Since trees and shrubs can live for hundreds of years, identifying these blue rings allows us to spot cold summers in the past. By looking at pine trees and juniper shrubs from northern Norway ...

Jamie Carter is an award-winning reporter who covers the night sky. NGC 2264 is a cluster ... shows an animated version of the Christmas Tree Cluster where its blue and white X-ray lights blink ...

Overall, only 2.1% of the pine trees' rings and 1.3% of the juniper shrubs' rings were blue; the cells which hadn't lignified properly were mainly found at the end of growth rings, in latewood ...