Joe Palca

There's a small spacecraft called Messenger that's been orbiting the planet Mercury for a year. Today, at the Lunar and Planetary Science Conference in Houston, astronomers revealed what they've learned about the innermost planet in our solar system, and some of the new knowledge is puzzling.

Maria Zuber, a planetary scientist at the Massachusetts Institute of Technology, studied a large crater 900 miles across called Caloris.

My sister is no science writer, and I'm no baker, but recently our worlds melded in a surprising way.

Here's what happened: Last October, I attended a workshop on artisanal bread and cheese-making at Salt Water Farms in Lincolnville, Maine. Farm manager Ladleah Dunn introduced us to the concept of making sourdough bread with levain, or starter, instead of packaged yeast.

A telescope in Arizona has taken some of the clearest pictures ever of distant celestial objects, including the first images of the innermost planet in a planetary system 127 light years from Earth. They achieved this astronomical tour de force using something called adaptive optics, a technique that eliminates the blurring caused by the Earth's atmosphere.

If you think astronauts just want dehydrated dinners and freeze-dried ice cream, think again. After a few days in space, they start reaching for the hot sauce.

In fact, they may start craving foods they didn't necessarily like on Earth.

Scientists can spend years working on problems that at first may seem esoteric and rather pointless. For example, there's a scientist in Arizona who's trying to find a way to measure the age of wild mosquitoes.

As weird as that sounds, the work is important for what it will tell scientists about the natural history of mosquitoes. It also could have major implications for human health.

There are few more sybaritic pleasures than scratching an itch.

But according to a study just out in the British Journal of Dermatology, the intensity of the scratching delight varies with the location of the itch.

Companies making genetically modified animals face a regulatory morass in this country. It's not always clear which federal agency has responsibility for regulating a particular animal, and even when one agency does take the lead, the approval process can drag on for years.

The companies say this uncertainty means their technologies may die without ever being given a chance.

Take the case of the British company Oxitec. It has developed a genetically modified mosquito that the company says can be used to combat a disease called dengue.

When scientists want to test new therapies for cancer or heart disease, they frequently turn to mice for help. For most mice, this isn't the best thing that could happen to them. Being a research subject has definite disadvantages, at least for mice.

But most people prefer a new therapy be tested in a rodent rather than making a human patient the guinea pig — if you'll forgive the twisted metaphor.