00:00:00 --> 00:00:02 Stuart Gary: This is space time series 29, episode
00:00:02 --> 00:00:05 133 full broadcast on the 6th of November
00:00:05 --> 00:00:08 2026. Coming up on Space Time,
00:00:08 --> 00:00:11 mysterious disturbances from Betelgeuse,
00:00:12 --> 00:00:14 solving the mystery of the Orion nebula.
00:00:15 --> 00:00:17 And America's X37B space
00:00:17 --> 00:00:20 shuttle continues its clandestine orbital
00:00:20 --> 00:00:22 mission. All that and more coming up
00:00:22 --> 00:00:24 on Space Time.
00:00:25 --> 00:00:28 Stuart Gary: Welcome to Space Time with Stuart
00:00:28 --> 00:00:28 G.
00:00:44 --> 00:00:47 Stuart Gary: Astronomers have detected strange happenings
00:00:47 --> 00:00:49 on the mysterious companion star that lurks
00:00:49 --> 00:00:52 in the shadows of the red giant Battlegars.
00:00:52 --> 00:00:55 The recently discovered companion star, known
00:00:55 --> 00:00:57 as Shawara, is smaller and far hotter than
00:00:57 --> 00:00:59 its binary partner. Uh. The new study
00:00:59 --> 00:01:02 reported in the Astronomical Journal used a
00:01:02 --> 00:01:04 very large telescope array in New Mexico and
00:01:04 --> 00:01:06 Alma, the Atacama Large Millimetre
00:01:06 --> 00:01:09 Submillimeter Array in Chile, to show that
00:01:09 --> 00:01:11 Betelgeuse's atmosphere is being actively
00:01:11 --> 00:01:13 perturbed by its close interstellar
00:01:13 --> 00:01:16 companion. The study's lead author, Lyn
00:01:16 --> 00:01:18 Matthews from the Haystack Observatory, says
00:01:18 --> 00:01:20 because radio waves of different frequencies
00:01:20 --> 00:01:22 probe different depths within a star's
00:01:22 --> 00:01:24 atmosphere, the combined data has built up a
00:01:24 --> 00:01:26 layer by layer picture of Betelgeuse's
00:01:26 --> 00:01:28 atmosphere from just above its visible
00:01:28 --> 00:01:30 surface out to several times the star's rate
00:01:30 --> 00:01:33 radius. Betelgeuse is the bright
00:01:33 --> 00:01:36 red supergiant marking the shoulder of Orion
00:01:36 --> 00:01:39 and has long captivated astronomers and sky
00:01:39 --> 00:01:42 watchers alike. It's one of the 10 brightest
00:01:42 --> 00:01:44 stars in the night sky. The name
00:01:44 --> 00:01:47 Betelgeuse, meaning Hand of the Big man, the
00:01:47 --> 00:01:49 Big man being Orion the Hunter, is a twisted
00:01:49 --> 00:01:51 corruption of its original Arabic name, Ibtal
00:01:51 --> 00:01:53 Yowza. Although to most of our listeners
00:01:53 --> 00:01:56 it'll probably better be known as Betelgeuse.
00:01:56 --> 00:01:58 Don't say it three times. And since
00:01:58 --> 00:02:01 Betelgeuse means hand of the Big man, the
00:02:01 --> 00:02:03 companion star, named Shiwara, means
00:02:03 --> 00:02:05 bracelet. Shiwara's existence
00:02:05 --> 00:02:08 was first proposed in 2024 to explain
00:02:08 --> 00:02:11 Betelgeuse's mysterious 2100 day brightness
00:02:11 --> 00:02:13 cycle and has since been confirmed by direct
00:02:13 --> 00:02:15 imaging and spectroscopic studies.
00:02:16 --> 00:02:18 Betelgeuse is located some 500 to 700
00:02:18 --> 00:02:21 light years away and is some 700 times
00:02:21 --> 00:02:24 larger than our Sun. In fact, if
00:02:24 --> 00:02:26 Betelgeuse were placed where our sun is at
00:02:26 --> 00:02:27 the centre of our solar system, its surface
00:02:27 --> 00:02:30 would extend all the way out to the orbit of
00:02:30 --> 00:02:32 Jupiter. In 2019,
00:02:32 --> 00:02:34 Betelgeuse experienced what we now call the
00:02:34 --> 00:02:36 Great Dimming Event, when it dramatically
00:02:36 --> 00:02:38 dropped in brightness, falling from 10th
00:02:38 --> 00:02:41 place down to around 20th. It was
00:02:41 --> 00:02:43 speculated that this could have been the
00:02:43 --> 00:02:45 prelude to the star going supernova, but it
00:02:45 --> 00:02:47 turned out to have simply been caused by A
00:02:47 --> 00:02:49 massive surface gas ejection that cooled and
00:02:49 --> 00:02:52 condensed into dust, temporarily blocking the
00:02:52 --> 00:02:54 star's light. Mind you, Betelgos will
00:02:54 --> 00:02:57 explode as a core collapse supernova. Soon.
00:02:57 --> 00:03:00 Of course, in astronomical terms, soon could
00:03:00 --> 00:03:02 mean in a thousand years from now. Or it
00:03:02 --> 00:03:03 could mean tomorrow.
00:03:04 --> 00:03:06 When it does blow up, Betelgos will become
00:03:06 --> 00:03:08 the second brightest object in the night sky
00:03:08 --> 00:03:10 after the Moon. And it will be bright enough
00:03:10 --> 00:03:12 to be clearly visible in daylight.
00:03:12 --> 00:03:15 In 2019, months before the Great Dimming, a
00:03:15 --> 00:03:17 UH study by Matthews found that Betelgeuse's
00:03:17 --> 00:03:20 atmosphere at radio wavelengths was unusually
00:03:20 --> 00:03:23 cool, a sign. Researchers proposed that a
00:03:23 --> 00:03:25 shock wave triggered by convection deep
00:03:25 --> 00:03:27 within the star had disturbed gas in its
00:03:27 --> 00:03:29 outer layers, setting the stage for the
00:03:29 --> 00:03:31 massive dust forming outburst that followed.
00:03:32 --> 00:03:34 The new observations show that the brightness
00:03:34 --> 00:03:36 temperature of the star's atmosphere at those
00:03:36 --> 00:03:38 same wavelengths has UH since climbed back to
00:03:38 --> 00:03:41 more typical levels. The star's gas now
00:03:41 --> 00:03:44 measures at around 3 kelvin, comparable
00:03:44 --> 00:03:46 to Betelgeuse's own surface temperature near
00:03:46 --> 00:03:49 a radius of around 2.7 times that of the
00:03:49 --> 00:03:51 star's own size. The data also
00:03:51 --> 00:03:53 confirmed a long suspected temperature
00:03:53 --> 00:03:56 minimum in Betelgeuse's atmosphere, a cool
00:03:56 --> 00:03:58 layer sandwiched between the star's visible
00:03:58 --> 00:04:00 surface, the photosphere, and the area above
00:04:00 --> 00:04:03 that known as the chromosphere. The author's
00:04:03 --> 00:04:05 highest frequency ALMA measurements, which
00:04:05 --> 00:04:07 reached closer to the star's surface than
00:04:07 --> 00:04:08 ever before, found gas temperatures dropping
00:04:08 --> 00:04:11 to roughly 2 kelvin, more than 1
00:04:11 --> 00:04:14 degrees cooler than the photosphere itself.
00:04:14 --> 00:04:17 That chilly layer coincides with the so
00:04:17 --> 00:04:19 called mole sphere, a shell of molecular gas
00:04:19 --> 00:04:21 long inferred from infrared observations, but
00:04:21 --> 00:04:23 rarely probe so directly at UH radio
00:04:23 --> 00:04:26 wavelengths. Perhaps the most
00:04:26 --> 00:04:28 striking result, however, concerns
00:04:28 --> 00:04:31 Betelgeuse's recently identified companion.
00:04:31 --> 00:04:33 Shiwara is thought to orbit deep within
00:04:33 --> 00:04:36 Betelgeuse's extended atmosphere at a
00:04:36 --> 00:04:38 distance of only about twice the giant
00:04:38 --> 00:04:41 planet's radius. Matthew says the companion
00:04:41 --> 00:04:43 stars orbiting so close to Betelgeuse it's
00:04:43 --> 00:04:46 like a jet boat tearing across a lake. It's
00:04:46 --> 00:04:48 likely leaving a wake in its path as the
00:04:48 --> 00:04:50 smaller star UH rips through the atmosphere.
00:04:50 --> 00:04:52 And and as the newly spatially resolved
00:04:52 --> 00:04:55 observations of Betelgeuse shows, Chiwara's
00:04:55 --> 00:04:57 presence is producing observable effects.
00:04:57 --> 00:04:59 By measuring the subtle egg like shape of
00:04:59 --> 00:05:02 Betelgeurs radio emitting atmosphere across
00:05:02 --> 00:05:04 multiple epochs, the authors found that the
00:05:04 --> 00:05:06 star became noticeably more elongated near
00:05:06 --> 00:05:08 the times when the companion was expected to
00:05:08 --> 00:05:11 be at its greatest apparent separation from
00:05:11 --> 00:05:13 Betelgur's and rounder uh when the companion
00:05:13 --> 00:05:15 is expected to be passing directly in front
00:05:15 --> 00:05:17 or behind the star as seen from Earth.
00:05:17 --> 00:05:20 Uh, this is space time
00:05:21 --> 00:05:23 still to come. Solving the mystery of the
00:05:23 --> 00:05:26 Orion nebula. And America's X37B
00:05:26 --> 00:05:28 space shuttle still on its clandestine
00:05:28 --> 00:05:31 mission orbiting the Earth. All that and more
00:05:31 --> 00:05:33 still to come. On space time,
00:05:49 --> 00:05:51 Astronomers may have finally solved the
00:05:51 --> 00:05:53 mystery of the Orion Nebula, the largest star
00:05:53 --> 00:05:54 forming region near Earth.
00:05:55 --> 00:05:57 For years, this giant stellar nursery has
00:05:57 --> 00:05:59 puzzled scientists with an age paradox,
00:06:00 --> 00:06:02 Namely, while some of its stars appear to be
00:06:02 --> 00:06:04 older than the molecular gas and dust clouds
00:06:04 --> 00:06:07 which created them. The new findings reported
00:06:07 --> 00:06:09 in the journal Astronomy and Astrophysics
00:06:09 --> 00:06:12 suggest the paradox was caused by the merger
00:06:12 --> 00:06:14 of two of the stars within the nebula.
00:06:15 --> 00:06:17 The Orion Nebula, which is also known as
00:06:17 --> 00:06:19 Messier or M. M42 is the largest star
00:06:19 --> 00:06:22 forming region visible to the unaided eye as
00:06:22 --> 00:06:24 what appears to be the middle star in orion
00:06:24 --> 00:06:27 sword. Located 1
00:06:27 --> 00:06:30 light years away and spanning some 25 light
00:06:30 --> 00:06:32 years across, the nebula contains some 2
00:06:33 --> 00:06:35 times the mass of our Sun. It's one of the
00:06:35 --> 00:06:37 most scrutinised and photographed objects in
00:06:37 --> 00:06:40 the night sky and is among the most intensely
00:06:40 --> 00:06:42 studied celestial features in astronomy,
00:06:42 --> 00:06:45 revealing much about the process of how stars
00:06:45 --> 00:06:47 and planetary systems are formed from
00:06:47 --> 00:06:49 collapsing clouds of molecular gas and dust.
00:06:50 --> 00:06:52 Astronomers have directly observed
00:06:52 --> 00:06:54 protoplanetary discs and brown dwarfs within
00:06:54 --> 00:06:57 the nebula. They've observed intense and
00:06:57 --> 00:06:59 turbulent motions of gas and the
00:06:59 --> 00:07:01 photoionizing effects of massive nearby
00:07:01 --> 00:07:04 stars. Some of the young stars in the nebula
00:07:04 --> 00:07:06 are, uh, surrounded by discs of gas and dust
00:07:06 --> 00:07:08 in which planets are actually forming.
00:07:09 --> 00:07:11 Radiation from the massive central star
00:07:11 --> 00:07:14 Theta1 Orionis C1 is gradually
00:07:14 --> 00:07:16 stripping material away from these discs,
00:07:16 --> 00:07:19 giving them shapes that resemble tadpoles.
00:07:19 --> 00:07:22 The discs are losing mass so rapidly that
00:07:22 --> 00:07:24 given the age of the stars, which is around a
00:07:24 --> 00:07:25 million years each, they should have
00:07:25 --> 00:07:28 disappeared long ago. The large gas
00:07:28 --> 00:07:30 shell surrounding the central star poses
00:07:30 --> 00:07:33 another puzzle. The star sets the surrounding
00:07:33 --> 00:07:36 gas in motion, causing the shell to expand at
00:07:36 --> 00:07:38 around 13 kilometres per second. Now, uh,
00:07:38 --> 00:07:40 extrapolating backwards from the speed
00:07:40 --> 00:07:42 suggests that the shell only formed a few
00:07:42 --> 00:07:45 hundred thousand years ago. The stars are
00:07:45 --> 00:07:46 therefore much older, uh, than both the gas
00:07:46 --> 00:07:49 shell and the dust disc that is the tadpoles,
00:07:49 --> 00:07:52 appear to be. The study's lead author,
00:07:52 --> 00:07:54 Matte Wilhelm from the Leiden University says
00:07:54 --> 00:07:57 Theta 1 Orionis C1, which has a mass of
00:07:57 --> 00:08:00 around 33.5 times that of the sun, formed
00:08:00 --> 00:08:02 when a binary star system merged.
00:08:02 --> 00:08:05 A binary system consists of two stars that
00:08:05 --> 00:08:07 orbit a common centre of gravity. Wilhelm and
00:08:07 --> 00:08:09 colleagues suspect that a third star
00:08:09 --> 00:08:11 disrupted the system, knocking one of the
00:08:11 --> 00:08:13 stars out of its stable orbit and eventually
00:08:13 --> 00:08:16 causing the two stars to collide. If the two
00:08:16 --> 00:08:18 stars did merge a few hundred thousand years
00:08:18 --> 00:08:21 ago, the resulting star's luminosity, that is
00:08:21 --> 00:08:23 the amount of light it emits, must have
00:08:23 --> 00:08:26 increased sharply from that point onwards. So
00:08:26 --> 00:08:28 the authors used computer simulations to show
00:08:28 --> 00:08:30 that before the collision, the two stars
00:08:30 --> 00:08:33 emitted much less radiation, allowing the
00:08:33 --> 00:08:35 surrounding dust discs to survive for most of
00:08:35 --> 00:08:38 their lifetime. Only after the merger
00:08:38 --> 00:08:40 did the star's radiation increase sharply,
00:08:40 --> 00:08:42 triggering the rapid evaporation of the
00:08:42 --> 00:08:45 discs. The rapid expansion of the gas
00:08:45 --> 00:08:47 shell, however, requires an additional
00:08:47 --> 00:08:50 explanation. See the merger alone is
00:08:50 --> 00:08:52 estimated to provide somewhere around 30
00:08:52 --> 00:08:54 times more driving force, whereas a factor of
00:08:54 --> 00:08:56 100 is needed to explain the observed
00:08:56 --> 00:08:59 expansion. Viltime and colleagues suspect
00:08:59 --> 00:09:01 that cool gas from the evaporating discs also
00:09:01 --> 00:09:04 plays a role. As this gas mixes with the
00:09:04 --> 00:09:06 hot gas inside the expanding bubble, it
00:09:06 --> 00:09:09 provides the additional driving force needed.
00:09:10 --> 00:09:12 This scenario could also account for two
00:09:12 --> 00:09:14 other unusual features of theta 1 Orionis C1
00:09:14 --> 00:09:17 its observed tilted magnetic field and a
00:09:17 --> 00:09:19 slight excess of nitrogen in the star.
00:09:20 --> 00:09:22 If correct, it's the first time astronomers
00:09:22 --> 00:09:24 have witnessed the consequences of a major
00:09:24 --> 00:09:26 stellar collision in our cosmic
00:09:26 --> 00:09:29 neighbourhood. It also shows that stellar
00:09:29 --> 00:09:30 collisions may be much more common than
00:09:30 --> 00:09:33 previously thought and that they have far
00:09:33 --> 00:09:35 reaching consequences for their surrounding
00:09:35 --> 00:09:38 space as a result. This is space
00:09:38 --> 00:09:40 time still to come. America's
00:09:40 --> 00:09:43 X37 space shuttle still on mission
00:09:43 --> 00:09:46 and the giant spiral galaxy M M31
00:09:46 --> 00:09:49 Andromeda, the Crab Nebula M1 and
00:09:49 --> 00:09:52 3 meteor showers are among the highlights of
00:09:52 --> 00:09:55 the November night skies on Skywatch.
00:10:00 --> 00:10:00 Foreign.
00:10:09 --> 00:10:12 The United States Space Force's X37B space
00:10:12 --> 00:10:15 plane is now almost 14 months into its latest
00:10:15 --> 00:10:17 clandestine mission testing new quantum
00:10:17 --> 00:10:20 inertial navigation technology. The
00:10:20 --> 00:10:23 flight's goal is to develop a completely self
00:10:23 --> 00:10:25 contained navigation alternative that
00:10:25 --> 00:10:26 eliminates dependency on gps.
00:10:28 --> 00:10:30 Traditional inertial measurement units rely
00:10:30 --> 00:10:32 on mechanical components or mirrors that
00:10:32 --> 00:10:34 experience microscopic drift over time,
00:10:34 --> 00:10:37 gradually introducing navigation errors. But
00:10:37 --> 00:10:40 the X37b's new quantum system bypasses
00:10:40 --> 00:10:43 this using atom interferometry. This
00:10:43 --> 00:10:45 involves ultra cold rubidium atoms or
00:10:45 --> 00:10:47 something similar trapped and cooled by fine
00:10:47 --> 00:10:50 tuned lasers to near absolute zero. That
00:10:50 --> 00:10:52 allows them to reach a stage where they
00:10:52 --> 00:10:54 behave like waves rather than particles.
00:10:55 --> 00:10:57 Laser pulses then split each atom into a
00:10:57 --> 00:10:59 quantum superpositioning state,
00:10:59 --> 00:11:01 simultaneously travelling along two different
00:11:01 --> 00:11:04 paths before recombining. When the paths
00:11:04 --> 00:11:06 recombine, they form an interference pattern
00:11:06 --> 00:11:08 resembling overlapping ripples on water.
00:11:09 --> 00:11:11 Because the atoms are perfectly identical and
00:11:11 --> 00:11:14 immutable, any tiny rotation or micro
00:11:14 --> 00:11:16 acceleration shifts the wave pattern
00:11:16 --> 00:11:18 detected, allowing the spacecraft to plot its
00:11:18 --> 00:11:20 position continuously without drift or
00:11:20 --> 00:11:23 external reference signals. The
00:11:23 --> 00:11:26 unmanned X37B spaceplane launched
00:11:26 --> 00:11:29 on its current mission designated UH OVT 8
00:11:29 --> 00:11:32 back in August last year from pad 39A at
00:11:32 --> 00:11:34 the Kennedy Space Centre in Florida aboard a
00:11:34 --> 00:11:35 Falcon 9 rocket.
00:11:35 --> 00:11:37 As well as testing quantum navigation in
00:11:37 --> 00:11:40 flight, it also tested laser communications
00:11:40 --> 00:11:42 systems, flew with an expanded service module
00:11:42 --> 00:11:44 hosting a number of classified experiments
00:11:44 --> 00:11:46 for the U.S. air Force Research Laboratory
00:11:46 --> 00:11:48 and the Defence Innovations Unit.
00:11:49 --> 00:11:52 The latest update on this classified mission
00:11:52 --> 00:11:53 comes as new images have been released
00:11:53 --> 00:11:56 exposing China's own highly secretive version
00:11:56 --> 00:11:59 of the X37B. And just
00:11:59 --> 00:12:02 like Russia's Buran space shuttle, was a copy
00:12:02 --> 00:12:03 of the more famous American shuttles.
00:12:03 --> 00:12:06 Beijing's version of the X37B, called the
00:12:06 --> 00:12:08 Shenglong or Divine Dragon, appears to be an
00:12:08 --> 00:12:10 almost carbon copy of its American
00:12:10 --> 00:12:13 counterpart, even down to the compact shuttle
00:12:13 --> 00:12:16 like body delta wings, twin vertical tail
00:12:16 --> 00:12:18 fins and central payload bay with hatches
00:12:18 --> 00:12:21 that open in orbit. It even includes a rear
00:12:21 --> 00:12:23 mounted service module complete with solar
00:12:23 --> 00:12:26 arrays. This is space, time.
00:12:31 --> 00:12:34 And time. Now to turn our eyes to the skies
00:12:34 --> 00:12:36 and check out the celestial sphere for
00:12:36 --> 00:12:38 November. On um Skywatch. High in the
00:12:38 --> 00:12:41 northern skies of November, you'll find the
00:12:41 --> 00:12:44 constellation Pegasus, the Mesopotamian and
00:12:44 --> 00:12:46 Etruscan mythical winged horse who was born
00:12:46 --> 00:12:48 from the blood of Medusa the Gorgon and after
00:12:48 --> 00:12:51 she was slain by Perseus. The brightest
00:12:51 --> 00:12:54 star in Pegasus is the orange supergiant
00:12:54 --> 00:12:57 Epsilon Pegasi. Located some 690 light
00:12:57 --> 00:12:59 years away, it's estimated to have about
00:12:59 --> 00:13:02 185 times the Sun's radius and 12 times
00:13:02 --> 00:13:05 its mass. Epsilon Pegasi, together with the
00:13:05 --> 00:13:08 stars Ma' Cab Al Janib, Shahit and
00:13:08 --> 00:13:11 Alpha Andromeda, forms the asterism or
00:13:11 --> 00:13:13 pattern of stars known as the Great Square of
00:13:13 --> 00:13:16 Pegasus. A bunch of bright naked ice stars
00:13:16 --> 00:13:19 shaped like a square. One of the stars in
00:13:19 --> 00:13:21 this constellation is 51 Pegasi.
00:13:22 --> 00:13:24 51 Pegasi is a Sun like star located
00:13:24 --> 00:13:26 51 light years away.
00:13:26 --> 00:13:29 On October 6, 1995, astronomers
00:13:29 --> 00:13:31 announced the discovery of an exoplanet
00:13:31 --> 00:13:33 orbiting the star. It was the first ever
00:13:33 --> 00:13:36 confirmed detection of a planet orbiting
00:13:36 --> 00:13:38 another star. The planet has around half the
00:13:38 --> 00:13:41 mass of Jupiter and is thought to be a gas
00:13:41 --> 00:13:43 giant. But it wasn't what scientists were
00:13:43 --> 00:13:46 expecting. The planet orbits the star in just
00:13:46 --> 00:13:48 four Earth days. That's much closer than
00:13:48 --> 00:13:51 Mercury's 88 day orbit around the sun.
00:13:51 --> 00:13:53 Because it orbits so close to the star 51
00:13:53 --> 00:13:56 Pegasi. B, as it's called, experiences
00:13:56 --> 00:13:58 temperatures estimated to be around 1200
00:13:58 --> 00:14:00 degrees Celsius at the Time of its
00:14:00 --> 00:14:03 discovery. This close distance was not
00:14:03 --> 00:14:04 compatible with theories of planetary
00:14:04 --> 00:14:07 formation and resulted in a lot of discussion
00:14:07 --> 00:14:10 among scientists about the idea of
00:14:10 --> 00:14:12 planetary migration. However, since its
00:14:12 --> 00:14:14 discovery, numerous other so called Hot
00:14:14 --> 00:14:16 Jupiters have been detected, pretty much
00:14:16 --> 00:14:18 confirming planetary migration.
00:14:18 --> 00:14:21 To be real. By the way, a light year,
00:14:21 --> 00:14:23 well that's the distance a photon can travel
00:14:23 --> 00:14:25 in a year at the speed of light, which is
00:14:25 --> 00:14:27 some 300 kilometres per second in a
00:14:27 --> 00:14:30 vacuum and the ultimate speed limit of the
00:14:30 --> 00:14:33 universe. Also visible in Pegasus
00:14:33 --> 00:14:35 is the M15 or NGC
00:14:35 --> 00:14:38 7078 globular cluster or, which is
00:14:38 --> 00:14:41 located around 33 light years
00:14:41 --> 00:14:43 away. Globular clusters are, uh, tight
00:14:43 --> 00:14:46 balls containing thousands of stars which are
00:14:46 --> 00:14:48 all originally formed at the same time out of
00:14:48 --> 00:14:50 the same molecular gas and dust cloud.
00:14:51 --> 00:14:54 M15 is estimated to be around 12 billion
00:14:54 --> 00:14:56 years old, making it one of the oldest known
00:14:56 --> 00:14:57 globular clusters.
00:14:58 --> 00:15:01 And it contains around 100 stars, making
00:15:01 --> 00:15:02 it one of the most densely packed globular
00:15:02 --> 00:15:05 clusters in the entire Milky Way galaxy.
00:15:05 --> 00:15:08 Its core has undergone a contraction known as
00:15:08 --> 00:15:11 core collapse. And it has a central density
00:15:11 --> 00:15:13 cusp with an enormous number of stars
00:15:13 --> 00:15:15 orbiting very rapidly around what appears to
00:15:15 --> 00:15:18 be a central black hole. M15
00:15:18 --> 00:15:21 also contains at least 112 variable stars,
00:15:21 --> 00:15:23 eight pulsars, including one double neutron
00:15:23 --> 00:15:25 star system and the first ever planetary
00:15:25 --> 00:15:27 nebula found in a globular cluster.
00:15:28 --> 00:15:30 Now, if you're in or near the northern
00:15:30 --> 00:15:32 hemisphere and away from city lights, you'll
00:15:32 --> 00:15:35 notice a fuzzy patch of light right next to
00:15:35 --> 00:15:35 Pegasus.
00:15:36 --> 00:15:39 This is the giant spiral galaxy
00:15:39 --> 00:15:41 M31. Andromeda.
00:15:42 --> 00:15:45 Andromeda is the biggest galaxy in our local
00:15:45 --> 00:15:48 galactic group, located some 2.5
00:15:48 --> 00:15:50 million light years away. Andromeda consists
00:15:50 --> 00:15:53 of more than a trillion stars, around twice
00:15:53 --> 00:15:56 the number found in the Milky Way. And it's
00:15:56 --> 00:15:59 huge, some 220 light years
00:15:59 --> 00:16:02 across. Based on current estimates,
00:16:02 --> 00:16:04 Andromeda appears to have more older stars
00:16:04 --> 00:16:07 than the Milky Way. It also has far less
00:16:07 --> 00:16:10 new star production going on than our galaxy.
00:16:10 --> 00:16:13 And the rate of supernovae in the Milky Way
00:16:13 --> 00:16:15 is also about double that in Andromeda.
00:16:15 --> 00:16:18 Andromeda is surrounded by a large massive
00:16:18 --> 00:16:21 halo of hot gas and plasma estimated to
00:16:21 --> 00:16:23 contain at least half the mass of the stars
00:16:23 --> 00:16:25 in the galaxy. This nearly invisible
00:16:25 --> 00:16:28 halo stretches about a million light years
00:16:28 --> 00:16:29 from its host galaxy.
00:16:29 --> 00:16:32 That's almost halfway towards the Milky Way.
00:16:32 --> 00:16:35 Using a good pair of binoculars or a backyard
00:16:35 --> 00:16:37 telescope, you'll see dark dust lanes in
00:16:37 --> 00:16:40 Andromeda's spiral arms and you'll see its
00:16:40 --> 00:16:43 bright central galactic core. Now,
00:16:43 --> 00:16:45 over time andromeda will become a lot
00:16:45 --> 00:16:48 clearer. That's because it's getting closer.
00:16:48 --> 00:16:50 You see, the Milky Way and Andromeda are
00:16:50 --> 00:16:53 expected to collide in about 3.7 to
00:16:53 --> 00:16:56 4.5 billion years from now. The two
00:16:56 --> 00:16:59 spirals eventually merging to form a new
00:16:59 --> 00:17:02 giant elliptical galaxy. What that means
00:17:02 --> 00:17:04 for the future of the Earth, the Sun and our
00:17:04 --> 00:17:07 solar system is a matter of great ongoing
00:17:07 --> 00:17:09 debate. The gravitational tidal
00:17:09 --> 00:17:11 perturbations from the encounter could rip
00:17:11 --> 00:17:14 our solar system apart or even fling us out
00:17:14 --> 00:17:17 into intergalactic space. At this stage,
00:17:18 --> 00:17:20 only time will tell. Uh, looking
00:17:20 --> 00:17:23 to the east and slightly south of Pegasus,
00:17:23 --> 00:17:25 you will see the ancient constellation of
00:17:25 --> 00:17:27 Cetus, the Great Whale, or sea monster.
00:17:28 --> 00:17:30 The brightest star in the constellation is
00:17:30 --> 00:17:33 Beta Ceti, or Denebketos, an orange
00:17:33 --> 00:17:35 giant located 96 light years away.
00:17:36 --> 00:17:39 The name Denebketos means the Whale's tail.
00:17:39 --> 00:17:42 Another one of the stars in Cetus is Mira,
00:17:42 --> 00:17:44 the first variable star ever discovered.
00:17:45 --> 00:17:47 Located some 420 light years away,
00:17:47 --> 00:17:50 Mira pulsates in brightness over a period of
00:17:50 --> 00:17:52 332 days, changing in
00:17:52 --> 00:17:55 diameter from around 400 to 500 times
00:17:55 --> 00:17:58 the diameter of our Sun. Also visible is
00:17:58 --> 00:18:01 Alpha Ceti, traditionally called Menkar the
00:18:01 --> 00:18:01 Nose.
00:18:02 --> 00:18:05 It's a red hued giant star some 220
00:18:05 --> 00:18:07 light years away. It's actually a double star
00:18:07 --> 00:18:10 with a secondary 93 SETI being a blue white
00:18:10 --> 00:18:13 star some 440 light years away.
00:18:13 --> 00:18:15 Gamma Ceti, or the Head of the Whale, is
00:18:15 --> 00:18:18 another double star. The primary is a
00:18:18 --> 00:18:20 yellow star 82 light years from Earth, while
00:18:20 --> 00:18:23 the secondary is a blue star. Also in
00:18:23 --> 00:18:26 cetus, located some, um, 11.9 light years
00:18:26 --> 00:18:29 away, is the yellow dwarf star Tau Ceti, the
00:18:29 --> 00:18:31 nearest sun like star to the Earth other than
00:18:31 --> 00:18:32 the Sun.
00:18:33 --> 00:18:35 Astronomers describe stars in terms of
00:18:35 --> 00:18:38 spectral types. It's a classification system
00:18:38 --> 00:18:39 based on temperature and other
00:18:39 --> 00:18:42 characteristics. The hottest, most massive
00:18:42 --> 00:18:45 and most luminous stars are known as spectral
00:18:45 --> 00:18:48 type O blue stars. That's followed by
00:18:48 --> 00:18:50 spectral type B, blue white stars, then
00:18:50 --> 00:18:53 spectral type A white stars, spectral
00:18:53 --> 00:18:56 type F, whitish yellow stars. Then comes
00:18:56 --> 00:18:58 spectral type G yellow stars. That's where
00:18:58 --> 00:19:01 our sun fits in. Slightly cooler are, uh,
00:19:01 --> 00:19:03 spectral type K orange stars. And then the
00:19:03 --> 00:19:06 coolest and least massive stars known are,
00:19:06 --> 00:19:09 uh, spectral type M red M stars. Each
00:19:09 --> 00:19:11 spectral classification can then further be
00:19:11 --> 00:19:13 subdivided using a numeric digit to represent
00:19:14 --> 00:19:16 temperature, with zero being the hottest and
00:19:16 --> 00:19:19 nine the coolest. And then you add a Roman
00:19:19 --> 00:19:21 numeral to represent luminosity.
00:19:21 --> 00:19:23 So at the end of all that, our sun is
00:19:23 --> 00:19:26 classified as a G2V, or if you prefer,
00:19:26 --> 00:19:28 G25 yellow dwarf star.
00:19:29 --> 00:19:31 Also included in the stellar classification
00:19:31 --> 00:19:33 system are, uh, spectral types LT and Y,
00:19:34 --> 00:19:36 which are assigned to failed stars known as
00:19:36 --> 00:19:38 brown dwarves, some of which were actually
00:19:38 --> 00:19:41 born as spectral type M red stars but then
00:19:41 --> 00:19:43 became brown dwarves after losing some of
00:19:43 --> 00:19:46 their mass. Brown dwarfs fit in a unique
00:19:46 --> 00:19:49 category between the largest planets, which
00:19:49 --> 00:19:51 are about 13 times the mass of Jupiter, and
00:19:51 --> 00:19:54 the small spectral type M red stars,
00:19:54 --> 00:19:56 which can be 75 to 80 times the mass of
00:19:56 --> 00:19:59 Jupiter, or 0.08 solar
00:19:59 --> 00:20:02 masses. South of Cetis,
00:20:02 --> 00:20:04 you'll see the brilliant star Achenar, which
00:20:04 --> 00:20:07 means the river's end as it marks the end of
00:20:07 --> 00:20:10 the river Eridanus. Achenar is a
00:20:10 --> 00:20:13 binary system which make up the star Alpha
00:20:13 --> 00:20:15 Eridni, which is the brightest star or point
00:20:15 --> 00:20:17 of light lying at the southern tip of the
00:20:17 --> 00:20:19 constellation Eridanis.
00:20:19 --> 00:20:22 The two components of Alpha Eridni are
00:20:22 --> 00:20:24 designated Alpha Rydni A and Alpha Rhydney
00:20:24 --> 00:20:27 B and are located some 139
00:20:27 --> 00:20:30 light years away. Of the 10
00:20:30 --> 00:20:33 apparent brightest stars in our night sky,
00:20:33 --> 00:20:35 Alpha Rhydney is the hottest and bluest in
00:20:35 --> 00:20:37 colour. That's due to Achenar being a
00:20:37 --> 00:20:39 spectral type B main sequence star.
00:20:40 --> 00:20:42 Achenar also has an unusually rapid
00:20:42 --> 00:20:44 rotational velocity, causing it to be quite
00:20:44 --> 00:20:47 oblate in shape. The second star in the
00:20:47 --> 00:20:49 system is the smallest spectral type A white
00:20:49 --> 00:20:51 star and orbits the primary star at a
00:20:51 --> 00:20:54 distance of around 12 astronomical units.
00:20:54 --> 00:20:56 An AH astronomical unit is the average
00:20:56 --> 00:20:58 distance between the Earth and the sun, which
00:20:58 --> 00:21:01 is about 150 million kilometres, or just over
00:21:01 --> 00:21:04 8.3 light minutes. Follow
00:21:04 --> 00:21:06 Eridanus towards the east and you'll see the
00:21:06 --> 00:21:09 magnificent constellation Orion the Hunter, a
00:21:09 --> 00:21:12 familiar signpost for southern summer skies.
00:21:13 --> 00:21:15 To the west of Orion is the constellation
00:21:15 --> 00:21:17 Taurus the Bull. And located in
00:21:17 --> 00:21:20 Taurus is M1, the Crab Nebula.
00:21:20 --> 00:21:23 It's the remnant of a star which Chinese
00:21:23 --> 00:21:25 astronomers saw explode as a supernova.
00:21:25 --> 00:21:28 On July 4th in the year 1054,
00:21:29 --> 00:21:31 they recorded the sudden appearance of a new
00:21:31 --> 00:21:33 star on their sky charts at the exact
00:21:33 --> 00:21:35 position of the Crab Nebula. The
00:21:35 --> 00:21:38 supernova appeared brighter than the planet
00:21:38 --> 00:21:40 Venus for weeks on end before finally
00:21:40 --> 00:21:43 fading completely from view after almost
00:21:43 --> 00:21:46 two years. The Crab Nebula is located
00:21:46 --> 00:21:48 some 7 light years away.
00:21:49 --> 00:21:51 It's expanding at a rate of over 5 million
00:21:51 --> 00:21:54 kilometres per hour. At the heart of the
00:21:54 --> 00:21:57 nebula is a rapidly spinning neutron star, or
00:21:57 --> 00:21:59 pulsar, rotating some 30 times every
00:21:59 --> 00:22:00 second.
00:22:00 --> 00:22:03 It's emitting radiation in all wavelengths,
00:22:03 --> 00:22:05 from gamma rays and X rays, through
00:22:05 --> 00:22:08 ultraviolet, optical and infrared and and on
00:22:08 --> 00:22:10 into radio waves. Observations indicate the
00:22:10 --> 00:22:13 pulse's spin rate is slowing down, and it
00:22:13 --> 00:22:16 will fall to just half its current rotational
00:22:16 --> 00:22:18 rate in the next thousand years.
00:22:19 --> 00:22:21 November is also a great time to check out
00:22:21 --> 00:22:23 the Pleiades, or Seven Sisters, one of the
00:22:23 --> 00:22:25 nearest and most spectacular open star
00:22:25 --> 00:22:28 clusters to Earth. Also known as M
00:22:28 --> 00:22:31 M45, the Pleiades are located in
00:22:31 --> 00:22:34 the constellation Taurus. Now, depending on
00:22:34 --> 00:22:36 whose measurements you prefer, the Pleiades
00:22:36 --> 00:22:38 are located somewhere between 118 and
00:22:38 --> 00:22:40 137 parsecs away,
00:22:41 --> 00:22:43 a parsec being 3.26 light years.
00:22:44 --> 00:22:47 The Pleiades are composed of mostly hot blue
00:22:47 --> 00:22:49 white stars, amazingly different
00:22:49 --> 00:22:51 cultures in vastly different parts of the
00:22:51 --> 00:22:54 world. All describe the Pleiades as Seven
00:22:54 --> 00:22:57 Sisters or seven women, possibly some sort
00:22:57 --> 00:22:59 of ancient throwback to very early human
00:22:59 --> 00:23:02 civilization. Just like
00:23:02 --> 00:23:05 October, November also sees three meteor
00:23:05 --> 00:23:08 showers. There's the November Orionids,
00:23:08 --> 00:23:10 as well as the Taurids and the Leonids.
00:23:10 --> 00:23:13 Although peaking in late October, the
00:23:13 --> 00:23:15 Orionids continue to sprinkle down during the
00:23:15 --> 00:23:17 start of November and are, uh, usually at
00:23:17 --> 00:23:19 their best in the wee small hours before
00:23:19 --> 00:23:20 dawn.
00:23:20 --> 00:23:23 They're generated by the debris trail left
00:23:23 --> 00:23:25 behind by the comet Hallie and appear to
00:23:25 --> 00:23:27 radiate out from the direction of the
00:23:27 --> 00:23:29 constellation Orion the Hunter, hence their
00:23:29 --> 00:23:32 name. The Taurids are generated by
00:23:32 --> 00:23:35 the comet Encke, and as their name suggests,
00:23:35 --> 00:23:37 they appear to radiate out from the
00:23:37 --> 00:23:40 constellation Taurus the Ball. Now, Encke and
00:23:40 --> 00:23:41 the Taurids are, uh, believed to be the
00:23:41 --> 00:23:43 remnants of a much larger comet which
00:23:43 --> 00:23:45 disintegrated sometime in the past 20,
00:23:46 --> 00:23:48 30 years, breaking into several
00:23:48 --> 00:23:51 pieces and releasing material by normal
00:23:51 --> 00:23:53 cometary activity and maybe occasionally
00:23:53 --> 00:23:55 through close encounters with the
00:23:55 --> 00:23:57 gravitational tidal force of the Earth and
00:23:57 --> 00:24:00 other planets. In fact, the cometary stream
00:24:00 --> 00:24:02 of material from the Taurids is the largest
00:24:02 --> 00:24:05 in the inner solar system. And being so
00:24:05 --> 00:24:07 spread out, the Earth takes several weeks to
00:24:07 --> 00:24:08 pass through it all.
00:24:09 --> 00:24:10 That means there's an extended period of
00:24:10 --> 00:24:13 meteor activity compared to the much smaller
00:24:13 --> 00:24:15 periods of activity for other meteor showers.
00:24:16 --> 00:24:18 Interactions with the giant gas planet
00:24:18 --> 00:24:20 Jupiter, uh, have also caused the Taurids to
00:24:20 --> 00:24:22 be segmented into separate northern and
00:24:22 --> 00:24:25 southern streams. The southern Taurids
00:24:25 --> 00:24:27 usually last from around September 25 to
00:24:27 --> 00:24:30 around November 25, while the northern
00:24:30 --> 00:24:33 Taurids go from October 12 to around December
00:24:33 --> 00:24:35 2. The Taurids are usually quite
00:24:35 --> 00:24:38 diffuse, only producing about seven meteors
00:24:38 --> 00:24:40 per hour. However, they're composed of far
00:24:40 --> 00:24:42 more massive material.
00:24:42 --> 00:24:45 Think of pebbles instead of dust grains. And
00:24:45 --> 00:24:46 so they tend to produce a higher percentage
00:24:46 --> 00:24:49 of very bright meteors, known as fireballs,
00:24:49 --> 00:24:51 produced by the larger meteoroids burning
00:24:51 --> 00:24:54 through the atmosphere. The Southern Taurids
00:24:54 --> 00:24:55 should be putting on their best show just
00:24:55 --> 00:24:58 after midnight around now. The
00:24:58 --> 00:25:00 third meteor shower in November are the
00:25:00 --> 00:25:03 Leonids which peak around November 18th.
00:25:03 --> 00:25:06 They usually produce around 15 meteors an
00:25:06 --> 00:25:08 hour but have been known to occasionally
00:25:08 --> 00:25:10 produce some spectacular meteor storms
00:25:11 --> 00:25:12 with showers in 1999,
00:25:13 --> 00:25:15 2001 and 2002 producing
00:25:15 --> 00:25:18 around 3 Leonid meteors per hour.
00:25:19 --> 00:25:21 But one of the best had to have been the
00:25:21 --> 00:25:23 Leonids meteor shower of 1966
00:25:23 --> 00:25:26 which generated literally thousands of
00:25:26 --> 00:25:29 meteors per minute falling like illuminated
00:25:29 --> 00:25:32 rain. The Leonids are usually picked up after
00:25:32 --> 00:25:34 midnight with peaks occurring just before
00:25:34 --> 00:25:37 dawn produced by debris from the comet
00:25:37 --> 00:25:39 Tempel Tuttle. The Leonids radiate out from
00:25:39 --> 00:25:42 the constellation Leo the Lion and they're a
00:25:42 --> 00:25:44 fast moving stream encountering the path of
00:25:44 --> 00:25:47 the Earth at 72 kilometres per second.
00:25:47 --> 00:25:49 Larger Leonids, which are about 10
00:25:49 --> 00:25:51 millimetres across can have a mass of half a
00:25:51 --> 00:25:53 gramme and are known to generate really
00:25:53 --> 00:25:56 bright meteors. It's been calculated that
00:25:56 --> 00:25:59 the annual Leonid's meteor shower can deposit
00:25:59 --> 00:26:01 12 to 13 tonnes of particles across the
00:26:01 --> 00:26:02 planet.
00:26:02 --> 00:26:05 Jonathan Nelly from Sky Telescope magazine
00:26:05 --> 00:26:07 joins us now for the rest of our tour uh, of
00:26:07 --> 00:26:09 the November night skies. Good
00:26:09 --> 00:26:11 Jonathan Nally: day Stuart? Yeah, well it's almost summer for
00:26:11 --> 00:26:12 those of us here in the southern hemisphere,
00:26:12 --> 00:26:14 almost winter of course for our friends in
00:26:14 --> 00:26:15 the northern hemisphere but for me this is
00:26:15 --> 00:26:17 the best time of the year for stargazing down
00:26:17 --> 00:26:18 here where it's getting warmer of course with
00:26:18 --> 00:26:20 a warm night, good weather and lots of
00:26:20 --> 00:26:22 fantastic things to see in the sky because
00:26:22 --> 00:26:24 some of the best constellations are visible
00:26:24 --> 00:26:26 towards the end of the year bringing lots of
00:26:26 --> 00:26:28 bright stars and lots of really good deep sky
00:26:28 --> 00:26:29 objects which is a thing that backyard
00:26:29 --> 00:26:31 astronomers really like. So the mid evening
00:26:31 --> 00:26:33 sky in November begins with the Milky Way.
00:26:33 --> 00:26:34 It's low in the west, not right down on the
00:26:34 --> 00:26:36 horizon but fairly low in the west. The Milky
00:26:36 --> 00:26:38 Way of course is just our galaxy scene from
00:26:38 --> 00:26:39 the inside. And if you're in the city you
00:26:39 --> 00:26:41 probably can't see the Milky Way. But if you
00:26:41 --> 00:26:42 can get out in the country or somewhere where
00:26:42 --> 00:26:44 it's dark you will see this big sort of milky
00:26:44 --> 00:26:46 band across the sky. That's the Milky Way,
00:26:46 --> 00:26:47 our galaxy seen from the inside.
00:26:47 --> 00:26:49 So it's down a bit in the west you can see
00:26:50 --> 00:26:51 see over there is constellation of Scorpius
00:26:51 --> 00:26:53 the Scorpion sticking straight up from the
00:26:53 --> 00:26:55 horizon with its tail and stinger sticking
00:26:55 --> 00:26:57 straight up. One of the few constellations
00:26:57 --> 00:26:58 that actually looks like what it's supposed
00:26:58 --> 00:27:00 to be. Another constellation, famous one
00:27:00 --> 00:27:02 Sagittarius is just next door. And
00:27:02 --> 00:27:04 Sagittarius, when you look in the direction
00:27:04 --> 00:27:05 of Sagittarius, you're looking towards the
00:27:05 --> 00:27:07 centre of our Milky Way galaxy. So there's
00:27:07 --> 00:27:09 lots of stuff to see in there because you're
00:27:09 --> 00:27:10 looking right into the busy part of the
00:27:10 --> 00:27:12 galaxy, you know, the heart of the
00:27:12 --> 00:27:12 Stuart Gary: galaxy.
00:27:12 --> 00:27:14 Jonathan Nally: Looking into downtown, looking in the central
00:27:14 --> 00:27:17 business district. That's right, yeah. Next
00:27:17 --> 00:27:18 door there's. That's a big constellation.
00:27:18 --> 00:27:20 Next door there's a little constellation
00:27:20 --> 00:27:22 called Corona Australis, which means the
00:27:22 --> 00:27:24 Southern Crown, which has a nice little
00:27:24 --> 00:27:26 compact group of stars in a semicircle, just
00:27:26 --> 00:27:28 like a crown or tiara. There's also a Corona
00:27:28 --> 00:27:31 Borealis in the northern part of the sky that
00:27:31 --> 00:27:32 our friends in the north can see. And it too
00:27:32 --> 00:27:34 is just like a little semicircle of stars,
00:27:34 --> 00:27:36 like a crown or tiara. But Corona Borealis is
00:27:36 --> 00:27:38 a bit bigger. Now, over in the eastern part
00:27:38 --> 00:27:40 of the sky, we've got the constellation Orion
00:27:40 --> 00:27:42 finally now up above the horizon, as is
00:27:42 --> 00:27:44 Taurus. This is the sign for us in the south
00:27:44 --> 00:27:47 that summer is approaching, or winter in the
00:27:47 --> 00:27:48 northern half of the planet. Our friends up
00:27:48 --> 00:27:49 in the northern half of the planet today,
00:27:49 --> 00:27:51 they love this time of year for stargazing
00:27:51 --> 00:27:52 because you can see all this great stuff.
00:27:52 --> 00:27:54 Unfortunately, though, it's quite. They've
00:27:54 --> 00:27:56 really got to rug up when they go outside. I
00:27:56 --> 00:27:56 mentioned Taurus.
00:27:56 --> 00:27:59 Taurus has two very easily seen star
00:27:59 --> 00:28:02 clusters. One is a large wedge shaped
00:28:02 --> 00:28:04 group of stars known as the Hyades or Hyades,
00:28:04 --> 00:28:06 and the other one is the smaller Pleiades,
00:28:06 --> 00:28:07 which is also known as the Seven Sisters. The
00:28:07 --> 00:28:09 Pleiades is a really good test of your
00:28:09 --> 00:28:11 eyesight and the quality of your sky, how
00:28:11 --> 00:28:13 much light pollution and everything you've
00:28:13 --> 00:28:14 got. If you've got good eyes, you can go out
00:28:14 --> 00:28:16 and have a look at this little star cluster
00:28:16 --> 00:28:18 and see how many stars you can see just with
00:28:18 --> 00:28:21 the unaided eye. And what you might have to
00:28:21 --> 00:28:23 do is use what's called averted vision.
00:28:23 --> 00:28:25 Don't look directly at the stars, just sort
00:28:25 --> 00:28:27 of look out the corner of your eye, sort of
00:28:27 --> 00:28:28 direct your eyes just a little bit to the
00:28:28 --> 00:28:30 right or the left and just look out the
00:28:30 --> 00:28:32 corner of your eye. And that sometimes makes
00:28:32 --> 00:28:35 it easier to see because the way our eye is
00:28:35 --> 00:28:36 set up, we've got these different receptors
00:28:36 --> 00:28:39 in it of rods and cones for bright colour
00:28:39 --> 00:28:41 vision and dim black and white vision, and of
00:28:41 --> 00:28:43 course, nighttime dim black and white. So you
00:28:43 --> 00:28:45 need to use the part of the eye that's. Or
00:28:45 --> 00:28:47 you don't have to but you know, it makes it
00:28:47 --> 00:28:49 better sometimes if you use slightly averted
00:28:49 --> 00:28:51 vision. Now the middle part of the sky, it's
00:28:51 --> 00:28:53 filled with a bunch of constellations that
00:28:53 --> 00:28:54 most non astronomers have never heard of.
00:28:55 --> 00:28:57 So we've got four nets, the furnace, we've
00:28:57 --> 00:28:59 got Horologium, the clock, got grass, the
00:28:59 --> 00:29:02 crane. Crane as in a bird, not the big thing
00:29:02 --> 00:29:04 that builds buildings. We've got Tucana, the
00:29:04 --> 00:29:06 toucan, we've got microscopium, the
00:29:06 --> 00:29:08 microscope, we've got Dorado which is a fish.
00:29:08 --> 00:29:11 We've got reticulum which is crosshairs,
00:29:11 --> 00:29:12 which I believe these are the sort of
00:29:12 --> 00:29:14 crosshairs that you would have in a telescope
00:29:14 --> 00:29:16 or a rifle sight or something like that. And
00:29:16 --> 00:29:17 there are plenty more as well.
00:29:17 --> 00:29:19 So there are 88 constellations all up and
00:29:19 --> 00:29:21 most of them most people have never heard of.
00:29:21 --> 00:29:22 Now if you're trying to find the Southern
00:29:22 --> 00:29:24 Cross which is down in the south, you have to
00:29:24 --> 00:29:27 be pretty quick or a long way south to to
00:29:27 --> 00:29:28 have a look at it this time of year. Because
00:29:28 --> 00:29:30 during the evening at this time of year the
00:29:30 --> 00:29:32 cross is upside down and either very low on
00:29:32 --> 00:29:35 the southern horizon for some people or it's
00:29:35 --> 00:29:37 hidden below the horizon for others. It dips
00:29:37 --> 00:29:39 down below. Just depends on the latitude of
00:29:39 --> 00:29:40 where you're looking from.
00:29:40 --> 00:29:42 So for me here in Sydney it's right down on
00:29:42 --> 00:29:44 the southern horizon, the theoretical flat
00:29:44 --> 00:29:46 southern horizon. But what I also have in the
00:29:46 --> 00:29:48 way is buildings on the other side of the
00:29:48 --> 00:29:50 street, other houses and things. So that
00:29:50 --> 00:29:52 tends to block it out, let alone light
00:29:52 --> 00:29:53 pollution. On the other hand, if you're
00:29:53 --> 00:29:55 stargazing in the pre dawn hours, if you're
00:29:55 --> 00:29:57 staying up late or you're getting up early,
00:29:57 --> 00:29:58 you'll be able to find the cross quite
00:29:58 --> 00:30:01 easily. It'll be lying on its left hand side
00:30:01 --> 00:30:02 about a third of the way up from the southern
00:30:02 --> 00:30:03 horizon.
00:30:03 --> 00:30:05 And the two Pointer stars are nearby too, one
00:30:05 --> 00:30:07 of them being the famous Alpha Centauri which
00:30:07 --> 00:30:09 is a triple star system. That's the closest
00:30:09 --> 00:30:11 star system to our solar system. So by
00:30:12 --> 00:30:14 about 3am or so in the morning the sky has
00:30:14 --> 00:30:16 changed quite a lot as the Earth has rotated
00:30:16 --> 00:30:18 and brought new constellations into view.
00:30:18 --> 00:30:21 Orion is now nice and high. We've got
00:30:21 --> 00:30:23 Canis Major with its bright star Sirius, the
00:30:23 --> 00:30:25 brightest star in the sky that's up nice and
00:30:25 --> 00:30:25 high.
00:30:25 --> 00:30:28 We've got Gemini and Leo and Cancer and some
00:30:28 --> 00:30:29 of these more famous constellations up in the
00:30:29 --> 00:30:31 northern half of the skies. And they'll be
00:30:31 --> 00:30:32 visible in the early morning now. But Give it
00:30:32 --> 00:30:34 a few months and they'll be visible in the
00:30:34 --> 00:30:35 evening. So that's why I say the end of the
00:30:35 --> 00:30:37 year period is really tremendous because, uh,
00:30:37 --> 00:30:40 a lot of good stuff is visible this time of
00:30:40 --> 00:30:41 year. Now, as far as the planets go, at the
00:30:41 --> 00:30:43 beginning of this month we only have Saturn
00:30:43 --> 00:30:45 on show, really during the hours before
00:30:45 --> 00:30:45 midnight.
00:30:45 --> 00:30:47 But it's pretty easy to spot because it's up
00:30:47 --> 00:30:49 nice and high, about halfway up from the
00:30:49 --> 00:30:50 northern horizon as seen from the southern
00:30:50 --> 00:30:52 hemisphere. So the naked eye, Saturn just
00:30:52 --> 00:30:54 looks like a bright star, but you get even a
00:30:54 --> 00:30:56 small telescope onto it, just even a little
00:30:56 --> 00:30:58 tiny one, and you will be able to see that
00:30:58 --> 00:30:59 it's not just a point of light, it is a
00:30:59 --> 00:31:02 planet. And even a small telescope will show
00:31:02 --> 00:31:04 its ring system. The rings at the moment are,
00:31:04 --> 00:31:06 uh, they're not edge on, but they're not
00:31:06 --> 00:31:08 really side on either. So they're sort of
00:31:08 --> 00:31:10 more towards edge on than side on.
00:31:10 --> 00:31:12 So they don't look as fantastic as they often
00:31:12 --> 00:31:14 do. But give it a few years and the way our
00:31:14 --> 00:31:17 line of sight, our perspective lines up from
00:31:17 --> 00:31:20 Earth to Saturn changes from year to year. So
00:31:20 --> 00:31:22 as the years come, we'll get a much better
00:31:22 --> 00:31:24 view of the ring system again. So Mars and
00:31:24 --> 00:31:26 Jupiter are next. They both rise over the
00:31:26 --> 00:31:28 northeastern horizon a little before three in
00:31:28 --> 00:31:30 the morning at the beginning of the month,
00:31:30 --> 00:31:32 but getting earlier as each day goes by.
00:31:32 --> 00:31:34 So by about 1am by the end of the month, and
00:31:34 --> 00:31:36 they're fairly easy to tell apart. Jupiter is
00:31:36 --> 00:31:39 big and bright and bold. Mars is a dimmer and
00:31:39 --> 00:31:42 a sort of a ruddy orange reddish sort
00:31:42 --> 00:31:44 of colour. They're reasonably close together
00:31:44 --> 00:31:45 to start with, but they'll move even closer
00:31:45 --> 00:31:47 together as the days go by this month,
00:31:47 --> 00:31:49 especially from around about the 12th to the
00:31:49 --> 00:31:51 20th, and on the morning of the 17th there'll
00:31:51 --> 00:31:53 be only three moon widths apart. That's when
00:31:53 --> 00:31:54 they're going to be closest.
00:31:54 --> 00:31:56 So that should be really quite something to
00:31:56 --> 00:31:58 see in the night sky. And speaking of the
00:31:58 --> 00:32:00 Moon, at the end of the month on the 1st of
00:32:00 --> 00:32:02 December, as the Moon is sort of making its
00:32:02 --> 00:32:05 way across the sky night after night, it will
00:32:05 --> 00:32:07 plonk itself right next to both Mars and
00:32:07 --> 00:32:09 Jupiter. So you'll have the three of them.
00:32:09 --> 00:32:12 And if that's not enough, also very close to
00:32:12 --> 00:32:14 this little trio, the whole time basically
00:32:14 --> 00:32:16 will be a bright star called Regulus, which
00:32:16 --> 00:32:18 is the brightest star in the constellation
00:32:18 --> 00:32:20 Leo. So you'll have, on the 1st of December,
00:32:20 --> 00:32:22 you'll have two planets, one moon and one
00:32:22 --> 00:32:24 really bright star all within A few degrees
00:32:24 --> 00:32:25 of each other.
00:32:25 --> 00:32:26 That's going to look pretty specky. I might
00:32:26 --> 00:32:28 actually even get up for that one and have a
00:32:28 --> 00:32:29 look. Now also in the morning sky we've got
00:32:29 --> 00:32:32 Venus which is rising in the east about 45
00:32:32 --> 00:32:34 minutes before the sun at the start of the
00:32:34 --> 00:32:35 month, which means you'll have to try and
00:32:35 --> 00:32:37 spot it mixed in with the sort of pre dawn
00:32:37 --> 00:32:40 glow. But as each day passes, Venus will rise
00:32:40 --> 00:32:43 higher and higher, so it means it's rising
00:32:43 --> 00:32:45 earlier and earlier before the sun and it
00:32:45 --> 00:32:46 will reach its maximum height above the
00:32:46 --> 00:32:49 horizon of about 25 degrees by the end of
00:32:49 --> 00:32:50 November. And at this stage, yes, it will
00:32:50 --> 00:32:52 have moved out of the worst of the predawn
00:32:52 --> 00:32:55 glow, the sort of beautiful orange dusky sort
00:32:55 --> 00:32:55 of colours in the dawn.
00:32:55 --> 00:32:57 So this month actually is a really good time
00:32:57 --> 00:32:59 to see Venus, as will December be, because
00:32:59 --> 00:33:01 Venus sort of slowly make its way back down
00:33:01 --> 00:33:04 towards the horizon. So Venus of course is
00:33:04 --> 00:33:06 the planet that is often known as the morning
00:33:06 --> 00:33:09 star in inverted commas or the evening star
00:33:09 --> 00:33:11 in inverted commas, depending on whether it's
00:33:11 --> 00:33:13 visible in the morning or even sometimes. It
00:33:13 --> 00:33:14 can't be both, it's one or the other.
00:33:14 --> 00:33:16 Stuart Gary: Or the UFO planet.
00:33:16 --> 00:33:17 Jonathan Nally: Yeah, the UFO planet, yeah.
00:33:17 --> 00:33:18 Because some of these things we all walk
00:33:18 --> 00:33:19 around with our heads down, looking, looking
00:33:19 --> 00:33:22 down at the ground, worrying about things and
00:33:22 --> 00:33:23 you look up and something. What on earth is
00:33:23 --> 00:33:25 that big bright light up there that wasn't
00:33:25 --> 00:33:27 there yesterday? Of course it was in there
00:33:27 --> 00:33:29 for weeks and weeks but don't often notice
00:33:29 --> 00:33:32 it. So yeah, it does spark a lot of UFO type
00:33:32 --> 00:33:34 reports. And while people have been even
00:33:34 --> 00:33:36 really freaked out by um, things because if
00:33:36 --> 00:33:38 you convince yourself that it's following
00:33:38 --> 00:33:40 you, it looks like it's following you.
00:33:41 --> 00:33:42 Uh, it's one of those funny things like
00:33:42 --> 00:33:44 those, you know, those cardboard cutouts of
00:33:44 --> 00:33:46 figures with uh, they, they arrange the eyes
00:33:46 --> 00:33:48 and these couple cutouts. The eyes follow
00:33:48 --> 00:33:50 you. Yeah, yeah, you can trick yourself with
00:33:50 --> 00:33:52 Venus as well. I remember reading an account
00:33:52 --> 00:33:54 of someone, a woman I think was driving
00:33:54 --> 00:33:56 through an avenue of sort of like an avenue
00:33:56 --> 00:33:58 of poplar trees. Gives you a sort of strobe
00:33:58 --> 00:34:00 like effect when Venus is sort of popping in
00:34:00 --> 00:34:02 and out between the trees as you're driving
00:34:02 --> 00:34:04 along and this woman was convinced that it
00:34:04 --> 00:34:05 was like a ufo only a few hundred metres
00:34:05 --> 00:34:07 away, flying alongside the road, following
00:34:07 --> 00:34:09 her and she drove straight to a police
00:34:09 --> 00:34:09 station to report it.
00:34:09 --> 00:34:11 But of course it's, it's a planet millions
00:34:11 --> 00:34:13 and millions of kilometres away, so it's easy
00:34:13 --> 00:34:14 to be tricked. Anyway, it looks really nice
00:34:14 --> 00:34:16 in the night sky, all the morning skies. It's
00:34:16 --> 00:34:18 going to be, um, for this one. So that's
00:34:18 --> 00:34:20 Stuart, the night, uh, sky for November,
00:34:20 --> 00:34:22 Stuart Gary: that senior science writer and Sky Telescope
00:34:22 --> 00:34:24 contributor Jonathan Nally.
00:34:24 --> 00:34:26 And this is Space Time.
00:34:41 --> 00:34:44 And that's the show for now. Space Time
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00:35:31 --> 00:35:33 This has been another quality podcast
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