What time is it on Mars? | Nagin Cox

133,602 views ・ 2017-02-24

TED


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So many of you have probably seen the movie "The Martian."
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But for those of you who did not, it's a movie about an astronaut
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who is stranded on Mars, and his efforts to stay alive
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until the Earth can send a rescue mission to bring him back to Earth.
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Gladly, they do re-establish communication
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with the character, astronaut Watney, at some point
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so that he's not as alone on Mars until he can be rescued.
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So while you're watching the movie, or even if you haven't,
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when you think about Mars,
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you're probably thinking about how far away it is and how distant.
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And, what might not have occurred to you is,
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what are the logistics really like of working on another planet --
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of living on two planets
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when there are people on the Earth and there are rovers or people on Mars?
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So think about when you have friends, families and co-workers
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in California, on the West Coast or in other parts of the world.
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When you're trying to communicate with them,
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one of the things you probably first think about is:
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wait, what time is it in California?
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Will I wake them up? Is it OK to call?
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So even if you're interacting with colleagues who are in Europe,
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you're immediately thinking about:
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What does it take to coordinate communication when people are far away?
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So we don't have people on Mars right now, but we do have rovers.
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And actually right now, on Curiosity, it is 6:10 in the morning.
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So, 6:10 in the morning on Mars.
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We have four rovers on Mars.
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The United States has put four rovers on Mars since the mid-1990s,
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and I have been privileged enough to work on three of them.
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So, I am a spacecraft engineer, a spacecraft operations engineer,
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at NASA's Jet Propulsion Laboratory in Los Angeles, California.
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And these rovers are our robotic emissaries.
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So, they are our eyes and our ears, and they see the planet for us
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until we can send people.
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So we learn how to operate on other planets through these rovers.
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So before we send people, we send robots.
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So the reason there's a time difference on Mars right now,
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from the time that we're at
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is because the Martian day is longer than the Earth day.
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Our Earth day is 24 hours,
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because that's how long it takes the Earth to rotate,
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how long it takes to go around once.
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So our day is 24 hours.
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It takes Mars 24 hours and approximately 40 minutes to rotate once.
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So that means that the Martian day is 40 minutes longer than the Earth day.
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So teams of people who are operating the rovers on Mars, like this one,
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what we are doing is we are living on Earth, but working on Mars.
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So we have to think as if we are actually on Mars with the rover.
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Our job, the job of this team, of which I'm a part of,
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is to send commands to the rover to tell it what to do the next day.
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To tell it to drive or drill or tell her whatever she's supposed to do.
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So while she's sleeping -- and the rover does sleep at night
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because she needs to recharge her batteries
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and she needs to weather the cold Martian night.
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And so she sleeps.
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So while she sleeps, we work on her program for the next day.
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So I work the Martian night shift.
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(Laughter)
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So in order to come to work on the Earth at the same time every day on Mars --
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like, let's say I need to be at work at 5:00 p.m.,
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this team needs to be at work at 5:00 p.m. Mars time every day,
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then we have to come to work on the Earth 40 minutes later every day,
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in order to stay in sync with Mars.
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That's like moving a time zone every day.
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So one day you come in at 8:00, the next day 40 minutes later at 8:40,
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the next day 40 minutes later at 9:20,
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the next day at 10:00.
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So you keep moving 40 minutes every day,
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until soon you're coming to work in the middle of the night --
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the middle of the Earth night.
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Right? So you can imagine how confusing that is.
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Hence, the Mars watch.
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(Laughter)
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This weights in this watch have been mechanically adjusted
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so that it runs more slowly.
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Right? And we didn't start out --
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I got this watch in 2004
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when Spirit and Opportunity, the rovers back then.
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We didn't start out thinking
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that we were going to need Mars watches.
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Right? We thought, OK, we'll just have the time on our computers
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and on the mission control screens, and that would be enough.
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Yeah, not so much.
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Because we weren't just working on Mars time,
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we were actually living on Mars time.
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And we got just instantaneously confused about what time it was.
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So you really needed something on your wrist to tell you:
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What time is it on the Earth? What time is it on Mars?
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And it wasn't just the time on Mars that was confusing;
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we also needed to be able to talk to each other about it.
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So a "sol" is a Martian day -- again, 24 hours and 40 minutes.
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So when we're talking about something that's happening on the Earth,
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we will say, today.
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So, for Mars, we say, "tosol."
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(Laughter)
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Yesterday became "yestersol" for Mars.
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Again, we didn't start out thinking, "Oh, let's invent a language."
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It was just very confusing.
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I remember somebody walked up to me and said,
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"I would like to do this activity on the vehicle tomorrow, on the rover."
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And I said, "Tomorrow, tomorrow, or Mars, tomorrow?"
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We started this terminology because we needed a way to talk to each other.
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(Laughter)
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Tomorrow became "nextersol" or "solorrow."
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Because people have different preferences for the words they use.
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Some of you might say "soda" and some of you might say "pop."
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So we have people who say "nextersol" or "solorrow."
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And then something that I noticed after a few years of working on these missions,
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was that the people who work on the rovers, we say "tosol."
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The people who work on the landed missions that don't rove around,
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they say "tosoul."
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So I could actually tell what mission you worked on from your Martian accent.
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(Laughter)
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So we have the watches and the language, and you're detecting a theme here, right?
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So that we don't get confused.
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But even the Earth daylight could confuse us.
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If you think that right now, you've come to work
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and it's the middle of the Martian night
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and there's light streaming in from the windows
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that's going to be confusing as well.
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So you can see from this image of the control room
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that all of the blinds are down.
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So that there's no light to distract us.
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The blinds went down all over the building about a week before landing,
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and they didn't go up until we went off Mars time.
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So this also works for the house, for at home.
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I've been on Mars time three times, and my husband is like,
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OK, we're getting ready for Mars time.
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And so he'll put foil all over the windows and dark curtains and shades
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because it also affects your families.
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And so here I was living in kind of this darkened environment, but so was he.
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And he'd gotten used to it.
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But then I would get these plaintive emails from him when he was at work.
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Should I come home? Are you awake?
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What time is it on Mars?
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And I decided, OK, so he needs a Mars watch.
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(Laughter)
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But of course, it's 2016, so there's an app for that.
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(Laughter)
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So now instead of the watches, we can also use our phones.
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But the impact on families was just across the board;
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it wasn't just those of us who were working on the rovers
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but our families as well.
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This is David Oh, one of our flight directors,
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and he's at the beach in Los Angeles with his family at 1:00 in the morning.
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(Laughter)
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So because we landed in August
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and his kids didn't have to go back to school until September,
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they actually went on to Mars time with him for one month.
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They got up 40 minutes later every day.
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And they were on dad's work schedule.
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So they lived on Mars time for a month and had these great adventures,
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like going bowling in the middle of the night
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or going to the beach.
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And one of the things that we all discovered
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is you can get anywhere in Los Angeles
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at 3:00 in the morning when there's no traffic.
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(Laughter)
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So we would get off work,
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and we didn't want to go home and bother our families,
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and we were hungry, so instead of going locally to eat something,
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we'd go, "Wait, there's this great all-night deli in Long Beach,
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and we can get there in 10 minutes!"
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So we would drive down -- it was like the 60s, no traffic.
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We would drive down there, and the restaurant owners would go,
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"Who are you people?
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And why are you at my restaurant at 3:00 in the morning?"
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So they came to realize that there were these packs of Martians,
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roaming the LA freeways, in the middle of the night --
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in the middle of the Earth night.
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And we did actually start calling ourselves Martians.
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So those of us who were on Mars time would refer to ourselves as Martians,
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and everyone else as Earthlings.
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(Laughter)
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And that's because when you're moving a time-zone every day,
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you start to really feel separated from everyone else.
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You're literally in your own world.
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So I have this button on that says, "I survived Mars time. Sol 0-90."
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And there's a picture of it up on the screen.
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So the reason we got these buttons is because we work on Mars time
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in order to be as efficient as possible with the rover on Mars,
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to make the best use of our time.
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But we don't stay on Mars time for more than three to four months.
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Eventually, we'll move to a modified Mars time, which is what we're working now.
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And that's because it's hard on your bodies, it's hard on your families.
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In fact, there were sleep researchers who actually were studying us
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because it was so unusual for humans to try to extend their day.
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And they had about 30 of us
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that they would do sleep deprivation experiments on.
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So I would come in and take the test and I fell asleep in each one.
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And that was because, again, this eventually becomes hard on your body.
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Even though it was a blast.
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It was a huge bonding experience with the other members on the team,
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but it is difficult to sustain.
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So these rover missions are our first steps out into the solar system.
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We are learning how to live on more than one planet.
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We are changing our perspective to become multi-planetary.
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So the next time you see a Star Wars movie,
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and there are people going from the Dagobah system to Tatooine,
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think about what it really means to have people spread out so far.
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What it means in terms of the distances between them,
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how they will start to feel separate from each other
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and just the logistics of the time.
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We have not sent people to Mars yet, but we hope to.
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And between companies like SpaceX and NASA
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and all of the international space agencies of the world,
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we hope to do that in the next few decades.
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So soon we will have people on Mars, and we truly will be multi-planetary.
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And the young boy or the young girl
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who will be going to Mars could be in this audience or listening today.
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I have wanted to work at JPL on these missions since I was 14 years old
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and I am privileged to be a part of it.
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And this is a remarkable time in the space program,
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and we are all in this journey together.
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So the next time you think you don't have enough time in your day,
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just remember, it's all a matter of your Earthly perspective.
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Thank you.
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(Applause)
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