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[00:00:00] This is SpaceTime Series 26 Episode 135 for broadcast on the 10th of November 2023.
[00:00:07] Coming up on SpaceTime.
[00:00:09] Mineral salts and organic compounds discovered on the Solar System's largest moon, Ganymede.
[00:00:15] A new space technology deal reached between Australia and the United States.
[00:00:20] And a new Russian space station to fly within four years.
[00:00:25] All that and more coming up on SpaceTime.
[00:00:30] Welcome to SpaceTime with Stuart Gary.
[00:00:49] NASA's Juno spacecraft has discovered mineral salts and organic compounds
[00:00:54] bubbling to the surface of the Solar System's largest moon, Ganymede.
[00:00:58] The findings reported in the journal Nature Astronomy will help scientists better understand
[00:01:03] the origins of the giant Jovian moon and the composition of its subsurface ocean.
[00:01:09] The detection was made by GyrAM, Juno's Jovian Infrared Ororal Mapper Spectrometer.
[00:01:15] Ganymede isn't just the biggest moon orbiting Jupiter, it's larger than the planet Mercury.
[00:01:20] And it's long been of interest to scientists due to its vast internal ocean of water hidden beneath its icy crust.
[00:01:28] Previous spectroscopic observations by NASA's Galileo spacecraft, the Hubble Space Telescope
[00:01:34] and the European Southern Observatory's very large telescope have all hinted at the presence of salts
[00:01:39] and organics, but the special resolution of these observations was simply too low to make a confirmed determination.
[00:01:46] But when Juno flew over Ganymede, passing just 1046 km above its icy surface,
[00:01:53] GyrAM was able to acquire infrared images and spectra which have now confirmed the presence
[00:01:58] of mineral salts and organic compounds. It allowed Juno scientists to detect and analyse the unique
[00:02:04] chemical signatures in the spectral data, highlighting non-water ice materials including
[00:02:09] hydrated sodium chloride, ammonium chloride, sodium bicarbonate and possibly alphatic aldehydes.
[00:02:17] The presence of ammoniated salts suggest that Ganymede may have accumulated materials
[00:02:22] cold enough to condense ammonia during its formation and carbonated salts could be the remnants of
[00:02:28] carbon dioxide rich ices. Previous modelling of Ganymede's magnetic fields determined the Moon's
[00:02:34] equatorial region up to a latitude of about 40 degrees is shielded from the energetic electron
[00:02:40] and heavy iron bombardment caused by Jupiter's hellish magnetic field. See the presence of
[00:02:45] such particle fluxes are well known to have a negative impact on salts and organics.
[00:02:50] But during its June 2021 flyby Juno's GyrAM covered a narrow range of latitudes 10 degrees north to
[00:02:57] 30 degrees north and a broader range of longitudes minus 35 degrees east to 40 degrees east in the
[00:03:03] Jupiter-facing hemisphere. Juno's principal investigator Scott Bolton from the Southwest
[00:03:09] Research Institute in San Antonio, Texas says Sight has found the greatest abundance of salts
[00:03:14] and organics in the dark and bright terrains at latitudes protected by the magnetic field.
[00:03:20] This suggests there are remnants of a deep ocean brine that reached all the way to the surface of
[00:03:24] this frozen world. Of course Ganymede isn't the only Jovian moon that Juno's flown past.
[00:03:31] The Moon Europa, which harbours a global subsurface ocean under its icy crust,
[00:03:36] has also come under Juno's gaze first in October 2021 then again in September 2022.
[00:03:43] And now Io is receiving the Juno flyby treatment. Its next close approach to the volcano Festoon
[00:03:50] Moon is scheduled for December 30th when the spacecraft will come within 1500 kilometers
[00:03:55] of Io's surface. We'll keep you informed. This is space time. Still to come, a new space deal
[00:04:04] reached between Australia and the United States and a new Russian space station slated for launch
[00:04:09] in four years time. All that and more still to come on space time.
[00:04:30] The United States and Australia have signed a new bilateral technology safeguards agreement
[00:04:36] providing the legal framework for American commercial space vehicles to launch from Australian soil.
[00:04:42] The White House says the deal protects sensitive US technology and data in Australia
[00:04:46] consistent with non-polliferation treaty goals. NASA have been launching rockets
[00:04:51] from Australia for years. Now private American companies will also have access to more high-quality
[00:04:57] launch sites allowing them to increase their frequency of operations. They'll be close
[00:05:02] to the equator where the Earth spins its fastest and say their rockets will gain an extra boost
[00:05:07] using less fuel to lift the same amount of payload. Of course back in the 1960s the
[00:05:13] warmer rocket range in Outback South Australia was the second busiest space port in the world
[00:05:18] beaten only by Cape Canaveral. But successive Australian governments on both sides of the aisle
[00:05:24] lacking vision and seeing only as far as the next election squandered that unique technological
[00:05:30] heritage condemning the nation to be nothing more than an insignificant minor player.
[00:05:36] The creation of the Australian Space Agency and the injection of funding by the previous
[00:05:40] coalition government provided a glimmer of hope that a turnaround had finally arrived.
[00:05:46] The hope was that Australia could ultimately claim a share of the global space economy which
[00:05:51] this year alone is valued at over $468 billion and is expected to pass $737 billion within a decade
[00:06:00] according to Euro consult. However a series of funding cuts by the Albanese government
[00:06:06] appears once again to be dampening that horizon. As to what happens next, only time will tell.
[00:06:13] This space time still to come. A new Russian space station to fly in four years time and the
[00:06:21] constellation of the winged horse Pegasus, the giant galaxy M31 Andromeda barreling towards us
[00:06:27] and three meteor showers in the one month are among the highlights of the November night skies on
[00:06:33] Skywatch. Russian President Vladimir Putin says the first module of the Kremlin's new
[00:06:54] space station should now be in orbit by 2027. Built by Nurgia, the module will form the basis of a new
[00:07:02] independent Russian space station which was slated for launch next year but suffered a series of
[00:07:07] ongoing setbacks. Russia has been announcing its intention to withdraw from the International
[00:07:13] Space Station on several occasions ever since Western sanctions were imposed following Moscow's
[00:07:18] invasion of Ukraine. Putin says the aim now is for there to be no gaps for the work to keep pace with
[00:07:25] the depletion of the International Space Station over the next few years and the uptake of
[00:07:29] operations by the new Russian space station. The Russian Federal Space Agency Roscosmos says
[00:07:35] the new Russian orbital station or ROS will be placed into a polar orbit and have several
[00:07:41] innovative and unique features. For example it'll be designed for the rapid swapping of
[00:07:46] modules with critical modules replaced as needed to continually extend the life of the space station
[00:07:51] indefinitely. Russia is also planning a very powerful and stable power supply module for us
[00:07:57] specially designed to support the next generation of research. Many of the new station's modules
[00:08:03] will detach and orbit independently for extended periods of time before redocking later.
[00:08:09] The Russian space industry once the pride of the Soviet Union has been suffering funding
[00:08:14] problems, corruption scandals and growing concerns over equipment reliability.
[00:08:19] NASA plans to keep its half of the International Space Station operational until at least 2030
[00:08:25] and despite the earlier threats to withdraw next year Moscow now says it'll remain
[00:08:29] committed to the current International Space Station until at least 2028. This is space time.
[00:08:52] Time now to turn our eyes to the skies and check out the zelostuous fee for November
[00:08:57] on Skywatch. November is the 11th and penultimate month of the year in both the Julian Angigorian
[00:09:03] calendars. It retained its name from the Latin November meaning 9 when January and February
[00:09:10] were added to the Roman calendar. High in the northern skies of November you'll find the
[00:09:16] constellation Pegasus, the Mesopotamian Etruscan mythological winged horse who was born from
[00:09:21] the blood of Medusa the Gorgon after she was slain by Perseus. The brightest star in Pegasus
[00:09:28] is the orange supergiant Epsom Pegasi located some 690 light years away. A light year is about 10
[00:09:35] trillion kilometers. The distance of photon can travel in a year at the speed of light
[00:09:40] which is about 300,000 kilometers per second in a vacuum and the ultimate speed limit of the
[00:09:45] universe. Astronomers describe stars in terms of spectro types a classification system based on
[00:09:53] temperature and characteristics. The hottest most massive and most luminous stars are known as
[00:09:59] spectro type O blue stars. They're followed by spectro type B blue white stars then spectro
[00:10:05] type A white stars, spectro type F whitish yellow stars, spectro type G yellow stars that's where
[00:10:13] our sun fits in, spectro type K orange stars and the coolest and least massive stars of all
[00:10:19] are the spectro type M red stars. Each special classification is further subdivided using a
[00:10:26] numeric digit to represent temperature with zero being the hottest and nine the coolest and then
[00:10:32] a Roman numeral is added to the end of all that to represent luminosity. Now put all that
[00:10:37] together and a star like our sun is known as a spectro type G2V or G25 yellow dwarf star.
[00:10:46] Also included in the stellar classification system are spectro types LT and Y which are assigned to
[00:10:52] failed stars known as brown dwarves some of which were born as spectro type M red stars
[00:10:58] but became brown dwarves after losing some of their mass. Brown dwarves fit into a category
[00:11:03] between the largest planets which are about 13 times the mass of Jupiter and the smallest
[00:11:08] spectro type M red dwarf stars which are about 75 to 80 times the mass of Jupiter or about 0.08
[00:11:16] solar masses. As for Epsilon Pegasi well it's estimated to have about 12 times the mass of our
[00:11:23] sun and about 185 times the Sun's radius. Epsilon Pegasi together with the stars Markab,
[00:11:30] Alginib, Sjeet and Alpha Andromedae form the asterism or pattern of stars known as the Great
[00:11:37] Square of Pegasus. A bunch of bright naked eye stars shaped like a huge square in the sky.
[00:11:45] One of the stars in the constellation is 51 Pegasi which was the first main sequence star
[00:11:50] beyond our sun to be discovered to host the planet. 51 Pegasi is a sun-like star located 50.45
[00:11:58] light years away. Its planet or more accurately exoplanet, meaning extra solar planet is designated
[00:12:06] 51 Pegasi B. The exoplanets discovery was announced on October the 6th 1995 in the journal Nature.
[00:12:14] It was detected using the radial velocity or so-called wobble method with a spectroscope
[00:12:19] used to detect very slight but regular Doppler shift changes in the star's spectral lines
[00:12:25] caused by the gravitational pull of the planet pulling the star one way and then the other
[00:12:30] as the planet orbits around it. 51 Pegasi B is about half the mass of Jupiter and orbits around
[00:12:37] its host star every four Earth days at a distance of just 7 million kilometers. At the time a
[00:12:44] gas giant orbiting so closely around the star was something that had never been seen before
[00:12:49] and this led to the creation of a new category of planets known as hot Jupiters.
[00:12:54] A category of gas giants thought to have formed further out from their host stars
[00:12:59] beyond the so-called snow line but which then migrated inwards towards their current positions.
[00:13:05] The discovery led to the realization that the gas giants of our solar system, Jupiter and Saturn,
[00:13:12] also migrated inwards closer to the sun during their early formation,
[00:13:16] something which explains many of the features of our own solar system including the late
[00:13:21] heavy bombardment, the asteroid belt and some unique characteristics of the ice giant
[00:13:26] Neptune and Uranus as well as the mass distribution of the four interterrestrial worlds Mercury,
[00:13:32] Venus, Earth and Mars. Also visible in Pegasus is the M15 or NGC 7078 globular cluster
[00:13:41] which is located about 33,600 light years away. Globular clusters are tight spheres containing
[00:13:48] thousands to millions of stars all originally formed at the same time in the same molecular
[00:13:54] gas and dust cloud. Many are thought to be the cause of small galaxies that have been cannibalized
[00:14:00] by larger ones. Our own Milky Way galaxy contains at least 150 globular clusters.
[00:14:07] M15 is estimated to be around 12 billion years old making it one of the oldest
[00:14:13] known globular clusters and it contains an estimated 100,000 stars making it one of the most densely
[00:14:19] packed globular clusters in the Milky Way galaxy. Its core has undergone a contraction
[00:14:25] known as core collapse and it has a central density cast with an enormous number of stars
[00:14:31] which appear to be surrounding what may well be a central black hole.
[00:14:35] M15 also contains at least a hundred and twelve variable stars, eight pulsars including one
[00:14:41] double neutron star system and the first ever planetary nebula found in a globular cluster.
[00:14:48] Now if you're away from city lights you may notice a fuzzy patch in the sky right next to Pegasus
[00:14:54] and that is the majestic giant spiral galaxy M31 Andromeda. Andromeda is the biggest galaxy
[00:15:03] in the local galactic group. It's located some 2.5 million light years away. Estimates
[00:15:09] suggest it contains over a trillion stars twice that of the Milky Way and is some 220,000 light
[00:15:15] years across. Now if you can't see it too well don't worry it's getting closer every day.
[00:15:21] You see the Milky Way and Andromeda galaxies are expected to collide in about 3.7 to 4.5
[00:15:28] billion years from now eventually merging to form what will be a new giant elliptical galaxy
[00:15:34] another case of galactic cannibalism in action. Now based on current estimates Andromeda
[00:15:40] appears to have more older stars than the Milky Way. It also appears to have far less
[00:15:45] new star production than the Milky Way, the Milky Way producing about one new solar mass star every
[00:15:51] year and the rate of supernovae in the Milky Way is also about double the rate of Andromeda.
[00:15:58] Andromeda is surrounded by a large and massive halo of hot gas,
[00:16:02] estimated to contain about half the mass of the stars in the galaxy. This nearly invisible halo
[00:16:08] stretches about a million light years from its host galaxy. That means it reaches almost halfway
[00:16:14] out to the Milky Way. Now using a good pair of binoculars or a small backyard telescope you'll
[00:16:20] even get to see the dust lanes in Andromeda spiral arms and its bright central galactic core
[00:16:26] which contains a monster supermassive black hole. Now located slightly to the east and south of Pegasus
[00:16:35] you'll see the ancient constellation of Cetus the Great Whale, sea monster.
[00:16:40] Bidysedio, Denib Catos is the brightest star in the constellation Cetus. It's an orange giant
[00:16:47] located about 96 light years away. By the way that name Denib Catos well it means the Whales
[00:16:53] Tail. One of the other stars in Cetus is Mira, the first variable star ever discovered.
[00:16:59] Located some 420 light years away, Mira pulsates in brightness over a period of 332 Earth days,
[00:17:07] changing in diameter from about 400 to 500 times the diameter of the Sun. Alpha Setti,
[00:17:13] traditionally called Mengar the nose, is a red huge giant star some 220 light years away.
[00:17:20] Now it's actually a double star system with the secondary star 93 Setti being a blue white star
[00:17:26] some 440 light years away. Another double star is Gamma Setti, the head of the Whale.
[00:17:32] The primary is a yellow star 82 light years from Earth while the secondary is a blue star.
[00:17:38] At 11.9 light years away the yellow dwarf Tau Setti is the nearest sun-like star to
[00:17:44] the Earth other than the Sun. Okay looking south of Cetus now and you'll see the brilliant star
[00:17:50] Akina which means the river's end as it marks the end of the river Eridanus. Eridanus is the
[00:17:56] sixth largest of the modern constellations and the one that extends further than the sky from
[00:18:01] north to south. Akina is a binary system and the primary star Alpha Eurydne actually consists
[00:18:08] of two stars Alpha Eurydne A and B located some 139 light years away. Of the 10 brightest stars in
[00:18:16] the night sky Alpha Eurydne is the hottest and bluest in color that's due to Akina being a
[00:18:22] spectrotype B blue main sequence star. Akina also has an unusually rapid rotational velocity
[00:18:29] causing it to become a blatant shape. The second star in the system is a smaller spectrotype
[00:18:34] A white star which orbits the primary at a distance of about 12 astronomical units. An
[00:18:40] astronomical unit is the average distance between the Earth and the Sun about 150 million kilometers
[00:18:47] or just over eight light minutes. Now if you follow Eridanus towards the east you'll find the
[00:18:53] constellation Orion a familiar signpost in the southern summer and northern winter skies.
[00:18:59] To the west of Orion is the constellation Taurus the Bull and located in Taurus is M1 the Crab Nebula.
[00:19:07] It's the remnant of a star which Chinese astronomers or explode as a supernova back on the fourth of
[00:19:13] July in the year 1054. They recorded the sudden appearance of a new star on their sky charts
[00:19:19] at exactly the position of the Crab Nebula. Their record show the supernova appeared brighter
[00:19:25] than the planet Venus for weeks on end before finally fading from view after about two years.
[00:19:33] The shockwave from the Crab Nebula's supernova explosion is continuing to blast outwards
[00:19:38] expanding at a rate of about five million kilometers per hour. At the heart of the
[00:19:44] nebula is a rapidly spinning neutron star a pulsar rotating at some 30 pulses per second.
[00:19:50] As it rotates it shines a beam like a lighthouse beacon sweeping across the galaxy.
[00:19:56] This beam emits radiation at all wavelengths from gamma rays and x-rays right through ultraviolet,
[00:20:02] optical and infrared even into the radio waves. Observations indicate the pulsar is slowing
[00:20:09] down and will fall to just half its current rotational rate in the next thousand years.
[00:20:14] November is also a great time to check out the Pleiades or Seven Sisters,
[00:20:18] one of the nearest open star clusters to Earth. Also known as M45,
[00:20:23] the Pleiades are located in the constellation Taurus the Bull and are composed mostly of
[00:20:28] hot blue-white stars. Now depending on whose measurement you prefer the Pleiades are
[00:20:34] somewhere between 118 and 137 parsecs away, a parsec being around 3.26 light years.
[00:20:42] The amazing thing about the Pleiades is that different cultures from vastly different parts
[00:20:47] of Earth have all described the Pleiades in the same way as seven women or Seven Sisters
[00:20:54] and this could possibly be some sort of ancient throwback to early human out of Africa civilization.
[00:21:02] Just like October, November sees three meteor showers. There's the November
[00:21:07] Orionids, the Taurids and the Leonids. Although peaking late October, the Orionids are continuing
[00:21:13] to sprinkle down during the start of November and are usually at their best during the wee small
[00:21:18] hours before dawn. They're generated by the debris trail left behind by the Comet Halley
[00:21:24] and appear to radiate out from the direction of the constellation Orion the Hunter.
[00:21:30] The Taurids meteor shower are generated by the Comet Enki and as their name suggests,
[00:21:35] they appear to radiate out from the constellation Taurus the Bull. Enki and the Taurids are believed
[00:21:41] to be the remnants of a large comet which disintegrated between 20 and 30,000 years ago,
[00:21:47] breaking into several pieces and releasing material both by normal cometary ablation
[00:21:52] and also occasionally by close gravitational encounters with the Earth and other planets.
[00:21:58] In fact the cometary stream of material left by Enki is the largest in the inner solar system.
[00:22:04] Being so spread out, the Earth takes several weeks to pass through it,
[00:22:07] causing an extended period of meteor activity compared to the much smaller periods of activity
[00:22:12] of other meteor showers. And further gravitational interactions with Jupiter have caused the Taurids
[00:22:18] to be segmented into separate northern and southern streams. The southern Taurids usually
[00:22:24] arise from around September 25th to November 25th. While the northern Taurids go from
[00:22:30] October 12th to December 2nd. But the Taurids do have their downside, they're quite diffuse,
[00:22:37] usually only producing about 7 meteors an hour. However they are composed of more massive material.
[00:22:44] Think of pebbles instead of dust grains and so they tend to produce a high percentage
[00:22:48] of very bright meteors known as fireballs produced as large meteoroids burn through the
[00:22:53] atmosphere. The southern Taurids put on their best show just after midnight on November 5th.
[00:23:01] Finally there's the Leonids Meteor Shower which we'll pick on November 18th.
[00:23:05] The Leonids are usually pretty reliable with 15 meteors an hour. However they have been known
[00:23:11] to occasionally produce spectacular meteor storms with showers in 1999, 2001 and 2002
[00:23:19] producing an amazing 3000 Leonids meteors an hour. Even more spectacular was the Leonids Meteor
[00:23:26] Shower of 1966 which generated thousands of meteors per minute falling like illuminated rain.
[00:23:34] The Leonids are usually picked up after midnight with peaks occurring just before dawn.
[00:23:39] They're produced by the debris stream from the Comet Temple Tuttle. And as their name suggests
[00:23:45] the Leonids radiate out from the constellation Leo the Lion. The Leonids are a fast moving stream
[00:23:52] which encounters the path of Earth at 72 kilometers per second. Larger Leonids which are
[00:23:57] about 10 millimeters across can have a massive half a gram and are renowned for generating
[00:24:02] bright meteors. Scientists estimate the annual Leonids Meteor Shower deposits between 12 and
[00:24:08] 13 tons of particles across the planet every year. Australian Astronomy and Science writer
[00:24:14] Jonathan Nally joins us now to check out the rest of the November night skies on Skywatch.
[00:24:45] Coming into winter so they've got the other opposite advantages and disadvantages just
[00:24:48] it goes around all the time but what's the stuff to see. So let's start with what we can see in
[00:24:52] the mid-evening sky. So once the sky is dark we can see that the tail and the stinger part of
[00:24:56] the constellation Scorpius sticking up from the western horizon sticking up into the sky but
[00:25:01] only for a short time but it's going to set very soon. Sagittarius is a bit high it's nearby
[00:25:06] and when we're looking in that direction of course we're looking towards the center
[00:25:09] of our Milky Way galaxy. Nothing to do with Sagittarius as such it's just that's where
[00:25:12] that constellation is in the sky and when we look into there we're looking into the star fields of
[00:25:16] the Milky Way galaxy. To the naked eye and everything you can't see the center of the galaxy
[00:25:20] because there are too many stars in the way but of course astronomers have with their big telescopes
[00:25:24] and filters and things they've been able to look right into the center and see the big black hole
[00:25:28] that's there and stuff orbiting around the black hole so it's really quite fascinating. When
[00:25:31] you look at that part of the sky even though you can't see it you know what's there. It's
[00:25:34] just brilliant as far as I'm concerned particularly if you can get out in the country side where
[00:25:37] the skies are a bit darker and then you really see their Milky Way it is really quite glorious.
[00:25:42] So up in the northern half of the sky this guy looks fairly bare actually and it's filled with
[00:25:46] a big bunch of constellations that have very few bright stars I'm talking constellations like
[00:25:51] Pegasus which is the winged horse you've got Pisces the fish you've got one called Cetus which
[00:25:56] is the whale you've got Aries the ram and there's another one called Aerodanus the river
[00:26:01] which is a big long constellation stretches from the northern sky down to the southern
[00:26:05] sky it's the sixth largest constellation by area but it's it's quite long and thin in places
[00:26:10] and it's the constellation that stretches farthest north and farthest south it's really
[00:26:15] quite long and it's nothing really spectacular and there's not a lot in there to see but it's
[00:26:20] just one of these constellations they made up a long long time ago. People are familiar with the
[00:26:23] zodiac type constellations you know tourists and Aries and Pisces and that sort of thing
[00:26:28] but there are actually 88 constellations up there 88 official ones so there are plenty
[00:26:32] other things to see in the sky now over in the eastern part of the sky around about 9 30 pm we
[00:26:36] start to see the constellation Orion poking its head above the horizon this is the sign that summer
[00:26:42] is approaching for the southern hemisphere or winter in the northern half of the planet when
[00:26:45] you see Orion starting to make an appearance in the late evening you know you're heading towards
[00:26:49] the end of the year. Now if you're trying to find the southern cross that's the other thing
[00:26:52] that people like to see all the time particularly you know visitors from the northern industry
[00:26:55] they come down here and say where's the southern cross? This time of the year it's a
[00:26:58] little difficult to see so if you can't spot it don't worry you're not going blind or anything
[00:27:02] like that during the evening hours of this time of the year the cross is upside down and either very
[00:27:07] low on the southern horizon for some people or even hidden below the horizon for others where I am
[00:27:12] if I had a perfectly clear horizon without the houses across the street there so it was just
[00:27:17] a bare horizon when the southern crosses down at its lowest I would see half of it cut off
[00:27:22] I'd only see half of it sticking up above the horizon so you do need to be fairly far south
[00:27:26] this time of the year if you want to see it in the evening time but if you're staying up after
[00:27:30] midnight you're out later or whatever oh if you're getting up early in the morning by then the earth
[00:27:34] will have turned and you will see the southern cross it'll be sort of to the south southeast
[00:27:39] and lying on its left hand side. Now by about 3 a.m that the sky has changed quite a lot
[00:27:45] as the earth has rotated and it's brought new constellations into view over the east
[00:27:48] Orion is really quite high now in the northern sky as seen from the southern hemisphere
[00:27:52] you've got the constellation Canis major with its bright star Sirius the brightest star in the sky
[00:27:57] that's high overhead for people to live in my part of the world and you've got Gemini and Leo
[00:28:01] and Cancer visible up in the northern half of the sky and lots of great things to see in there
[00:28:06] if you've got a pair of binoculars or a small telescope. Now looking at the planets taking
[00:28:09] them in order we've got Mercury, Mercury is back on the scene it was out of view last month
[00:28:14] you'll find it not far above the western horizon after sunset so once the sun's gone down
[00:28:18] and the sky's starting to get dark you'll see what looks like a pretty bright intense looking
[00:28:23] small star and that'll be Mercury. Now Saturn is very easy to see in the evening sky as well
[00:28:28] it's actually close to overhead pretty much after sunset in the mid from the mid southern
[00:28:33] latitude just look up and you'll see this fairly bright thing that looks like a star but it's
[00:28:36] actually Saturn it's got a slightly yellowish tinge to it Mars well Mars is out of view at
[00:28:41] the moment because it's around the other side of the sun so it's lost in the solar glare
[00:28:45] and it'll take a few months to come back it's not going to really come back into view
[00:28:48] until January when it will appear in the morning sky out to the east before the sun rises
[00:28:54] out there right now in the east before the sun rises you can see Venus it's rising around about
[00:28:59] four a.m it's big and it's bright and you really can't miss it so if you're up early to go to
[00:29:04] work or you've just had an all nighter or something you're around about four o'clock
[00:29:07] or five o'clock in the morning look to the east and you'll see this big bright white
[00:29:11] star looking thing yes it's not a flying saucer it is Venus the planet it causes uh
[00:29:16] it's it's the cause of a lot of reports of UFOs and things because most people don't look up most
[00:29:21] people don't look at the sky and then suddenly when they do they think what's that big bright white
[00:29:26] like that wasn't there yesterday of course it was they just weren't looking yesterday
[00:29:30] and they think gee that's big and bright that doesn't seem to be moving oh gee that must be
[00:29:33] a UFO or something but no it's just Venus finally the planet of the moment is Jupiter
[00:29:38] because Jupiter reaches opposition this month opposition is when one of the outer planets and
[00:29:43] the sun are opposite each other in the sky as seen from earth right so 180 degrees apart and what this
[00:29:50] means is that when the sun is setting in the west the planet is rising in the east as we see it
[00:29:55] and we therefore have the whole night to study it or observe it take a look at it
[00:29:58] opposition's also roughly when any particular planet of the outer planets and Jupiter in
[00:30:03] this case is closest to the earth which means that it's biggest and brightest within a
[00:30:07] view through a telescope so go outside wait until the sun has gone down in the west and give it a
[00:30:11] little while half an hour or so before Jupiter come up to come up rising above the eastern horizon
[00:30:17] and clear any trees or buildings that might be in the way and there it'll be big bright white star
[00:30:22] looking thing but it's actually Jupiter they have a pair of binoculars or a small telescope you
[00:30:26] can even see some of its moons there are four bright moons the Galilean moons the ones that
[00:30:30] were spotted by Galileo himself and you can actually see them as little tiny points of
[00:30:34] light just with a normal pair of binoculars or a small telescope and the great thing about them
[00:30:39] is that they orbit the planet so rapidly that if you were to say have a look at them at seven o'clock
[00:30:45] in the evening and then if you got up early the next morning went and had a look again
[00:30:49] they'll have all moved and certainly by the next day they'll have moved around and the next
[00:30:53] day after that they'll have moved around again because they're all going at different speeds
[00:30:56] sometimes you'll see two on one side and a planet two on the other side sometimes you'll see
[00:30:59] three on one side and one on the other sometimes you might only see three because the fourth one
[00:31:03] is around behind Jupiter and it's in its shadow so it's really fun to go out and have a look and
[00:31:08] just follow the course of these little moons going around not little moons actually some of them are
[00:31:13] quite big going around Jupiter it really is quite incredible and you can think you can see this
[00:31:17] just with a normal pair of binoculars seven by fifties or something or even a small telescope
[00:31:21] so if you've got the chance to do it please go out and have a look that's Australian
[00:31:24] Astronomian Science writer Jonathan Alley and this is Space Time and that's the show for now
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