Though millions of dreamers have anticipated their chance to travel in space, fewer than 650 earthlings have viewed our planet from a spaceship. Alan Ladwig, former manager of NASA’s Space Flight Participant Program, examines the promise, expectations, principal personalities, and milestones surrounding space tourism and reviews what has remained constant for decades: our motivation to float among the stars.
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.
