ScienceDaily: Space & Time News

Scientists at Cornell University and the American Museum of Natural History have identified 2,034 nearby star-systems - within the small cosmic distance of 326 light-years - that could find Earth merely by watching our pale blue dot cross our sun.

A new analysis of known exoplanets has revealed that Earth-like conditions on potentially habitable planets may be much rarer than previously thought. The work focuses on the conditions required for oxygen-based photosynthesis to develop on a planet, which would enable complex biospheres of the type found on Earth.

Data from 500 young stars observed with the Atacama Large Millimeter/submilliter Array (ALMA) is giving scientists a window back through time, allowing them to predict what exoplanetary systems looked like through each stage of their formation. And it all starts with a link between higher mass stars, disks with gaps in them, and a high occurrence of observed exoplanets.

New research suggests that carbon, oxygen, and hydrogen cosmic rays travel through the galaxy toward Earth in a similar way, but, surprisingly, that iron arrives at Earth differently. The international research team analyzed data from the CALET instrument on the International Space Station to arrive at the results, which help address the age-old question: How is matter generated and distributed across the universe?