You didn’t have to be a solar expert to see stunning beauty in the images that satellite-borne instruments sent to Earth in the late 1990s. The sophisticated new tools sampled the Sun’s electromagnetic energy at a variety of wavelengths, resolutions, and intervals, producing data that were both visually compelling and rich in science-relevant detail.

A team of scientists is tackling a scenario that is the stuff of Hollywood thrillers: What happens if a medium-sized asteroid strikes Earth? In particular, what if it crashes into the ocean? The question is not fanciful.

The concepts of environmental sustainability that broke into public awareness in the 1970s took on new overtones two decades later. In its first report, released in 1990, the Intergovernmental Panel on Climate Change (IPCC) made it clear that ever-increasing amounts of human-produced greenhouse gases posed a real risk to a sustainable future.

Atmospheric research made enormous gains in the 1990s through the growth of high-speed data exchange facilitated by the Internet. At the same time, another byproduct of government research—the Global Positioning System—was bringing its own benefits to the field.

As a child on a Navajo reservation in Arizona, Carl Etsitty was both profoundly respectful of nature, declaring to Mother Earth that “I will forever be a steward of the land.” His reverence for the environment was paired with intense curiosity, but those attitudes clashed in the early 1990s when Etsitty went to college.