[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:03.79,Default,,0000,0000,0000,,I'm going to tell you a story\Nfrom 200 years ago.
Dialogue: 0,0:00:04.79,0:00:08.06,Default,,0000,0000,0000,,In 1820, French astronomer Alexis Bouvard
Dialogue: 0,0:00:08.08,0:00:13.31,Default,,0000,0000,0000,,almost became the second person\Nin human history to discover a planet.
Dialogue: 0,0:00:13.33,0:00:16.64,Default,,0000,0000,0000,,He'd been tracking the position\Nof Uranus across the night sky
Dialogue: 0,0:00:16.67,0:00:18.39,Default,,0000,0000,0000,,using old star catalogs,
Dialogue: 0,0:00:18.42,0:00:20.73,Default,,0000,0000,0000,,and it didn't quite go around the Sun
Dialogue: 0,0:00:20.75,0:00:23.18,Default,,0000,0000,0000,,the way that his predictions\Nsaid it should.
Dialogue: 0,0:00:23.21,0:00:25.31,Default,,0000,0000,0000,,Sometimes it was a little too fast,
Dialogue: 0,0:00:25.33,0:00:27.02,Default,,0000,0000,0000,,sometimes a little too slow.
Dialogue: 0,0:00:27.04,0:00:30.77,Default,,0000,0000,0000,,Bouvard knew that\Nhis predictions were perfect.
Dialogue: 0,0:00:30.79,0:00:34.06,Default,,0000,0000,0000,,So it had to be that those\Nold star catalogs were bad.
Dialogue: 0,0:00:34.08,0:00:36.14,Default,,0000,0000,0000,,He told astronomers of the day,
Dialogue: 0,0:00:36.17,0:00:38.60,Default,,0000,0000,0000,,"Do better measurements."
Dialogue: 0,0:00:38.62,0:00:39.89,Default,,0000,0000,0000,,So they did.
Dialogue: 0,0:00:39.92,0:00:42.06,Default,,0000,0000,0000,,Astronomers spent the next two decades
Dialogue: 0,0:00:42.08,0:00:46.14,Default,,0000,0000,0000,,meticulously tracking the position\Nof Uranus across the sky,
Dialogue: 0,0:00:46.17,0:00:49.85,Default,,0000,0000,0000,,but it still didn't fit\NBouvard's predictions.
Dialogue: 0,0:00:49.88,0:00:52.02,Default,,0000,0000,0000,,By 1840, it had become obvious.
Dialogue: 0,0:00:52.04,0:00:55.10,Default,,0000,0000,0000,,The problem was not\Nwith those old star catalogs,
Dialogue: 0,0:00:55.12,0:00:57.98,Default,,0000,0000,0000,,the problem was with the predictions.
Dialogue: 0,0:00:58.00,0:00:59.52,Default,,0000,0000,0000,,And astronomers knew why.
Dialogue: 0,0:00:59.54,0:01:03.73,Default,,0000,0000,0000,,They realized that there must be\Na distant, giant planet
Dialogue: 0,0:01:03.75,0:01:05.43,Default,,0000,0000,0000,,just beyond the orbit of Uranus
Dialogue: 0,0:01:05.46,0:01:07.27,Default,,0000,0000,0000,,that was tugging along at that orbit,
Dialogue: 0,0:01:07.29,0:01:09.85,Default,,0000,0000,0000,,sometimes pulling it along a bit too fast,
Dialogue: 0,0:01:09.88,0:01:11.54,Default,,0000,0000,0000,,sometimes holding it back.
Dialogue: 0,0:01:12.75,0:01:14.77,Default,,0000,0000,0000,,Must have been frustrating back in 1840
Dialogue: 0,0:01:14.79,0:01:18.18,Default,,0000,0000,0000,,to see these gravitational effects\Nof this distant, giant planet
Dialogue: 0,0:01:18.21,0:01:21.98,Default,,0000,0000,0000,,but not yet know how to actually find it.
Dialogue: 0,0:01:22.00,0:01:24.06,Default,,0000,0000,0000,,Trust me, it's really frustrating.
Dialogue: 0,0:01:24.08,0:01:25.56,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:01:25.58,0:01:27.81,Default,,0000,0000,0000,,But in 1846, another French astronomer,
Dialogue: 0,0:01:27.83,0:01:29.14,Default,,0000,0000,0000,,Urbain Le Verrier,
Dialogue: 0,0:01:29.17,0:01:30.43,Default,,0000,0000,0000,,worked through the math
Dialogue: 0,0:01:30.46,0:01:33.18,Default,,0000,0000,0000,,and figured out how to predict\Nthe location of the planet.
Dialogue: 0,0:01:33.21,0:01:36.18,Default,,0000,0000,0000,,He sent his prediction\Nto the Berlin observatory,
Dialogue: 0,0:01:36.21,0:01:37.64,Default,,0000,0000,0000,,they opened up their telescope
Dialogue: 0,0:01:37.67,0:01:40.73,Default,,0000,0000,0000,,and in the very first night\Nthey found this faint point of light
Dialogue: 0,0:01:40.75,0:01:42.85,Default,,0000,0000,0000,,slowly moving across the sky
Dialogue: 0,0:01:42.88,0:01:44.14,Default,,0000,0000,0000,,and discovered Neptune.
Dialogue: 0,0:01:44.17,0:01:48.29,Default,,0000,0000,0000,,It was this close on the sky\Nto Le Verrier's predicted location.
Dialogue: 0,0:01:49.88,0:01:54.39,Default,,0000,0000,0000,,The story of prediction\Nand discrepancy and new theory
Dialogue: 0,0:01:54.42,0:01:57.48,Default,,0000,0000,0000,,and triumphant discoveries is so classic
Dialogue: 0,0:01:57.50,0:02:00.39,Default,,0000,0000,0000,,and Le Verrier became so famous from it,
Dialogue: 0,0:02:00.42,0:02:03.14,Default,,0000,0000,0000,,that people tried to get in\Non the act right away.
Dialogue: 0,0:02:03.17,0:02:05.68,Default,,0000,0000,0000,,In the last 163 years,
Dialogue: 0,0:02:05.71,0:02:11.31,Default,,0000,0000,0000,,dozens of astronomers have used\Nsome sort of alleged orbital discrepancy
Dialogue: 0,0:02:11.33,0:02:15.25,Default,,0000,0000,0000,,to predict the existence\Nof some new planet in the solar system.
Dialogue: 0,0:02:16.29,0:02:19.00,Default,,0000,0000,0000,,They have always been wrong.
Dialogue: 0,0:02:20.12,0:02:22.31,Default,,0000,0000,0000,,The most famous\Nof these erroneous predictions
Dialogue: 0,0:02:22.33,0:02:23.77,Default,,0000,0000,0000,,came from Percival Lowell,
Dialogue: 0,0:02:23.79,0:02:28.52,Default,,0000,0000,0000,,who was convinced that there must be\Na planet just beyond Uranus and Neptune,
Dialogue: 0,0:02:28.54,0:02:30.52,Default,,0000,0000,0000,,messing with those orbits.
Dialogue: 0,0:02:30.54,0:02:33.10,Default,,0000,0000,0000,,And so when Pluto was discovered in 1930
Dialogue: 0,0:02:33.12,0:02:34.77,Default,,0000,0000,0000,,at the Lowell Observatory,
Dialogue: 0,0:02:34.79,0:02:39.23,Default,,0000,0000,0000,,everybody assumed that it must be\Nthe planet that Lowell had predicted.
Dialogue: 0,0:02:39.25,0:02:41.64,Default,,0000,0000,0000,,They were wrong.
Dialogue: 0,0:02:41.67,0:02:45.77,Default,,0000,0000,0000,,It turns out, Uranus and Neptune\Nare exactly where they're supposed to be.
Dialogue: 0,0:02:45.79,0:02:47.35,Default,,0000,0000,0000,,It took 100 years,
Dialogue: 0,0:02:47.38,0:02:49.14,Default,,0000,0000,0000,,but Bouvard was eventually right.
Dialogue: 0,0:02:49.17,0:02:52.77,Default,,0000,0000,0000,,Astronomers needed to do\Nbetter measurements.
Dialogue: 0,0:02:52.79,0:02:54.56,Default,,0000,0000,0000,,And when they did,
Dialogue: 0,0:02:54.58,0:02:57.77,Default,,0000,0000,0000,,those better measurements\Nhad turned out that
Dialogue: 0,0:02:57.79,0:03:02.81,Default,,0000,0000,0000,,there is no planet just beyond\Nthe orbit of Uranus and Neptune
Dialogue: 0,0:03:02.83,0:03:05.52,Default,,0000,0000,0000,,and Pluto is thousands of times too small
Dialogue: 0,0:03:05.54,0:03:08.18,Default,,0000,0000,0000,,to have any effect on those orbits at all.
Dialogue: 0,0:03:08.21,0:03:11.85,Default,,0000,0000,0000,,So even though Pluto\Nturned out not to be the planet
Dialogue: 0,0:03:11.88,0:03:13.48,Default,,0000,0000,0000,,it was originally thought to be,
Dialogue: 0,0:03:13.50,0:03:16.93,Default,,0000,0000,0000,,it was the first discovery\Nof what is now known to be
Dialogue: 0,0:03:16.96,0:03:21.68,Default,,0000,0000,0000,,thousands of tiny, icy objects\Nin orbit beyond the planets.
Dialogue: 0,0:03:21.71,0:03:24.60,Default,,0000,0000,0000,,Here you can see the orbits of Jupiter,
Dialogue: 0,0:03:24.62,0:03:27.14,Default,,0000,0000,0000,,Saturn, Uranus and Neptune,
Dialogue: 0,0:03:27.17,0:03:30.18,Default,,0000,0000,0000,,and in that little circle\Nin the very center is the Earth
Dialogue: 0,0:03:30.21,0:03:33.18,Default,,0000,0000,0000,,and the Sun and almost everything\Nthat you know and love.
Dialogue: 0,0:03:33.21,0:03:35.02,Default,,0000,0000,0000,,And those yellow circles at the edge
Dialogue: 0,0:03:35.04,0:03:37.81,Default,,0000,0000,0000,,are these icy bodies\Nout beyond the planets.
Dialogue: 0,0:03:37.83,0:03:40.10,Default,,0000,0000,0000,,These icy bodies are pushed and pulled
Dialogue: 0,0:03:40.12,0:03:42.27,Default,,0000,0000,0000,,by the gravitational fields of the planets
Dialogue: 0,0:03:42.29,0:03:44.81,Default,,0000,0000,0000,,in entirely predictable ways.
Dialogue: 0,0:03:44.83,0:03:49.54,Default,,0000,0000,0000,,Everything goes around the Sun\Nexactly the way it is supposed to.
Dialogue: 0,0:03:50.96,0:03:52.23,Default,,0000,0000,0000,,Almost.
Dialogue: 0,0:03:52.25,0:03:54.31,Default,,0000,0000,0000,,So in 2003,
Dialogue: 0,0:03:54.33,0:03:56.23,Default,,0000,0000,0000,,I discovered what was at the time
Dialogue: 0,0:03:56.25,0:03:59.93,Default,,0000,0000,0000,,the most distant known object\Nin the entire solar system.
Dialogue: 0,0:03:59.96,0:04:02.43,Default,,0000,0000,0000,,It's hard not to look\Nat that lonely body out there
Dialogue: 0,0:04:02.46,0:04:04.52,Default,,0000,0000,0000,,and say, oh yeah, sure,\Nso Lowell was wrong,
Dialogue: 0,0:04:04.54,0:04:06.48,Default,,0000,0000,0000,,there was no planet just beyond Neptune,
Dialogue: 0,0:04:06.50,0:04:09.06,Default,,0000,0000,0000,,but this, this could be a new planet.
Dialogue: 0,0:04:09.08,0:04:10.56,Default,,0000,0000,0000,,The real question we had was,
Dialogue: 0,0:04:10.58,0:04:12.89,Default,,0000,0000,0000,,what kind of orbit\Ndoes it have around the Sun?
Dialogue: 0,0:04:12.92,0:04:14.85,Default,,0000,0000,0000,,Does it go in a circle around the Sun
Dialogue: 0,0:04:14.88,0:04:16.43,Default,,0000,0000,0000,,like a planet should?
Dialogue: 0,0:04:16.46,0:04:20.35,Default,,0000,0000,0000,,Or is it just a typical member\Nof this icy belt of bodies
Dialogue: 0,0:04:20.38,0:04:24.43,Default,,0000,0000,0000,,that got a little bit tossed outward\Nand it's now on its way back in?
Dialogue: 0,0:04:24.46,0:04:26.98,Default,,0000,0000,0000,,This is precisely the question
Dialogue: 0,0:04:27.00,0:04:31.60,Default,,0000,0000,0000,,the astronomers were trying\Nto answer about Uranus 200 years ago.
Dialogue: 0,0:04:31.62,0:04:35.39,Default,,0000,0000,0000,,They did it by using\Noverlooked observations of Uranus
Dialogue: 0,0:04:35.42,0:04:37.77,Default,,0000,0000,0000,,from 91 years before its discovery
Dialogue: 0,0:04:37.79,0:04:39.52,Default,,0000,0000,0000,,to figure out its entire orbit.
Dialogue: 0,0:04:39.54,0:04:41.56,Default,,0000,0000,0000,,We couldn't go quite that far back,
Dialogue: 0,0:04:41.58,0:04:46.18,Default,,0000,0000,0000,,but we did find observations\Nof our object from 13 years earlier
Dialogue: 0,0:04:46.21,0:04:48.89,Default,,0000,0000,0000,,that allowed us to figure out\Nhow it went around the Sun.
Dialogue: 0,0:04:48.92,0:04:50.18,Default,,0000,0000,0000,,So the question is,
Dialogue: 0,0:04:50.21,0:04:52.93,Default,,0000,0000,0000,,is it in a circular orbit\Naround the Sun, like a planet,
Dialogue: 0,0:04:52.96,0:04:54.35,Default,,0000,0000,0000,,or is it on its way back in,
Dialogue: 0,0:04:54.38,0:04:56.27,Default,,0000,0000,0000,,like one of these typical icy bodies?
Dialogue: 0,0:04:56.29,0:04:57.98,Default,,0000,0000,0000,,And the answer is
Dialogue: 0,0:04:58.00,0:04:59.27,Default,,0000,0000,0000,,no.
Dialogue: 0,0:04:59.29,0:05:02.06,Default,,0000,0000,0000,,It has a massively elongated orbit
Dialogue: 0,0:05:02.08,0:05:06.02,Default,,0000,0000,0000,,that takes 10,000 years\Nto go around the Sun.
Dialogue: 0,0:05:06.04,0:05:08.06,Default,,0000,0000,0000,,We named this object Sedna
Dialogue: 0,0:05:08.08,0:05:09.93,Default,,0000,0000,0000,,after the Inuit goddess of the sea,
Dialogue: 0,0:05:09.96,0:05:14.02,Default,,0000,0000,0000,,in honor of the cold, icy places\Nwhere it spends all of its time.
Dialogue: 0,0:05:14.04,0:05:15.64,Default,,0000,0000,0000,,We now know that Sedna,
Dialogue: 0,0:05:15.67,0:05:17.43,Default,,0000,0000,0000,,it's about a third the size of Pluto
Dialogue: 0,0:05:17.46,0:05:19.52,Default,,0000,0000,0000,,and it's a relatively typical member
Dialogue: 0,0:05:19.54,0:05:22.35,Default,,0000,0000,0000,,of those icy bodies out beyond Neptune.
Dialogue: 0,0:05:22.38,0:05:26.23,Default,,0000,0000,0000,,Relatively typical,\Nexcept for this bizarre orbit.
Dialogue: 0,0:05:26.25,0:05:28.02,Default,,0000,0000,0000,,You might look at this orbit and say,
Dialogue: 0,0:05:28.04,0:05:30.77,Default,,0000,0000,0000,,"Yeah, that's bizarre,\N10,000 years to go around the Sun,"
Dialogue: 0,0:05:30.79,0:05:32.73,Default,,0000,0000,0000,,but that's not really the bizarre part.
Dialogue: 0,0:05:32.75,0:05:34.94,Default,,0000,0000,0000,,The bizarre part is\Nthat in those 10,000 years,
Dialogue: 0,0:05:34.96,0:05:38.93,Default,,0000,0000,0000,,Sedna never comes close\Nto anything else in the solar system.
Dialogue: 0,0:05:38.96,0:05:41.27,Default,,0000,0000,0000,,Even at its closest approach to the Sun,
Dialogue: 0,0:05:41.29,0:05:43.60,Default,,0000,0000,0000,,Sedna is further from Neptune
Dialogue: 0,0:05:43.62,0:05:45.83,Default,,0000,0000,0000,,than Neptune is from the Earth.
Dialogue: 0,0:05:47.04,0:05:49.18,Default,,0000,0000,0000,,If Sedna had had an orbit like this,
Dialogue: 0,0:05:49.21,0:05:51.81,Default,,0000,0000,0000,,that kisses the orbit of Neptune\Nonce around the Sun,
Dialogue: 0,0:05:51.83,0:05:54.85,Default,,0000,0000,0000,,that would have actually been\Nreally easy to explain.
Dialogue: 0,0:05:54.88,0:05:56.64,Default,,0000,0000,0000,,That would have just been an object
Dialogue: 0,0:05:56.67,0:05:58.93,Default,,0000,0000,0000,,that had been in\Na circular orbit around the Sun
Dialogue: 0,0:05:58.96,0:06:00.39,Default,,0000,0000,0000,,in that region of icy bodies,
Dialogue: 0,0:06:00.42,0:06:02.94,Default,,0000,0000,0000,,had gotten a little bit\Ntoo close to Neptune one time,
Dialogue: 0,0:06:02.96,0:06:05.80,Default,,0000,0000,0000,,and then got slingshot out\Nand is now on its way back in.
Dialogue: 0,0:06:07.33,0:06:12.06,Default,,0000,0000,0000,,But Sedna never comes close\Nto anything known in the solar system
Dialogue: 0,0:06:12.08,0:06:14.48,Default,,0000,0000,0000,,that could have given it that slingshot.
Dialogue: 0,0:06:14.50,0:06:16.52,Default,,0000,0000,0000,,Neptune can't be responsible,
Dialogue: 0,0:06:16.54,0:06:19.64,Default,,0000,0000,0000,,but something had to be responsible.
Dialogue: 0,0:06:19.67,0:06:22.60,Default,,0000,0000,0000,,This was the first time since 1845
Dialogue: 0,0:06:22.62,0:06:27.56,Default,,0000,0000,0000,,that we saw the gravitational effects\Nof something in the outer solar system
Dialogue: 0,0:06:27.58,0:06:29.08,Default,,0000,0000,0000,,and didn't know what it was.
Dialogue: 0,0:06:30.21,0:06:33.10,Default,,0000,0000,0000,,I actually thought I knew\Nwhat the answer was.
Dialogue: 0,0:06:33.12,0:06:37.14,Default,,0000,0000,0000,,Sure, it could have been\Nsome distant, giant planet
Dialogue: 0,0:06:37.17,0:06:38.43,Default,,0000,0000,0000,,in the outer solar system,
Dialogue: 0,0:06:38.46,0:06:40.81,Default,,0000,0000,0000,,but by this time,\Nthat idea was so ridiculous
Dialogue: 0,0:06:40.83,0:06:42.68,Default,,0000,0000,0000,,and had been so thoroughly discredited
Dialogue: 0,0:06:42.71,0:06:44.52,Default,,0000,0000,0000,,that I didn't take it very seriously.
Dialogue: 0,0:06:44.54,0:06:45.81,Default,,0000,0000,0000,,But 4.5 billion years ago,
Dialogue: 0,0:06:45.83,0:06:50.68,Default,,0000,0000,0000,,when the Sun formed in a cocoon\Nof hundreds of other stars,
Dialogue: 0,0:06:50.71,0:06:51.98,Default,,0000,0000,0000,,any one of those stars
Dialogue: 0,0:06:52.00,0:06:54.64,Default,,0000,0000,0000,,could have gotten\Njust a little bit too close to Sedna
Dialogue: 0,0:06:54.67,0:06:58.64,Default,,0000,0000,0000,,and perturbed it onto the orbit\Nthat it has today.
Dialogue: 0,0:06:58.67,0:07:02.56,Default,,0000,0000,0000,,When that cluster of stars\Ndissipated into the galaxy,
Dialogue: 0,0:07:02.58,0:07:06.35,Default,,0000,0000,0000,,the orbit of Sedna would have been\Nleft as a fossil record
Dialogue: 0,0:07:06.38,0:07:08.85,Default,,0000,0000,0000,,of this earliest history of the Sun.
Dialogue: 0,0:07:08.88,0:07:10.68,Default,,0000,0000,0000,,I was so excited by this idea,
Dialogue: 0,0:07:10.71,0:07:12.18,Default,,0000,0000,0000,,by the idea that we could look
Dialogue: 0,0:07:12.21,0:07:14.43,Default,,0000,0000,0000,,at the fossil history\Nof the birth of the Sun,
Dialogue: 0,0:07:14.46,0:07:16.06,Default,,0000,0000,0000,,that I spent the next decade
Dialogue: 0,0:07:16.08,0:07:18.81,Default,,0000,0000,0000,,looking for more objects\Nwith orbits like Sedna.
Dialogue: 0,0:07:18.83,0:07:22.27,Default,,0000,0000,0000,,In that ten-year period, I found zero.
Dialogue: 0,0:07:22.29,0:07:23.31,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:07:23.33,0:07:26.85,Default,,0000,0000,0000,,But my colleagues, Chad Trujillo\Nand Scott Sheppard, did a better job,
Dialogue: 0,0:07:26.88,0:07:29.89,Default,,0000,0000,0000,,and they have now found several objects\Nwith orbits like Sedna,
Dialogue: 0,0:07:29.92,0:07:31.68,Default,,0000,0000,0000,,which is super exciting.
Dialogue: 0,0:07:31.71,0:07:33.23,Default,,0000,0000,0000,,But what's even more interesting
Dialogue: 0,0:07:33.26,0:07:36.02,Default,,0000,0000,0000,,is that they found that all these objects
Dialogue: 0,0:07:36.04,0:07:39.93,Default,,0000,0000,0000,,are not only on these distant,\Nelongated orbits,
Dialogue: 0,0:07:39.96,0:07:45.31,Default,,0000,0000,0000,,they also share a common value\Nof this obscure orbital parameter
Dialogue: 0,0:07:45.33,0:07:49.29,Default,,0000,0000,0000,,that in celestial mechanics we call\Nargument of perihelion.
Dialogue: 0,0:07:50.25,0:07:53.18,Default,,0000,0000,0000,,When they realized it was clustered\Nin argument of perihelion,
Dialogue: 0,0:07:53.21,0:07:54.98,Default,,0000,0000,0000,,they immediately jumped up and down,
Dialogue: 0,0:07:55.00,0:07:57.98,Default,,0000,0000,0000,,saying it must be caused\Nby a distant, giant planet out there,
Dialogue: 0,0:07:58.00,0:08:01.06,Default,,0000,0000,0000,,which is really exciting,\Nexcept it makes no sense at all.
Dialogue: 0,0:08:01.08,0:08:03.60,Default,,0000,0000,0000,,Let me try to explain it\Nto you why with an analogy.
Dialogue: 0,0:08:03.62,0:08:06.93,Default,,0000,0000,0000,,Imagine a person walking down a plaza
Dialogue: 0,0:08:06.96,0:08:10.29,Default,,0000,0000,0000,,and looking 45 degrees to his right side.
Dialogue: 0,0:08:11.12,0:08:13.18,Default,,0000,0000,0000,,There's a lot of reasons\Nthat might happen,
Dialogue: 0,0:08:13.21,0:08:15.14,Default,,0000,0000,0000,,it's super easy to explain, no big deal.
Dialogue: 0,0:08:15.17,0:08:16.98,Default,,0000,0000,0000,,Imagine now many different people,
Dialogue: 0,0:08:17.00,0:08:20.89,Default,,0000,0000,0000,,all walking in different\Ndirections across the plaza,
Dialogue: 0,0:08:20.92,0:08:24.18,Default,,0000,0000,0000,,but all looking 45 degrees\Nto the direction that they're moving.
Dialogue: 0,0:08:24.21,0:08:26.23,Default,,0000,0000,0000,,Everybody's moving\Nin different directions,
Dialogue: 0,0:08:26.25,0:08:28.39,Default,,0000,0000,0000,,everybody's looking\Nin different directions,
Dialogue: 0,0:08:28.42,0:08:31.73,Default,,0000,0000,0000,,but they're all looking 45 degrees\Nto the direction of motion.
Dialogue: 0,0:08:31.75,0:08:33.58,Default,,0000,0000,0000,,What could cause something like that?
Dialogue: 0,0:08:34.92,0:08:36.18,Default,,0000,0000,0000,,I have no idea.
Dialogue: 0,0:08:36.21,0:08:39.93,Default,,0000,0000,0000,,It's very difficult to think of any reason\Nthat that would happen.
Dialogue: 0,0:08:39.96,0:08:41.31,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:08:41.33,0:08:44.18,Default,,0000,0000,0000,,And this is essentially\Nwhat that clustering
Dialogue: 0,0:08:44.21,0:08:47.60,Default,,0000,0000,0000,,in argument of perihelion was telling us.
Dialogue: 0,0:08:47.62,0:08:51.18,Default,,0000,0000,0000,,Scientists were generally baffled\Nand they assumed it must just be a fluke
Dialogue: 0,0:08:51.21,0:08:52.56,Default,,0000,0000,0000,,and some bad observations.
Dialogue: 0,0:08:52.58,0:08:54.35,Default,,0000,0000,0000,,They told the astronomers,
Dialogue: 0,0:08:54.38,0:08:56.77,Default,,0000,0000,0000,,"Do better measurements."
Dialogue: 0,0:08:56.79,0:08:59.89,Default,,0000,0000,0000,,I actually took a very careful look\Nat those measurements, though,
Dialogue: 0,0:08:59.92,0:09:01.18,Default,,0000,0000,0000,,and they were right.
Dialogue: 0,0:09:01.21,0:09:03.10,Default,,0000,0000,0000,,These objects really did all share
Dialogue: 0,0:09:03.12,0:09:05.60,Default,,0000,0000,0000,,a common value of argument of perihelion,
Dialogue: 0,0:09:05.62,0:09:07.02,Default,,0000,0000,0000,,and they shouldn't.
Dialogue: 0,0:09:07.04,0:09:09.25,Default,,0000,0000,0000,,Something had to be causing that.
Dialogue: 0,0:09:11.12,0:09:15.43,Default,,0000,0000,0000,,The final piece of the puzzle\Ncame into place in 2016,
Dialogue: 0,0:09:15.46,0:09:17.98,Default,,0000,0000,0000,,when my colleague, Konstantin Batygin,
Dialogue: 0,0:09:18.00,0:09:20.64,Default,,0000,0000,0000,,who works three doors down from me, and I
Dialogue: 0,0:09:20.67,0:09:23.27,Default,,0000,0000,0000,,realized that the reason\Nthat everybody was baffled
Dialogue: 0,0:09:23.29,0:09:28.02,Default,,0000,0000,0000,,was because argument of perihelion\Nwas only part of the story.
Dialogue: 0,0:09:28.04,0:09:30.10,Default,,0000,0000,0000,,If you look at these\Nobjects the right way,
Dialogue: 0,0:09:30.12,0:09:34.18,Default,,0000,0000,0000,,they are all actually lined up\Nin space in the same direction,
Dialogue: 0,0:09:34.21,0:09:37.93,Default,,0000,0000,0000,,and they're all tilted in space\Nin the same direction.
Dialogue: 0,0:09:37.96,0:09:42.31,Default,,0000,0000,0000,,It's as if all those people on the plaza\Nare all walking in the same direction
Dialogue: 0,0:09:42.33,0:09:45.77,Default,,0000,0000,0000,,and they're all looking\N45 degrees to the right side.
Dialogue: 0,0:09:45.79,0:09:47.06,Default,,0000,0000,0000,,That's easy to explain.
Dialogue: 0,0:09:47.08,0:09:49.56,Default,,0000,0000,0000,,They're all looking at something.
Dialogue: 0,0:09:49.58,0:09:53.71,Default,,0000,0000,0000,,These objects in the outer solar system\Nare all reacting to something.
Dialogue: 0,0:09:55.00,0:09:56.73,Default,,0000,0000,0000,,But what?
Dialogue: 0,0:09:56.75,0:09:59.73,Default,,0000,0000,0000,,Konstantin and I spent a year
Dialogue: 0,0:09:59.75,0:10:04.56,Default,,0000,0000,0000,,trying to come up with any explanation\Nother than a distant, giant planet
Dialogue: 0,0:10:04.58,0:10:05.85,Default,,0000,0000,0000,,in the outer solar system.
Dialogue: 0,0:10:05.88,0:10:11.31,Default,,0000,0000,0000,,We did not want to be the 33rd and 34th\Npeople in history to propose this planet
Dialogue: 0,0:10:11.33,0:10:13.67,Default,,0000,0000,0000,,to yet again be told we were wrong.
Dialogue: 0,0:10:14.79,0:10:16.56,Default,,0000,0000,0000,,But after a year,
Dialogue: 0,0:10:16.58,0:10:17.89,Default,,0000,0000,0000,,there was really no choice.
Dialogue: 0,0:10:17.92,0:10:20.06,Default,,0000,0000,0000,,We could come up with no other explanation
Dialogue: 0,0:10:20.08,0:10:22.58,Default,,0000,0000,0000,,other than that there is a distant,
Dialogue: 0,0:10:22.62,0:10:25.89,Default,,0000,0000,0000,,massive planet on an elongated orbit,
Dialogue: 0,0:10:25.92,0:10:27.98,Default,,0000,0000,0000,,inclined to the rest of the solar system,
Dialogue: 0,0:10:28.00,0:10:30.73,Default,,0000,0000,0000,,that is forcing these patterns\Nfor these objects
Dialogue: 0,0:10:30.75,0:10:32.77,Default,,0000,0000,0000,,in the outer solar system.
Dialogue: 0,0:10:32.79,0:10:34.93,Default,,0000,0000,0000,,Guess what else a planet like this does.
Dialogue: 0,0:10:34.96,0:10:36.81,Default,,0000,0000,0000,,Remember that strange orbit of Sedna,
Dialogue: 0,0:10:36.83,0:10:39.77,Default,,0000,0000,0000,,how it was kind of pulled away\Nfrom the Sun in one direction?
Dialogue: 0,0:10:39.79,0:10:43.52,Default,,0000,0000,0000,,A planet like this would make\Norbits like that all day long.
Dialogue: 0,0:10:43.54,0:10:45.85,Default,,0000,0000,0000,,We knew we were onto something.
Dialogue: 0,0:10:45.88,0:10:48.85,Default,,0000,0000,0000,,So this brings us to today.
Dialogue: 0,0:10:48.88,0:10:53.06,Default,,0000,0000,0000,,We are basically 1845, Paris.
Dialogue: 0,0:10:53.08,0:10:54.27,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:10:54.29,0:10:59.60,Default,,0000,0000,0000,,We see the gravitational effects\Nof a distant, giant planet,
Dialogue: 0,0:10:59.62,0:11:01.85,Default,,0000,0000,0000,,and we are trying to work out\Nthe calculations
Dialogue: 0,0:11:01.88,0:11:04.89,Default,,0000,0000,0000,,to tell us where to look,\Nto point our telescopes,
Dialogue: 0,0:11:04.92,0:11:06.18,Default,,0000,0000,0000,,to find this planet.
Dialogue: 0,0:11:06.21,0:11:08.58,Default,,0000,0000,0000,,We've done massive suites\Nof computer simulations,
Dialogue: 0,0:11:09.29,0:11:11.23,Default,,0000,0000,0000,,massive months of analytic calculations
Dialogue: 0,0:11:11.25,0:11:13.81,Default,,0000,0000,0000,,and here's what I can tell you so far.
Dialogue: 0,0:11:13.83,0:11:17.02,Default,,0000,0000,0000,,First, this planet,\Nwhich we call Planet Nine,
Dialogue: 0,0:11:17.04,0:11:19.62,Default,,0000,0000,0000,,because that's what it is,
Dialogue: 0,0:11:20.75,0:11:24.02,Default,,0000,0000,0000,,Planet Nine is six times\Nthe mass of the Earth.
Dialogue: 0,0:11:24.04,0:11:26.27,Default,,0000,0000,0000,,This is no slightly-smaller-than-Pluto,
Dialogue: 0,0:11:26.29,0:11:29.02,Default,,0000,0000,0000,,let's-all-argue-about-\Nwhether-it's-a-planet-or-not thing.
Dialogue: 0,0:11:29.04,0:11:32.35,Default,,0000,0000,0000,,This is the fifth largest planet\Nin our entire solar system.
Dialogue: 0,0:11:32.38,0:11:36.02,Default,,0000,0000,0000,,For context, let me show you\Nthe sizes of the planets.
Dialogue: 0,0:11:36.04,0:11:40.18,Default,,0000,0000,0000,,In the back there,\Nyou can the massive Jupiter and Saturn.
Dialogue: 0,0:11:40.21,0:11:42.85,Default,,0000,0000,0000,,Next to them, a little bit smaller,\NUranus and Neptune.
Dialogue: 0,0:11:42.88,0:11:46.35,Default,,0000,0000,0000,,Up in the corner, the terrestrial planets,\NMercury, Venus, Earth and Mars.
Dialogue: 0,0:11:46.38,0:11:47.73,Default,,0000,0000,0000,,You can even see that belt
Dialogue: 0,0:11:47.75,0:11:50.89,Default,,0000,0000,0000,,of icy bodies beyond Neptune,\Nof which Pluto is a member,
Dialogue: 0,0:11:50.92,0:11:52.78,Default,,0000,0000,0000,,good luck figuring out which one it is.
Dialogue: 0,0:11:52.80,0:11:55.22,Default,,0000,0000,0000,,And here is Planet Nine.
Dialogue: 0,0:11:56.58,0:11:59.02,Default,,0000,0000,0000,,Planet Nine is big.
Dialogue: 0,0:11:59.04,0:12:00.31,Default,,0000,0000,0000,,Planet Nine is so big,
Dialogue: 0,0:12:00.33,0:12:02.93,Default,,0000,0000,0000,,you should probably wonder\Nwhy haven't we found it yet.
Dialogue: 0,0:12:02.96,0:12:04.23,Default,,0000,0000,0000,,Well, Planet Nine is big,
Dialogue: 0,0:12:04.25,0:12:06.35,Default,,0000,0000,0000,,but it's also really, really far away.
Dialogue: 0,0:12:06.38,0:12:11.06,Default,,0000,0000,0000,,It's something like\N15 times further away than Neptune.
Dialogue: 0,0:12:11.08,0:12:14.35,Default,,0000,0000,0000,,And that makes it about 50,000 times\Nfainter than Neptune.
Dialogue: 0,0:12:14.38,0:12:17.31,Default,,0000,0000,0000,,And also, the sky is a really big place.
Dialogue: 0,0:12:17.33,0:12:19.48,Default,,0000,0000,0000,,We've narrowed down where we think it is
Dialogue: 0,0:12:19.50,0:12:22.02,Default,,0000,0000,0000,,to a relatively small area of the sky,
Dialogue: 0,0:12:22.04,0:12:23.93,Default,,0000,0000,0000,,but it would still take us years
Dialogue: 0,0:12:23.96,0:12:26.31,Default,,0000,0000,0000,,to systematically cover\Nthe area of the sky
Dialogue: 0,0:12:26.33,0:12:28.18,Default,,0000,0000,0000,,with the large telescopes that we need
Dialogue: 0,0:12:28.21,0:12:31.52,Default,,0000,0000,0000,,to see something that's\Nthis far away and this faint.
Dialogue: 0,0:12:31.54,0:12:34.68,Default,,0000,0000,0000,,Luckily, we might not have to.
Dialogue: 0,0:12:34.71,0:12:39.60,Default,,0000,0000,0000,,Just like Bouvard used\Nunrecognized observations of Uranus
Dialogue: 0,0:12:39.62,0:12:42.39,Default,,0000,0000,0000,,from 91 years before its discovery,
Dialogue: 0,0:12:42.42,0:12:46.18,Default,,0000,0000,0000,,I bet that there are unrecognized images
Dialogue: 0,0:12:46.21,0:12:49.08,Default,,0000,0000,0000,,that show the location of Planet Nine.
Dialogue: 0,0:12:50.00,0:12:53.06,Default,,0000,0000,0000,,It's going to be a massive\Ncomputational undertaking
Dialogue: 0,0:12:53.08,0:12:55.39,Default,,0000,0000,0000,,to go through all of the old data
Dialogue: 0,0:12:55.42,0:12:58.33,Default,,0000,0000,0000,,and pick out that one faint moving planet.
Dialogue: 0,0:12:59.29,0:13:00.64,Default,,0000,0000,0000,,But we're underway.
Dialogue: 0,0:13:00.67,0:13:02.98,Default,,0000,0000,0000,,And I think we're getting close.
Dialogue: 0,0:13:03.00,0:13:05.52,Default,,0000,0000,0000,,So I would say, get ready.
Dialogue: 0,0:13:05.54,0:13:09.52,Default,,0000,0000,0000,,We are not going to match Le Verrier's
Dialogue: 0,0:13:09.54,0:13:10.81,Default,,0000,0000,0000,,"make a prediction,
Dialogue: 0,0:13:10.83,0:13:12.73,Default,,0000,0000,0000,,have the planet found in a single night
Dialogue: 0,0:13:12.75,0:13:14.93,Default,,0000,0000,0000,,that close to where\Nyou predicted it" record.
Dialogue: 0,0:13:14.96,0:13:18.89,Default,,0000,0000,0000,,But I do bet that within\Nthe next couple of years
Dialogue: 0,0:13:18.92,0:13:21.31,Default,,0000,0000,0000,,some astronomer somewhere
Dialogue: 0,0:13:21.33,0:13:23.56,Default,,0000,0000,0000,,will find a faint point of light,
Dialogue: 0,0:13:23.58,0:13:25.85,Default,,0000,0000,0000,,slowly moving across the sky
Dialogue: 0,0:13:25.88,0:13:29.18,Default,,0000,0000,0000,,and triumphantly announce\Nthe discovery of a new,
Dialogue: 0,0:13:29.21,0:13:31.64,Default,,0000,0000,0000,,and quite possibly not the last,
Dialogue: 0,0:13:31.67,0:13:34.14,Default,,0000,0000,0000,,real planet of our solar system.
Dialogue: 0,0:13:34.17,0:13:35.43,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:13:35.46,0:13:39.08,Default,,0000,0000,0000,,(Applause)