WEBVTT - Could Orbital Chaos Make the Planets Collide? 0:00:01.840 --> 0:00:07.520 Welcome to Brainstuff, a production of iHeartRadio. Hey, brain Stuff, 0:00:07.560 --> 0:00:12.239 Laurin Vogelbaum. Here, we all know that the planets of 0:00:12.280 --> 0:00:15.200 the Solar System revolve around the Sun in a calm 0:00:15.240 --> 0:00:19.200 and orderly fashion. In fact, the planets move with such 0:00:19.320 --> 0:00:24.320 clockwork precision that astronomers can calculate orbital characteristics like eclipses 0:00:24.360 --> 0:00:28.600 and planetary alignments with certainty. Want a list of solar 0:00:28.640 --> 0:00:33.400 eclipses for the next ten thousand years, No problem. And 0:00:33.440 --> 0:00:36.360 now let's say you want to look further into the future, 0:00:36.400 --> 0:00:40.600 not thousands of years, but billions. How will those dusty 0:00:40.680 --> 0:00:45.120 astronomical tables hold up? Then? Not so well if you 0:00:45.280 --> 0:00:49.400 take into account the principles of chaos theory. A chaos 0:00:49.440 --> 0:00:53.120 theory says that small inputs in an enormously complex system 0:00:53.400 --> 0:00:57.680 can produce large scale outputs. This is what's sometimes called 0:00:57.760 --> 0:01:00.760 the butterfly effect. The idea is that when a butterfly 0:01:00.800 --> 0:01:03.960 flaps its wings in say Brazil, it could lead to 0:01:03.960 --> 0:01:07.920 a chain reaction that causes a thunderstorm to develop over Australia. 0:01:09.640 --> 0:01:12.399 Some scientists now propose that the evolution of the Solar 0:01:12.440 --> 0:01:16.559 system may adhere to chaos theory, and that way way 0:01:16.680 --> 0:01:20.480 way into the future. This could cause Earth to collide 0:01:20.640 --> 0:01:25.840 with either Venus or Mars. A pair of scientists from 0:01:25.880 --> 0:01:29.000 the Paris Observatory published a letter with this determination in 0:01:29.040 --> 0:01:31.360 an issue of the journal Nature back in two thousand 0:01:31.360 --> 0:01:34.800 and nine. For their research, they tapped into the power 0:01:34.840 --> 0:01:38.600 of the Jade supercomputer, located at France's National Computing Center 0:01:38.680 --> 0:01:42.080 for Higher Education and Research, which at the time was 0:01:42.120 --> 0:01:47.720 around the twentieth most powerful computer in the world. So 0:01:48.000 --> 0:01:51.040 what were they trying to calculate with that veritable muscle 0:01:51.080 --> 0:01:54.919 car of computational capacity. It has to do with Isaac 0:01:54.960 --> 0:01:59.280 Newton's universal law of gravitation, which states that gravity exists 0:01:59.360 --> 0:02:04.560 between any to given objects. This gravitational force is directly 0:02:04.600 --> 0:02:08.600 proportional to the object's masses and inversely proportional to the 0:02:08.639 --> 0:02:12.560 square of the distance separating them, meaning that the more 0:02:12.600 --> 0:02:15.680 massive an object is, the more gravity it will exert 0:02:15.760 --> 0:02:19.800 on another object, but the further away an object is, 0:02:20.200 --> 0:02:25.240 the less gravity it will exert on another object. A 0:02:25.280 --> 0:02:28.520 Newton then proposed that the Sun's gravity is what holds 0:02:28.520 --> 0:02:32.280 the planets in their orbits. But it's not that simple. 0:02:33.000 --> 0:02:35.760 According to his own law, the planets and all of 0:02:35.800 --> 0:02:39.040 the other objects in the Solar System, including moons and asteroids, 0:02:39.440 --> 0:02:42.399 also exert at least a little gravity on each other. 0:02:43.520 --> 0:02:47.760 So could the complex interplay of those forces cause the 0:02:47.760 --> 0:02:52.760 stability of the Solar System to degrade over time in 0:02:52.800 --> 0:02:57.520 the short term Nope. Even over longer periods, astronomers have 0:02:57.639 --> 0:03:01.040 generally supported the idea that the Solar System would remain stable. 0:03:01.919 --> 0:03:04.639 It just sort of makes sense. After all, the Sun 0:03:04.760 --> 0:03:08.240 is overwhelmingly more massive than anything else in the Solar System. 0:03:08.919 --> 0:03:11.520 Out of the Solar System's total mass, the Sun accounts 0:03:11.520 --> 0:03:16.120 for ninety nine point eight percent of it. But a 0:03:16.160 --> 0:03:19.840 few cosmologists began to wonder if chaos theory might apply 0:03:20.000 --> 0:03:24.680 to planetary orbits. If so, small changes in planetary movements 0:03:24.720 --> 0:03:29.480 could get magnified over time into something substantial. But how 0:03:29.520 --> 0:03:35.520 long would it take? Thousands of years, millions billions? To 0:03:35.560 --> 0:03:38.120 answer that question, you'd have to build a sort of 0:03:38.240 --> 0:03:40.920 model to account for the movements of all of the planets, 0:03:41.200 --> 0:03:43.640 as well as all of the forces being exerted as 0:03:43.680 --> 0:03:47.040 that movement occurs. Then you'd need to let your Solar 0:03:47.040 --> 0:03:50.720 system model run like a clock. So the planets cycled 0:03:50.720 --> 0:03:55.080 through hundreds of thousands of orbits. As this occurred, you'd 0:03:55.080 --> 0:03:58.400 need to track key data about each planet. One of 0:03:58.400 --> 0:04:00.880 the most important pieces of data to collect would be 0:04:01.000 --> 0:04:04.480 orbital eccentricity, which is a measure of how far a 0:04:04.520 --> 0:04:08.320 planet deviates from a perfectly circular shape as it moves 0:04:08.400 --> 0:04:13.040 around the Sun. Orbital eccentricity determines whether two planets might 0:04:13.080 --> 0:04:18.560 come closer to having a close encounter. This is not 0:04:18.680 --> 0:04:20.919 the kind of simulation you could run in your head 0:04:21.200 --> 0:04:24.400 or with whatever fancy device you have at home, which 0:04:24.440 --> 0:04:27.320 is why the researchers selected the Jade's supercomputer to do 0:04:27.400 --> 0:04:32.120 their heavy lifting. Their inputs consisted of two five hundred 0:04:32.120 --> 0:04:36.320 and one orbital scenarios, where each one altered Mercury's orbit 0:04:36.440 --> 0:04:40.680 by just a few millimeters. They chose Mercury because, as 0:04:40.720 --> 0:04:43.520 the runt of the Solar System, it's the biggest pushover, 0:04:44.200 --> 0:04:48.239 and because its orbit synchronizes with jupiters to create changes 0:04:48.279 --> 0:04:54.160 that ripple across the entire Solar System. For each hypothetical scenario, 0:04:54.480 --> 0:04:57.240 they tracked the motion of all planets for more than 0:04:57.320 --> 0:05:00.520 five billion years, which is the estimated life span of 0:05:00.520 --> 0:05:04.520 the Sun. Even with the high powered CPU in the 0:05:04.600 --> 0:05:08.240 Jade unit, each solution required four months of computing to 0:05:08.279 --> 0:05:14.440 generate results. Luckily, for any future life on Earth, the 0:05:14.480 --> 0:05:17.520 Solar System remained stable in ninety nine percent of the 0:05:17.560 --> 0:05:21.560 researcher's scenarios. That is, no planets got set on collision 0:05:21.600 --> 0:05:26.040 courses or ejected from their orbits. But in one percent 0:05:26.120 --> 0:05:28.960 of their models, the ones in which the orbital chaos 0:05:29.000 --> 0:05:33.480 had the greatest cumulative effect, Mercury's orbit became eccentric enough 0:05:33.560 --> 0:05:37.560 to cause catastrophic changes in the Solar System. Some of 0:05:37.600 --> 0:05:41.400 those catastrophes only involved Mercury, which could either crash into 0:05:41.400 --> 0:05:44.320 the Sun or get dislodged from its orbit and flung 0:05:44.360 --> 0:05:48.599 out into space, but other scenarios played out with Earth 0:05:48.720 --> 0:05:54.279 colliding into either Mars or Venus. According to their models, 0:05:54.360 --> 0:05:57.680 collision with Venus would occur through five steps, all of 0:05:57.720 --> 0:06:04.640 which illustrate the cumulative effects orbital chaos. First, interaction between 0:06:04.720 --> 0:06:08.039 Jupiter and Mercury about three point one three seven billion 0:06:08.120 --> 0:06:11.479 years in the future, could cause the orbital eccentricity of 0:06:11.520 --> 0:06:16.720 Mercury to increase. This would transfer some angular momentum from 0:06:16.800 --> 0:06:20.960 the outer planets to the inner planets. This transfer would 0:06:20.960 --> 0:06:24.480 destabilize the rest of the inner planets, so the orbital 0:06:24.520 --> 0:06:29.440 eccentricities of Venus, Earth, and Mars would increase. This would 0:06:29.520 --> 0:06:32.039 cause Earth to have a near miss with Mars, which 0:06:32.080 --> 0:06:36.440 would disturb the eccentricity of Mars even more. This would 0:06:36.480 --> 0:06:40.159 cause some weird reinforcing interactions among the inner planets to 0:06:40.320 --> 0:06:44.480 decrease the eccentricity of Mercury but further increase the eccentricities 0:06:44.480 --> 0:06:49.000 of Venus and Earth. Venus and Earth would have several 0:06:49.000 --> 0:06:52.640 near misses until at three point three five two eight 0:06:52.760 --> 0:06:55.800 nine one billion years in the future, the two planets 0:06:55.839 --> 0:07:02.800 collided in an epic explosion that would destroy both worlds. Again. 0:07:03.120 --> 0:07:06.760 In ninety nine percent of their simulations, everything was fine 0:07:07.520 --> 0:07:12.760 until the Sun died. Of course, none of these models 0:07:12.760 --> 0:07:15.960 may be accurate at all. First of all, we're still 0:07:16.000 --> 0:07:19.720 discovering new bodies around our Solar System like asteroids, moons, 0:07:19.760 --> 0:07:23.840 and comets all the time, and relatedly, they could make 0:07:23.880 --> 0:07:26.800 more of a difference than the researchers originally accounted for. 0:07:27.960 --> 0:07:30.480 In a follow up study of the same scientists along 0:07:30.520 --> 0:07:33.480 with a larger team, looked at interactions between some of 0:07:33.520 --> 0:07:36.120 the large bodies in the belt between Mars and Jupiter, 0:07:36.600 --> 0:07:40.440 including the dwarf planet Series and major asteroids like Palace 0:07:40.640 --> 0:07:45.160 and Vesta. They then extrapolated out what those interactions would 0:07:45.160 --> 0:07:48.960 mean for the planets. What they concluded was that the 0:07:49.080 --> 0:07:53.960 chaotic interactions between Series and Vesta specifically, should quickly amplify 0:07:54.200 --> 0:07:58.120 even the tiniest of measurement errors, making it impossible to 0:07:58.160 --> 0:08:01.120 predict what planetary orbits should look like based on the 0:08:01.160 --> 0:08:05.040 current information beyond just sixty million years into the future 0:08:05.640 --> 0:08:11.520 or into the past. Basically, all of this means that 0:08:11.600 --> 0:08:15.000 the Solar System is filled with lots of stuff, and 0:08:15.320 --> 0:08:18.200 even though it's pretty spread out, all of these objects 0:08:18.280 --> 0:08:22.280 exert gravitational force on one another, and these forces can 0:08:22.360 --> 0:08:26.440 change planetary orbits a lot, even if we can't measure 0:08:26.480 --> 0:08:31.840 those changes very accurately. In fact, astronomers have evidence of 0:08:31.880 --> 0:08:35.760 other Solar systems self destructing. In two thousand and eight, 0:08:35.880 --> 0:08:39.360 a team from the Harvard Smithsonian Center for Astrophysics spotted 0:08:39.400 --> 0:08:42.520 a Saturn sized planet orbiting a star in the constellation 0:08:42.640 --> 0:08:46.000 Centaurus that was giving off way too much heat for 0:08:46.040 --> 0:08:50.040 its planetary size. The scientists believe that the planet is 0:08:50.160 --> 0:08:53.400 radiating massive amounts of heat because of a collision with 0:08:53.440 --> 0:08:59.720 a Urinous sized Protoplanet in the astronomically recent past, and 0:09:00.080 --> 0:09:03.520 in two thousand and nine, NASA's Spitzer space telescope spotted 0:09:03.559 --> 0:09:05.719 the aftermath of a mash up between an object the 0:09:05.800 --> 0:09:08.200 size of our moon and another the size of mercury, 0:09:08.520 --> 0:09:11.440 about one hundred light years away in the constellation Pavo. 0:09:11.840 --> 0:09:16.960 The peacock instruments on Spitzer detected the teltale signatures of 0:09:17.240 --> 0:09:21.479 amorphous silica, a substance that forms on Earth when meteorites 0:09:21.559 --> 0:09:27.440 slam into the ground. Of course, even if our solar 0:09:27.480 --> 0:09:31.120 system doesn't succumb to orbital chaos and a Billiard like 0:09:31.160 --> 0:09:36.160 crashing of the inner planets, stars don't last forever. In 0:09:36.240 --> 0:09:39.720 about five billion years, when the Sun exhausts fuel supply, 0:09:40.240 --> 0:09:42.800 all of the inner planets will disappear into the belly 0:09:42.960 --> 0:09:48.240 of our rapidly expanding star. Either way, chaos induced collision 0:09:48.320 --> 0:09:51.679 or stellar death, our tiny blue world won't go out 0:09:51.720 --> 0:09:59.599 with a whimper, but with a bang. Today's episode a 0:09:59.640 --> 0:10:02.880 space the article will orbital chaos cause Earth, Venus, and 0:10:02.920 --> 0:10:06.200 Mars to collide On HowStuffWorks dot com written by William Harris. 0:10:06.640 --> 0:10:09.560 Rain Stuff is production of iHeartRadio in partnership with HowStuffWorks 0:10:09.559 --> 0:10:12.120 dot com and it is produced by Tyler Klang. Four 0:10:12.200 --> 0:10:16.120 more podcasts My Heart Radio, visit the iHeartRadio app, Apple Podcasts, 0:10:16.320 --> 0:10:18.200 or wherever you listen to your favorite shows.