There had been a lot of thrilling firsts lately. The first time on the campus, the first night the entire group of ASCANs went to the Outpost Tavern together, the first time seeing the Saturn V rocket and the space suits used during the Apollo program.

But walking into Mission Control created a pull she felt deep down in the layers of her skin. It was the same feeling she’d had when she’d first seen the belts of Jupiter through her telescope. The same one as when she’d convinced her parents to take her to Death Valley the summer before her senior year and—with the clearest view of the sky she’d ever yet seen—she’d spotted the Andromeda Galaxy, two and a half million light-years away.

Astronomy was history. Because space was time. And that was the thing she loved most about the universe itself. When you look at the red star Antares in the southern sky, you are looking over thirty-three hundred trillion miles away. But you are also looking more than five hundred and fifty years into the past. Antares is so far away that its light takes five hundred and fifty years to reach your eye on Earth. Five hundred and fifty light-years away. So when you look out at the sky, the farther you can see, the further back you are looking in time. The space between you and the star is time.

And yet, most of the stars have been there for so long, burning so bright, that every human generation could have looked up and seen them. When you gaze up at the sky and you see Antares, with its reddish hue, in the middle of the constellation Scorpius, you are looking at the same star the Babylonians cataloged as early as 1100 B.C.E.

To look up at the nighttime sky is to become a part of a long line of people throughout human history who looked above at that same set of stars. It is to witness time unfolding.

That was the stuff that made her knees buckle.

Standing there in the theater of Mission Control, Joan felt exceptionally aware that she was not just embarking on a grand adventure. She was also joining the succession of those dedicating their life to working to understand this Earth, and the galaxy around it, for the betterment of all of humanity. She was part of something that had started well before recorded history and continued through the times of Aristotle and Aryabhata and al-Sufi and Shoujing and Copernicus, through Galileo and Kepler and Rømer and Newton, the Herschels and Leavitt and Rubin and Einstein and Hubble and beyond.

She knew her name would never be on that list. She had no desire to add her name to a list like that, in part because the idea that astronomy advances because of any one great mind struck her as simplistic. It was a collective pursuit, groups and cultures building upon and learning from what came before them.