Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey, brain Stuff,
Speaker 1: Laurin Vogelbaum. Here, we all know that the planets of
Speaker 1: the Solar System revolve around the Sun in a calm
Speaker 1: and orderly fashion. In fact, the planets move with such
Speaker 1: clockwork precision that astronomers can calculate orbital characteristics like eclipses
Speaker 1: and planetary alignments with certainty. Want a list of solar
Speaker 1: eclipses for the next ten thousand years, No problem. And
Speaker 1: now let's say you want to look further into the future,
Speaker 1: not thousands of years, but billions. How will those dusty
Speaker 1: astronomical tables hold up? Then? Not so well if you
Speaker 1: take into account the principles of chaos theory. A chaos
Speaker 1: theory says that small inputs in an enormously complex system
Speaker 1: can produce large scale outputs. This is what's sometimes called
Speaker 1: the butterfly effect. The idea is that when a butterfly
Speaker 1: flaps its wings in say Brazil, it could lead to
Speaker 1: a chain reaction that causes a thunderstorm to develop over Australia.
Speaker 1: Some scientists now propose that the evolution of the Solar
Speaker 1: system may adhere to chaos theory, and that way way
Speaker 1: way into the future. This could cause Earth to collide
Speaker 1: with either Venus or Mars. A pair of scientists from
Speaker 1: the Paris Observatory published a letter with this determination in
Speaker 1: an issue of the journal Nature back in two thousand
Speaker 1: and nine. For their research, they tapped into the power
Speaker 1: of the Jade supercomputer, located at France's National Computing Center
Speaker 1: for Higher Education and Research, which at the time was
Speaker 1: around the twentieth most powerful computer in the world. So
Speaker 1: what were they trying to calculate with that veritable muscle
Speaker 1: car of computational capacity. It has to do with Isaac
Speaker 1: Newton's universal law of gravitation, which states that gravity exists
Speaker 1: between any to given objects. This gravitational force is directly
Speaker 1: proportional to the object's masses and inversely proportional to the
Speaker 1: square of the distance separating them, meaning that the more
Speaker 1: massive an object is, the more gravity it will exert
Speaker 1: on another object, but the further away an object is,
Speaker 1: the less gravity it will exert on another object. A
Speaker 1: Newton then proposed that the Sun's gravity is what holds
Speaker 1: the planets in their orbits. But it's not that simple.
Speaker 1: According to his own law, the planets and all of
Speaker 1: the other objects in the Solar System, including moons and asteroids,
Speaker 1: also exert at least a little gravity on each other.
Speaker 1: So could the complex interplay of those forces cause the
Speaker 1: stability of the Solar System to degrade over time in
Speaker 1: the short term Nope. Even over longer periods, astronomers have
Speaker 1: generally supported the idea that the Solar System would remain stable.
Speaker 1: It just sort of makes sense. After all, the Sun
Speaker 1: is overwhelmingly more massive than anything else in the Solar System.
Speaker 1: Out of the Solar System's total mass, the Sun accounts
Speaker 1: for ninety nine point eight percent of it. But a
Speaker 1: few cosmologists began to wonder if chaos theory might apply
Speaker 1: to planetary orbits. If so, small changes in planetary movements
Speaker 1: could get magnified over time into something substantial. But how
Speaker 1: long would it take? Thousands of years, millions billions? To
Speaker 1: answer that question, you'd have to build a sort of
Speaker 1: model to account for the movements of all of the planets,
Speaker 1: as well as all of the forces being exerted as
Speaker 1: that movement occurs. Then you'd need to let your Solar
Speaker 1: system model run like a clock. So the planets cycled
Speaker 1: through hundreds of thousands of orbits. As this occurred, you'd
Speaker 1: need to track key data about each planet. One of
Speaker 1: the most important pieces of data to collect would be
Speaker 1: orbital eccentricity, which is a measure of how far a
Speaker 1: planet deviates from a perfectly circular shape as it moves
Speaker 1: around the Sun. Orbital eccentricity determines whether two planets might
Speaker 1: come closer to having a close encounter. This is not
Speaker 1: the kind of simulation you could run in your head
Speaker 1: or with whatever fancy device you have at home, which
Speaker 1: is why the researchers selected the Jade's supercomputer to do
Speaker 1: their heavy lifting. Their inputs consisted of two five hundred
Speaker 1: and one orbital scenarios, where each one altered Mercury's orbit
Speaker 1: by just a few millimeters. They chose Mercury because, as
Speaker 1: the runt of the Solar System, it's the biggest pushover,
Speaker 1: and because its orbit synchronizes with jupiters to create changes
Speaker 1: that ripple across the entire Solar System. For each hypothetical scenario,
Speaker 1: they tracked the motion of all planets for more than
Speaker 1: five billion years, which is the estimated life span of
Speaker 1: the Sun. Even with the high powered CPU in the
Speaker 1: Jade unit, each solution required four months of computing to
Speaker 1: generate results. Luckily, for any future life on Earth, the
Speaker 1: Solar System remained stable in ninety nine percent of the
Speaker 1: researcher's scenarios. That is, no planets got set on collision
Speaker 1: courses or ejected from their orbits. But in one percent
Speaker 1: of their models, the ones in which the orbital chaos
Speaker 1: had the greatest cumulative effect, Mercury's orbit became eccentric enough
Speaker 1: to cause catastrophic changes in the Solar System. Some of
Speaker 1: those catastrophes only involved Mercury, which could either crash into
Speaker 1: the Sun or get dislodged from its orbit and flung
Speaker 1: out into space, but other scenarios played out with Earth
Speaker 1: colliding into either Mars or Venus. According to their models,
Speaker 1: collision with Venus would occur through five steps, all of
Speaker 1: which illustrate the cumulative effects orbital chaos. First, interaction between
Speaker 1: Jupiter and Mercury about three point one three seven billion
Speaker 1: years in the future, could cause the orbital eccentricity of
Speaker 1: Mercury to increase. This would transfer some angular momentum from
Speaker 1: the outer planets to the inner planets. This transfer would
Speaker 1: destabilize the rest of the inner planets, so the orbital
Speaker 1: eccentricities of Venus, Earth, and Mars would increase. This would
Speaker 1: cause Earth to have a near miss with Mars, which
Speaker 1: would disturb the eccentricity of Mars even more. This would
Speaker 1: cause some weird reinforcing interactions among the inner planets to
Speaker 1: decrease the eccentricity of Mercury but further increase the eccentricities
Speaker 1: of Venus and Earth. Venus and Earth would have several
Speaker 1: near misses until at three point three five two eight
Speaker 1: nine one billion years in the future, the two planets
Speaker 1: collided in an epic explosion that would destroy both worlds. Again.
Speaker 1: In ninety nine percent of their simulations, everything was fine
Speaker 1: until the Sun died. Of course, none of these models
Speaker 1: may be accurate at all. First of all, we're still
Speaker 1: discovering new bodies around our Solar System like asteroids, moons,
Speaker 1: and comets all the time, and relatedly, they could make
Speaker 1: more of a difference than the researchers originally accounted for.
Speaker 1: In a follow up study of the same scientists along
Speaker 1: with a larger team, looked at interactions between some of
Speaker 1: the large bodies in the belt between Mars and Jupiter,
Speaker 1: including the dwarf planet Series and major asteroids like Palace
Speaker 1: and Vesta. They then extrapolated out what those interactions would
Speaker 1: mean for the planets. What they concluded was that the
Speaker 1: chaotic interactions between Series and Vesta specifically, should quickly amplify
Speaker 1: even the tiniest of measurement errors, making it impossible to
Speaker 1: predict what planetary orbits should look like based on the
Speaker 1: current information beyond just sixty million years into the future
Speaker 1: or into the past. Basically, all of this means that
Speaker 1: the Solar System is filled with lots of stuff, and
Speaker 1: even though it's pretty spread out, all of these objects
Speaker 1: exert gravitational force on one another, and these forces can
Speaker 1: change planetary orbits a lot, even if we can't measure
Speaker 1: those changes very accurately. In fact, astronomers have evidence of
Speaker 1: other Solar systems self destructing. In two thousand and eight,
Speaker 1: a team from the Harvard Smithsonian Center for Astrophysics spotted
Speaker 1: a Saturn sized planet orbiting a star in the constellation
Speaker 1: Centaurus that was giving off way too much heat for
Speaker 1: its planetary size. The scientists believe that the planet is
Speaker 1: radiating massive amounts of heat because of a collision with
Speaker 1: a Urinous sized Protoplanet in the astronomically recent past, and
Speaker 1: in two thousand and nine, NASA's Spitzer space telescope spotted
Speaker 1: the aftermath of a mash up between an object the
Speaker 1: size of our moon and another the size of mercury,
Speaker 1: about one hundred light years away in the constellation Pavo.
Speaker 1: The peacock instruments on Spitzer detected the teltale signatures of
Speaker 1: amorphous silica, a substance that forms on Earth when meteorites
Speaker 1: slam into the ground. Of course, even if our solar
Speaker 1: system doesn't succumb to orbital chaos and a Billiard like
Speaker 1: crashing of the inner planets, stars don't last forever. In
Speaker 1: about five billion years, when the Sun exhausts fuel supply,
Speaker 1: all of the inner planets will disappear into the belly
Speaker 1: of our rapidly expanding star. Either way, chaos induced collision
Speaker 1: or stellar death, our tiny blue world won't go out
Speaker 1: with a whimper, but with a bang. Today's episode a
Speaker 1: space the article will orbital chaos cause Earth, Venus, and
Speaker 1: Mars to collide On HowStuffWorks dot com written by William Harris.
Speaker 1: Rain Stuff is production of iHeartRadio in partnership with HowStuffWorks
Speaker 1: dot com and it is produced by Tyler Klang. Four
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