00:00:00 --> 00:00:03 this is spacetime series 28 episode 2
00:00:03 --> 00:00:05 for broadcast on the 3rd of January
00:00:05 --> 00:00:09 2025 coming up on SpaceTime a new study
00:00:09 --> 00:00:11 claims we're unlikely to ever find
00:00:11 --> 00:00:14 liquid water on the red planet Mars
00:00:14 --> 00:00:16 discovery of a new population of small
00:00:16 --> 00:00:19 main belt asteroids and Australia's
00:00:19 --> 00:00:21 lunar rover project takes another step
00:00:21 --> 00:00:26 forward all that and more coming up on
00:00:26 --> 00:00:29 SpaceTime welcome to SpaceTime with
00:00:29 --> 00:00:31 Stuart G
00:00:31 --> 00:00:38 [Music]
00:00:46 --> 00:00:48 more than a 100 years ago astronomer
00:00:48 --> 00:00:50 persal L made the case for the existence
00:00:50 --> 00:00:53 of possible Canali or canals on Mars
00:00:53 --> 00:00:55 designed to redistribute water from the
00:00:55 --> 00:00:58 Martian ice caps down to lower drier
00:00:58 --> 00:01:00 latitudes now this necess necessarily
00:01:00 --> 00:01:02 meant the existence of intelligent life
00:01:02 --> 00:01:05 on Mars that built the canals while L
00:01:05 --> 00:01:07 was proven to be wrong the question of
00:01:07 --> 00:01:09 whether there is liquid water on Mars
00:01:09 --> 00:01:12 continues to tantalize researchers
00:01:12 --> 00:01:14 liquid water is essential for Life as we
00:01:14 --> 00:01:17 know it consequently it's a precondition
00:01:17 --> 00:01:19 for a habitable planet yet the
00:01:19 --> 00:01:21 combination of low temperature
00:01:21 --> 00:01:23 atmospheric pressure and water vapor
00:01:23 --> 00:01:26 mean the triple point for water doesn't
00:01:26 --> 00:01:27 allow liquid water to exist on the
00:01:27 --> 00:01:30 Martian surface any water that was
00:01:30 --> 00:01:32 liquid on the Martian surface would
00:01:32 --> 00:01:34 likely freeze or sublimate in other
00:01:34 --> 00:01:37 words boil or evaporate immediately yet
00:01:37 --> 00:01:39 a much thicker atmosphere in the past
00:01:39 --> 00:01:41 with higher pressure would have also
00:01:41 --> 00:01:43 meant warmer temperatures and that would
00:01:43 --> 00:01:44 have allowed liquid water to exist on
00:01:44 --> 00:01:46 the red planet surface and there's
00:01:46 --> 00:01:48 plenty of evidence to confirm that
00:01:48 --> 00:01:51 that's exactly what did happen but the
00:01:51 --> 00:01:53 once warm wet world of the red planet is
00:01:54 --> 00:01:56 today a freeze-dried desert and that
00:01:56 --> 00:01:58 raises the question could liquid water
00:01:58 --> 00:02:00 exist anywhere on the red planet today
00:02:00 --> 00:02:03 most likely is a salty brine which is a
00:02:03 --> 00:02:05 lower freezing point than pure liquid
00:02:05 --> 00:02:07 water of special interest has been the
00:02:07 --> 00:02:09 discovery of recurring slope lineer
00:02:09 --> 00:02:11 which are dark linear features often
00:02:11 --> 00:02:14 found on the side of steep slopes and
00:02:14 --> 00:02:17 these display seasonal changes appearing
00:02:17 --> 00:02:19 to form in warmer seasons and then
00:02:19 --> 00:02:21 fading away again in cooler ones now
00:02:21 --> 00:02:23 that's a way that's consistent with the
00:02:23 --> 00:02:26 behavior of liquid water but now new
00:02:26 --> 00:02:28 research reported in the Journal of the
00:02:28 --> 00:02:29 proceedings of the National Academy of
00:02:29 --> 00:02:31 Science es has thrown cold water on the
00:02:31 --> 00:02:34 ID that were ever likely to find liquid
00:02:34 --> 00:02:36 water on Mars be it in the form of
00:02:36 --> 00:02:39 recurring slope line permafrost or pools
00:02:39 --> 00:02:41 of brine one of the studies authors
00:02:41 --> 00:02:43 Vincent chevrier from the University of
00:02:43 --> 00:02:45 Arkansas says there's a lot of confusion
00:02:45 --> 00:02:47 misunder understandings and erroneous
00:02:47 --> 00:02:49 interpretations of what researchers
00:02:49 --> 00:02:51 really say about the state of liquid
00:02:51 --> 00:02:53 water on the red planet He suggests that
00:02:53 --> 00:02:56 a closer look at recurring slope line
00:02:56 --> 00:02:58 indicates their behavior is consistent
00:02:58 --> 00:03:00 with sand and dust flows and that no
00:03:00 --> 00:03:02 water would be needed to create them
00:03:02 --> 00:03:04 available data from Mars orbiters can
00:03:04 --> 00:03:07 confirm that liquid water plays any role
00:03:07 --> 00:03:09 in their development however other
00:03:09 --> 00:03:11 Studies have shown High hydroxy levels
00:03:11 --> 00:03:14 associated with recurring slope line
00:03:14 --> 00:03:15 supporting the idea that it could really
00:03:15 --> 00:03:18 be melting permafrost seeping out of the
00:03:18 --> 00:03:20 ground other researchers believe that
00:03:20 --> 00:03:22 brins which are solutions with high
00:03:22 --> 00:03:24 concentrations of salts could hold the
00:03:24 --> 00:03:27 key to finding liquid water on Mars and
00:03:27 --> 00:03:28 of course there is an abundance of salts
00:03:28 --> 00:03:31 on Mars of these salts perchlorates
00:03:31 --> 00:03:33 would seem the most promising since they
00:03:33 --> 00:03:36 have extremely low tic temperatures
00:03:36 --> 00:03:37 that's when the melting point of the
00:03:37 --> 00:03:39 combined mixture is lower than that of
00:03:39 --> 00:03:42 any single ingredient in it for instance
00:03:42 --> 00:03:44 a calcium perchlorate brine solidifies
00:03:44 --> 00:03:48 atus 75° Celsius mass is an average
00:03:48 --> 00:03:50 surface temperature of -50° C at the
00:03:50 --> 00:03:52 equator theoretically that suggest that
00:03:52 --> 00:03:54 there could be zones where calcium
00:03:54 --> 00:03:56 perchlorate brins could stay liquid
00:03:56 --> 00:03:59 especially in the subsurface the authors
00:03:59 --> 00:04:00 of this new study examined all the
00:04:00 --> 00:04:02 arguments for and against Brian's
00:04:02 --> 00:04:04 potentially forming stable liquids on
00:04:04 --> 00:04:06 the red planet now ultimately They
00:04:06 --> 00:04:08 concluded that the various limiting
00:04:08 --> 00:04:10 factors including the relatively low
00:04:10 --> 00:04:12 amounts of the most promising salts
00:04:12 --> 00:04:14 water vapor pressure and Ice locations
00:04:14 --> 00:04:16 strongly limited the abundances of brins
00:04:16 --> 00:04:18 both on the surface or for that matter
00:04:18 --> 00:04:21 in the shallow subsurface and the
00:04:21 --> 00:04:23 authors conclude that even if brinds did
00:04:23 --> 00:04:24 form they would remain highly
00:04:24 --> 00:04:28 unhabitable by Earth's standards this is
00:04:28 --> 00:04:31 spacetime still to come discovery of a
00:04:31 --> 00:04:33 new population of small maint asteroids
00:04:33 --> 00:04:35 and Australia's lunar rover project
00:04:36 --> 00:04:38 takes another step forward all that and
00:04:38 --> 00:04:41 more still to come on
00:04:41 --> 00:04:55 [Music]
00:04:55 --> 00:04:57 SpaceTime astronomers using NASA's
00:04:57 --> 00:05:00 webspace telescope have disc CED a new
00:05:00 --> 00:05:02 population of celestial bodies in the
00:05:02 --> 00:05:04 main asteroid belt between Mars and
00:05:04 --> 00:05:07 Jupiter the 138 new asteroids range in
00:05:07 --> 00:05:09 size from that of a bus to about the
00:05:09 --> 00:05:12 size of a football stadium and that's a
00:05:12 --> 00:05:13 size range within the main asteroid
00:05:13 --> 00:05:15 built that has not previously been
00:05:15 --> 00:05:18 observed knowing how many main belt
00:05:18 --> 00:05:19 asteroids there are in different size
00:05:19 --> 00:05:21 ranges can tell astronomers something
00:05:21 --> 00:05:23 about how asteroids have changed over
00:05:23 --> 00:05:26 time thanks to ongoing collisions and
00:05:26 --> 00:05:28 that process is related to how some of
00:05:28 --> 00:05:30 them have escaped the main as built over
00:05:30 --> 00:05:32 the solar systems history and even how
00:05:32 --> 00:05:35 some meteorites end up on Earth one of
00:05:35 --> 00:05:37 the study's authors Tom Green from Nas's
00:05:37 --> 00:05:39 Ames Research Center in California
00:05:39 --> 00:05:41 Silicon Valley says we Now understand
00:05:41 --> 00:05:43 more about how small objects in the
00:05:43 --> 00:05:45 asteroid build are formed and how many
00:05:45 --> 00:05:48 there could be asteroids this size
00:05:48 --> 00:05:50 likely form through collisions between
00:05:50 --> 00:05:52 larger ones and they're also likely to
00:05:52 --> 00:05:54 drift towards the vicinity of the Earth
00:05:54 --> 00:05:57 and the Sun over time so insights from
00:05:57 --> 00:05:59 this research could hope astronomers
00:05:59 --> 00:06:00 working on the asteroid threat
00:06:00 --> 00:06:02 assessment project at ases which is
00:06:02 --> 00:06:04 studying what would happen in the case
00:06:04 --> 00:06:06 of an Earth impact and modeling the
00:06:06 --> 00:06:10 associated risks this is spacetime still
00:06:10 --> 00:06:12 to come Australia's lunar rover project
00:06:12 --> 00:06:14 takes another step forward and planet
00:06:14 --> 00:06:16 Earth reaches perah helion the brightest
00:06:16 --> 00:06:19 star in the night sky serus the missing
00:06:19 --> 00:06:21 constellation argonavis and the
00:06:21 --> 00:06:23 quadrants meteor showers are among the
00:06:23 --> 00:06:25 celestial highlights during the month of
00:06:25 --> 00:06:27 January on Skywatch
00:06:27 --> 00:06:42 [Music]
00:06:42 --> 00:06:44 Luna alut says its Australian Branch
00:06:44 --> 00:06:46 will lead efforts by the ot2 Consortium
00:06:46 --> 00:06:48 to build and operate Australia's first
00:06:48 --> 00:06:51 lunar rover the $42 million initiative
00:06:51 --> 00:06:53 is being funded by the federal
00:06:53 --> 00:06:55 government through ASA the Australian
00:06:55 --> 00:06:57 space agency The Rovers be named the
00:06:57 --> 00:06:59 Rover through a public naming camp
00:06:59 --> 00:07:01 campaign and if you think that sounds
00:07:01 --> 00:07:02 bad remember it could have been a lot
00:07:02 --> 00:07:04 worse after all they might have called
00:07:04 --> 00:07:07 it Rover Mac roverf face Luna alpur
00:07:07 --> 00:07:09 initially developed four prototype
00:07:09 --> 00:07:11 Rovers over 15 months in order to test
00:07:11 --> 00:07:13 different technical features such as
00:07:13 --> 00:07:16 autonomous systems for remote operations
00:07:16 --> 00:07:18 meanwhile swinburn university has been
00:07:18 --> 00:07:19 selected to provide essential technology
00:07:20 --> 00:07:22 for the new Rover including evaluating
00:07:22 --> 00:07:23 and testing at space radiation
00:07:24 --> 00:07:25 resistance and active lunar dust
00:07:25 --> 00:07:27 mitigation Technologies in the extreme
00:07:27 --> 00:07:30 lunar environment Moon dust remains a
00:07:30 --> 00:07:33 key problem for any lunar surface
00:07:33 --> 00:07:35 operations you see the dust is as fine
00:07:36 --> 00:07:38 as talcum powder and it's composed of
00:07:38 --> 00:07:41 sharp glass-like shards small enough to
00:07:41 --> 00:07:43 get into any opening and sharp enough to
00:07:43 --> 00:07:45 clog up critical mechanisms including
00:07:45 --> 00:07:47 equipment conveyors cameras and vacuum
00:07:47 --> 00:07:49 systems so it's a problem which needs to
00:07:49 --> 00:07:52 be solved if reliability on the moon is
00:07:52 --> 00:07:57 to be achieved this is spacetime
00:07:57 --> 00:08:05 [Music]
00:08:11 --> 00:08:13 and time that to turn our eyes to the
00:08:13 --> 00:08:15 skies and check out the celestial sphere
00:08:15 --> 00:08:18 for January on Skywatch January is the
00:08:18 --> 00:08:20 first month of the year in the Julian
00:08:20 --> 00:08:23 and gorian calendars the name originates
00:08:23 --> 00:08:25 in the Latin word for door that's
00:08:25 --> 00:08:27 because January is the door to the new
00:08:27 --> 00:08:30 year and an opening to New Beginnings
00:08:30 --> 00:08:32 the month is conventionally thought of
00:08:32 --> 00:08:35 as being named after Janus the mythical
00:08:35 --> 00:08:37 Roman god of beginnings and transitions
00:08:37 --> 00:08:39 but according to the ancient Roman
00:08:39 --> 00:08:42 Farmers Almanac it was actually Juno who
00:08:42 --> 00:08:44 was the traditional God of January of
00:08:44 --> 00:08:46 course from an astronomical point of
00:08:46 --> 00:08:48 view January marks Earth's closest
00:08:48 --> 00:08:50 orbital position to the sun perhelion
00:08:50 --> 00:08:52 which occurs about 2 weeks after the
00:08:52 --> 00:08:55 December solce planets including the
00:08:55 --> 00:08:57 Earth don't orbit the Sun in perfect
00:08:57 --> 00:08:59 circles but rather in EV changing
00:08:59 --> 00:09:02 elliptical orbits the shape of these
00:09:02 --> 00:09:04 orbits vary due to gravitational
00:09:04 --> 00:09:06 influences from other planetary objects
00:09:06 --> 00:09:08 and in Earth's case that especially
00:09:08 --> 00:09:09 includes the moon which is almost
00:09:10 --> 00:09:11 massive enough to be considered a binary
00:09:11 --> 00:09:14 partner so over a roughly 100 years
00:09:15 --> 00:09:17 cycle Earth's orbit changes in shape
00:09:17 --> 00:09:19 from almost circular to far more
00:09:19 --> 00:09:22 elliptical this difference is known as
00:09:22 --> 00:09:24 eccentricity and the nearest pointing
00:09:24 --> 00:09:26 Earth's orbit around the Sun is called
00:09:26 --> 00:09:29 perhelion this Ed perhelion will occur
00:09:29 --> 00:09:32 on Sunday the 5th of January at 12:28 in
00:09:32 --> 00:09:33 the morning Australian eastern daylight
00:09:33 --> 00:09:36 time when the earth will be just 147
00:09:36 --> 00:09:38 million1
00:09:38 --> 00:09:42 3 km from the Sun that's 8:28 in the
00:09:42 --> 00:09:44 morning of January the 4th us Eastern
00:09:44 --> 00:09:47 Standard Time and 1 128 in the afternoon
00:09:47 --> 00:09:49 of January the 4th Greenwich
00:09:49 --> 00:09:52 meantime around 6 months later and about
00:09:52 --> 00:09:54 2 weeks after the June Solstice Earth
00:09:54 --> 00:09:56 will be at its furthest orbital position
00:09:56 --> 00:10:00 from the Sun a location known as aelan
00:10:00 --> 00:10:02 okay let's start our tour of the January
00:10:02 --> 00:10:04 night sky by looking to the Northeast
00:10:04 --> 00:10:06 right next to the constellation Orion
00:10:06 --> 00:10:08 where you'll see the brightest star in
00:10:08 --> 00:10:11 the night sky the dog star serus soall
00:10:11 --> 00:10:12 because it's the brightest star at the
00:10:12 --> 00:10:15 constellation Canis Major the big dog
00:10:15 --> 00:10:18 the name serus actually means scorching
00:10:18 --> 00:10:20 or brilliant a clear reference to its
00:10:20 --> 00:10:22 spectacular brightness in the sky as
00:10:22 --> 00:10:24 well as being one of the nearest stars
00:10:24 --> 00:10:27 to the Sun at just 8.7 light years it's
00:10:27 --> 00:10:29 also intrinsically bright and almost
00:10:29 --> 00:10:30 twice as bright as the second brightest
00:10:31 --> 00:10:33 St in the night skies canopus a light
00:10:33 --> 00:10:36 year is about 10 trillion kilm the
00:10:36 --> 00:10:38 distance of photon can travel in a year
00:10:38 --> 00:10:41 at 300 km/s the speed of light in a
00:10:41 --> 00:10:43 vacuum and the ultimate speed limit of
00:10:43 --> 00:10:46 the universe Sirius is the fifth closest
00:10:46 --> 00:10:48 start of the Sun and it's gradually
00:10:48 --> 00:10:50 moving closer to the solar system so
00:10:50 --> 00:10:52 it'll steadily increase in brightness
00:10:52 --> 00:10:55 over the next 60 years after which
00:10:55 --> 00:10:57 time it will begin moving away again and
00:10:57 --> 00:11:00 it will gradually become fater fainter
00:11:00 --> 00:11:01 but it will still continue to be the
00:11:01 --> 00:11:03 brightest star in Earth's night sky for
00:11:03 --> 00:11:07 at least the next 210 years Sirius
00:11:07 --> 00:11:10 is a binary star system comprising a
00:11:10 --> 00:11:12 spectr type a main sequence white star
00:11:13 --> 00:11:15 called Sirius a and a small white dwarf
00:11:15 --> 00:11:18 companion Serius B which orbits between
00:11:18 --> 00:11:21 8.2 and 31.5 astronomical units away
00:11:21 --> 00:11:24 from the primary star an astronomical
00:11:24 --> 00:11:26 unit is the average distance between the
00:11:26 --> 00:11:30 Earth and the Sun about 150 million km
00:11:30 --> 00:11:32 main sequence stars are those undergoing
00:11:32 --> 00:11:34 hydrogen fusion into helium in their
00:11:35 --> 00:11:38 core astronomist describe stars in terms
00:11:38 --> 00:11:40 of spectral types A classification
00:11:40 --> 00:11:42 system based on temperature and
00:11:42 --> 00:11:44 characteristics the hottest most massive
00:11:44 --> 00:11:46 and most luminous stars are known as
00:11:46 --> 00:11:49 spectr type O blue stars they're
00:11:49 --> 00:11:51 followed by spectr type B blue white
00:11:51 --> 00:11:54 stars then spectr type a white stars
00:11:54 --> 00:11:56 spectral type f whitish yellow stars
00:11:56 --> 00:11:58 spectral type G yellow stars that's
00:11:58 --> 00:12:01 where Sun fits in spectr type K orange
00:12:01 --> 00:12:04 stars and the coolest and least massive
00:12:04 --> 00:12:07 stars known are spectr Type M red stars
00:12:07 --> 00:12:09 each spectral classification can also be
00:12:09 --> 00:12:11 subdivided using a numeric digit to
00:12:11 --> 00:12:13 represent temperature with zero being
00:12:13 --> 00:12:15 the hottest and nine the coolest and a
00:12:15 --> 00:12:18 Roman numeral to represent Luminosity
00:12:18 --> 00:12:20 now put all that together and our sun
00:12:20 --> 00:12:25 becomes a g2v or G25 yellow dwarf star
00:12:25 --> 00:12:27 also included in the spectral
00:12:27 --> 00:12:29 classification system a spectr types T
00:12:29 --> 00:12:31 and Y which are assigned to fail Stars
00:12:31 --> 00:12:33 known as brown dwarves some of which
00:12:33 --> 00:12:36 were born as spectr Type M red stars but
00:12:36 --> 00:12:38 became Brown dwarves after losing some
00:12:38 --> 00:12:41 of their Mass BR dwarves fit into a
00:12:41 --> 00:12:43 category between the largest planets
00:12:43 --> 00:12:45 which are about 13 times the mass of
00:12:45 --> 00:12:47 Jupiter and the smallest stars those
00:12:47 --> 00:12:49 spectr type M red dwarfs we talked about
00:12:49 --> 00:12:52 before which are about 75 to 80 times
00:12:52 --> 00:12:55 the mass of Jupiter or around 0.08 solar
00:12:56 --> 00:12:58 masses Brown dwarves don't have enough
00:12:58 --> 00:13:00 Mass to build up the sorts of
00:13:00 --> 00:13:01 temperatures and pressures in their
00:13:01 --> 00:13:03 cores needed to trigger the nuclear
00:13:03 --> 00:13:05 fusion process which Mak stars like our
00:13:06 --> 00:13:07 sun
00:13:07 --> 00:13:10 shine Sirius a has at least twice the
00:13:10 --> 00:13:12 mass of the Sun and is about 25 times
00:13:13 --> 00:13:16 more luminous the Sirus binary system is
00:13:16 --> 00:13:18 between 200 and 300 million years old
00:13:18 --> 00:13:20 quite Young by astronomical standards
00:13:20 --> 00:13:22 and it originally consisted of two
00:13:22 --> 00:13:25 bright spectr type a white stars the
00:13:25 --> 00:13:28 more massive of these two stars serus B
00:13:28 --> 00:13:29 consumed its resource es and became a
00:13:30 --> 00:13:31 red giant before shedding off its outer
00:13:31 --> 00:13:33 layers and collapsing into its current
00:13:33 --> 00:13:36 state as a white dwarf around 120
00:13:36 --> 00:13:39 million years ago a white dwarf is the
00:13:39 --> 00:13:42 Stellar corpse of a sunlike star having
00:13:42 --> 00:13:44 used up its nuclear fuel supply fusing
00:13:44 --> 00:13:46 hydrogen into helium in its core it
00:13:46 --> 00:13:49 expands into a red giant as it fuses
00:13:49 --> 00:13:51 helium into carbon and oxygen now
00:13:51 --> 00:13:53 biggest stars can fuse progressively
00:13:53 --> 00:13:55 heavier and heavier elements but low
00:13:55 --> 00:13:57 mass stars like the sun simply aren't
00:13:57 --> 00:13:59 big enough to fuse carbon and oxygen
00:13:59 --> 00:14:02 into heavier elements and so they turn
00:14:02 --> 00:14:05 off the outer gases envelope separates
00:14:05 --> 00:14:06 and floats off into space as a
00:14:06 --> 00:14:09 spectacular object called a planetary
00:14:09 --> 00:14:12 nebula What's Left Behind is a super
00:14:12 --> 00:14:14 dense white hot Stellar core about the
00:14:14 --> 00:14:17 size of the Earth called a white dwarf
00:14:17 --> 00:14:19 which will slowly cool down over the
00:14:19 --> 00:14:22 aons of time our sun will become a white
00:14:22 --> 00:14:26 dwarf in about 7 billion years from now
00:14:26 --> 00:14:28 5 years ago the ancient Egyptians
00:14:28 --> 00:14:31 looked at serious and they saw it as the
00:14:31 --> 00:14:33 god an nubis lord of the underworld who
00:14:33 --> 00:14:35 had the head of a dog and who invented
00:14:35 --> 00:14:38 himing the funeral rights and who guided
00:14:38 --> 00:14:40 one through the underworld to judgment
00:14:40 --> 00:14:42 where he attended the scales during the
00:14:42 --> 00:14:44 weighing of the heart to determine one's
00:14:44 --> 00:14:47 fate in the afterlife Anubis was later
00:14:47 --> 00:14:50 replaced in Egyptian mythology by Osiris
00:14:50 --> 00:14:52 as the lord of the underworld and Sirius
00:14:52 --> 00:14:55 became the Goddess Isis by carefully
00:14:55 --> 00:14:57 watching sirus's movements across the
00:14:57 --> 00:14:59 sky the ancient egyp Egyptians
00:14:59 --> 00:15:00 determined that it would be visible
00:15:00 --> 00:15:03 every night for 295 and a quarter nights
00:15:03 --> 00:15:06 followed by 70 nights of absence and
00:15:06 --> 00:15:08 this allowed them to determine that a
00:15:08 --> 00:15:12 year was 365 and a/4 days long the
00:15:12 --> 00:15:14 calculations were accurate to within 11
00:15:14 --> 00:15:17 minutes the helical rising of Sirius
00:15:17 --> 00:15:19 also marked the annual flooding of the
00:15:19 --> 00:15:21 River Nile in ancient Egypt and the hot
00:15:21 --> 00:15:23 sultry dog days of summer for the
00:15:23 --> 00:15:26 ancient Greeks in Greek mythology Sirius
00:15:26 --> 00:15:29 was the dog star and the canine
00:15:29 --> 00:15:32 companion of Ryan the hunter helical
00:15:32 --> 00:15:33 Rising refers to the first time of the
00:15:33 --> 00:15:35 year when star becomes visible above the
00:15:35 --> 00:15:38 Eastern Horizon for a brief moment just
00:15:38 --> 00:15:39 Before
00:15:39 --> 00:15:41 Sunrise it's been claimed that the Doon
00:15:41 --> 00:15:43 people in Marley and western Africa have
00:15:44 --> 00:15:46 ancient stories describing the 50e
00:15:46 --> 00:15:47 orbital period of Sirius and its
00:15:48 --> 00:15:50 companion white dwarf which predate the
00:15:50 --> 00:15:52 white dwarf's Discovery by modern
00:15:52 --> 00:15:54 astronomers it's also claimed that these
00:15:54 --> 00:15:57 Legends were handed to the Doon people
00:15:57 --> 00:15:59 by ancient aquatic space Travelers who
00:15:59 --> 00:16:01 told them of a third star accompanying
00:16:01 --> 00:16:04 series A and B however a report in the
00:16:04 --> 00:16:06 journal current anthropology raised
00:16:06 --> 00:16:08 serious doubts about whether the Stars
00:16:08 --> 00:16:10 referred to by the Doon people were in
00:16:10 --> 00:16:12 fact Sirius a and its white dwarf
00:16:12 --> 00:16:14 companion that's because senior Doon
00:16:15 --> 00:16:16 claim the story actually refers to a
00:16:16 --> 00:16:19 different grouping of stars also other
00:16:19 --> 00:16:21 researchers have pointed out the Doon
00:16:21 --> 00:16:23 could have heard about the discovery of
00:16:23 --> 00:16:25 sirus's companion and then simply
00:16:25 --> 00:16:27 incorporated into their mythology in
00:16:27 --> 00:16:29 1893 when a French Expedition arrived in
00:16:29 --> 00:16:32 Central West Africa to observe an April
00:16:32 --> 00:16:34 16 total eclipse and were overheard
00:16:34 --> 00:16:36 discussing the
00:16:36 --> 00:16:38 discovery looking due north just above
00:16:38 --> 00:16:40 the Horizon this time of year and you'll
00:16:40 --> 00:16:42 see the bright yellowish star capella
00:16:42 --> 00:16:44 the brightest star in the constellation
00:16:44 --> 00:16:47 Orga the charioteer capella is the Latin
00:16:47 --> 00:16:50 term for a small female goat the star's
00:16:50 --> 00:16:52 alternative name is Capra which was more
00:16:52 --> 00:16:55 commonly used in classical times
00:16:55 --> 00:16:56 although it appears to be a single star
00:16:56 --> 00:16:59 of the uned eye capella is actually a
00:16:59 --> 00:17:02 system of four stars in Two binary pairs
00:17:02 --> 00:17:04 the first pair comprises two bright
00:17:04 --> 00:17:06 yellow giant stars both of which were
00:17:06 --> 00:17:08 around 2 and 1/ half times the mass of
00:17:08 --> 00:17:10 the Sun having exhausted their core
00:17:10 --> 00:17:13 hydrogen supplies both stars have cooled
00:17:13 --> 00:17:15 and expanded out to become Giants moving
00:17:15 --> 00:17:18 off the main sequence designated capella
00:17:18 --> 00:17:21 AA and capella AB they're in a very
00:17:21 --> 00:17:24 tight circular orbit some 0.76
00:17:24 --> 00:17:26 astronomical units apart orbiting each
00:17:26 --> 00:17:30 other every 104 Earth days capella AA is
00:17:30 --> 00:17:32 the cooler and more luminous of the two
00:17:32 --> 00:17:35 with some 78 times the luminosity and 12
00:17:35 --> 00:17:38 times the radius of the Sun known as an
00:17:38 --> 00:17:40 aging red Clump star capillar AA is
00:17:40 --> 00:17:43 fusing helium into carbon and oxygen in
00:17:43 --> 00:17:46 its core capillar AB is a slightly
00:17:46 --> 00:17:49 smaller but hotter subgiant about 73
00:17:49 --> 00:17:51 times as luminous and almost nine times
00:17:52 --> 00:17:54 the radius of the Sun and it's in the
00:17:54 --> 00:17:56 process of expanding out to become a red
00:17:56 --> 00:17:58 giant the capillar system is one of the
00:17:58 --> 00:18:00 brightest sources of x-rays in the sky
00:18:00 --> 00:18:02 thought to come primarily from the
00:18:02 --> 00:18:05 corona of the more massive giant the
00:18:05 --> 00:18:06 second pair of stars in Capella are
00:18:06 --> 00:18:09 located about 10 astronomical units
00:18:09 --> 00:18:11 from the first pair they consist of two
00:18:11 --> 00:18:14 faint small relatively cool spectr Type
00:18:14 --> 00:18:17 M main sequence red dwarf stars the two
00:18:17 --> 00:18:20 red dwars have been designated capella H
00:18:20 --> 00:18:23 and capella L now almost directly
00:18:23 --> 00:18:25 overhead this time of year a position in
00:18:25 --> 00:18:28 the sky known as Zenith we find kopus
00:18:28 --> 00:18:30 the second brightest star in the night
00:18:30 --> 00:18:33 sky after Sirius located some 3133 light
00:18:33 --> 00:18:35 years away in the constellation Kore of
00:18:35 --> 00:18:38 the Keel canopus looks incredibly bright
00:18:38 --> 00:18:41 because it is huge it's a giant spectral
00:18:41 --> 00:18:44 type a white star with some 10 times the
00:18:44 --> 00:18:48 mass 71 times the diameter and 10
00:18:48 --> 00:18:51 times the Luminosity of the sun kopus is
00:18:51 --> 00:18:53 another bride x-ray Source also most
00:18:53 --> 00:18:55 likely produced by its Corona
00:18:55 --> 00:18:57 magnetically heed to several million
00:18:57 --> 00:18:59 Kelvin the temperatures is also likely
00:18:59 --> 00:19:01 to be stimulated by fast rotation
00:19:01 --> 00:19:03 combined with strong internal convection
00:19:03 --> 00:19:05 currents percolating through the Stars
00:19:05 --> 00:19:08 outer layers no star in our night sky
00:19:08 --> 00:19:11 closer than canopus is more luminous
00:19:11 --> 00:19:13 than it and it's been the brightest star
00:19:13 --> 00:19:14 in Earth's night sky during three
00:19:14 --> 00:19:17 different epochs over the past 4 million
00:19:17 --> 00:19:20 years other stars appear brighter only
00:19:20 --> 00:19:22 during relatively temporary periods
00:19:22 --> 00:19:23 during which they're passing the solar
00:19:24 --> 00:19:26 system at much closer distances than
00:19:26 --> 00:19:29 canopus about 990 years ago serus
00:19:29 --> 00:19:31 move close enough that it appeared to be
00:19:31 --> 00:19:33 brighter in our night sky than canopus
00:19:33 --> 00:19:35 and as we mentioned earlier that'll
00:19:35 --> 00:19:37 Remain the case for another 210
00:19:37 --> 00:19:40 years but in 480 years from now
00:19:40 --> 00:19:43 kobis will once again be the brightest
00:19:43 --> 00:19:45 star in the night sky and it will remain
00:19:45 --> 00:19:49 so for a period of about 510
00:19:49 --> 00:19:52 years in Greek mythology kopus was a
00:19:52 --> 00:19:54 Helmsman and the navigator for the fleet
00:19:54 --> 00:19:56 of min's King of Sparta which was
00:19:57 --> 00:19:59 sailing back from the battle of Troy
00:19:59 --> 00:20:01 canopus is said to have died when the
00:20:01 --> 00:20:03 fleet arrived at the Port of Alexandria
00:20:03 --> 00:20:06 in Egypt and so a star which was visible
00:20:06 --> 00:20:09 in the Horizon was named in his honor
00:20:09 --> 00:20:10 now as we said it's the brightest star
00:20:10 --> 00:20:12 of the constellation Kina which
00:20:12 --> 00:20:15 represents the kill of the boat Argo
00:20:15 --> 00:20:17 used by Jason and the Argonauts in their
00:20:17 --> 00:20:19 quest for the Golden Fleece located
00:20:19 --> 00:20:22 nearby are the vessel sails represented
00:20:22 --> 00:20:24 by the constellation V and the roof of
00:20:24 --> 00:20:26 the birs re cabin or poop deck which is
00:20:27 --> 00:20:29 represented by the constellation papus
00:20:29 --> 00:20:32 combined Karina V and papus used to form
00:20:32 --> 00:20:34 the constellation Argo Navas
00:20:34 --> 00:20:36 representing the ship Argo skimming
00:20:36 --> 00:20:39 along the river of the Milky Way But
00:20:39 --> 00:20:40 modern day astronomers considered the
00:20:40 --> 00:20:42 constellation simply too big as it was
00:20:42 --> 00:20:45 28% larger than the next largest
00:20:45 --> 00:20:47 constellation had more than 180 easily
00:20:47 --> 00:20:50 visible stars so it was divided into
00:20:50 --> 00:20:53 three smaller constellations Kina verer
00:20:53 --> 00:20:55 and puus in
00:20:55 --> 00:20:58 1755 kopus forms part of the Stellar
00:20:58 --> 00:21:00 Association asterism known as the false
00:21:00 --> 00:21:03 cross which straddles the constellations
00:21:03 --> 00:21:05 Kina and V of the cells and is often
00:21:05 --> 00:21:08 confused with the real Southern Cross or
00:21:08 --> 00:21:10 Crooks this time of the year the
00:21:10 --> 00:21:12 Southern Cross is upside down low down
00:21:12 --> 00:21:14 in the southern Skies during the early
00:21:14 --> 00:21:16 evening for our listeners north of say
00:21:16 --> 00:21:18 Brisbane it'll most likely be hidden by
00:21:18 --> 00:21:20 trees and buildings on the horizon
00:21:20 --> 00:21:23 during the early evening but later on as
00:21:23 --> 00:21:25 the Earth turns the Southern Cross will
00:21:25 --> 00:21:27 rise above the Horizon in the South
00:21:27 --> 00:21:29 Southeast for our Northern listeners and
00:21:29 --> 00:21:32 appear to be lying on its left side one
00:21:32 --> 00:21:33 of the best things about living in the
00:21:33 --> 00:21:35 southern hemisphere is that most of the
00:21:35 --> 00:21:38 brightest stars in the night sky are
00:21:38 --> 00:21:41 visible during January nights Sirius the
00:21:41 --> 00:21:43 dog star is the brightest followed by
00:21:43 --> 00:21:45 canopus the navigation star third
00:21:45 --> 00:21:48 brightest is alent Tori the furthest of
00:21:48 --> 00:21:50 the two pointer Stars pointing to the
00:21:50 --> 00:21:52 Southern Cross and the nearest star
00:21:52 --> 00:21:55 system to the Sun the fourth and fifth
00:21:55 --> 00:21:57 brighter stars acturus and Vega aren't
00:21:57 --> 00:21:58 visible in the southern hemisphere
00:21:58 --> 00:22:00 featuring January but the sixth
00:22:01 --> 00:22:03 brightest capella is visible just above
00:22:03 --> 00:22:06 the northern Horizon and the seventh
00:22:06 --> 00:22:09 rigel marks Orion's knee next in eighth
00:22:09 --> 00:22:12 place is prion the little dog and Ninth
00:22:12 --> 00:22:15 is akar at the end of the river eridanus
00:22:15 --> 00:22:18 finally there's bleers Orion shoulder
00:22:18 --> 00:22:20 the 10th brightest star in the night sky
00:22:20 --> 00:22:22 so that's eight of the 10 brightest
00:22:22 --> 00:22:24 stars in the night sky all visible at
00:22:24 --> 00:22:26 once on a warm Summer's evening in the
00:22:26 --> 00:22:29 southern hemisphere
00:22:29 --> 00:22:31 January also plays host to one primary
00:22:31 --> 00:22:34 meteor shower the quadrantids most
00:22:34 --> 00:22:36 meteor showers radiate out from a
00:22:36 --> 00:22:38 recognizable constellation like Leo's
00:22:38 --> 00:22:41 leonids or Gemini's Geminids or Orion's
00:22:41 --> 00:22:44 orionids but the quadrantids and meteors
00:22:44 --> 00:22:45 that appear to radiate out from the
00:22:45 --> 00:22:48 location of the former quadran Morales
00:22:48 --> 00:22:51 constellation in the early 1920s the
00:22:51 --> 00:22:53 international astronomical Union divided
00:22:53 --> 00:22:55 the sky into 88 official
00:22:55 --> 00:22:57 constellations however that means more
00:22:57 --> 00:22:59 than 30 other historical constellations
00:23:00 --> 00:23:02 didn't make the cut the quadran Morales
00:23:02 --> 00:23:04 area of the sky falls within the
00:23:04 --> 00:23:06 boundaries of the official constellation
00:23:06 --> 00:23:09 booties the radiant point of the shower
00:23:09 --> 00:23:11 is near the Big Dipper between the end
00:23:11 --> 00:23:13 of the handle and the quadrilateral of
00:23:13 --> 00:23:14 stars marking the head of the
00:23:14 --> 00:23:17 constellation Draco the quadrantids are
00:23:17 --> 00:23:18 usually one of the year's most
00:23:18 --> 00:23:21 spectacular meteor showers with up to
00:23:21 --> 00:23:23 eight meteors per hour they're best seen
00:23:23 --> 00:23:25 from the Northern Hemisphere and unlike
00:23:25 --> 00:23:27 other meteor showers which tend to pick
00:23:27 --> 00:23:28 for at least a day or two the
00:23:28 --> 00:23:30 quadrantids only pick for a couple of
00:23:30 --> 00:23:33 hours while most meteor showers are
00:23:33 --> 00:23:34 produced by the Earth passing through
00:23:34 --> 00:23:37 debris Trails left behind by comets the
00:23:37 --> 00:23:38 quadrantids are one of only two meteor
00:23:38 --> 00:23:41 shs known to be produced by asteroids
00:23:41 --> 00:23:43 they're associated with the asteroid
00:23:43 --> 00:23:46 2003 eh1 which is thought to be the
00:23:46 --> 00:23:48 remains of a cometry nucleus that
00:23:48 --> 00:23:51 fragmented and broke apart centuries ago
00:23:51 --> 00:23:53 eh1 still circles the sun in a 5 and a
00:23:53 --> 00:23:55 half Earth yearlong elongated comet-like
00:23:55 --> 00:23:58 orbit which extends out Beyond Jupiter
00:23:58 --> 00:24:00 the progenitor is thought to be the
00:24:00 --> 00:24:03 comet c490 y1 which was first observed
00:24:03 --> 00:24:05 by Chinese Japanese and Korean
00:24:05 --> 00:24:07 astronomers 500 years ago it was
00:24:08 --> 00:24:09 classified as an asteroid when it was
00:24:10 --> 00:24:11 discovered by a neear asteroid
00:24:11 --> 00:24:15 telescopic survey in 2003 the only other
00:24:15 --> 00:24:17 major meteor shower associated with an
00:24:17 --> 00:24:19 asteroid are the Geminids which occur in
00:24:19 --> 00:24:21 December and are caused by a debris left
00:24:21 --> 00:24:23 behind by the asteroid 3200 faton which
00:24:24 --> 00:24:25 is also thought to be the remains of a
00:24:25 --> 00:24:28 comet Jonathan nelli from sky telescope
00:24:28 --> 00:24:30 magazine joins us now for the rest of
00:24:30 --> 00:24:33 our tour of the January night skies good
00:24:33 --> 00:24:34 day Stuart yeah well there's plenty to
00:24:34 --> 00:24:36 see in the night sky during January as
00:24:36 --> 00:24:38 long of course as you have reasonably
00:24:38 --> 00:24:39 Dark Skies or you can travel to where
00:24:39 --> 00:24:42 there are few or no artificial lights
00:24:42 --> 00:24:42 because of course it's the light
00:24:42 --> 00:24:44 pollution in the cities and towns that
00:24:45 --> 00:24:46 mainly spoils our view of the night sky
00:24:46 --> 00:24:48 so try and get away from lights I
00:24:48 --> 00:24:49 thought we'd try something a little
00:24:49 --> 00:24:50 different this time we'll take a bit of
00:24:50 --> 00:24:52 a tour along the length of the Milky Way
00:24:52 --> 00:24:54 or at least the half of the Milky Way
00:24:54 --> 00:24:55 that we can see during the hours before
00:24:55 --> 00:24:57 midnight this time of the year because
00:24:57 --> 00:24:58 it's the other half of Milky Way of
00:24:58 --> 00:24:59 course that we can't see because at the
00:24:59 --> 00:25:00 moment it's on the other side of the
00:25:00 --> 00:25:02 Earth but we'll start down the South
00:25:02 --> 00:25:03 with a sudden cross it's part of the Noy
00:25:03 --> 00:25:06 way and at the moment it's right down
00:25:06 --> 00:25:08 south not far above the southern Horizon
00:25:08 --> 00:25:09 so you need to be in the Southern
00:25:09 --> 00:25:10 Hemisphere and you need to look right
00:25:10 --> 00:25:12 down in the southern Horizon in the mid
00:25:12 --> 00:25:14 evening hours this time of year it's
00:25:14 --> 00:25:16 sort of more or less upside down sort of
00:25:16 --> 00:25:18 angled a bit to the left and remember it
00:25:18 --> 00:25:20 looks like a kite shape and it looks
00:25:20 --> 00:25:22 like upside down kite shape and once you
00:25:22 --> 00:25:24 spot the cross you don't usually have
00:25:24 --> 00:25:25 any trouble finding it again but it's
00:25:25 --> 00:25:27 that first time trying to spot the cross
00:25:27 --> 00:25:29 that tricks a lot people because it's
00:25:29 --> 00:25:31 really quite small most people expect to
00:25:31 --> 00:25:32 see something huge dominating the
00:25:32 --> 00:25:33 strikers they've always heard of the
00:25:34 --> 00:25:35 Southern Cross and they expect it to be
00:25:35 --> 00:25:36 really really big but it's actually
00:25:37 --> 00:25:38 really small in fact it's the smallest
00:25:38 --> 00:25:41 of all the 88 official constellations or
00:25:41 --> 00:25:42 they get mixed up with the false cross
00:25:42 --> 00:25:43 that's the other thing that happens a
00:25:43 --> 00:25:45 lot there's the false cross and there's
00:25:45 --> 00:25:46 another cross called the diamond cross
00:25:46 --> 00:25:48 which sort of sort of a similar sort of
00:25:48 --> 00:25:49 shape I mean you can make a cross out of
00:25:49 --> 00:25:52 anything just join the dots but
00:25:52 --> 00:25:53 certainly the false cross here now that
00:25:53 --> 00:25:55 is big that's much bigger than the
00:25:55 --> 00:25:56 Southern Cross when we say cross it's
00:25:56 --> 00:25:59 just four stars and and lines and join
00:25:59 --> 00:26:01 the dots yeah the false cross is often
00:26:01 --> 00:26:02 mistaken because it's the same sort of
00:26:02 --> 00:26:05 shape just much larger than the Southern
00:26:05 --> 00:26:07 Cross sort of surrounding the Southern
00:26:07 --> 00:26:08 Cross constellation is another
00:26:08 --> 00:26:10 constellation called curus and this
00:26:10 --> 00:26:12 one's full of lots and lots of
00:26:12 --> 00:26:14 interesting sights deep Sky objects and
00:26:14 --> 00:26:15 things although not many of them can
00:26:15 --> 00:26:16 actually be seen at this time of the
00:26:16 --> 00:26:19 year because cus is really right down on
00:26:19 --> 00:26:20 the horizon but if you give it a couple
00:26:20 --> 00:26:22 of months the constellation will have
00:26:22 --> 00:26:23 risen higher in the night sky after the
00:26:23 --> 00:26:25 sun goes down and that'll bring some
00:26:25 --> 00:26:26 much wonders into view because if you
00:26:26 --> 00:26:28 can just make out a galaxy to the ne eye
00:26:28 --> 00:26:29 there you can see some star clusters
00:26:29 --> 00:26:31 with a naked eye and plenty of things
00:26:31 --> 00:26:33 with telescope or even binoculars the
00:26:33 --> 00:26:35 next constellation along the Milky Way
00:26:35 --> 00:26:38 is called Karina and Karina is home to a
00:26:38 --> 00:26:40 very large nebula called naturally
00:26:40 --> 00:26:42 enough the Karina nebula and you can
00:26:42 --> 00:26:44 easily see it actually if you have dark
00:26:44 --> 00:26:45 skies it looks like a bit of a fuzzy
00:26:45 --> 00:26:47 patch but it's about as wide as the moon
00:26:47 --> 00:26:49 it's really really big and in fact a lot
00:26:49 --> 00:26:51 of Amer astronomers consider this to be
00:26:51 --> 00:26:53 the best nebula in the in the whole
00:26:53 --> 00:26:56 night sky and to get the view that you
00:26:56 --> 00:26:58 need to appreciate that you do need to
00:26:58 --> 00:27:00 to use a telescope but you can see the
00:27:00 --> 00:27:02 Kina nebula as a fuzzy catch just with
00:27:02 --> 00:27:04 the naked eye a small telescope you much
00:27:04 --> 00:27:05 better view even a pair of binoculars
00:27:05 --> 00:27:07 will give you a great view around there
00:27:07 --> 00:27:08 and you spend some time just looking
00:27:08 --> 00:27:10 around the constellation Karina because
00:27:10 --> 00:27:11 there stacks of things in there which
00:27:11 --> 00:27:13 you can see just with binoculars Karina
00:27:13 --> 00:27:14 actually was once part of a a much
00:27:14 --> 00:27:16 larger constellation known as aronis the
00:27:17 --> 00:27:19 ship of the Argonauts but that was split
00:27:19 --> 00:27:22 up many years ago and became Kina and
00:27:22 --> 00:27:24 two other constellations V and puppet
00:27:24 --> 00:27:26 and indeed V is the next one Along on
00:27:26 --> 00:27:28 our tour just the next one up The Noy
00:27:28 --> 00:27:30 way there's not a lot of great interest
00:27:30 --> 00:27:33 in this one for casual stargazers but
00:27:33 --> 00:27:34 amateur astronomers who know exactly
00:27:34 --> 00:27:36 where to look can find all sorts of
00:27:36 --> 00:27:39 interesting sites in V including Dean
00:27:39 --> 00:27:40 star clusters and things there's a
00:27:40 --> 00:27:43 famous Pulsar in V you don't see that
00:27:43 --> 00:27:45 with am equipment but that's one of its
00:27:45 --> 00:27:47 most famous inhabitants and after V
00:27:47 --> 00:27:50 we've got puppet which has a plethora of
00:27:50 --> 00:27:52 viewing targets for those because it's
00:27:52 --> 00:27:54 the poop deck the poop deck yeah so Aron
00:27:54 --> 00:27:56 got split into three you got Karina
00:27:56 --> 00:27:58 which was the Keel Z is the sh and
00:27:58 --> 00:28:00 puppet is the poop deck of this old ship
00:28:00 --> 00:28:02 and yeah lots of stuff to see in puppet
00:28:02 --> 00:28:04 if you have a tot scope and even if you
00:28:04 --> 00:28:05 don't there's one thing you can see for
00:28:05 --> 00:28:06 instance with the nak eye you can just
00:28:06 --> 00:28:09 make it out it's called m46 or Mia 46
00:28:09 --> 00:28:11 which is a starbuster so if you got good
00:28:11 --> 00:28:13 dark stars and you got good eyes and you
00:28:13 --> 00:28:14 let yourself your dark adjusted and you
00:28:15 --> 00:28:16 get a star map or something and you know
00:28:16 --> 00:28:17 exactly where to look you should be able
00:28:17 --> 00:28:20 to see this star cluster for m46 still
00:28:20 --> 00:28:21 going along the next constellation we
00:28:21 --> 00:28:24 come to is kis major the greater dog and
00:28:24 --> 00:28:26 it's bright star Serius which is the
00:28:26 --> 00:28:28 brightest star in the night sky it
00:28:28 --> 00:28:30 outshines everything apart from the Sun
00:28:30 --> 00:28:32 the moon and the planets Venus and
00:28:32 --> 00:28:33 Jupiter Venus and Jupiter become
00:28:33 --> 00:28:35 brighter than serious but nothing else
00:28:35 --> 00:28:36 does apart from the Sun and the Moon the
00:28:36 --> 00:28:38 next part of the Milky Way if you go
00:28:38 --> 00:28:39 along it's a bit thin on major
00:28:39 --> 00:28:41 attractions but just either side of it
00:28:41 --> 00:28:43 are some famous constellations and some
00:28:43 --> 00:28:45 really good sites the first of these is
00:28:45 --> 00:28:47 one we've spoken about many many times
00:28:47 --> 00:28:49 on the show and that's AR and the Hunter
00:28:49 --> 00:28:50 and it's good reason because it really
00:28:50 --> 00:28:52 is amazing if you join the dots with its
00:28:52 --> 00:28:55 Stars it has a really distinctive shape
00:28:55 --> 00:28:57 and has a lot of bright stars intact so
00:28:57 --> 00:28:59 it really does stand out and it's
00:28:59 --> 00:29:01 bookended by two Bright Stars R and
00:29:01 --> 00:29:03 Beetle Juice and in the middle there's a
00:29:03 --> 00:29:05 row of three stars which are very easy
00:29:05 --> 00:29:07 to spot it's very evenly distributed row
00:29:07 --> 00:29:09 of three stars and it's known as the
00:29:09 --> 00:29:11 Hunter's belt and between the belt and
00:29:11 --> 00:29:14 the star rigel are a couple of stars and
00:29:14 --> 00:29:15 if your eyesight is good enough a little
00:29:16 --> 00:29:17 smudge of light if you got Dark Skies
00:29:17 --> 00:29:19 again and you got good eyesight and you
00:29:19 --> 00:29:20 let yourself get dark adapted you should
00:29:20 --> 00:29:22 see a little smudge of light just with
00:29:22 --> 00:29:24 the naked eye now that smudge is the
00:29:24 --> 00:29:26 famous Ry nebula which is a huge region
00:29:26 --> 00:29:28 of interstellar gas and dut that really
00:29:28 --> 00:29:30 looks magnificent through a telescope
00:29:30 --> 00:29:32 and of course even better on photos can
00:29:32 --> 00:29:34 even sort of start to get a bit of an
00:29:34 --> 00:29:35 idea of that if you've got a pair of say
00:29:35 --> 00:29:38 10 by 50 binoculars as well so when you
00:29:38 --> 00:29:39 look at that you think okay it might
00:29:39 --> 00:29:41 just looks like a fuzzy SMUD or
00:29:41 --> 00:29:42 something but when you then look at a
00:29:42 --> 00:29:43 picture of the irion neula and you
00:29:43 --> 00:29:45 realize I'm looking at that that's
00:29:45 --> 00:29:47 incredible it's 1500 light years away
00:29:47 --> 00:29:49 this is a place where stars and planets
00:29:49 --> 00:29:50 and things have being born they call it
00:29:50 --> 00:29:52 a star forming region it really is quite
00:29:52 --> 00:29:53 amazing this is the thing you know you
00:29:53 --> 00:29:55 look at some stars and star clusters and
00:29:55 --> 00:29:58 in the night sky and depending on the
00:29:58 --> 00:29:59 just using your own eyes or maybe a
00:29:59 --> 00:30:01 small telescope that doesn't give you
00:30:01 --> 00:30:03 the best view okay it might not look
00:30:03 --> 00:30:04 super amazing but when you think about
00:30:04 --> 00:30:06 what it is that you're seeing and how
00:30:06 --> 00:30:08 far away it might be and therefore how
00:30:08 --> 00:30:11 long ago the staright left that thing
00:30:11 --> 00:30:12 could be hundreds of years could be
00:30:12 --> 00:30:14 thousands could be 10 thousands of years
00:30:14 --> 00:30:16 of theight left you know you think back
00:30:16 --> 00:30:18 to what Humanity was doing 10 years
00:30:18 --> 00:30:21 ago not a lot so you looking back in
00:30:21 --> 00:30:23 time the sky is sort of a time capsu you
00:30:23 --> 00:30:25 look out there and things are different
00:30:25 --> 00:30:27 distances from us and those distances
00:30:28 --> 00:30:30 equate to time and that's how far back
00:30:30 --> 00:30:31 we're looking in time and the Orion
00:30:31 --> 00:30:34 Nebula has been such a fascinating thing
00:30:34 --> 00:30:36 for scientists to study too it Tau us
00:30:36 --> 00:30:38 about globular clusters and about Brown
00:30:38 --> 00:30:41 dwarves and the evolution of planets and
00:30:41 --> 00:30:43 stars it's all by looking at this nebula
00:30:43 --> 00:30:45 of AR m42 yeah yeah look it is quite
00:30:45 --> 00:30:47 amazing I mean we're lucky in a way I
00:30:47 --> 00:30:48 mean I suppose wherever the Earth was
00:30:48 --> 00:30:50 situated in the Galaxy we' have lots of
00:30:50 --> 00:30:51 good things to see but we're lucky that
00:30:51 --> 00:30:53 we are where we are so that we can see
00:30:53 --> 00:30:55 the AR that from the right direction and
00:30:55 --> 00:30:57 yeah use it as a sort of a laboratory a
00:30:57 --> 00:30:59 dist distant laboratory to learn about
00:30:59 --> 00:31:00 all the things that are out there in
00:31:00 --> 00:31:02 space yeah not far away is the HSE head
00:31:02 --> 00:31:04 nebula yeah the horad nebula is just off
00:31:04 --> 00:31:06 the end of that little row of tre Stars
00:31:06 --> 00:31:07 I was talking about earlier on now if
00:31:07 --> 00:31:09 people have seen a picture of the horse
00:31:09 --> 00:31:11 head neb think oh wow I've got to get a
00:31:11 --> 00:31:12 telescope and go out and see that well
00:31:12 --> 00:31:14 you can but you need a fairly big
00:31:14 --> 00:31:16 telescope because the horse NE is quite
00:31:16 --> 00:31:19 small and bit hard to see so yeah it
00:31:19 --> 00:31:21 looks beautiful in photos lot of lots of
00:31:21 --> 00:31:22 things in the sty look beautiful in
00:31:22 --> 00:31:24 photos but the reality when you look
00:31:24 --> 00:31:25 through a telescope might be a little
00:31:25 --> 00:31:26 bit different yeah Ayan nebula looks
00:31:26 --> 00:31:28 great through a telescope because it's
00:31:28 --> 00:31:30 really big it's huge so is that Pina
00:31:30 --> 00:31:32 neul I was talking about earlier on it's
00:31:32 --> 00:31:33 big it's huge lots of things to see in
00:31:33 --> 00:31:35 there it could be getting easier to see
00:31:35 --> 00:31:37 too as time goes by because there are
00:31:37 --> 00:31:40 two huge OB blue stars that are reaching
00:31:40 --> 00:31:42 the end of their lives inside the
00:31:42 --> 00:31:44 homunculus nebula which is inside the
00:31:44 --> 00:31:46 Kina nebula and they're about to go
00:31:46 --> 00:31:47 supernova and they could do that any day
00:31:47 --> 00:31:49 now which in astronomical terms means
00:31:49 --> 00:31:51 tomorrow or maybe a million years from
00:31:51 --> 00:31:53 now yes well I can sort of sympathize
00:31:53 --> 00:31:54 with a huge blow to the king that's
00:31:54 --> 00:31:59 going to uh sort of on on the FL ws and
00:31:59 --> 00:32:00 now now just beyond a let's get back to
00:32:00 --> 00:32:02 the Stars just beyond a we've got Taurus
00:32:02 --> 00:32:04 constellation Taurus and it's got a
00:32:04 --> 00:32:06 bright red star called Al Deon and it's
00:32:06 --> 00:32:08 got a wedge shaped cluster of stars
00:32:08 --> 00:32:10 known as the hi 8es and not far from
00:32:10 --> 00:32:12 them is perhaps the most famous star
00:32:12 --> 00:32:14 cluster visible to the uned ey which is
00:32:14 --> 00:32:15 the plees or the Seven Sisters we've
00:32:15 --> 00:32:17 talken about that a lot on the pr so we
00:32:17 --> 00:32:19 won't go through it again now but it it
00:32:19 --> 00:32:20 looks really really good get a pair of
00:32:20 --> 00:32:22 Noles on that it's really quite lovely
00:32:22 --> 00:32:24 really it's beautiful little cluster
00:32:24 --> 00:32:25 Stars opposite Forest on the other side
00:32:26 --> 00:32:28 of the Milky Way we've got Gemini
00:32:28 --> 00:32:30 and Gemini stands out because it has two
00:32:30 --> 00:32:33 stars called Castor and poock which are
00:32:33 --> 00:32:35 sort of the head of each of these two
00:32:35 --> 00:32:37 figures the sort of you do the join the
00:32:37 --> 00:32:38 dots thing and you use a bit of
00:32:38 --> 00:32:39 imagination and you can think oh maybe
00:32:39 --> 00:32:41 there I can see two people standing in
00:32:41 --> 00:32:42 the sky next to each other well those
00:32:42 --> 00:32:44 two stars pestor and polet sort of Mark
00:32:45 --> 00:32:46 their heads of each of those two
00:32:46 --> 00:32:47 characters now there look there's a lot
00:32:47 --> 00:32:49 more to the mie way as I said but not at
00:32:49 --> 00:32:51 this time of year that's the main ones
00:32:51 --> 00:32:52 that we can go through and see we have
00:32:53 --> 00:32:55 to wait until sort of mid year-ish to
00:32:55 --> 00:32:56 see some of the other Mighty
00:32:56 --> 00:32:57 constellations that will be around
00:32:57 --> 00:32:59 during the southern winter or the
00:32:59 --> 00:33:01 northern summer M such as Sagittarius
00:33:01 --> 00:33:04 and Scorpius and endless things to see
00:33:04 --> 00:33:05 inside those constellations now turning
00:33:05 --> 00:33:07 to the planets see what's up planet wise
00:33:07 --> 00:33:10 this time of the year so Venus is very
00:33:10 --> 00:33:11 easy to see at the moment after Sunset
00:33:11 --> 00:33:13 you can't miss it it's above the Western
00:33:13 --> 00:33:15 Horizon Fair Way up above the Western
00:33:15 --> 00:33:17 Horizon actually but you really can't
00:33:17 --> 00:33:18 miss it because it's very big and bright
00:33:18 --> 00:33:21 and white a little higher up above Venus
00:33:21 --> 00:33:24 you've got Saturn Saturn now it's dimmer
00:33:24 --> 00:33:26 than Venus but it does have a a not
00:33:26 --> 00:33:28 noticeable yellowish t so you should be
00:33:28 --> 00:33:30 able to spot that one quite easily now
00:33:30 --> 00:33:32 the thing is keep an eye on these two
00:33:32 --> 00:33:34 planets as the weeks pass because while
00:33:34 --> 00:33:36 Saturn doesn't shift or doesn't seem to
00:33:36 --> 00:33:37 shift its position very much in the
00:33:37 --> 00:33:40 night sky during January Venus will be
00:33:40 --> 00:33:42 so from night to night Venus will have
00:33:42 --> 00:33:44 moved a little bit and over the course
00:33:44 --> 00:33:46 of the first fourth night of January
00:33:46 --> 00:33:47 you'll see that Venus gets closer and
00:33:47 --> 00:33:49 closer and closer to Saturn and on the
00:33:49 --> 00:33:51 nights of the 18th and the 19th of
00:33:51 --> 00:33:53 January they'll be quite close together
00:33:53 --> 00:33:55 about 2 and a half degrees apart which
00:33:55 --> 00:33:57 is about 5 Moon weeks apart which is
00:33:57 --> 00:33:59 that we CL together so that should look
00:33:59 --> 00:34:01 pretty pretty pretty if that makes sense
00:34:01 --> 00:34:02 pretty pretty so got big bright big
00:34:02 --> 00:34:05 bright white Venus and slightly dimmer
00:34:05 --> 00:34:06 yellowish sat so that should be really
00:34:06 --> 00:34:08 nice to see Jupiter is around at the
00:34:08 --> 00:34:09 moment you can see that in the evening
00:34:09 --> 00:34:11 18 constellation Taurus very close to
00:34:11 --> 00:34:13 that star I mentioned earlier on called
00:34:13 --> 00:34:15 Al Deon and finally Mars Mars can be
00:34:15 --> 00:34:17 seen rising over the northeastern
00:34:17 --> 00:34:18 Horizon that's for us in the south at
00:34:18 --> 00:34:21 least just start at 10 p.m. at the start
00:34:21 --> 00:34:22 of the month and it gets bit earlier
00:34:22 --> 00:34:24 each night thereafter on the 15th of
00:34:24 --> 00:34:26 January it reaches a point in its orbit
00:34:26 --> 00:34:27 known as opposition this is something
00:34:27 --> 00:34:29 that am astronomers and particularly
00:34:29 --> 00:34:31 Planet Watchers are always look forward
00:34:31 --> 00:34:33 to because when a planet gets to the
00:34:33 --> 00:34:34 point for opposition it means that from
00:34:34 --> 00:34:37 our vage point on Earth looking out into
00:34:37 --> 00:34:38 space the sun is in One Direction and
00:34:38 --> 00:34:40 the planet is 180 degrees in the
00:34:40 --> 00:34:42 opposite direction so the upshot of that
00:34:42 --> 00:34:44 the Practical upshot of that is that for
00:34:44 --> 00:34:46 Mars since this during January when the
00:34:46 --> 00:34:48 Sun goes down in the west Mars will be
00:34:48 --> 00:34:50 rising in the East and that means you've
00:34:50 --> 00:34:52 got all night to have a look at it okay
00:34:52 --> 00:34:54 because Venus for instance we mentioned
00:34:54 --> 00:34:55 Venus earlier on it's you know high up
00:34:55 --> 00:34:58 in the Western sky after well it'll only
00:34:58 --> 00:35:00 be there for a couple of hours or so and
00:35:00 --> 00:35:01 then it will set so you don't have too
00:35:01 --> 00:35:03 long to look at it but with Mars during
00:35:03 --> 00:35:05 January it's going to be up all night so
00:35:05 --> 00:35:07 as long as you've got some good weather
00:35:07 --> 00:35:08 you should be able to see it and the
00:35:08 --> 00:35:10 other thing too is that when the planet
00:35:10 --> 00:35:12 is at opposition that's roughly the same
00:35:12 --> 00:35:14 time as when it is at its closest to the
00:35:14 --> 00:35:17 earth so Mars is a small planet is
00:35:17 --> 00:35:18 really quite small so when you look
00:35:18 --> 00:35:21 through a telescope it doesn't look big
00:35:21 --> 00:35:23 so the best time to see it at its
00:35:23 --> 00:35:25 biggest is when it's at its closest
00:35:25 --> 00:35:26 which is around the time of opposition
00:35:26 --> 00:35:28 so a lot of turn watch will be out there
00:35:28 --> 00:35:30 withs trying to get the best view of
00:35:30 --> 00:35:33 Mars this year because it'll take
00:35:33 --> 00:35:34 another roughly two years before
00:35:34 --> 00:35:36 opposition comes around again for Mars
00:35:36 --> 00:35:38 so I'm sure people will be making the
00:35:38 --> 00:35:39 most of it toew and this is also the
00:35:39 --> 00:35:42 time when space agencies tend to launch
00:35:42 --> 00:35:43 rockets towards Mars when they've got
00:35:43 --> 00:35:45 missions going that way although none
00:35:45 --> 00:35:47 this year yeah well yeah you want to
00:35:47 --> 00:35:49 when you launch a rocket to a planet
00:35:49 --> 00:35:50 like Mars you want to try and um
00:35:50 --> 00:35:52 minimize the amount of fuel uh and you
00:35:52 --> 00:35:54 sort of Rocket blasts off at a great
00:35:54 --> 00:35:56 rate of knots but then the spacecraft
00:35:56 --> 00:35:58 just coasts all the rest of the way on a
00:35:58 --> 00:36:00 sort of a curving trajectory and you
00:36:00 --> 00:36:01 want to get it there as quick as
00:36:01 --> 00:36:03 possible using the minimum fuel yeah
00:36:03 --> 00:36:05 you've got to launch at the right time
00:36:05 --> 00:36:07 when Earth and Mars are in the right
00:36:07 --> 00:36:08 spot and of course you don't aim for
00:36:08 --> 00:36:10 where Mars is right now you aim for
00:36:10 --> 00:36:12 where Mars will be in seven or eight or
00:36:12 --> 00:36:13 nine months by the time you planic get
00:36:14 --> 00:36:15 sort of aiming ahead like an
00:36:15 --> 00:36:17 interception course and that's do it is
00:36:17 --> 00:36:19 the sky for January that's Jonathan
00:36:19 --> 00:36:22 Nelly from sky and Telescope magazine
00:36:22 --> 00:36:25 and this is spacetime
00:36:25 --> 00:36:39 [Music]
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