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Urban Alignments and Cosmic Parking Spots · Star Trails: From Backyard Astronomy to Cosmic Wonder

• 0:07
  Howdy stargazers, and welcome to this episode
• 0:10
  of Star Trails. Drew here, and I'll be your guide
• 0:14
  to the night sky for the week starting June 1st
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  through the 7th. This week, the rising summer
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  triangle lets us know that warmer nights are
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  ahead. We take a moment to explore a peculiar
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  solar alignment in New York City known as Manhattan
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  Hinge, and later we explore the parking lots
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  of space known as the Lagrange Points. Whether
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  you're tuning in from the backyard, the balcony,
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  or just your imagination, I'm glad you're here.
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  So find a cozy spot, let your eyes adjust, and
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  let's see what the sky holds for us this week.
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  The moon is currently waxing. Tonight it's in
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  a crescent phase with about 6 % illumination.
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  It will reach first quarter on June 3rd with
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  the full moon arriving around the middle of next
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  week. Venus is shining brilliantly at magnitude
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  negative 4 and it's just reached its greatest
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  western elongation, making it a prominent morning
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  star in the eastern sky before sunrise. Saturn
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  is still visible in the early morning sky, rising
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  in the east during the predawn hours. While not
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  as bright as Venus, it's distinguishable by its
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  steady yellowish glow. Look westward after sunset
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  tonight to spot a conjunction of the moon and
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  Mars. The waxing crescent moon will appear close
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  to Mars, offering a picturesque pairing for evening
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  observers. Mercury is currently too close to
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  the Sun to be easily observed, but it will become
• 1:53
  more visible in the evening sky later this month.
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  As summer creeps closer, the night sky starts
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  to show off its southern stars, and this week
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  you'll have some real stunners to track down.
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  Low in the southeast after dark, you'll spot
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  the curve of Scorpius, one of the few constellations
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  that actually looks like what it's named after.
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  Its brightest star, Antares, whose name actually
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  means rival of Mars, is a massive red supergiant
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  nearing the end of its life, and like Mars, it
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  glows with a deep, rusty hue. Just to the west
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  of Antares is M4, a dense globular cluster that
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  looks like a fuzzy star in binoculars. Right
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  next door to Scorpius is Sagittarius, home to
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  the famous teapot asterism. If you can trace
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  the teapot shape, imagine steam rising from its
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  spout. That glowing steam is actually the densest
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  part of the Milky Way, and it's pointing straight
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  toward the galactic core. Now, you can't see
• 3:02
  the center of the galaxy directly. It's hidden
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  behind gas and dust. But you can look in the
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  exact direction of it, which is kind of amazing.
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  And right there, about 26 ,000 light years away,
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  lies Sagittarius A, a supermassive black hole
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  anchoring the Milky Way's spiral arms. The area
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  around it is absolutely loaded with deep sky
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  gems. There's M8, the Lagoon Nebula, a bright
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  stellar nursery. M20, the Trifid Nebula, is a
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  beautiful mix of newly born stars and dark dust.
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  Also check out M22, one of the best globular
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  clusters in the sky, and also easy to spot with
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  binoculars. Even to the naked eye under dark
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  skies, this part of the Milky Way looks puffier,
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  brighter, and deeper. It's like the galaxy is
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  exhaling. And of course, the summer triangle
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  is rising. High in the east, later in the evening,
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  you'll see three bright stars forming a giant
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  triangle. Vega, Altair, and Deneb. The Triangle
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  is up for most of the night and offers a gateway
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  to other fun targets like the Ring Nebula M57
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  in Lyra and the North America Nebula near Deneb.
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  Have you ever seen the sun set perfectly between
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  city buildings like it was aiming right down
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  the street? If you were in New York City last
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  week, you might have caught Manhattan Hinge.
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  That's when the sun lines up just right with
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  Manhattan's grid, beaming down the east -west
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  streets like a spotlight. But if you missed it,
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  and if you happen to be in New York City in a
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  few weeks, you'll get another shot to see it.
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  The next Manhattan Hinge is happening around
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  July the 12th and 13th. And if you're nowhere
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  near Manhattan, stick around because your city
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  might have its own version of this urban sky
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  alignment. So what exactly is Manhattan Hinge?
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  It's a twice -a -year event when the setting
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  sun aligns with Manhattan's slightly tilted street
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  grid. The result is, for a few minutes, the sun
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  drops directly between the buildings, lighting
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  up the avenues in a perfect glowing frame. New
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  York's street grid is rotated about 29 degrees
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  off True East and West, so this solar alignment
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  happens only when the Sun's path intersects that
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  angle, once in late May and again in mid -July.
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  Some top spots to view it include 42nd Street,
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  34th Street, and 14th Street. The phenomenon
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  was dubbed Manhattan Hinge by science educator
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  Neil deGrasse Tyson, and that of course is a
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  reference to Stonehenge, the prehistoric stone
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  circle in England that forms a cosmic calendar,
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  and it aligns with the summer solstice sunrise
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  and winter solstice sunset. Stonehenge has modern
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  pagans who gather to experience the solar phenomenon,
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  while New York City has, well, taxis. New York
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  isn't the only place that gets this light show.
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  Cities like Chicago, Toronto, Montreal, Philadelphia,
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  and Salt Lake City all experience similar events,
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  sometimes at sunset, sometimes at sunrise, depending
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  on their grid orientation. For example, Chicago
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  has Chicago Hinge near the spring and fall equinoxes
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  because its street grid runs true east to west.
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  So, how can you tell if your city has a hinge
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  of its own? This is where a little digital astronomy
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  comes in handy. There's a great tool called the
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  photographer's ephemeris, and it lets you map
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  the sun's path for any date and place on Earth.
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  You can overlay that info onto your city's street
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  grid and figure out when the sun will align with
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  your favorite thoroughfare. It's super useful
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  if you're chasing that perfect golden hour photo
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  or just want to know when your city might surprise
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  you with a solar corridor. So maybe there's a
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  hinge waiting just a few blocks from you. Let's
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  shift gears a little from stargazing with your
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  eyes to something that's mostly invisible but
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  still incredibly important. Tonight, I want to
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  take you behind the scenes of the solar system
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  into the hidden architecture that holds things
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  steady in space. We're talking about the Lagrange
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  points, those weird gravitational sweet spots
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  that make spaceflight smarter, smoother, and
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  in some cases, just a little bit spooky. If you've
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  never heard of them before, Lagrange points,
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  sometimes just called L points, are specific
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  spots in space where the gravity of two large
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  objects, like the Earth and the Sun, balances
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  out just right. So right, in fact, that a third,
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  much smaller object, like a satellite, can just
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  sort of hang out there, using no thrusters or
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  any fuel. It just drifts along in harmony with
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  the big cosmic players. So picture this, you've
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  got the Earth orbiting the Sun, and both of them
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  are tugging on a satellite with their combined
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  gravity. Normally, that would yank the satellite
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  around unpredictably, but at a Lagrange point,
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  the gravitational pulls and the orbital motion
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  all sync up perfectly, like a cosmic dance step
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  where the satellite always lands right on the
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  beat. There are five of these Lagrange points
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  in any two -body system. Let's stick with the
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  big show for now, the Earth -Sun system. L1 is
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  for sun watchers. The first Lagrange point, L1,
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  sits directly between Earth and the Sun. It's
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  about a million miles from Earth, closer to the
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  Sun than we are, but locked in Earth's orbital
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  path. This is where we park solar observatories
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  like SOHO and the Discover spacecraft because
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  L1 gives them an uninterrupted view of the Sun,
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  which is perfect for studying solar flares, sunspots,
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  and space weather that can affect satellites
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  and even power grids down here on Earth. It's
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  the front row seat for solar drama, and it's
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  always in the light. Now L2 is a nice place for
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  deep space stargazers. L2 is located about a
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  million miles away from Earth, but on the far
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  side away from the Sun. This spot is special
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  because it allows telescopes to stay in Earth's
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  shadow, with the Sun, Earth, and Moon all behind
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  them. That makes it incredibly cold and dark,
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  just what you want for observing faint galaxies
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  and distant stars. This is where the James Webb
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  Space Telescope lives. Its mirrors and instruments
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  are designed to pick up the faintest heat signatures
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  in the universe, so it needs that cold, quiet
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  neighborhood. Think of L2 as the astronomer's
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  porch, but with the light turned off. L3 is sometimes
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  called the phantom point. L3 sits on the far
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  side of the Sun, directly opposite Earth. It's
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  always hidden from our view. You can't see it
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  from here, and that's what's given rise to all
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  kinds of fun science fiction ideas like secret
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  planets, alien outposts, or even doppelganger
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  Earths hiding in the blind spot. But in real
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  life, L3 isn't all that stable. If you tried
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  to park a satellite there, it would eventually
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  drift away. Think of L4 and L5 as the cosmic
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  rest stops. These points form the tips of an
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  equilateral triangle with the Earth and the Sun.
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  That means they lead and trail Earth in its orbit
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  about 60 degrees ahead of and behind. L4 and
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  L5 are really stable. Objects placed there tend
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  to stay put even if they get nudged a little.
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  They often collect space debris, dust clouds,
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  and even asteroids. Jupiter, for example, has
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  thousands of asteroids camped out at its L4 and
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  L5 points. Earth has a few too, though they're
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  much smaller and harder to spot. Some scientists
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  even speculate that alien probes, if they existed,
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  would choose L4 or L5 as a parking spot. They're
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  hidden, stable, and offer a great long -term
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  view of Earth. So what makes these places so
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  valuable? For one, they reduce the energy needed
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  to keep spacecraft in a fixed position. That
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  means less fuel, longer missions, and more stable
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  instruments. And for future space infrastructure,
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  things like observatories, solar power stations,
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  or even planetary defense systems, Lagrange points
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  offer premium real estate. They also give us
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  strategic vantage points, whether we're monitoring
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  solar storms, peering into deep space, or preparing
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  for interplanetary travel. These points let us
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  place our tools exactly where they'll be most
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  effective. So the next time you hear about a
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  new space telescope or satellite mission, listen
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  closely and there's a good chance it's heading
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  for one of these gravitational sweet spots. For
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  the math of motion and the poetry of space come
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  together just right. If the stars spoke to you
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  this week or if a question's been on your mind,
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  I'd love to hear it. Visit our website, StarTrails
• 13:34
  .Show, where you can contact me and explore past
• 13:38
  episodes. Be sure to follow us on Mastodon, Blue
• 13:42
  Sky, and YouTube. Links are in the show notes.
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  Until we meet again beneath the stars, clear
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  skies everyone.