520 Everyone loves to see the beauty of the star-studded night sky, but how many of us understand what makes stars shine, where Saturn's rings come from, or why galaxies have their distinctive shapes. Observational astronomy excels at cataloging celestial objects, but it takes a more rigorous discipline to come up with physical explanations for them. That field is astrophysics, which uses the laws of physics to investigate everything beyond Earth....

Learn how ancient Egyptians, Greeks, Indians, Chinese, and other cultures saw the sky and how the sun, moon, and stars were their clock, calendar, and compass. Constellations encoded their mythologies and the perfection of the heavens inspired religious and philosophical ideas, ultimately laying the foundation for modern science.