Some of the most traumatic highlights in Earth's history can be found in ancient tree rings.

Dark energy can't be seen but space scientists say it can be measured through the outward movement of supernovae and galaxies.

Researchers are revolutionizing medical imaging by creating extremely small devices that can see inside the human body.

Scientists are studying the biological connections within and between species that benefit both. University of Arizona evolutionary biologist Judith Bronstein identifies examples of mutualism, ranging from bacterial organisms to plant pollinators.

Astronomers are focusing on the smallest and most distant galaxies in the universe. University of Arizona researcher David Sand describes how he locates dwarf galaxies through digital sky surveys and gathers information about them using ground-based telescopes in the Southern Hemisphere.

Now that people are driving electric cars and buses, researchers are working on the feasibility of all-electric airplanes.

Visitors imagine Biosphere 2 as a place for large scale research on plant life and ocean biology.

Arizona's ties to copper go back to the territorial era, but the mineral also plays a big part in human health.

Plants and their pollinators work together to promote successful natural growth.

People coping with clinical amnesia provide a window to the importance of memory.