Latest / Star Trails: From Backyard Astronomy to Cosmic Wonder / The Silence Between the Stars

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The Silence Between the Stars · Star Trails: From Backyard Astronomy to Cosmic Wonder

• 0:07
  Howdy Star Gazers and welcome to Star Trails.
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  I'm Drew and I'll be your guide to the night
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  sky for the week of October 26 through November
• 0:16
  the 1st. The calendar is turning toward November
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  now and the stars have that unmistakable autumn
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  clarity. The air is a little sharper, the nights
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  come earlier, and the sky feels deeper, like
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  it's holding its breath before winter sets in.
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  Also, Halloween is later this week, and for our
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  final episode of October, we're going to examine
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  another eerie topic. In a universe as vast as
• 0:45
  ours, we ask the question, where is everybody?
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  We're not looking for little green men or flying
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  saucers necessarily, but with all the potential
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  worlds that surround us, why haven't we received
• 0:58
  any indication that someone or something is out
• 1:02
  there? Could it be that we truly are alone? It's
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  called the Fermi paradox and we'll take a detour
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  into that and more in the second half of the
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  show. Before I get into the night sky report
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  for this week, I just have a quick update on
• 1:18
  the show website. If you're a new listener to
• 1:22
  the show, you might be wondering which other
• 1:24
  episodes would be good to go back and listen
• 1:27
  to. So, I've created a section on the website
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  StarTrails .Show with resources for beginning
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  astronomers and new listeners. On the site, you'll
• 1:39
  see a new option in the top menu called Start
• 1:42
  Here. On this page, you'll find a collection
• 1:45
  of my favorite episodes from the more than 80
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  we've published since last year. Some of these
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  are very much aimed at the new astronomer, while
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  others cover topics that might be a bit off the
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  wall but still thought -provoking. I've also
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  compiled a collection of links that new astronomers
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  might find helpful, from some of the stargazing
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  apps I use to websites that are helpful for astronomers
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  at any skill level. And, as always, if you have
• 2:16
  a question or comment about the show, you can
• 2:18
  use the contact form on the site to send me feedback.
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  I really enjoy those listener questions. So with
• 2:26
  that announcement out of the way, let's see what's
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  up in the sky this week. The moon begins as a
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  slender, waxing crescent and grows brighter each
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  night, reaching its first quarter phase on Wednesday.
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  Early in the week, you'll still have dark evening
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  skies, making it a prime time for faint objects
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  and binocular or small -scope observing. By midweek,
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  the moon will shine high at sunset and show off
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  sharp craters and mountain ranges along the terminator,
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  the line between lunar night and day. After that,
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  the moon transitions into a waxing gibbous, staying
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  up later into each night. That brighter moon
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  may wash out faint deep sky targets, but it opens
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  great opportunities for lunar surface photography
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  or simply enjoying the moonlit landscape. Farther
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  out, Saturn is still ruling the evening sky.
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  You'll find it glowing a soft yellow -white in
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  the southeast after sunset. climbing higher through
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  the night. Even a modest telescope will reveal
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  its rings and a few of its moons. Jupiter arises
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  later, around mid -evening, and dominates the
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  eastern sky. If you're up late or awake before
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  dawn, it's one of the showstoppers. Mercury makes
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  a fleeting appearance this week. On the 29th,
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  it will reach its greatest eastern elongation.
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  that's its furthest angular separation from the
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  Sun in the evening sky. Keep a clear view toward
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  the western horizon just after sunset, about
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  30 or so minutes after sundown. If the sky is
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  clear and the horizon is free of trees or buildings,
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  you might spot the elusive twilight planet. Mars
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  is fading low in the west after sunset and chasing
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  into twilight. And Venus is now a morning star
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  rising just before dawn in the east. It's worth
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  a glance if you're an early riser. Our solar
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  system is still hosting two special guests, and
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  if you've been active on any astrophotography
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  forums lately, you've probably seen some beautiful
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  images of at least one of them. Our photogenic
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  visitor is Comet C2025A6 or Comet Lemmon. Discovered
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  earlier this year by the Mount Lemmon Survey,
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  it's on a long -period orbit of roughly 1 ,150
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  years. It's currently brightening and may be
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  visible even with the naked eye under very dark
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  skies, though binoculars will make it much easier
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  to spot. For observers in North America, it's
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  best after sunset in the northwest to west sky.
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  It's low right now, but becoming more accessible.
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  If you have a clear horizon, try locating it
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  with binoculars in the constellation Boötes,
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  a little more than five degrees northeast of
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  Arcturus. And if you can't find it, just keep
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  enjoying those stunning images other astronomers
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  are capturing. It has a well -defined coma and
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  a long tail that looks like it's shimmering in
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  a cosmic breeze. The second visitor that has
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  many people intrigued is interstellar object
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  3I Atlas. This object arrived from outside our
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  solar system and it just cruised past Mars a
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  couple weeks ago. It's classified as an interstellar
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  object because its trajectory is hyperbolic,
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  meaning it's not bound to our Sun. And it's only
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  the third such object like this we've ever recorded.
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  Scientists are studying it carefully, though
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  for backyard observers it's faint and difficult
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  to spot. The buzz about it is largely thanks
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  to its interstellar origins. You may have seen
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  some of the speculation and conspiracies claiming
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  it might be artificial or alien in origin, but
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  mainstream science strongly supports the view
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  that it's a natural body. So while it's a fascinating
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  object to follow, keep your expectations grounded
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  because it's not much to look at, at least right
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  now. Now for the constellations and the quieter
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  stars of fall. We've mentioned them in the past
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  few episodes, but high overhead you'll find the
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  Great Square of Pegasus, that large distinctive
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  square shape marking the winged horse of myth.
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  From its top corner you can trace a line northeast
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  to the Andromeda Galaxy, our galactic neighbor.
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  A pair of binoculars will help you find it. North
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  of that, you'll find Cassiopeia, the queen of
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  the northern sky, hanging high from mid -northern
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  latitudes. Just below Cassiopeia lies one of
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  my favorite binocular targets, the double cluster
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  in Perseus, a pair of star clusters, bright and
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  compact, easily enjoyed even in modest skies.
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  The Milky Way isn't as obvious as it is in summer,
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  but if you're under dark skies early in the week
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  while the moon is still thin, you can trace its
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  faint river starting south and moving through
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  Cygnus, Cassiopeia, and into Perseus before it
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  drifts into the northeast. It's a subtle beauty,
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  less dramatic than the summer belt, but rewarding
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  all the same. Meteor activity from the Orionids
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  is tapering off, but don't rule out a stray meteor
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  before dawn. If you're out late, keep a casual
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  eye toward Orion rising in the east and you may
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  catch a bright one. As always, to truly appreciate
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  the fall sky, take a moment between targets.
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  Let your eyes adapt to darkness for about 10
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  to 15 minutes. With the heat of summer gone,
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  the air is clearer and your view reaches farther.
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  Next up, we'll step into that stillness more
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  deeply, exploring the vast silence between the
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  stars and why, in a universe so old and full
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  of worlds, no one seems to be there to answer
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  us. That's coming up after the break. Stay with
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  us. Welcome back. There's a kind of silence in
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  the cosmos that feels different from any other
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  kind. It isn't peaceful or serene. It's unsettling.
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  It's the silence of absence, the long echo of
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  a question that's never been answered. We call
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  it the Fermi paradox, the contradiction between
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  how likely life seems to be and how alone we
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  appear to be. In 1950, physicist Enrico Fermi
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  was having lunch with colleagues at Los Alamos.
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  The conversation turned to UFO sightings, and
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  Fermi simply asked, where is everybody? It was
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  both a joke and a revelation, because by that
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  time, astronomers already knew the galaxy was
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  ancient, 10 billion years older than the Earth,
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  and vast beyond comprehension. Even if just a
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  tiny fraction of those stars had planets and
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  an even tinier fraction had life, shouldn't we
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  see some sign of it? And keep in mind, at this
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  point in astronomy we hadn't discovered a single
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  exoplanet. That breakthrough was still more than
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  40 years away. A decade after Fermi's question,
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  astronomer Frank Drake tried to make sense of
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  it mathematically. In 1961 he hosted a small
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  meeting at the Green Bank Observatory in West
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  Virginia, the first gathering devoted to the
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  search for extraterrestrial intelligence. He
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  scribbled a simple formula on a blackboard to
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  structure their discussion, never imagining it
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  would become iconic. That formula became the
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  Drake Equation. It looks intimidating at a first
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  glance, full of variables and symbols, but the
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  idea is straightforward, and it's solvable using
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  basic algebra, provided you can fill in the variables.
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  Drake broke the problem into seven factors. How
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  many stars form each year? What fraction of those
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  have planets? How many of those worlds could
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  support life? How many of those worlds indeed
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  produce life? How often life develops intelligence?
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  How often intelligent life develops technology?
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  And finally, how long such civilizations can
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  send detectable signals into space? Simply multiply
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  those together and you get an estimate of how
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  many civilizations might be communicating right
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  now in the Milky Way. But the genius of the equation
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  wasn't its precision, it was its humility. It
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  showed us exactly where our ignorance lay. Every
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  variable is a mystery to be solved and each new
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  discovery exoplanets, biosignatures, radio surveys,
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  tightened the numbers a little more. Right now,
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  if you plug some hopeful numbers into the equation,
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  you might get a few dozen civilizations in our
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  galaxy right now. If you use more careful or
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  skeptical numbers, you might end up with a number
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  less than one, meaning we could be the only ones
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  here at this moment. The problem is, most of
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  the numbers in the equation are giant question
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  marks. We don't know how often life begins, how
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  often it becomes intelligent, or how long a civilization
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  like ours stays detectable before it disappears.
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  The math is strangely easy. It's the facts we
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  don't have. Drake didn't stop there. He also
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  co -founded Project Osma. the first modern SETI
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  experiment using the Green Bank Telescope to
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  listen for radio signals from two nearby stars.
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  The effort was modest, just a few months of listening,
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  but it sparked something profound. Soon after
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  came the idea that we shouldn't just listen,
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  but speak. In 1974, the Arecibo message was transmitted
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  toward the globular cluster M13. a tightly packed
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  group of stars 25 ,000 light years away. The
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  signal, composed entirely of binary digits, encoded
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  the numbers 1 through 10, the elements essential
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  to life, DNA's double helix, a stick figure representing
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  a human, the solar system, and the Arecibo telescope
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  itself. It was symbolic more than practical.
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  By the time the signal arrives, M13 will have
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  drifted away. But it was a statement. We are
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  here. A few years before Arecibo, in 1972 and
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  73, NASA's Pioneer 10 and 11 spacecraft became
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  the first human -made objects to leave the solar
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  system. Each carried a small aluminum plaque
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  etched with a map of our location in the galaxy
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  and the image of a man and woman greeting whoever
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  might find it. The Voyager 1 and 2 spacecraft
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  went further. Each carried a gold -plated record
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  sealed against time containing music from Bach
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  to Chuck Berry, greetings in dozens of languages
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  and sounds of our planet such as wind, rain,
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  laughter. thunder, bird song, and even the heartbeat
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  of a mother and child. Together, these were our
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  cosmic time capsules, drifting ever outward at
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  17 kilometers per second, bearing a message for
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  listeners we may never meet. We covered the Golden
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  Record in episode 52 and included many sounds
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  from it in the episode, so go back and check
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  it out if you missed it. By the 1990s, the search
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  took a new form. digital crowdsourcing. The SETI
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  at Home project turned ordinary computers into
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  a distributed radio telescope. Millions of volunteers,
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  and I was one of them and maybe you were too,
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  downloaded screensavers that processed chunks
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  of data collected by the Arecibo Observatory,
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  searching for narrow -band signals that might
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  indicate alien transmissions. For two decades
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  it quietly scanned billions of frequencies running
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  in the background on computers around the world.
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  Humans, united by curiosity, gave their idle
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  CPU cycles to the search for cosmic company.
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  It was science as global collaboration and the
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  largest volunteer computing project in history.
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  Sadly, SETI at home never discovered any alien
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  signals. The program went into hibernation in
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  2020, but its legacy continues in new AI -driven
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  searches like Breakthrough Listen, which now
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  monitors billions of stars with unprecedented
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  sensitivity. And yet the silence persists. Which
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  brings us back to Fermi's haunting question.
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  Some have speculated a great filter, a stage
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  in evolution so perilous that few make it past.
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  Perhaps intelligence carries the seeds of its
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  own destruction. Ecological collapse, nuclear
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  war, or even artificial intelligence run amok.
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  If the filter lies behind us, we're lucky. If
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  it lies ahead, the silence may be a warning.
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  Others suggest more poetic explanations. Maybe
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  civilizations retreat inward, turning to virtual
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  worlds richer than reality itself. Maybe they
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  transcend physical space altogether, existing
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  as patterns of energy or information. Or maybe
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  the galaxy is a dark forest where every civilization
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  hides in terror, knowing that to announce their
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  presence might invite annihilation. In that sense,
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  silence isn't failure, it's a strategy. And then
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  there's the humbling possibility that we simply
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  don't know how to listen. Alien intelligence
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  might communicate in ways beyond our comprehension,
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  through neutrinos or gravitational waves or quantum
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  entanglement. Their language could be encoded
• 18:24
  in magnetic fields or stellar oscillations. To
• 18:28
  them, our radio beacons might be as primitive
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  as cave paintings. Personally, I believe in the
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  simplest explanation. Space is unimaginably vast.
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  The nearest star, Proxima Centauri, is more than
• 18:48
  four light years away. That's about 25 trillion
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  miles. Even if we sent a message traveling at
• 18:55
  light speed, it would take more than eight years
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  for a round -trip conversation. And that's our
• 19:01
  closest neighbor. The rest of the galaxy stretches
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  across a hundred thousand light years. Also,
• 19:09
  radio waves, like light, weaken as they travel.
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  What begins as a clear signal near its source
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  dissolves into noise over cosmic distances. If
• 19:19
  you're involved in ham radio, you've likely seen
• 19:22
  signals fade dramatically over just hundreds
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  of miles. The signals that escape Earth fade
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  into the background hum of the universe long
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  before they reach most of the stars we dream
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  about. It's not like the beginning of the movie
• 19:37
  Contact, where we zoom into the solar system
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  from light years away, hearing our earliest broadcasts
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  echo through the void as clear as they were the
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  day they were made. It's entirely possible that
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  the cosmos is teeming with voices each calling
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  out into the dark But none strong enough to bridge
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  the gulf between them a million lonely transmitters
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  all speaking all unheard Maybe the idea of that
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  loneliness creates a feeling of existential dread
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  and here's another eerie Halloween thought When
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  you look up, much of the starlight falling on
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  your eyes began its journey long before humans
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  even existed. It crossed unimaginable distances,
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  unbothered by our loneliness, carrying no reply,
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  just photons from ancient suns. And the silence
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  isn't nothing. The quiet between the stars may
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  be the most profound message of all. A reminder
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  that the universe is vast enough to contain both
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  our fears and our hopes, our solitude and our
• 20:50
  longing. If the stars spoke to you this week
• 20:57
  or if a question's been on your mind, I'd love
• 20:59
  to hear it. Visit StarTrails .Show where you
• 21:03
  can contact me and explore past episodes. Be
• 21:06
  sure to follow Star Trails on Blue Sky and YouTube.
• 21:10
  Links are in the show notes. Until we meet again
• 21:13
  beneath the stars, clear skies everyone.