1 00:00:01,840 --> 00:00:07,520 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey, brain Stuff, 2 00:00:07,560 --> 00:00:12,239 Speaker 1: Laurin Vogelbaum. Here, we all know that the planets of 3 00:00:12,280 --> 00:00:15,200 Speaker 1: the Solar System revolve around the Sun in a calm 4 00:00:15,240 --> 00:00:19,200 Speaker 1: and orderly fashion. In fact, the planets move with such 5 00:00:19,320 --> 00:00:24,320 Speaker 1: clockwork precision that astronomers can calculate orbital characteristics like eclipses 6 00:00:24,360 --> 00:00:28,600 Speaker 1: and planetary alignments with certainty. Want a list of solar 7 00:00:28,640 --> 00:00:33,400 Speaker 1: eclipses for the next ten thousand years, No problem. And 8 00:00:33,440 --> 00:00:36,360 Speaker 1: now let's say you want to look further into the future, 9 00:00:36,400 --> 00:00:40,600 Speaker 1: not thousands of years, but billions. How will those dusty 10 00:00:40,680 --> 00:00:45,120 Speaker 1: astronomical tables hold up? Then? Not so well if you 11 00:00:45,280 --> 00:00:49,400 Speaker 1: take into account the principles of chaos theory. A chaos 12 00:00:49,440 --> 00:00:53,120 Speaker 1: theory says that small inputs in an enormously complex system 13 00:00:53,400 --> 00:00:57,680 Speaker 1: can produce large scale outputs. This is what's sometimes called 14 00:00:57,760 --> 00:01:00,760 Speaker 1: the butterfly effect. The idea is that when a butterfly 15 00:01:00,800 --> 00:01:03,960 Speaker 1: flaps its wings in say Brazil, it could lead to 16 00:01:03,960 --> 00:01:07,920 Speaker 1: a chain reaction that causes a thunderstorm to develop over Australia. 17 00:01:09,640 --> 00:01:12,399 Speaker 1: Some scientists now propose that the evolution of the Solar 18 00:01:12,440 --> 00:01:16,559 Speaker 1: system may adhere to chaos theory, and that way way 19 00:01:16,680 --> 00:01:20,480 Speaker 1: way into the future. This could cause Earth to collide 20 00:01:20,640 --> 00:01:25,840 Speaker 1: with either Venus or Mars. A pair of scientists from 21 00:01:25,880 --> 00:01:29,000 Speaker 1: the Paris Observatory published a letter with this determination in 22 00:01:29,040 --> 00:01:31,360 Speaker 1: an issue of the journal Nature back in two thousand 23 00:01:31,360 --> 00:01:34,800 Speaker 1: and nine. For their research, they tapped into the power 24 00:01:34,840 --> 00:01:38,600 Speaker 1: of the Jade supercomputer, located at France's National Computing Center 25 00:01:38,680 --> 00:01:42,080 Speaker 1: for Higher Education and Research, which at the time was 26 00:01:42,120 --> 00:01:47,720 Speaker 1: around the twentieth most powerful computer in the world. So 27 00:01:48,000 --> 00:01:51,040 Speaker 1: what were they trying to calculate with that veritable muscle 28 00:01:51,080 --> 00:01:54,919 Speaker 1: car of computational capacity. It has to do with Isaac 29 00:01:54,960 --> 00:01:59,280 Speaker 1: Newton's universal law of gravitation, which states that gravity exists 30 00:01:59,360 --> 00:02:04,560 Speaker 1: between any to given objects. This gravitational force is directly 31 00:02:04,600 --> 00:02:08,600 Speaker 1: proportional to the object's masses and inversely proportional to the 32 00:02:08,639 --> 00:02:12,560 Speaker 1: square of the distance separating them, meaning that the more 33 00:02:12,600 --> 00:02:15,680 Speaker 1: massive an object is, the more gravity it will exert 34 00:02:15,760 --> 00:02:19,800 Speaker 1: on another object, but the further away an object is, 35 00:02:20,200 --> 00:02:25,240 Speaker 1: the less gravity it will exert on another object. A 36 00:02:25,280 --> 00:02:28,520 Speaker 1: Newton then proposed that the Sun's gravity is what holds 37 00:02:28,520 --> 00:02:32,280 Speaker 1: the planets in their orbits. But it's not that simple. 38 00:02:33,000 --> 00:02:35,760 Speaker 1: According to his own law, the planets and all of 39 00:02:35,800 --> 00:02:39,040 Speaker 1: the other objects in the Solar System, including moons and asteroids, 40 00:02:39,440 --> 00:02:42,399 Speaker 1: also exert at least a little gravity on each other. 41 00:02:43,520 --> 00:02:47,760 Speaker 1: So could the complex interplay of those forces cause the 42 00:02:47,760 --> 00:02:52,760 Speaker 1: stability of the Solar System to degrade over time in 43 00:02:52,800 --> 00:02:57,520 Speaker 1: the short term Nope. Even over longer periods, astronomers have 44 00:02:57,639 --> 00:03:01,040 Speaker 1: generally supported the idea that the Solar System would remain stable. 45 00:03:01,919 --> 00:03:04,639 Speaker 1: It just sort of makes sense. After all, the Sun 46 00:03:04,760 --> 00:03:08,240 Speaker 1: is overwhelmingly more massive than anything else in the Solar System. 47 00:03:08,919 --> 00:03:11,520 Speaker 1: Out of the Solar System's total mass, the Sun accounts 48 00:03:11,520 --> 00:03:16,120 Speaker 1: for ninety nine point eight percent of it. But a 49 00:03:16,160 --> 00:03:19,840 Speaker 1: few cosmologists began to wonder if chaos theory might apply 50 00:03:20,000 --> 00:03:24,680 Speaker 1: to planetary orbits. If so, small changes in planetary movements 51 00:03:24,720 --> 00:03:29,480 Speaker 1: could get magnified over time into something substantial. But how 52 00:03:29,520 --> 00:03:35,520 Speaker 1: long would it take? Thousands of years, millions billions? To 53 00:03:35,560 --> 00:03:38,120 Speaker 1: answer that question, you'd have to build a sort of 54 00:03:38,240 --> 00:03:40,920 Speaker 1: model to account for the movements of all of the planets, 55 00:03:41,200 --> 00:03:43,640 Speaker 1: as well as all of the forces being exerted as 56 00:03:43,680 --> 00:03:47,040 Speaker 1: that movement occurs. Then you'd need to let your Solar 57 00:03:47,040 --> 00:03:50,720 Speaker 1: system model run like a clock. So the planets cycled 58 00:03:50,720 --> 00:03:55,080 Speaker 1: through hundreds of thousands of orbits. As this occurred, you'd 59 00:03:55,080 --> 00:03:58,400 Speaker 1: need to track key data about each planet. One of 60 00:03:58,400 --> 00:04:00,880 Speaker 1: the most important pieces of data to collect would be 61 00:04:01,000 --> 00:04:04,480 Speaker 1: orbital eccentricity, which is a measure of how far a 62 00:04:04,520 --> 00:04:08,320 Speaker 1: planet deviates from a perfectly circular shape as it moves 63 00:04:08,400 --> 00:04:13,040 Speaker 1: around the Sun. Orbital eccentricity determines whether two planets might 64 00:04:13,080 --> 00:04:18,560 Speaker 1: come closer to having a close encounter. This is not 65 00:04:18,680 --> 00:04:20,919 Speaker 1: the kind of simulation you could run in your head 66 00:04:21,200 --> 00:04:24,400 Speaker 1: or with whatever fancy device you have at home, which 67 00:04:24,440 --> 00:04:27,320 Speaker 1: is why the researchers selected the Jade's supercomputer to do 68 00:04:27,400 --> 00:04:32,120 Speaker 1: their heavy lifting. Their inputs consisted of two five hundred 69 00:04:32,120 --> 00:04:36,320 Speaker 1: and one orbital scenarios, where each one altered Mercury's orbit 70 00:04:36,440 --> 00:04:40,680 Speaker 1: by just a few millimeters. They chose Mercury because, as 71 00:04:40,720 --> 00:04:43,520 Speaker 1: the runt of the Solar System, it's the biggest pushover, 72 00:04:44,200 --> 00:04:48,239 Speaker 1: and because its orbit synchronizes with jupiters to create changes 73 00:04:48,279 --> 00:04:54,160 Speaker 1: that ripple across the entire Solar System. For each hypothetical scenario, 74 00:04:54,480 --> 00:04:57,240 Speaker 1: they tracked the motion of all planets for more than 75 00:04:57,320 --> 00:05:00,520 Speaker 1: five billion years, which is the estimated life span of 76 00:05:00,520 --> 00:05:04,520 Speaker 1: the Sun. Even with the high powered CPU in the 77 00:05:04,600 --> 00:05:08,240 Speaker 1: Jade unit, each solution required four months of computing to 78 00:05:08,279 --> 00:05:14,440 Speaker 1: generate results. Luckily, for any future life on Earth, the 79 00:05:14,480 --> 00:05:17,520 Speaker 1: Solar System remained stable in ninety nine percent of the 80 00:05:17,560 --> 00:05:21,560 Speaker 1: researcher's scenarios. That is, no planets got set on collision 81 00:05:21,600 --> 00:05:26,040 Speaker 1: courses or ejected from their orbits. But in one percent 82 00:05:26,120 --> 00:05:28,960 Speaker 1: of their models, the ones in which the orbital chaos 83 00:05:29,000 --> 00:05:33,480 Speaker 1: had the greatest cumulative effect, Mercury's orbit became eccentric enough 84 00:05:33,560 --> 00:05:37,560 Speaker 1: to cause catastrophic changes in the Solar System. Some of 85 00:05:37,600 --> 00:05:41,400 Speaker 1: those catastrophes only involved Mercury, which could either crash into 86 00:05:41,400 --> 00:05:44,320 Speaker 1: the Sun or get dislodged from its orbit and flung 87 00:05:44,360 --> 00:05:48,599 Speaker 1: out into space, but other scenarios played out with Earth 88 00:05:48,720 --> 00:05:54,279 Speaker 1: colliding into either Mars or Venus. According to their models, 89 00:05:54,360 --> 00:05:57,680 Speaker 1: collision with Venus would occur through five steps, all of 90 00:05:57,720 --> 00:06:04,640 Speaker 1: which illustrate the cumulative effects orbital chaos. First, interaction between 91 00:06:04,720 --> 00:06:08,039 Speaker 1: Jupiter and Mercury about three point one three seven billion 92 00:06:08,120 --> 00:06:11,479 Speaker 1: years in the future, could cause the orbital eccentricity of 93 00:06:11,520 --> 00:06:16,720 Speaker 1: Mercury to increase. This would transfer some angular momentum from 94 00:06:16,800 --> 00:06:20,960 Speaker 1: the outer planets to the inner planets. This transfer would 95 00:06:20,960 --> 00:06:24,480 Speaker 1: destabilize the rest of the inner planets, so the orbital 96 00:06:24,520 --> 00:06:29,440 Speaker 1: eccentricities of Venus, Earth, and Mars would increase. This would 97 00:06:29,520 --> 00:06:32,039 Speaker 1: cause Earth to have a near miss with Mars, which 98 00:06:32,080 --> 00:06:36,440 Speaker 1: would disturb the eccentricity of Mars even more. This would 99 00:06:36,480 --> 00:06:40,159 Speaker 1: cause some weird reinforcing interactions among the inner planets to 100 00:06:40,320 --> 00:06:44,480 Speaker 1: decrease the eccentricity of Mercury but further increase the eccentricities 101 00:06:44,480 --> 00:06:49,000 Speaker 1: of Venus and Earth. Venus and Earth would have several 102 00:06:49,000 --> 00:06:52,640 Speaker 1: near misses until at three point three five two eight 103 00:06:52,760 --> 00:06:55,800 Speaker 1: nine one billion years in the future, the two planets 104 00:06:55,839 --> 00:07:02,800 Speaker 1: collided in an epic explosion that would destroy both worlds. Again. 105 00:07:03,120 --> 00:07:06,760 Speaker 1: In ninety nine percent of their simulations, everything was fine 106 00:07:07,520 --> 00:07:12,760 Speaker 1: until the Sun died. Of course, none of these models 107 00:07:12,760 --> 00:07:15,960 Speaker 1: may be accurate at all. First of all, we're still 108 00:07:16,000 --> 00:07:19,720 Speaker 1: discovering new bodies around our Solar System like asteroids, moons, 109 00:07:19,760 --> 00:07:23,840 Speaker 1: and comets all the time, and relatedly, they could make 110 00:07:23,880 --> 00:07:26,800 Speaker 1: more of a difference than the researchers originally accounted for. 111 00:07:27,960 --> 00:07:30,480 Speaker 1: In a follow up study of the same scientists along 112 00:07:30,520 --> 00:07:33,480 Speaker 1: with a larger team, looked at interactions between some of 113 00:07:33,520 --> 00:07:36,120 Speaker 1: the large bodies in the belt between Mars and Jupiter, 114 00:07:36,600 --> 00:07:40,440 Speaker 1: including the dwarf planet Series and major asteroids like Palace 115 00:07:40,640 --> 00:07:45,160 Speaker 1: and Vesta. They then extrapolated out what those interactions would 116 00:07:45,160 --> 00:07:48,960 Speaker 1: mean for the planets. What they concluded was that the 117 00:07:49,080 --> 00:07:53,960 Speaker 1: chaotic interactions between Series and Vesta specifically, should quickly amplify 118 00:07:54,200 --> 00:07:58,120 Speaker 1: even the tiniest of measurement errors, making it impossible to 119 00:07:58,160 --> 00:08:01,120 Speaker 1: predict what planetary orbits should look like based on the 120 00:08:01,160 --> 00:08:05,040 Speaker 1: current information beyond just sixty million years into the future 121 00:08:05,640 --> 00:08:11,520 Speaker 1: or into the past. Basically, all of this means that 122 00:08:11,600 --> 00:08:15,000 Speaker 1: the Solar System is filled with lots of stuff, and 123 00:08:15,320 --> 00:08:18,200 Speaker 1: even though it's pretty spread out, all of these objects 124 00:08:18,280 --> 00:08:22,280 Speaker 1: exert gravitational force on one another, and these forces can 125 00:08:22,360 --> 00:08:26,440 Speaker 1: change planetary orbits a lot, even if we can't measure 126 00:08:26,480 --> 00:08:31,840 Speaker 1: those changes very accurately. In fact, astronomers have evidence of 127 00:08:31,880 --> 00:08:35,760 Speaker 1: other Solar systems self destructing. In two thousand and eight, 128 00:08:35,880 --> 00:08:39,360 Speaker 1: a team from the Harvard Smithsonian Center for Astrophysics spotted 129 00:08:39,400 --> 00:08:42,520 Speaker 1: a Saturn sized planet orbiting a star in the constellation 130 00:08:42,640 --> 00:08:46,000 Speaker 1: Centaurus that was giving off way too much heat for 131 00:08:46,040 --> 00:08:50,040 Speaker 1: its planetary size. The scientists believe that the planet is 132 00:08:50,160 --> 00:08:53,400 Speaker 1: radiating massive amounts of heat because of a collision with 133 00:08:53,440 --> 00:08:59,720 Speaker 1: a Urinous sized Protoplanet in the astronomically recent past, and 134 00:09:00,080 --> 00:09:03,520 Speaker 1: in two thousand and nine, NASA's Spitzer space telescope spotted 135 00:09:03,559 --> 00:09:05,719 Speaker 1: the aftermath of a mash up between an object the 136 00:09:05,800 --> 00:09:08,200 Speaker 1: size of our moon and another the size of mercury, 137 00:09:08,520 --> 00:09:11,440 Speaker 1: about one hundred light years away in the constellation Pavo. 138 00:09:11,840 --> 00:09:16,960 Speaker 1: The peacock instruments on Spitzer detected the teltale signatures of 139 00:09:17,240 --> 00:09:21,479 Speaker 1: amorphous silica, a substance that forms on Earth when meteorites 140 00:09:21,559 --> 00:09:27,440 Speaker 1: slam into the ground. Of course, even if our solar 141 00:09:27,480 --> 00:09:31,120 Speaker 1: system doesn't succumb to orbital chaos and a Billiard like 142 00:09:31,160 --> 00:09:36,160 Speaker 1: crashing of the inner planets, stars don't last forever. In 143 00:09:36,240 --> 00:09:39,720 Speaker 1: about five billion years, when the Sun exhausts fuel supply, 144 00:09:40,240 --> 00:09:42,800 Speaker 1: all of the inner planets will disappear into the belly 145 00:09:42,960 --> 00:09:48,240 Speaker 1: of our rapidly expanding star. Either way, chaos induced collision 146 00:09:48,320 --> 00:09:51,679 Speaker 1: or stellar death, our tiny blue world won't go out 147 00:09:51,720 --> 00:09:59,599 Speaker 1: with a whimper, but with a bang. Today's episode a 148 00:09:59,640 --> 00:10:02,880 Speaker 1: space the article will orbital chaos cause Earth, Venus, and 149 00:10:02,920 --> 00:10:06,200 Speaker 1: Mars to collide On HowStuffWorks dot com written by William Harris. 150 00:10:06,640 --> 00:10:09,560 Speaker 1: Rain Stuff is production of iHeartRadio in partnership with HowStuffWorks 151 00:10:09,559 --> 00:10:12,120 Speaker 1: dot com and it is produced by Tyler Klang. Four 152 00:10:12,200 --> 00:10:16,120 Speaker 1: more podcasts My Heart Radio, visit the iHeartRadio app, Apple Podcasts, 153 00:10:16,320 --> 00:10:18,200 Speaker 1: or wherever you listen to your favorite shows.