Though the concept of black holes can be traced back to the late 1700s, the quest to understand their nature and how they shape our universe continues. Kelly Beatty, senior editor at Sky & Telescope magazine, discusses how cosmologists still grapple with precisely what black holes are and how best to study them.
The Sun, the 4.5-billion-year-old star at the center of the solar system, is the glue that holds it together, and its activity provides a protective bubble that shields the planets from damaging galactic radiation. Astrophysicist and cosmologist Hakeem Oluseyi shines a light on this special star.
Mercury, the innermost planet in the solar system, remained relatively unexplored until NASA’s MESSENGER probe orbited and studied it from 2011 to 2015. Physicist Ronald J. Vervack Jr., who worked on the MESSENGER mission, highlights how Mercury provides insight into the formation, evolution, and current state of the solar system.
In this solar system, Venus is the planet most like Earth in size and density, yet it has a toxic atmosphere and is the hottest planet, contrasting with habitable Earth. Astrophysicist Stephen Kane reveals clues that point to a possible habitable past of Venus and discusses how its environment might have become hostile to life.
Our understanding of science has advanced immeasurably over 500 years, yet many fundamental mysteries of existence persist: How did our Universe begin? Is time travel possible? How did life on Earth arise? Covering time, space, matter, life, and consciousness, theoretical physicist Lawrence Krauss explores the greatest unanswered questions at the forefront of science today—and why they will shape its next century.
