Space, science, and the human mind. Since 1995.
Life Signs
A Space Daily column

Life Signs

Nature and earth science

Life Signs is where Space Daily looks down instead of up. Animals, ecosystems, and Earth science, with a bias for peer-reviewed studies over press-release hype. The living world turns out to be at least as strange as anything in orbit.

Marsdaily

Mars lost its global magnetic field, most of its thick atmosphere and much of its surface water billions of years ago—yet Curiosity recovered more than 20 organic molecules from 3.5-billion-year-old clay-bearing sandstone in Gale Crater, including a nitrogen-bearing structure related to DNA and RNA chemistry: a chemical archive that outlasted the wet world around it.

Curiosity's Mary Anning 3 sample preserved diverse macromolecular organic chemistry for 3.5 billion years, but its possible nitrogen heterocycle remains far short of evidence for life.

Science

Carbon monoxide is best known as a poison, but the human body manufactures small amounts during heme breakdown, and research suggests that at trace levels this two-atom gas helps regulate inflammation and cellular responses to stress inside tissues far below the concentrations that block oxygen delivery

Carbon monoxide kills at 1,000 parts per million in a snowbound car, but the same three atoms are manufactured inside human cells by heme oxygenase as a signalling molecule regulating inflammation and blood flow. The gap between the two doses is roughly six orders of magnitude — and it is the entire story.

Flora And Fauna

Sea sponges pushed through a fine mesh separate into individual cells that then crawl back together over hours and reassemble into a functioning sponge, an extreme case of whole-body regeneration that biologists have watched under microscopes since 1907

Force a living sea sponge through a fine mesh and it separates into single cells. Hours later those cells crawl back together and rebuild a functioning sponge — a trick, first demonstrated in 1907, that appears to be unique in the animal kingdom.