Today is astronaut Reid Wiseman's first day on Earth after spending 166 days in orbit aboard the International Space Station.
Along the way, Wiseman has tweeted some of the most breathtaking and inspiring photos from outer space.
Awe-inspiring pictures that change the way we think of our planet...
...and astonishing photos that put city life into perspective.
He's brought us into the midst of the aurora borealis.
And revealed the grand forces of nature.
He showed us the stunning beauty of a moonrise...
...and the equally gorgeous moonset.
He shared what day-to-day life at the International Space Station looks like.
Breakfast in bed anyone?
Perhaps a haircut?
Or a space lettuce?
And made us all wish we could live in zero gravity.
Who wouldn't want to press the "so long" button?
And he totally won by bringing the #selfie to entirely new heights.