speed.

Inorder to do that, you should find out your upload speed by using one of the million speed test sites out there.Personally I prefer using Speakeasy Speed Test because I live in the U.S.

»Remove the TCP connection Limit

You might have realized that your Torrent speeds have diminished marginally after you upgraded to windows xp service pack 2.What you fail to realize is that with the update to SP2,microsoft has limited the amount of tcp connections required by torrent programs.Currently the connection limit is capped at a maximum of 10 in service pack 2.

This was implemented by microsoft inorder to limit the spread of worms,trojans and other security threats.The whole idea behind service pack 2 was to secure your computer by all means possible.The most effective way to override the limit on you tcp connections is by using the Event ID4226 patch.Basically what the patch does is override the connection limit imposed by SP2 to any number.I do not recommend setting the connection limit too high,due to security reasons mentioned.An effective number would be anywhere between 50-100 connections.

[More info on the Author of the patch] [Direct link to download EvID4226Patch]

»Unblock Ports in your Router

Most of the time,slow torrent speeds are due to this problem.Usually beginners to torrents do not realize the effect routers have on Bittorent applications.It is important to realize that torrents commonly use ports ranging from 6881~6889 for high speed downloading.

If you do not know how to port forward those ports I mentioned above then visiting this site would be best.The author gives a detailed look into how its done.

If you want to specific on which ports to forward for the your exact application.You should begin by finding out the manufacturer of your router and the specific model.Then you should head over to Portforward.com and begin by choosing the the model of your router.The rest should be very simple.

»Disable Windows Firewall

Windows Firewall was designed to limit traffic in and out of your computer for security purposes.However that is not beneficial for torrent users who need all the extra bandwidth they can get.The best thing to do is simply disable windows firewall and get a more torrent friendly one such as zone alarm.

If you insist on keeping windows firewall on but want to use your internet connection to its maximum,then follow this:

note:Opening ports within windows xp’s built in firewall can be time consuming, because you can not add port ranges. Only single ports, so you will need to do this about 16 or so times, for each port between 6881 ~ 6889…

1. Click Start, click Control Panel, click Network and Internet Connections and then click Network Connections.
2. If you have a cable modem or digital subscriber line (DSL) connection, under LAN or High-Speed Internet, click the connection you use for the Internet.
3. Under Network Tasks, click Change settings of this connection.
4. On the Advanced tab, make sure that the check box Protect my computer and network by limiting or preventing access to this computer from the Internet is selected.
5. Click Settings.
6. On the Services tab, click Add.
7. In Description of service, type a name so that you can identify the port you want to open. For example: Torrent. Type a name that will help you remember the service and the port. You can use any name that you want. The name does not have any effect on the functionality but is only to help you remember.
8. In Name or IP address of the computer hosting this service on your network, type your ip address
9. In External Port number for this service and Internal Port number for this service, type the port number (the same number in both boxes).
10. Click either TCP or UDP, and then click OK.
11. Repeat this process for each port that needs to be opened. That means you need to repeat every step, adding both TCP and UDP ports for each number from 6881 ~ 6889. When your done, you should have 16 services added in there.It is best to name them something like Torrent1_tcp, Torrent1_udp, Torrent2_tcp, Torrent2_udp and so on.

»Choose your Torrents Wisely

Choose torrents that have a good seed to peer ratio.Most of the time,torrent users fail to realize the demand for certain files are very high and those serving it are low.You want to download torrent files that have seeds more than or almost equal to the peers.For example a file having 100 seeds and 100 peers is much better than having 100 seeds and 200 peers.

Web development - Recommended OS X tools

Development applications & utilities surface with announcements and updates on a regular basis promising increased productivity, time-saving innovative features, and my all-time favorite - the ability to “deliver awesome standards-based sites in no time!” If only achieving the end results were so simple…

I have fielded a handful questions from contacts inquiring about applications used in my daily routine. The following are the applications & utilities which have proven their merit through the past few months of work. Applications which I have personally trusted / relied on and would happily endorse. I urge potential users to ignore claims promised in the first few introductory lines on a developers page opting instead to try each one out for them self.

Setting the local stage - MySQL, Apache, RoR

If you enjoy the idea of using valuable time setting up the necessary environments correctly in order to begin your personal web development projects, Google is littered with tutorials & How-to’s (e.g. install MySQL) on diving straight in downloading the necessary packages and spending a little time within the Terminal.

Personally, I grew tiresome of the tediousness of the entire process. Especially after having to move from various machines on multiple occasions within very short time spans. There is a much easier method of achieving the appropriate development environments, and they come in very simple drag ‘n drop installations. All-in-one solutions meaning everything needed is contained with a single directory which you can drop into your ‘Applications’ folder. Backups? Moving to a new machine? No messy exports needed. Simply drag your all-in-one environments to your new hardrive and continue where you left off.

MAMP - Macintosh, Apache, Mysql and PHP - The essentials conveniently packed into a single 214MB directory which can reside anywhere on your Mac. MAMP is completely self-contained meaning that the installation does not make any changes to any existing Apache installations that you may have installed on your machine. Furthermore, if and when the times comes that you decide to move your work, simply copy the entire directory to an external drive or thumbdrive and trash the local copy (leaving no trace of your previous work). All web documents to be served as web pages are stored in an ‘htdocs’ within the MAMP directory while both the Apache & MySQL server are controlled via a simple GUI interface or convenient Dashboard widget. Loathed the idea of manipulating your MySQL tables from within the Terminal? MAMP comes with phpMyAdmin making managing your MySQL tables.

Ruby on Rails development? Go Locomotive - Similar to MAMP, Locomotive is the complete solution for beginning and veteran RoR (Ruby on Rails) developers to make the best of their time. Gone are the days of hunting for necessary libraries or resolving incompatibilities. Like all things simple on OS X, Locomotive is a single utility to get up and running developing on rails.

TextMate - A single tool for all development needs

Previously mentioned in the Top 100 apps to supplement blogging post, TextMate continues its reign as the single most used tool in my ‘Applications’ folder behind the default browser. The reason? The application comes stuffed to the brim with features and functionality rivaled by little else. Web development specific features include a slew of customizable auto-completion shortcuts & snippets, bundles [blogging anyone?], code preview, and my favorite inline W3C Validation. Additionally, TextMate allows users to create “projects” which may contain any number of directories or files (aliases). My Desktop is littered with these little projects - which when clicked - open all pertinent files required for editing a page / site.

ColourMod Dashboard - Simplify color selection

Previously, my hunt for colors was remedied with with the help of Photoshop. Extremely resource heavy, CS2 was replaced with a convenient Dashboard widget known as ColourMod Dashboard [previously: Recommended Dashboard Widgets]. Quite simply one of the most valuable color tools any OS X user can get their hands on without the extra weight of extraneous features.

Parallels & CrossOver - Who needs a Windows box?

Developing on OS X does not necessarily mean that Internet Explorer users must be ignored. One of the greatest values of Intel powered Apple hardware is the ability to run everyones favorite browser natively (incredible sarcasm). Although PPC variants are very much capable of emulating the Windows operating system [Virtual PC for Mac] in order to achieve the same testing environment, the results are sluggishly slow.

Parallels Desktop for Mac - A popular method of getting Windows running on OS X. Run the entire operating system at near native speed. I prefer the convenience of starting any Windows application without needing to reboot. I currently use Parallels for nothing else but to run multiple versions of Internet Explorer.

CodeWeavers CrossOver - Despite being in an active beta state, CrossOver shows incredible promise. Coupled with CrossOver, Intel powered Mac users can run Windows applications without the need to boot into the Windows OS using Boot Camp or Parallels. Although I have yet to experiment with any other applications aside from Internet Explorer 6 (no working method for getting Internet Explorer 7 working), I look forward to the progress made by the CodeWeavers team. Noticeable rendering bug is inaccurate font handling due to the fact that IE6 is unable to access correct fonts.

Transmit - Seamless file upload & download

Tried and true, Panic’s Transmit FTP client is among the best that I have ever toyed with. As with an OS X application, there are always alternative that users will offer up in defense. Personally, the simplicity of the interface, connection options - FTP/SFTP, Bonjour, Favorites, iDisk support are all convincing enough to retain Transmit the FTP client of choice.

Open source alternatives?

Although some may balk at the fact that most of the aforementioned applications and tools require registration fees, those interested in open source alternative list may enjoy the version listed below:

• Development environments: MAMP & Locomotive
• Editor: Smultron + replacement icons
• Color selection: ColourMod
• Internet Explorer testing: IE6 with Wine (long-winded tutorial)
• FTP Client: Cyberduck

Storm's giant eye on Saturn

NASA's Cassini spacecraft has discovered a new wonder on Saturn--a huge vortex at the ringed planet's south pole. Images released Thursday show the first storm of its kind seen on another planet. Winds are swirling around an eye, just like a hurricane on Earth, except the winds on Saturn are blowing at about 350 miles per hour. A Category 5 hurricane on Earth contains winds of more than 156 miles per hour.

Clouds casting a shadow in the center of the vortex extend from 20 to 45 miles above the surface. This storm has a diameter of about 5,000 miles.

Credit: NASA/JPL/Space Science Institute

The four monochrome images were taken by the imaging science subsystem of the Cassini spacecraft and show the storm gathering intensity.

Hundreds of storm clouds encircle the pole, appearing as both bright and dark spots in images taken in sunlight (blue image) and as dark spots in the infrared spectrometer thermal image (red image).

Credit: NASA/JPL/Space Science Institute/University of Arizona

Cassini's instruments show the eye of the storm above Saturn's south pole is much warmer than the fringes of the storm.

Credit: NASA/JPL/Space Science Institute/GSFC

The most famous storm in the solar system is within the Great Red Spot on Jupiter. That storm, which could fit three Earths, has been raging for at least 400 years. A new storm called Red Spot Jr. (lower left in photo) turned red within the past year.

Credit: NASA, ESA, I. de Pater and M. Wong/University of California at Berkeley

Big Bang In Antarctica: Killer Crater Found Under Ice

Planetary scientists have found evidence of a meteor impact much larger and earlier than the one that killed the dinosaurs -- an impact that they believe caused the biggest mass extinction in Earth's history.

An ancient mega-catastrophe paved the way for the dinosaurs and spawned the Australian continent, new research suggests. (Image courtesy of Ohio State University)

The 300-mile-wide crater lies hidden more than a mile beneath the East Antarctic Ice Sheet. And the gravity measurements that reveal its existence suggest that it could date back about 250 million years -- the time of the Permian-Triassic extinction, when almost all animal life on Earth died out.

Its size and location -- in the Wilkes Land region of East Antarctica, south of Australia -- also suggest that it could have begun the breakup of the Gondwana supercontinent by creating the tectonic rift that pushed Australia northward.

Scientists believe that the Permian-Triassic extinction paved the way for the dinosaurs to rise to prominence. The Wilkes Land crater is more than twice the size of the Chicxulub crater in the Yucatan peninsula, which marks the impact that may have ultimately killed the dinosaurs 65 million years ago. The Chicxulub meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide -- four or five times wider.

"This Wilkes Land impact is much bigger than the impact that killed the dinosaurs, and probably would have caused catastrophic damage at the time," said Ralph von Frese, a professor of geological sciences at Ohio State University.

He and Laramie Potts, a postdoctoral researcher in geological sciences, led the team that discovered the crater. They collaborated with other Ohio State and NASA scientists, as well as international partners from Russia and Korea. They reported their preliminary results in a recent poster session at the American Geophysical Union Joint Assembly meeting in Baltimore.

The scientists used gravity fluctuations measured by NASA's GRACE satellites to peer beneath Antarctica's icy surface, and found a 200-mile-wide plug of mantle material -- a mass concentration, or "mascon" in geological parlance -- that had risen up into the Earth's crust.

Mascons are the planetary equivalent of a bump on the head. They form where large objects slam into a planet's surface. Upon impact, the denser mantle layer bounces up into the overlying crust, which holds it in place beneath the crater.

When the scientists overlaid their gravity image with airborne radar images of the ground beneath the ice, they found the mascon perfectly centered inside a circular ridge some 300 miles wide -- a crater easily large enough to hold the state of Ohio.

Taken alone, the ridge structure wouldn't prove anything. But to von Frese, the addition of the mascon means "impact." Years of studying similar impacts on the moon have honed his ability to find them.

"If I saw this same mascon signal on the moon, I'd expect to see a crater around it," he said. "And when we looked at the ice-probing airborne radar, there it was."

"There are at least 20 impact craters this size or larger on the moon, so it is not surprising to find one here," he continued. "The active geology of the Earth likely scrubbed its surface clean of many more."

He and Potts admitted that such signals are open to interpretation. Even with radar and gravity measurements, scientists are only just beginning to understand what's happening inside the planet. Still, von Frese said that the circumstances of the radar and mascon signals support their interpretation.

"We compared two completely different data sets taken under different conditions, and they matched up," he said.

To estimate when the impact took place, the scientists took a clue from the fact that the mascon is still visible.

"On the moon, you can look at craters, and the mascons are still there," von Frese said. "But on Earth, it's unusual to find mascons, because the planet is geologically active. The interior eventually recovers and the mascon goes away." He cited the very large and much older Vredefort crater in South Africa that must have once had a mascon, but no evidence of it can be seen now.

"Based on what we know about the geologic history of the region, this Wilkes Land mascon formed recently by geologic standards -- probably about 250 million years ago," he said. "In another half a billion years, the Wilkes Land mascon will probably disappear, too."

Approximately 100 million years ago, Australia split from the ancient Gondwana supercontinent and began drifting north, pushed away by the expansion of a rift valley into the eastern Indian Ocean. The rift cuts directly through the crater, so the impact may have helped the rift to form, von Frese said.

But the more immediate effects of the impact would have devastated life on Earth.

"All the environmental changes that would have resulted from the impact would have created a highly caustic environment that was really hard to endure. So it makes sense that a lot of life went extinct at that time," he said.

He and Potts would like to go to Antarctica to confirm the finding. The best evidence would come from the rocks within the crater. Since the cost of drilling through more than a mile of ice to reach these rocks directly is prohibitive, they want to hunt for them at the base of the ice along the coast where the ice streams are pushing scoured rock into the sea. Airborne gravity and magnetic surveys would also be very useful for testing their interpretation of the satellite data, they said.

NSF and NASA funded this work. Collaborators included Stuart Wells and Orlando Hernandez, graduate students in geological sciences at Ohio State; Luis Gaya-Piqué and Hyung Rae Kim, both of NASA's Goddard Space Flight Center; Alexander Golynsky of the All-Russia Research Institute for Geology and Mineral Resources of the World Ocean; and Jeong Woo Kim and Jong Sun Hwang, both of Sejong University in Korea.

The world's most dangerous road

It seems perverse that one of the main roads out of one of the highest cities on Earth should actually climb as it leaves town.

"Every year it is estimated 200 to 300 people die on a stretch of road less than 50 miles long." Enlarge Image

But climb it does - just short of a lung-sapping five kilometres (three miles) above sea level, where even the internal combustion engine is forced to toil and splutter.

Then it pauses for a while on the snow-flecked crest of the Andes before pitching - like a giant white knuckle ride - into the abyss.

The road from Bolivia's main city, La Paz, to a region known as the Yungas was built by Paraguayan prisoners of war back in the 1930s.

Many of them perished in the effort. Now it is mainly Bolivians who die on the road - in their thousands.

In 1995, the Inter American Development Bank christened it the most dangerous road in the world. And, as you start your descent, and your driver whispers a prayer, you begin to see why.

The bird's eye view is on the left, on the front seat passenger's side, where the Earth itself seems to open up.

Crosses at the roadside mark the locations of fatal accidents.

A gigantic vertical crack appears. Way below, more than half a mile beneath your passenger window, you can see - cradled between canyon walls - a thin silver thread: the Coroico River rushing to join the Amazon.

On the driver's side there is a sheer rock wall rising to the heavens. There is no margin of error. The road itself is barely three metres wide. That is if you can call it a road.

After the initial stretch to the top of the mountain it is just dirt track. And yet - incredibly - it is a major route for trucks and buses.

Hairpin bends

Drivers stop to pour libations of beer into the earth - to beseech the goddess Pachamama for safe passage.

Then, chewing coca leaves to keep themselves awake, they are off at break-neck speeds in vehicles which should not be on any road, let alone this one.

Perched on hairpin bends over dizzying precipices, crosses and stone cairns mark the places where travellers' prayers went unheeded. Where, for someone - the road ended.

But even these stark warnings are all too often ignored. As first one - and then a second impatient motorist - overtook our car on the ravine side of the road, my own driver - who hardly ever spoke a word and only then in his native Aymara - intoned loudly, eerily and in perfect English..."You will die."

It is not a rash prediction to make.

Extreme weather conditions make driving more hazardous.

Every year it is estimated 200 to 300 people die on a stretch of road less than 50 miles long. In one year alone, 25 vehicles plunged off the road and into the ravine. That is one every two weeks.

It is the end of the dry season in Bolivia. Soon the rains will come - cascading down the walls of the chasm. Huge waterfalls will drench the road - turning its surface to slime.

Then will come those heart-stopping moments when wheels skid and brakes fail to grip. There are stories told of truckers too tired - or too afraid - to continue, who pull over for the night, hoping to see out an Andean storm. But they have parked too close to the edge. And as they sleep in their cabs, the road is washed away around them.

This is not the place to drop off.

Cliff edge

But for now the road is a ribbon of dust. Every vehicle passing along it churns up a sandstorm in its wake.

Choking, blinding clouds obscure the way ahead. Around one hairpin, a cloud of debris was beginning to clear.

Further down the road we passed a spot where a set of fresh tyre tracks headed out into the void

As it did, I could see people milling around in the road. Passengers from one of the overloaded and decrepit buses which run the gauntlet of this road.

It seemed at first that they had got off to stretch their legs, while their driver argued with another vehicle coming in the other direction about who should give way. (Reversing is not something you undertake lightly on a cliff edge.)

It transpired instead though, that the bus driver was dying. Blinded by the dust, he had run into the back of a truck. The bus's steering column had gone through him - severing his legs.

There was nothing anyone could do. Mobile phones do not work here. In any case, who would you call? There are no emergency services.

And no way of getting help through, even if any were to be found. The bus driver bled to death.

We edged past the crumpled bus, and headed on.

Further down the road we passed a spot where a set of fresh tyre tracks headed out into the void. They told their own story.

High in the Andes, they are building a new road. A by-pass, to replace the old one. But this is Bolivia, and already it has been 20 years in the making.

Who knows when it will be complete? Until it is, people will have to continue offering up their prayers, and taking their lives in their hands on the most dangerous road in the world.