Earth is a 7,917-mile-wide rock drifting through the vacuum of space — a fact that's shockingly easy to forget.

But every so often, a mind-boggling picture appears before our eyes and reminds us just how small, lucky, and plucky we are as human beings.

Some images take us on a billion-year journey back in time. Others bring the blue marble of our home planet into view. And from the ground, we can follow companies and governments on their quests to reach the stars.

The year 2017 brought some of the most astounding space and astronomy images to date. We've rounded up some of our favorites.