Environment Forum

A solar-powered all-terrain vehicle, on extremely unfamiliar terrain

On Earth, we consider design, fuel efficiency, and enduring power when thinking of “green” vehicles. But there’s one solar-powered all-terrain vehicle that has by some lights out-performed anything rolling around on Earth. It is the doughty little robotic rover Opportunity, doggedly using its seven-year-old solar array to chug over the rocky surface of Mars. Opportunity, like its twin rover Spirit, was designed to drive about .6 mile (1 kilometer) along the martian surface; by last month, Opportunity had driven more than 30 times that distance. It completed its primary mission in 2004 and since then has made important discoveries about parts of ancient Mars that might have been hospitable to microscopic life. Like many earthly vehicles that are a bit past their prime, Opportunity has a few quirks, according to NASA’s Dave Lavery, who spoke at a briefing on the rover’s latest findings. “We’re no longer driving a hot sports car,” he said. “We’re now driving a 1965 Mustang that hasn’t been restored.” Even though Opportunity’s “drivers” are on Earth, controlling the golf-cart-sized robot remotely, they plainly feel a fair amount of affection for the little craft. NASA’s John Callas described the rover’s status almost as if it were a spunky grandparent.

“We have a very senior rover that’s showing her age,” Callas told reporters. “She had some arthritis and other issues, but generally she’s in good health, she’s sleeping well at night, her cholesterol levels are excellent and so we look forward to productive scientific exploration for the period ahead.”

Operating it takes a bit of doing. First off, to avoid wear on some gear teeth, Opportunity drove most of her latest jaunt backwards. Her NASA operators also warmed up actuators to the rover’s wheels, which made lubricants flow better — like applying a heating pad to an arthritic joint before a game of tennis, Callas said.

The backwards-driving had to work around an antenna that was supposed to be on the back of the craft but was recently right in the center of the robotic vehicle’s “windshield” as it drove in reverse for miles. “It’s much like trying to drive a car and your child is waving a toy in front of your face,” according to Callas.

There was also some stiffness in the rover’s robotic arm, cutting back on its freedom of movement.

However, Opportunity’s batteries are in good health, suggesting that the rover will continue to send back information on the martian crater Endeavour. Opportunity has already outlasted its twin Spirit, which stopped communicating in March 2010.

Is it accurate to call these robots all-terrain vehicles, since strictly speaking the only place where there’s terrain is on Earth? If not, should we call Opportunity an all-martian vehicle?

Amazon’s drought, seen from space

How green is the Amazon?

Not as green as it used to be, as shown in an analysis of satellite images made during last year’s record-breaking drought.

Because greenness is an indication of health in the Amazon, a decline in this measurement means this vast area is getting less healthy — bad news for biodiversity and some native peoples in the region.

What does a drop in the greenness index look like? It looks gold, orange and red in a graphic accompanying an article to be published in the journal Geophysical Research Letters:

Gray areas are the norm, based on a decade of satellite observations that cover every acre (actually every square kilometer) on the planet. Dots that are gold, orange or deep red show areas with a decrease in greenness. Scientists call this the Normalized Difference Vegetation Index (NDVI on this chart) or the greenness index.

The chart shows what happened during July, August and September of 2010, the height of the dry season — a deep loss of greenness. The researchers found that the 2010 drought reduced the greenness of approximately 965,000 square miles (2.5 million square kilometers) of vegetation in the Amazon,  more than four times the area affected by the last severe drought in 2005.

Even when rains came in late October, greenness didn’t bounce back, according to Ranga Myneni, one of the scientists who worked on this research.

Appropriately enough, it’s National Tsunami Awareness Week

The U.S. government has announced this as National Tsunami Awareness Week, starting just days after a disastrous tsunami powered over Japan’s northeast coast. Not that anyone necessarily needed reminding.

This week’s advisory, which urges U.S. residents to be prepared for a damaging series of waves, was scheduled before the March 11 Japanese catastrophe, according to the National Oceanic and Atmospheric Administration. This is the second annual observance of Tsunami Awareness Week. It’s too soon to tell if there might be a pattern emerging: last year’s observance came not long after a giant wave hit the Chilean port of Talcahuano following an 8.8 magnitude quake along Chile’s coast.

Here’s how the Japanese tsunami spread its force across the Pacific:

While the United States may not seem like a prime tsunami target, the Hawaiian Islands and Alaska have long been susceptible. NOAA notes the United States has more coastline than any country on Earth and is in proximity to several major fault lines. Any coastline is potentially in a tsunami’s path.

Because the danger from tsunamis can’t be eliminated, NOAA is concentrating on preparedness, including its main tsunami website. President Barack Obama stressed early warning systems in a statement this week.

“As we offer our assistance to those impacted by this tragedy, we also renew our commitment to ensuring preparedness along our shores,” Obama said. “Efficient warning systems and awareness in coastal communities are vital to protecting Americans in at-risk areas of the country.”

What’s up with all the earthquakes?

This article by Julia Kumari Drapkin originally appeared in Global Post. The views expressed are her own.

The quake that hit China Wednesday was the latest in a string of earthquakes in the news lately. Many people are wondering what’s going on, so we decided to ask NASA. Eric Fielding is a geophysicist who uses satellites to study earthquakes at the Jet Propulsion Laboratories in California.

GlobalPost: So first question is the one on everybody’s mind. What on earth, literally, is going on? What’s up with the earthquakes?

Eric Fielding: The most important thing to remember is there are earthquakes all the time, someplace in the world. In a normal year, there are around 16 earthquakes with magnitudes 7 or higher. So far this year we’ve had six earthquakes like that. So we’re well within the expected range for a three or four month period.

Is there ever a pattern to a series of earthquakes?

A rocket man’s view of solar energy

After nearly 25 years in the computer science and aerospace industries, including a stint at NASA’s Jet Propulsion Laboratory, Doug Caldwell decided to pursue a career-long dream of putting his engineering skills to use for the environment. So the Southern California native left his own start-up, a company that builds cameras for spacecraft launch systems, to explore his options.

He didn’t have to look far, or for very long. Within months Caldwell had landed work on a solar power development project, recruited by an old buddy from his days launching model rockets in the desert. Perhaps more ironic is the company he ended up working for — Boeing Co.

Two years later, Caldwell, 47, is chief engineer of the project, which employs about 60 people in a $45 million endeavor to design a new type of photovoltaic solar technology for what would be a 20-megawatt power plant.

One thing he has learned from the experience is that renewable energy development is more of a dollars-and-cents proposition than building rockets. “It’s not about engineering. It’s about business and finance,” Caldwell says.

While space science is largely mission-driven, albeit within the confines of a budget, the paramount concern for clean energy is making it cost-effective and achieving a reasonable return on one’s investment. Moreover, he says, the history of U.S. energy development, and how closely it’s tied to the economy, will make the nation’s transition to cleaner energy especially tough.

Americans, he says, are “spoiled” by cheap energy prices that fail to account for the true costs of environmental damage wrought by extracting and burning fossil fuels, or the national security implications of maintaining access to foreign oil.

“Everybody wants to be green, but no one wants to pay for it,” he says. With sizable investments required to transform the energy sector, the development of low-carbon alternatives is going to be “very dependent on public sector incentives.”

Antarctic ice expands — global warming at work?

Ice getting bigger hardly sounds like a sign of global warming but that’s apparently what is happening in the seas around Antarctica.

Leading climate scientists say that a tiny trend towards bigger ice in winter floating on the oceans around the frozen continent since the late 1970s — the maximum extent is around now, in September — is consistent with models of climate change that predict harsher winds and less warmer water at the surface.

It may even be that there’s more snow and rain falling onto the southern oceans because of climate change — that can raise the amount of fresh water on the surface and, hey presto, fresh water freezes at a higher temperature than salt water.

At Reuters News my colleagues and I often write stories about the shrinking of summer ice at the other end of the world, in the Arctic, as one of the clearest signs of global warming that is blamed by the U.N. Climate Panel on human use of fossil fuels.

In response to those stories, I often get e-mails from people sceptical about climate change who say that ice at the other end of the earth, around Antarctica, is expanding.

But it turns out that leading scientists at NASA, the British Antarctic Survey and Norway’s Nansen Center say the two things are not contradictory — the world reacts to greenhouse gases in different ways.

Antarctica is a gigantic frozen continent and winds sweep around it in the southern oceans, without drawing in much warmer air from further north. The Arctic is an open ocean ringed by continents, and more vulnerable to currents and winds blowing up from the south.

A green energy solution that’s out of this world

The quest for more renewable energy sources recently got a boost that’s out of this world.

NASA researchers this week said they are using global satellite data to create maps of ocean areas best suited for wind energy.

The maps will be useful in planning where to build offshore wind farms that can convert wind energy to electricity, according to NASA’s Jet Propulsion Laboratory in Pasadena, California. Islands of floating wind farms have the potential to generate 500 to 800 watts per square meter, according to research conducted by Tim Liu, a senior research scientist at the JPL.

“No group of people have measured the amount of wind power over the entire ocean. Now for the first time we have a map,” Liu said in an interview. “You can actually quantify how much power is in what place. The map gives you this tool for where to place these (wind) farms.”

NASA’s QuikSCAT satellite tracks the power, speed and direction of ocean wind using a specialized microwave radar.  Created in 1999, the QuikSCAT is normally used for predicting storms and checking the accuracy of weather forecasts.

Offshore wind farms are one answer to critics’ claims that towering wind turbines disturb wildlife habitats and spoil landscapes. Also, the wind blows stronger over the ocean because it doesn’t have hills, mountains or buildings blocking its way.

The challenge of moving the electricity from the middle of the ocean to utility customers on land, however, is formidable and costly. A spat over plans to build a wind farm off the coast Massachusetts’ Cape Cod is playing out now, with state and local authorities arguing over a burying the electric cables needed to connect the farm to the power grid.