Now, the NASA technical people tell me that it will take four minutes for my words to reach you, and four more before I get to hear your reply. So I figure we can’t have much of a conversation. I just want to say this, as you talk to us from the Valley of Mangala. Our progress in space — continuing to take giant steps for all mankind — is a tribute to American teamwork and excellence. And we can be proud to say: We are first; we are the best; and we are so because we’re free.

America has always been greatest when we dared to be great. We have reached for greatness again. We can follow our dreams to the planets and to distant stars, living and working in space for peaceful, economic, and scientific gain…

York — standing on the pad in the reality of the glowing landscape, and with the weight of her pack heavy on her back — endured the remote, distorted voice.

…Now I’m going to shut up, Natalie and Phil, but I want you to indulge us with just a couple of minutes of your time. Please tell us how it feels to be, at last, on the surface of Mars.

Reagan fell silent, and the radio link hissed.

Stone said: “Thank you, Mr. President. It’s an honor and a privilege for us to be here, representing not only the United States, but all of mankind. Natalie…”

Natalie, tell them how it feels.

The oldest question in the world, the most difficult to answer — and, maybe, the most important, she thought.

The one question the Apollo astronauts could never answer.

Now I must try.

In the pink sky, the sun was continuing to strengthen, and the world was a bowl of shades of red and brown, of light scattering from the dust on the ground and suspended in the air. The light from the hatchway shone as brilliantly white as before, incongruous.

“Okay, sir. The MEM is standing here on the flats north of Mangala Vallis. It’s a late-fall morning — we’re only about eighty days away from the winter solstice, here in the northern hemisphere of Mars. The sky is uniformly ocher. The dust suffuses everything with a pale, salmon hue. The red planet isn’t really so red: the dominant color is a moderate yellow-brown, reflected from the land. There’s no green, or blue, anywhere. If humans ever colonize Mars for good — no, make that when — we’ll have to invent a lot of new words for shades of brown.