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Perseids, Planets, and the Smell of Space · Star Trails: From Backyard Astronomy to Cosmic Wonder

• 0:07
  Howdy Star Gazers and welcome to this episode
• 0:10
  of Star Trails. Drew here, and I'll be your guide
• 0:13
  to the night sky for the week starting August
• 0:16
  the 10th to the 16th. This week the Perseids
• 0:20
  peak Mercury returns Jupiter and Venus cozy up
• 0:24
  and in the second half of our show We turn our
• 0:28
  noses to the sky and learn what space smells
• 0:32
  like Whether you're tuning in from the backyard
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  the balcony or just your imagination. I'm glad
• 0:38
  you're here So find a cozy spot. Let your eyes
• 0:41
  adjust and let's see what the sky holds for us
• 0:44
  this week We're coming off the bright and bold
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  sturgeon moon, which peaked just before this
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  week began. That means we start with a waning
• 0:54
  gibbous, and as each night passes, the moon shrinks
• 0:58
  and rises later, giving us a little more breathing
• 1:01
  room for darker skies. By week's end, we'll reach
• 1:05
  last quarter. This half -moon phase rises around
• 1:09
  midnight and lingers through the early morning.
• 1:11
  So while the moon's brightness will wash out
• 1:14
  the fainter stars and objects for a few nights,
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  conditions improve dramatically midweek for stargazing
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  and meteor hunting. Speaking of meteor showers,
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  this is the one. The Perseids are peaking this
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  week, officially on August 12th and 13th. Normally,
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  this would be a real showstopper with upwards
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  of 100 meteors per hour under ideal conditions.
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  But we've got a problem. The bright waning gibbous
• 1:43
  moon is going to be hanging out near the radiant
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  point, Perseus, and flooding the sky with light.
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  That doesn't mean you won't see anything, but
• 1:53
  it will cut the number of visible meteors way
• 1:56
  down. Expect perhaps a dozen or so per hour,
• 2:00
  and mostly the brightest ones. Your best bet?
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  Get out during the predawn hours of the 13th,
• 2:07
  find a spot with a clear view of the sky, and
• 2:10
  try to block the moon with a building or a tree.
• 2:13
  And here's a wild card, the Kappa signids. They're
• 2:17
  a minor shower that also peaks around August
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  the 16th, and while they only deliver a few meteors
• 2:23
  per hour, they're known for occasional fireballs.
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  If you're out late anyway, it's worth keeping
• 2:29
  an eye out. Their origins are still a bit mysterious,
• 2:33
  just the way we like it. Now, let's talk planets,
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  because this week brings one of the prettiest
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  planetary pairings of the year. In the pre -dawn
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  eastern sky, look low near the horizon around
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  August 11th and 12th, and you'll spot Venus and
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  Jupiter just a single degree apart. That's close
• 2:54
  enough to cover with your fingertip at arm's
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  length. Venus is the brighter of the two, but
• 3:00
  both will be striking, especially if you're up
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  early. And there's more. Mercury ends its retrograde
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  on August the 11th, and while it's still tricky
• 3:11
  to see, it's starting to climb back into the
• 3:14
  dawn. Meanwhile, Saturn rises in the southeast
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  just after midnight and is beautifully placed
• 3:20
  for telescope viewing by the wee hours. Neptune
• 3:24
  is hanging around nearby too, but at magnitude
• 3:27
  7 .8, you'll need binoculars or a scope. Still,
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  it's fun to know you're staring at a planet nearly
• 3:34
  3 billion miles away. It's August, so you'll
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  still see the summer triangle this week. Vega,
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  Deneb, and Altair holding court high overhead.
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  But let's talk about some underdogs. First up,
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  Sagitta, the arrow. This one's tiny, just four
• 3:54
  stars forming a narrow spear below Volpecula,
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  but it punches above its weight in charm. Its
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  brightest star, Gamma Sagittae, is an orange
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  giant that's quietly burning out in the background
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  of the Milky Way. Another one worth your time
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  is Draco, the dragon. It winds its way around
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  the Little Dipper and never really sets for those
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  of us in the Northern Hemisphere. Hidden within
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  its coils is the Cat's Eye Nebula, one of the
• 4:23
  most complex planetary nebula we know of. If
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  you've got a scope and good skies, go check it
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  out. We've talked about the Ring Nebula before,
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  but what about its louder cousin? Check out the
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  Dumbbell Nebula, also known as Messier 27, hanging
• 4:41
  out in Volpecula. It's a planetary nebula about
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  1200 light years away. formed when a dying star
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  blew off its outer layers. You'll find it nestled
• 4:52
  within the summer triangle, and it's bright enough
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  to spot with binoculars under dark skies. If
• 4:58
  you want a challenge, go after the cocoon nebula
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  in Cygnus. It's a beautiful combination of reflection
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  and emission nebula with a dark tail of dust
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  called Bernard 168. That makes it look like a
• 5:13
  tiny comet with its hair on fire. And, if you
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  have a telescope and a dark, southern horizon,
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  you might just catch a glimpse of the Helix Nebula
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  in Aquarius, sometimes called the Eye of God.
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  It's one of the closest planetary nebula to Earth,
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  and also one of the most haunting. For an added
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  challenge, try finding V Sagittae, a star in
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  the Sagittae constellation I mentioned earlier.
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  It's a binary system destined to merge and explode
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  in a nova sometime around 2083. When it does,
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  it'll briefly rival Sirius in brightness. For
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  now, it's just another humble spec, but you'll
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  be able to say, I saw it before it blew. While
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  you're out watching the Perseids this week, consider
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  this. Back on August 10th, 1972, something extraordinary
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  happened. In broad daylight, a massive fireball
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  streaked across the skies of the western United
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  States and Canada. Not at night, in daylight.
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  It was so bright, it cast shadows. It triggered
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  sonic booms, and it scared the hell out of anyone
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  who happened to be looking up. Known as the Great
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  Daylight Fireball, it entered Earth's atmosphere
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  at a shallow angle, about 35 miles above Utah,
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  and traveled northward at hypersonic speed, eventually
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  exiting back into space somewhere over Alberta.
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  That's right, it didn't burn up, it bounced off
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  our atmosphere like a cosmic skipping stone.
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  Scientists called it an earth -grazing fireball,
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  and this one was big, estimated to be the size
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  of a small car, and moving at nearly 9 miles
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  per second. Had it entered at a steeper angle,
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  it could have struck with the force of a small
• 7:12
  nuclear device. Instead, it just gave us a show
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  and left behind an eerie contrail that lingered
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  in the sky. The entire event was photographed,
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  filmed, and even tracked by US military satellites.
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  In a time before smartphones, it still managed
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  to go viral, at least by 1972 standards. Before
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  we head on, I want to pause for a moment to remember
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  Commander Jim Lovell, who passed away last week
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  at the age of 97. Lovell flew on Gemini 7, Gemini
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  12, Apollo 8, and of course, Apollo 13. These
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  were missions that carried humanity to new heights
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  and, in one case, brought a crew safely home
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  against staggering odds. He was there for Earth's
• 8:01
  first journey around the moon, and he was the
• 8:05
  calm center during Apollo 13's long, dangerous
• 8:08
  return. His legacy isn't just written in mission
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  logs, it's in the way he showed us that even
• 8:14
  when things go wrong, ingenuity and teamwork
• 8:17
  can carry us through. Coming up, astronauts can't
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  take their helmets off to catch a whiff of outer
• 8:25
  space, but we do know what it smells like. That's
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  after the break. Stay with us. Today I want to
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  talk about something that's just a little out
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  of left field or out of the airlock really Something
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  that you've probably never associated with astronomy.
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  Let's talk about the smell of space and Now I
• 8:58
  know you're thinking space doesn't have an atmosphere.
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  So how can it have a smell and that is true?
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  Space is a vacuum and a vacuum doesn't carry
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  scent the way air does But if you talk to astronauts,
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  especially those who've done spacewalks outside
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  the International Space Station, they'll tell
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  you otherwise. In fact, some have remarked that
• 9:21
  when they come back in from the void, their suits,
• 9:24
  even the airlock, carry a distinct smell. One
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  they often describe as metallic, burnt, like
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  welding fumes, or seared steak, or ozone after
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  a lightning storm. So basically, space stinks.
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  Well, maybe that's a little harsh, but there's
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  definitely a smell. NASA astronauts like Peggy
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  Whitson, Thomas Jones, and Chris Hadfield have
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  all reported it. When the cabin repressurizes
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  and they crack open the hatch, they say there's
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  a unique lingering odor that clings to their
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  suits. Hadfield described it as a rather pleasant
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  metallic sensation. like sweet -smelling welding
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  fumes. Others have likened it to the smell of
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  gunpowder, burnt metal, or a hot engine. One
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  astronaut even said it reminded him of the air
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  after a fireworks display. So what causes it?
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  Although space doesn't have an atmosphere like
• 10:23
  Earth, it does contain trace elements, free -floating
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  atoms, ions, solar particles, and cosmic dust.
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  Most of the time, they're too sparse to notice,
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  but in certain conditions, especially outside
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  a space station where machinery is exposed to
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  a vacuum, UV radiation, and the solar wind, interesting
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  things happen. One of the main suspects behind
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  the so -called space smell is a group of molecules
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  known as polycyclic aromatic hydrocarbons. These
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  are complex carbon -based molecules formed when
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  carbon atoms bond together in ring shapes. You'll
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  find them here on Earth in things like grilled
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  meat, car exhaust, forest fires, and industrial
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  fumes. Basically, anything that's been burned
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  or scorched probably released these hydrocarbons.
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  And, as it turns out, they're pretty common in
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  space too, especially in places where stars are
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  forming or dying. So when an astronaut goes for
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  a spacewalk, their suit gets bombarded by high
• 11:29
  -energy particles. The materials of the suit
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  and the station itself interact with oxygen and
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  ultraviolet radiation, triggering subtle chemical
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  changes. When they return inside, the sudden
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  reintroduction of air allows these altered particles
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  to react, and that's when the smell kicks in.
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  It's not space itself that has a scent. It's
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  what space does to the things we send into it.
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  Now, let's take a deeper look or smell. These
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  aromatic hydrocarbons I mentioned, they are found
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  in vast clouds of gas and dust throughout the
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  galaxy. In fact, when we peer into the nebula
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  with space telescopes like the James Webb or
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  the old Spitzer infrared telescope, we often
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  detect these hydrocarbons by the light they emit.
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  These molecules are ancient. Some scientists
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  believe that they could have played a role in
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  the origin of life on Earth. They're carbon rich,
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  complex, and durable. Three things that life
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  tends to like. So when astronauts say space smells
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  like burnt steak or welding fumes, they're literally
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  catching a whiff of star stuff. Cooked carbon.
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  the chemical echoes of dying stars and expanding
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  galaxies, its cosmic perfume. And speaking of
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  perfume, NASA actually commissioned a chemist
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  and a perfumer named Steve Pearce to recreate
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  the smell of space back in the early 2000s. They
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  wanted to use it in astronaut training simulations,
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  so space rookies wouldn't be surprised when that
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  burnt metal smell hit them post -EVA. Pierce
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  worked with astronaut reports and chemical analysis
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  to design a fragrance that mimicked the effect.
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  He even worked on a scent profile for the moon.
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  It was something like spent gunpowder mixed with
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  dust and dry minerals, as described by Apollo
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  astronauts. Years later, these scents were released
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  commercially in limited fashion under names like
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  Ode to Space and Moon Smell. I'd caution against
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  trying these as date night fragrances unless
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  your date is into planetary science, in which
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  case you've probably hit the jackpot. While we
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  think of the universe as cold, empty, and silent,
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  it's also textured, tangible, and even aromatic.
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  We tend to think of smell as something grounded
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  and earthly, baking bread, fresh rain. hot asphalt,
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  but space has its own language of scent through
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  the chemistry of combustion and radiation and
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  through the invisible fingerprints of molecules
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  drifting across the cosmos. Space may not smell
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  like roses, but it smells like creation. If the
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  stars spoke to you this week or if a question's
• 14:29
  been on your mind, I'd love to hear it. Visit
• 14:32
  our website, StarTrails .Show, where you can
• 14:35
  contact me and explore past episodes. Be sure
• 14:39
  to follow us on Blue Sky and YouTube. Links are
• 14:42
  in the show notes. Until we meet again beneath
• 14:45
  the stars, clear skies, everyone.