Space Photos This Week: Rocket Test, Tropical Storm, More
The world's strongest solid rocket motor revs up, a star nursery is seen in its sharpest view yet, and more in this week's best space pictures.
Gravitational Waves: Ripples in Spacetime
Gravitational waves are distortions in the fabric of space and time. Massive objects like planets, stars and black holes can create curves in that fabric, like a bowling ball on a trampoline. When massive objects move, those curves can become waves.