To most people, the sun is a steady, never-changing source of heat and light. But to scientists, it's a dynamic star, constantly in flux, sending energy out into space. Experts say the sun is now in its most active period in two decades, causing potential disruptions to radio and satellite communications. John Yang speaks with Bill Murtagh of NOAA's Space Weather Prediction Center to learn more. PBS News is supported by - https://www.pbs.org/newshour/about/funders

New research is revealing the secrets of Io, the mysterious volcanic moon of Jupiter. Four centuries after Galileo discovered Io in 1610, NASA sent a spacecraft called Juno on a five-year mission to Jupiter and its moons. Last week, NASA released animated artists' conceptions of Io based on data Juno collected during two flybys. John Yang reports. PBS News is supported by - https://www.pbs.org/newshour/about/funders

Data shows that global levels of the three main heat-trapping greenhouse gases -- carbon dioxide, methane and nitrous oxide -- all reached record highs in 2023 for the second year in the row, and experts say there's no end in sight. But a new book, 'H Is for Hope,' says there is reason for hope in the fight against climate change. William Brangham speaks with its author, Elizabeth Kolbert. PBS News is supported by - https://www.pbs.org/newshour/about/funders

Millions of people on Monday watched a rare total eclipse cut across the U.S., Mexico and Canada, plunging some towns and cities into darkness for several minutes. In many other places it was a chance to view a partial eclipse. Miles O'Brien, who witnessed the spectacle from Dallas, has our report. PBS News is supported by - https://www.pbs.org/newshour/about/funders

More than 2 billion people, about a third of the world's population, face food insecurity. At the same time, a recent UN report estimated that more than 1 billion metric tons of food went to waste in 2022, enough to give each person facing hunger around the world more than one meal a day. Ali Rogin speaks with Dana Gunders, executive director of ReFED, to learn more. PBS News is supported by - https://www.pbs.org/newshour/about/funders

While the U.S. has made great progress improving air quality in recent decades, air pollution is still a driver of many serious health conditions both domestically and globally. According to a new report, only seven countries met the World Health Organization's air quality guidelines for pollution in 2023. Glory Dolphin Hammes, North American CEO for IQAir, joins William Brangham to discuss. PBS News is supported by - https://www.pbs.org/newshour/about/funders

On Jekyll Island off the Georgia coast, some sea turtles and people who care about their survival marked a small victory on Thursday. The Georgia Sea Turtle Center teamed up with volunteers from Northeast aquariums and conservation groups to move 33 Kemp's ridley sea turtles and one green sea turtle to warmer southeastern waters where they can thrive. John Yang reports. PBS News is supported by - https://www.pbs.org/newshour/about/funders

We're less than three days away from the total solar eclipse that will be seen in the U.S., Mexico and Canada. Monday's eclipse will cut across 13 states with more than 30 million people living in the path of totality while millions more are traveling to get a good look. Science correspondent Miles O'Brien and astrophysicist Neil DeGrasse Tyson have a viewer's guide on what you need to know. PBS News is supported by - https://www.pbs.org/newshour/about/funders

An annual, celebrated event took place this past week in Washington, D.C., and it didn't have anything to do with politics. It's known as peak bloom, the day 70 percent of blossoms are open on Washington's iconic cherry trees around the Tidal Basin. But for 158 of the trees, this year will be their last bloom. John Yang reports. PBS News is supported by - https://www.pbs.org/newshour/about/funders

Kevlar is a fiber that's stronger than steel, and it's revolutionized everything from military and police body armor to sports equipment. For our "Hidden Histories" series this Women's History Month, we learn about Stephanie Kwolek, the pioneering researcher who invented Kevlar in 1965. PBS News is supported by - https://www.pbs.org/newshour/about/funders