Think of large earth moving projects: highway interchanges, coal mines or Boston's Big Dig. According to Roger LeBaron Hooke, a University of Maine scientist, such activities have propelled humans into becoming arguably the most potent force in shaping the planet, surpassing rivers, wind and other natural phenomena.

A new analysis shows that the Sun is more active now than it has been at anytime in the previous 1,000 years. Scientists based at the Institute for Astronomy in Zurich used ice cores from Greenland to construct a picture of our star's activity in the past. They say that over the last century the number of sunspots rose at the same time that the Earth's climate became steadily warmer. This latest analysis shows that the Sun has had a considerable influence on the global climate in the past, causing the Earth to warm or chill, and that mankind is amplifying the Sun's latest attempt to warm the Earth.

At the Astrobiology Science Conference on March 30, scientists and science fiction writers faced off in front of a packed audience to debate the promise and pitfalls of terraforming Mars. In part 4 of this 7-part series, Greg Bear ponders the evolution of humans into Martians.

Only nuclear energy can slow down the rapid and potentially devastating warming of the earth, a veteran British scientist and environmental campaigner argued on Monday. "Only one immediately available source does not cause global warming and that is nuclear energy," James Lovelock wrote in an opinion piece published in the Independent newspaper.

As the Martian rovers continue their search for more evidence of life-giving water, a Prairie View A&M University researcher is creating life using an artificial soil simulating that found on Mars. For the past four years, Raul Cuero has used NASA's factory-made soil to breed microbes in his lab, much like 100 other scientific researchers in the nation -- and seven others in Texas -- have done since 1998. And as Opportunity sits at Endurance, a 430-foot-wide crater on Mars, awaiting NASA's command to jump in, Cuero has moved forward in his discovery that Mars soil may lead to solutions that could rid Earth of toxins.

For 25 years, Ross Hoffman has had a vision: to use tiny changes in the environment to alter the paths of hurricanes, slow down snow storms and turn dark days bright. For most of those years, Hoffman kept his ideas largely to himself. His adviser at the Massachusetts Institute of Technology told him weather control was too outlandish for his Ph.D. thesis. The chances of a buttoned-down foundation or government agency funding such research were so slim, Hoffman didn't even bother to ask. But, in 2001, all that changed. Hoffman stumbled upon a tiny, obscure cranny of the American space program -- the NASA Institute for Advanced Concepts, or NIAC. In this $4 million-a-year agency, Hoffman found a place where the wildest of ideas were not only tolerated, they were welcome.

Space enthusiasts are conducting a lively debate about whether to make the planet Mars habitable for human beings, or to leave it in its pristine state as a place hostile to life. Technology offers various ways to provide Mars with an Earth-style atmosphere and gradually warm it up over several centuries. The prospect recalls warnings from cosmologist and physicist Stephen Hawking that continued climate change on Earth may one day leave humanity no other choice but to emigrate to another world.

A remarkable expedition to the waters of Antarctica reveals that iron supply to the Southern Ocean may have controlled Earth's climate during past ice ages. A multi-institutional group of scientists, led by Dr. Kenneth Coale of Moss Landing Marine Laboratories (MLML) and Dr. Ken Johnson of the Monterey Bay Aquarium Research Institute (MBARI), fertilized two key areas of the Southern Ocean with trace amounts of iron. Their goal was to observe the growth and fate of microscopic marine plants (phytoplankton) under iron-enriched conditions, which are thought to have occurred in the Southern Ocean during past ice ages. They report the results of these important field experiments (known as SOFeX, for Southern Ocean Iron Enrichment Experiments) in the April 16, 2004 issue of Science.

He can't quite make money grow from trees, but a New Zealand scientist has devised a way to harvest gold from plants. The idea: Use common crops to soak up contaminants in soil from gold-mining sites and return the areas to productive agriculture. The gold harvested from the process pays for the cleanup - with money left over for training in sustainable agriculture.

Engineers are trying to build a system to remove the greenhouse gas carbon dioxide from the atmosphere in an effort to reduce climate warming. Two companies based in Tucson, Arizona, in the US are involved in the project, which aims to complete the first phase of a working unit by early 2005.

Scientists hope to use a process known as `terraforming' to thicken Mars' atmosphere and increase the temperature to accommodate life from Earth. Finding life on Mars has proved an elusive dream for decades. But now scientists believe they may be able to do it for themselves -- by turning the Red Planet into a blue world with streams, green fields and fresh breezes and filling it with earthly creatures.

Finding life on Mars has proved an elusive dream for decades. But scientists now believe they may be able to do it for themselves - by turning the Red Planet into a blue world with streams, green fields and fresh breezes and filling it with Earthly creatures. The idea - known as terraforming - sounds like science fiction. But turning Mars into an Earthly paradise is being taken seriously by increasing numbers of researchers. They believe that, billions of years after its last seas and rivers dried up, Mars could be restored to its ancient glory thanks to human ingenuity.

A group of science fiction writers, academic luminaries and NASA scientists will hold a lively debate about terraforming Mars at NASA Ames Research Center on March 30, 2004. The debate is the first in a new series of discussions entitled "Science Fiction Meets Science Fact." This series is the result of a shared vision between NASA, Breakpoint Media and the Science Fiction Museum and Hall of Fame in Seattle, scheduled to open in summer 2004. The free, open-to-the-public debate will take place from 7 p.m. to 9 p.m. PST in the main tent on the Moffett Field parade grounds at NASA Ames.

Carbon dioxide, the gas largely blamed for global warming, has reached record-high levels in the atmosphere after growing at an accelerated pace in the past year, say scientists monitoring the sky from this 2-mile-high station atop a Hawaiian volcano. Carbon dioxide, mostly from burning of coal, gasoline and other fossil fuels, traps heat that otherwise would radiate into space. A leading climatologist, Ralph Keeling, whose father, Charles D. Keeling, developed methods for measuring carbon dioxide, noted that the rate "does fluctuate up and down a bit," and said it was too early to reach conclusions. But he added: "People are worried about 'feedbacks.' We are moving into a warmer world." He explained that warming itself releases carbon dioxide from the ocean and soil. By raising the gas's level in the atmosphere, that in turn could increase warming, in a "positive feedback," said Keeling, of San Diego's Scripps Institution of Oceanography.

An astronomy team led by a Boulder-Colo.-based Space Science Institute researcher has detected hydrogen peroxide for the first time in the martian atmosphere. Antiseptic and life-killing, the chemical helps explain why the martian atmosphere and surface are void of life. Acting as a catalyst, it drives the abundance of carbon dioxide and carbon monoxide in the martian atmosphere. Without hydrogen peroxide, molecular oxygen -- now a tiny sliver -- would soar to compose 10 percent of the martian atmosphere.

Mars’ brush with Earth in August - closest in 60,000 years - gave astronomers a peek into the Red Planet’s atmosphere that revealed why oxygen levels remain too low for humans to breathe. The culprit, researchers are reporting today, is hydrogen peroxide - the stuff familiar on Earth as an antiseptic for cuts. Dr. R. Todd Clancy, who headed the research, in an interview described it as the first detection of hydrogen peroxide in the Martian atmosphere, and a landmark in understanding that thin shroud of gases.

Greenhouse gases might one day be used to warm the cold surface of Mars, and make the planet habitable for humans.

Inhabitants would need to take their own food and water, at least at first. But while the Moon is a barren wasteland, water could be recycled and more food grown in greenhouses lit by nuclear power. Once a base is established, future generations might live in the Moon’s giant network of lava tubes — caves formed by past volcanic activity. Surprisingly Mars is a far MORE realistic prospect for habitation. The planet, 64million miles away, has a day-night cycle like ours. Its atmosphere is thick enough to mask harmful Sun radiation. And gravity, while only a third the strength of Earth’s, is much more to our taste than the Moon’s.

NASA scientists say soot, mostly from diesel engines, is causing as much as a quarter of all observed global warming by reducing the ability of snow and ice to reflect sunlight. Their findings on how soot affects reflective ability, known as albedo, raise new questions about human-caused climate change from the Arctic to the Alps.

New research from NASA scientists suggests emissions of black soot alter the way sunlight reflects off snow. According to a computer simulation, black soot may be responsible for 25 percent of observed global warming over the past century. Soot in the higher latitudes of the Earth, where ice is more common, absorbs more of the sun's energy and warmth than an icy, white background. Dark-colored black carbon, or soot, absorbs sunlight, while lighter colored ice reflects sunlight. Soot in areas with snow and ice may play an important role in climate change.

Of all Solar System planets, Mars has the climate most like that of Earth, both sensitive to small changes in orbital parameters. So the discovery of recent gullies, buried ice and possible snowpack on Mars has stimulated interest among both terrestrial and planetary scientists. New data from the Odyssey and Mars Global Surveyor missions provide more evidence of an icy past. Deposits formed during an ice age 2.1 million to 400,000 years ago point to ice cover at latitudes equivalent to the southern United States and Saudi Arabia on Earth. The cover image shows how Mars would have looked at the height of the ice age. Simulated surface deposit has been superposed on MOLA topography and albedo map.

NASA's Mars Global Surveyor and Mars Odyssey missions have provided evidence of a relatively recent ice age on Mars. In contrast to Earth's ice ages, a Martian ice age waxes when the poles warm, and water vapor is transported toward lower latitudes. Martian ice ages wane when the poles cool and lock water into polar icecaps. The "pacemakers" of ice ages on Mars appear to be much more extreme than the comparable drivers of climate change on Earth. Variations in the planet's orbit and tilt produce remarkable changes in the distribution of water ice from Polar Regions down to latitudes equivalent to Houston or Egypt. Researchers, using NASA spacecraft data and analogies to Earth's Antarctic Dry Valleys, report their findings in Thursday's edition of the journal Nature.

The massive amounts of heat and pollution that rise from the world's cities both delay and stimulate the fall of precipitation, cheating some areas of much-needed rain and snow while dousing others, scientists said. The findings support growing evidence that urbanization has a sharp and alarming effect on the climate, and those changes can wreak havoc with precipitation patterns that supply life's most precious resource: water.

Measurements of ancient air bubbles trapped in Antarctic ice offered evidence that humans have been changing the global climate since thousands of years before the industrial revolution. The combined increases of carbon dioxide and methane gases implicated in global warming were slow but steady and staved off what should have been a period of significant natural cooling, said Bill Ruddiman, emeritus professor at the University of Virginia.

Scientists have suspected in recent years that Mars might be undergoing some sort of global warming. New data points to the possibility it is emerging from an ice age. NASA's Mars Odyssey orbiter has been surveying the planet for nearly a full Martian year now, and it has spotted seasonal changes like the advance and retreat of polar ice. It's also gathering data of a possible longer trend. There appears to be too much frozen water at low-latitude regions -- away from the frigid poles -- given the current climate of Mars. The situation is not in equilibrium, said William Feldman of the Los Alamos National Laboratory.

Scientists say they have found a way to boost tree growth but so far there they haven't found a practical use for the fast-growing plants. A tree species at N.C. State's Upper Piedmont Research Station in Reidsville grew up to 20 feet in a single year, about double its usual rate. A typical tree in the area grows about 18 inches in a good year.

A student from Welwyn Garden City whose experiment was destroyed when a rocket crashed last year has seen her second attempt return safely after two months in outer space. Ms Tamara Banerjee, 22, of Blakemere Road, is one of a team of four medical students researching how bacteria grow in zero gravity.

The Canadian and the United States militaries are developing a new weapon in the war against landmines - genetically modified plants. Anthony Faust, a researcher with the landmine detection branch of the Department of National Defence, came up with the genetically modified plant idea after watching a TV newscast. "I caught the tail end of a clip that talked about sending genetically modified plants to Mars. These plants were going to be modified to be sensitive to heavy metals.

As five spacecraft from countries around this world rapidly approach Mars, NASA educators are challenging students to learn about the 'red planet' and design creatures that could survive in the harsh Martian environment. On Oct. 13, NASA Quest at NASA Ames Research Center, located in California's Silicon Valley, will launch the 'Design-a-Martian Challenge.' NASA Quest is an educational Web site dedicated to bringing the NASA experience to K-12 students. The seven-week challenge builds upon the growing excitement about the red planet, and provides students an opportunity to interact with NASA Mars experts and other students from around the world. "The Design-a-Martian Challenge is a great opportunity to have students actively participate in one of the greatest scientific endeavors in recent history," said Donald James, education director at NASA Ames. "With the knowledge gained from the challenge, the students will be Mars experts within their families and classrooms when the twin Mars Exploration Rovers land on Mars at the beginning of 2004."

Mars is sneaking up on us this week. On 27 August the red planet will be less than 56 million kilometres from Earth, the closest it's been for 60,000 years. Stargazers on the ground will be able to marvel at the bronze orb in the southeastern skies. Scientists are more blasé about the record-breaking encounter, but have capitalized on it to dispatch a fleet of visiting spacecraft.

When Houston is hit by a sudden storm, the city may be partly to blame. Increasingly, urban centers don't merely endure bad weather; they help create it. Researchers believe the phenomenon may be more common now than ever before. Scientists have known for 200 years that the temperature in a city can be higher than that in its environs — something they learned when an amateur weather watcher detected a 1.58°F temperature difference between London and its suburbs. Modern cities, with their cars and heat-trapping buildings, can create an even bigger temperature gap, sometimes as much as 10°F.

A lichen which may one day be used to plant life on Mars has been found growing inside rocks near the South Pole. Waikato University biologist Professor Allan Green told the NZ Antarctic Conference in Dunedin this week that an international team of scientists was amazed to find 15 species of lichens in a small rock outcrop on Mt Kyffin, 750km south of Scott Base. Eight species were found in the Taylor Valley, a "dry valley" west of Scott Base which has received virtually no rain for millions of years.

Mars' north and south poles are loaded with frozen water trapped under a crust of "dry ice" -- frozen carbon dioxide -- but this is not necessarily good news for any earthly visitor looking for a drink, scientists reported today. Apparent indications of surface water, including features that look like channels and river valleys, suggest the Red Planet might once have been warm and wet enough to sustain liquid water, and therefore to allow for the possibility of Earth-type life. But new findings reported in the current edition of the journal Science show that while there may be lots of water ice, there is nowhere near enough carbon dioxide to ever warm the planet up enough to make the water drinkable.

Here's a cinch of an idea: How about a little Van Allen Belt tightening? By using highly charged orbiting space tethers, the Earth's cocoon of menacing and deadly radiation belts might be easily and largely aced out. For one, satellites in the future could live longer not having to fend off the frenzy of energetic particles. Moreover, human-carrying spacecraft would be far safer zooming about in Earth orbit or speeding outward to distant destinations. The novel concept is called the High Voltage Orbiting Long Tether (HiVOLT) System - a proposal from Tethers Unlimited, Inc. of Lynnwood, Washington.

Microbes may be able to survive on Mars according to new simulations of the Martian environment. Researchers used a device called the Andromeda Chamber to simulate Martian conditions. They discovered that microorganisms called methanogens could grow at low pressures. They say their findings imply that life could have existed on the Red Planet in the past, present, or at some point in the future.

Scientists have revealed the full technical details of their discovery of vast reservoirs of ice beneath the Martian surface. So much ice has been found in the polar regions that if it were to melt it would deluge the planet. The ice may stretch far underground to regions where it is warm, raising the possibility of warm caverns of meltwater in which scientists hesitantly speculate conditions could be suitable for life. But they caution that we may never know until we have rock and ice samples returned to Earth by an unmanned probe for analysis.

Last week I wrote about environmental issues growing out of human missions to Mars, and the obligation of the United States (and other space powers) under the 1967 Outer Space Treaty to prevent "harmful contamination" of Mars. But what about beneficial contamination? Mars, as far as we can tell, is a dead world. Even if it turns out to host some forms of life, they are almost certain to be limited to bacteria, akin to the extremophiles that populate places like volcanoes, undersea thermal vents, and deep subsurface rock formations, and their distribution is likely to be similarly circumscribed. Algae would be big, big news. But Mars needn't remain dead (or near-dead). For several decades people have been looking at "terraforming" Mars by giving it an earthlike - or at least more earthlike - climate. (For the technically inclined, there is a superb engineering textbook on the subject, Martyn Fogg's Terraforming: Engineering Planetary Environments, a thoroughly practical book published by the thoroughly practical SAE).

Today the Red Planet is dry and barren, but what about tomorrow? New data suggest that the long story of water on Mars isn't over yet. Mars was once wet, but now it is dry. Spacecraft photos of Mars reveal signs of ancient rivers, lakes and maybe even an ocean. They might have been filled with water billions of years ago, but something happened -- no one knows what -- and the planet became a global desert. Wherever the moisture went, new data suggest it might not be gone for good. Indeed, water may have flowed on Mars literally as recent as "yesterday or last year," declares James Garvin, Chief Scientist for Mars exploration at NASA headquarters. Evidence is mounting that water lies beneath the Martian terrain, he says. Furthermore, every few centuries weather conditions might become clement enough for that water to "come and go" on the surface as well.

Scientists are rapidly developing technology for genetically engineering fast-growing supertrees. The economic advantages for timber companies seem clear. The environmental repercussions are less certain. Forest biotechnology, scientits predict, will ultimately transform such disparate industries as housing and fuel; some even suggest that this technology may help humankind colonize Mars. "Genetically engineered trees could produce gasoline or alcohol or almost any other chemical from sunlight," says Freeman Dyson, a professor of physics at the Institute for Advanced Study in Princeton, N.J. "Think of tapping trees for chemicals the way you tap them for maple syrup -- the possibilities are marvelous."

Imagine turning the barren red planet Mars into a lush green oasis. Aside from the small problem of finding enough water, scientists have developed just the plant to do it. Actually, many different plant types could be used, but they would have to be modified with a gene known as Rubisco. Professor John Andrews and Dr Spencer Whitney, from the Australian National University's Research School of Biological Sciences, have led the world's first team to successfully replace a key enzyme of photosynthesis that converts carbon dioxide to plant sugar. Professor Andrews said the team had genetically inserted a bacterial version of the gene Rubisco which is able to grow in an atmosphere much like that on Mars.

Mars is undergoing global warming that could profoundly change the planet's climate in a few thousand years, new data suggests. High-resolution images taken by NASA's Mars Global Surveyor show that the permanent south polar "ice" cap shrank significantly between two successive Martian summers - a period roughly corresponding to two Earth years. If the trend continues at the same rate and the polar cap is entirely frozen carbon dioxide, "the whole cap would be evaporated in a few thousand years," Mike Caplinger of Malin Space Science Systems told New Scientist. This would release enough carbon dioxide to give Mars an atmosphere one-tenth the density of the Earth's. "That takes us from a situation of working in a near vacuum with a space suit to being able to run around on the surface with an oxygen mask and a heavy coat. It's what the terraforming people were always talking about," says Caplinger.

High-resolution images snapped by NASA's Mars Global Surveyor show that levels of frozen water and carbon dioxide at the Red Planet's poles have dwindled dramatically — by more than 10 feet — over a single Martian year (equivalent to 687 days or about two Earth years). Michael Caplinger of San Diego's Malin Space Science Systems points out that if the warming were to continue at the same rate (that's a big "if"), Mars could become a nearly inhabitable place for people within 5,000 years or so. "Rather than wearing a spacesuit, you could get away with wearing just an oxygen mask and a thick parka," said Caplinger, who co-authored a study about the observations in this week's issue of Science. "It would be like standing on top of Everest."

The unique flora of Antarctica appears to be resisting damage from the ozone hole over the South Pole far better than anyone expected, Dutch scientists say. The hole has triggered fears that Antarctica's fragile plants could suffer severe DNA damage as they are exposed to higher intensities of ultra-violet light, which is normally filtered out by the ozone layer in the stratosphere. But a team led by Daniela Lud from the Netherlands Institute of Ecology in Yerseke says many plant species seem to have a repair kit that enables them to fix any damage almost overnight, the British weekly New Scientist reports in next Saturday's issue.

With the prospects for finding life at Mars looking up, proponents of elaborate human settlements there are ready to defend themselves against charges of contaminating what's possibly already thriving there. And so-called terraforming advocates already have some scientists on their side, offering up data and theories that can be used to bolster the case for transforming the Red Planet into an Earth II. Tantalizing images returned in the past 18 months from robotic probes have shown Mars to be an astounding planet. Liquid water may have been active in recent geologic times, suggesting that past and even present life on Mars is a decent bet.

Are we the new Martians? No, we’re not talking about alien abductions doing fiendish things to our DNA; we’re dealing here with the eventual colonisation of Mars by ourselves, by converting the red and seemingly dead planet into a home for future human generations. And rather than any future settlers having to lead a confined and precarious existence in space suits and sealed domes, as protection against the decidedly hostile Martian environment, a growing school of thought suggests that it might well be possible - using already existing technology - to transform that forbidding planet into a world far more conducive to human habitation. "Terraforming" is the name of the game - the idea of altering an unfriendly planetary environment to suit us - and it is discussed at length in a forthcoming episode of BBC1’s current Space documentary series, presented by the actor Sam Neill.

They're coming back from the future, 1,000 pilgrims, heads swimming with visions of the world to come. Reading and writing have vanished. Hospitals have "smart beds" that control your medications. We're fat and consumed with "cyber road rage," but we've turned a corner in our civilization. We've colonized Mars. The future took place for three days, through Tuesday at the Hilton in Minneapolis. We're talking about the annual conference of the World Future Society, which drew 1,000 people, mostly from the United States and Canada but also from Mexico, Colombia, Venezuela and Germany.

Scientists Say Adjusting Earth's Path Could Rescue It From the Dying Sun. "We started thinking that if you could move the Earth, you could buy some time," says Don Korycansky, lead author of a recent paper in Astrophysics and Space Science and a researcher at the University of California at Santa Cruz. He and two other scientists propose gradually shifting Earth's orbit to keep pace with the expansion of the sun.

The first colonists on Mars probably won't be humans. More likely, they'll be plants. And the prototypes of these leafy pioneers are under development right now. As part of a proposed mission that could put plants on Mars as soon as 2007, University of Florida professor Rob Ferl is bioengineering tiny mustard plants. He's not altering these plants so that they can adapt more easily to Martian conditions. Instead, he's adding reporter genes: part plant, part glowing jellyfish -- so that these diminutive explorers can send messages back to Earth about how they are faring on another planet.

It's been nearly 25 years since NASA sent biological experiments to Mars. Chris McKay, a planetary scientist at NASA's Ames Research Center and a member of the NASA Astrobiology Institute, thinks it's time to try again. McKay helped organize a NASA conference last year on terraforming -- that is, what it might take to make Mars fit for human habitation. In a presentation at the conference, McKay proposed an intriguing experiment.

In what reads like a story from a 1950s science fiction magazine, a team of University of Florida scientists has genetically modified a tiny plant to send reports back from Mars in a most unworldly way: by emitting an eerie, fluorescent glow. If all goes as planned, 10 varieties of the plant could be on their way to the Red Planet as part of a $300 million mission scheduled for 2007. The plant experiment, which is funded by $290,000 from NASA's Human Exploration and Development in Space program, may be a first step toward making Mars habitable for humans, said Rob Ferl, assistant director of the Biotechnology Program at UF

The term Terraform refers to a world that has been made habitable or earthlike, supporting life where none previously existed. The inspiration for this work was two-fold: to create an experiential virtual space within the walls of a traditional gallery and to bring together a group of artists from diverse backgrounds and at varying stages of their careers to envision and construct it.

THE dominance of Man over nature is highlighted today in an extraordinary new series of satellite maps that reveal how one half of the Earth carries the "ecological footprint" of humanity. A vast swathe of pink - once the colour used to mark the British Empire but now chosen to show land that has been ploughed up or paved over - stretches across 24 per cent of all available land in the world. Another 26 per cent is pasture for livestock. The scientists who created the map from remote sensing satellites said yesterday that humans had become a force of nature "comparable to volcanoes or to cyclical variation in the Earth's orbit".

Mankind will soon have the ability to move the Earth into a new orbit, say a team of astronomers. The planetary manoeuvre may more than double the time life can survive on our planet, they believe. Using the well-understood "gravitational sling shot" technique that has been employed to send space probes to the outer planets, the researchers now think a large asteroid could be used to reposition the Earth to maintain a benign global climate. It is an "alarmingly simple" technique, the astronomers say. It could ensure humanity's survival and even allow our descendants to alter our Solar System to move moons and planets to make new Earths.

Trees that can grow their own protective greenhouses and computers smart enough to figure out things for themselves are some of the tools that will help future space explorers settle Mars, scientists predicted on Friday.