November 30, 2007

Meanwhile, on Venus...

Lately, Earth and Mars seem to get all the press, but the NASA has ignored Venus since the NASA's Magellan mission used radar to map the planet in 1994 . Venus is Earth's neighbor, on the side closer to the Sun. The planet has roughly the same mass, size, and composition as Earth. Evidence shows that Venus was once partially covered by deep oceans of water. Today, Venus is unimaginably hot, with only a little water left on its surface. How could two planets that were once so essentially alike end up so different?

This week, the European Space Agency (ESA) released eight papers in Nature magazine documenting the findings of the Venus Express mission, their unmanned probe launched in 2005. The ESA has been building their understanding of Venusian weather, which to Earthlings is astounding: above the planet's 460-degree-C surface, the Sun’s energy blasts thick sulphuric acid clouds through an atmosphere that is about 95 percent carbon dioxide.

On Earth, a small amount of atmospheric carbon dioxide warms the surface, which is tempered by vast oceans. On Venus, the thin spots of surface water are vaporizing into space under intense heat. With an atmosphere composed mainly of carbon dioxide, no oceans to cool lava that flows to its surface, and a closer proximity to the sun, Venus experiences an extreme greenhouse effect.

Venus' inhospitable conditions ruins our chances of finding any remaining record of past life there, and makes the possibility of landing an astronaut there a pipe dream. link

November 28, 2007

Beer fridges are widening our carbon footprints

According to a researcher at the University of Alberta, the secondary refrigerators found in many Canadian households are significant contributors to greenhouse gas emissions.

In Canada, one in three households have a second refrigerator, and most of these second refrigerators are used to keep beverages cold. Beer fridges tend to be older and less energy efficient, 65 percent are more than 10 years old. According to a Canadian researcher, secondary refrigerators in Canada consumed at least as much electricity as 100,000 US homes.

Although the study did not include the US, it's fair to assume that US households contributing to greenhouse emissions in a similar way. The According to the National Resources Defense Council, 98 to 99 percent of US homes have at least one refrigerator, and 18 percent of those have two or more refrigerators. link

November 27, 2007

Emryonic stem cells - without the embryos

Embryonic stem cells are pluripotent-- they have an almost magical ability to grow into any kind of cell and perform any function. There is a good possibility that some day we may use cells like this to heal injuries and deceases. Until recently, the only way to get these cells was to remove them from the cells of a embryo, a process that is fatal to the embryo and controversial to many.

It was reported on November 20 that a method was developed for making pluripotent stem cells from ordinary skin cells, with no need for an embryo. Two different scientific teams developed the method independently, using specialized viruses to deliver four genes to the skin cell's genetic code. Adding four genes is all it takes to make a embryonic-like stem cell from a skin cell.

Anytime genes are added to normal cells, there is a risk that the cells can grow cancerous. But, researchers are confident that they will soon find a way to switch the cell's genes instead of adding to them, removing the cancer risk.

Having a method for making pluripotent stem cells without using embryos will extinguish the controversy that beleaguers stem cell research. "People working on ethics will have to find something new to worry about," says stem cell researcher Jose Cibelli of Michigan State University. link