A laboratory experiment at NASA's Jet Propulsion Laboratory,
Pasadena, Calif., simulating the atmosphere of Saturn's moon
Titan suggests complex organic chemistry that could eventually
lead to the building blocks of life extends lower in the
atmosphere than previously thought. The results now point out
another region on the moon that could brew up prebiotic
materials. Following up on Wednesday’s surprise announcement
that a cosmic ray detector on board the International Space
Station had possibly made the first instrumented detection of
dark matter, an article from the U.S. Department of Energy
describes the methodology behind the discovery and what lies
ahead for researchers. As the shapes of galaxies go, the spiral
disk—with its characteristic pinwheel profile—is by far the most
pedestrian. But despite their common morphology, how galaxies
like ours get and maintain their characteristic arms has proved
to be an enduring puzzle in astrophysics. How do the arms of
spiral galaxies arise? Do they change or come