Science Briefing

Mars rover wheel stops working

Efforts to free the rover Spirit from its Martian sand trap have been dealt a blow -- the rover’s right rear wheel appears to have stopped working.

Spirit’s right front wheel broke down in 2006, and the new problem would leave the rover with only four operable wheels, only one of them on the right side. If engineers can’t get the wheel working again, it will be even more difficult to maneuver the rover out of the patch of soft sand in which it has been snared for months.

Spirit’s twin, Opportunity, continues to explore Mars’ opposite side.

Maui summit to get big telescope

The National Science Foundation has picked the Haleakala mountaintop in Maui, Hawaii, as the site for the world’s largest solar optical telescope.

The $300-million project is due to be built near the dormant volcano’s summit. It will enable scientists to observe sunspots, flares and other phenomena too small to be seen with current equipment.

Opponents of the project say it would defile a place sacred to Native Hawaiians.

The federal agency announced the choice Tuesday in the Federal Register.

New treatment for bad memories

U.S. researchers have found a drug-free way to block fearful memories, opening up the possibility of new treatment approaches for problems such as post traumatic stress disorder, they reported Wednesday.

The findings in people build on studies in rats that showed that reactivating a memory -- by showing objects that stimulate the fearful memory -- opens up a specific time window in which the memory can be edited before it is stored again.

The study appeared in the journal Nature.

Lonely rats more prone to tumors

Lonely, stressed-out rats were far more likely to develop breast tumors than rats living in a social group, a finding that suggests loneliness can have a profound effect on health, researchers said Monday.

They said rats that were separated from a social group shortly after birth had a three times higher risk of developing breast tumors than did rats living in a social group, and the tumors in the isolated rats were more deadly.

The study appeared in the journal Proceedings of the National Academy of Sciences.

-- times staff and wire reports