*Martian meteorite upsets planet formation theory
A new study of an old Martian meteorite is contradicting current ideas of planetary formation.
*Another six space tourist kiss the edge of space aboard New Shepard
Blue Origin has undertaken its fifth manned space tourism flight.
*First Ariane 5 launch for 2022
The European Space Agency has undertaken its first Ariane 5 flight of the year placing two telecommunications satellites into geostationary orbit.
*SpaceX rounds off a busy launch schedule with more than a dozen flights
It’s been busy times for SpaceX and its Falcon 9 workhorse with more than a dozen launches taking place on what seems like a futuristic space age production line with one launch after another.
Planet Earth reaches its furthest orbital distance from the Sun, the spectacular Southern Cross constellation, and the ticking time bomb known as Antares…
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SpaceTime S25E75 AI Transcript
Stuart: This is Spacetime series 25, episode 75 for broadcast on 8 July 2022. Coming up on space time a Martian meteorite upsets planetary formation theory. Another SpaceX. Space tourists kiss the edge of space aboard New Shepherd, and SpaceX rounds off a busy launch schedule with more than a dozen flights. All that and more, coming up on Space Time.
Guest: Welcome to space time uh, with Stewart Gary.
Stuart: A new study based on an old Martian meteorite is contradicting current ideas about planetary formation. The findings were reported in the journal Science. Rings into question existing hypotheses on how the terrestrial worlds planets like the Earth, Mars, Venus and Mercury acquire their volatile elements such as hydrogen, carbon, oxygen, nitrogen and noble gases as they form. The basic assumption about planetary formation is that planets first collect these volatiles from the protoplanetary nebula surrounding a young forming star. Uh, different elements condensate out of the nebula at different temperatures and consequently, at different distances. Now, because the forming planet is still a ball of molten rock at this point, these elements initially dissolve into the magma ocean and then Degass back into the atmosphere. Later on, contradict meteorites crashing into the young planet deliver more of these volatile materials. So scientists expect that the volatile elements found in the interior of the planet should reflect the composition of the solar nebula, or at least a mixture of solar and meteoritic volatiles. While the volatiles in the atmosphere would come mostly from meteorites, these two sources, solar and conjuretic, can be distinguished by the ratios of isotopes, uh, of noble gases, in particular, Krypton. Mars is of special interest here because it formed relatively quickly solidifying during the first 4 million years since the birth of the solar system 4.6 billion years ago. On the other hand, it's thought the Earth took a lot longer, between 50 and 100 million years, to form. Remember, it had to deal with an interplanetary crash with a planet there which would eventually form the Earth Moon system as we know it today. The studies lead author, Sandring Perron from the University of California, Davis, says scientists can reconstruct the history of volatile delivery for the first few million years of the solar system. And they know that some meteorites that fell on Earth came from Mars, and most of those came from surface rocks that had been exposed to the Martian atmosphere. However, uh, one meteorite which fell to Earth in northeastern France in 1815 is rare. That's because it's thought to represent the interior of the Red Planet rather than just some surface rock that was ejected into space following an asteroid collision. Peronik colleagues studied this meteorite, making extremely careful measurements of a new quantities of Kryptonisotopes in samples of the meteorite using a new method set up at the UC Davis Noble Gas Laboratory in order to determine the origin of the elements in the rock. But they were shocked to find that the cryptIn isotopes in the meteorite corresponded to those from Candytic meteorites, not the solar nebula. That means that meteorites were delivering volatile elements to the forming planet much earlier than previously thought and in the presence of the nebula, reversing conventional thinking. Ron says the Martian interior composition for Krypton is nearly purely quadritic. But the atmosphere is solar uh, and the difference is very distinct. The results show that the Martian atmosphere can let it form purely by outgassing from the mantle, as that would have given it a quadritic composition. So the planet must have acquired atmosphere from the solar nebula directly after the magmarosian cooled in order to prevent substantial mixing between interior quandritic gases and atmospheric solar gases. The new results suggest that the Red Planet's growth was completed before the solar nebula had been dissipated by radiation from the sun. But the problem is the Irradiation would also have blown off the nebular atmosphere on Mars, suggesting the atmospheric Krypton must somehow have been preserved, possibly trapped underground or in the polar ice caps. And the thing there is that would have required Mars to be really cold in the immediate aftermath of its creation. While this study clearly points to contrary gases in the Martian interior, it also raises some interesting questions about the origin and composition of the early Martian atmosphere. And eventually, these two will need to be addressed. This is space time. Still to come, another six space tourists kiss the edge of space aboard New Shepard and the first Ariane Five launch for 2022. All that and more still to come on Space time. Blue Origin has undertaken its fifth man space tourism flight. The New Shepard launch vehicle and capsule carried six passengers on the ten minute ride from the company's West Texas launchpad up to the edge of space. This is the flight director on channel one and UHF. Voice for the GoPole. Uh, for terminal count and launch.
Commentator: Capsule. Go.
Stuart: Booster? Go.
Stuart: Go. Safety? Go.
Stuart: Go. First step, this is your flight director.
Guest: New Shepard is go for launch.
Stuart: Booster, commence the terminal account.
Guest: The aft fins, those fins at the base of the vehicle that help direct the vehicle on ascent and descent, exercising their full range of motion. The be three. Propulsion Module. Nozzle. Gimbaling. This is the primary form of control for the vehicle on ascent and of course, for landing. Doing a full range of checks, ensuring free range of motion. Those tanks are at variables pressure and temperature. And the cryogenic tanks in the green zone, that's what they're watching in Mission Control.
Stuart: Two out of ten, 98765. Four.
Guest: Flip off at 3700ft above MSL. That's about how far we are above sea level out here. And launch site one.
Guest: And that Be Three. Engine rumble really coming through as the vehicle approaches the maximum dynamic pressure, the point where the aerodynamic stresses on the vehicle are at their maximum. That Be Three engine will throttle back just a little bit. Max Q here in about 30 seconds. Kyo will see the Be 03:00 P.m. Engine shut off for main engine cut off.
Guest: Miko and Miko main engine cut off. The vehicle is now coasting at over 2000 mph.
Guest: Okay, we should have separation of, uh, the capsule and the booster here momentarily. Laura Styles will cue the astronauts to unbuckle their harnesses and start floating around the capsule. Victor Viscovo catches Harding, Jason Robinson, Victor Carafana and Evan Dick are now in.
Guest: Zero g. We just received confirmation. The crew capsules apogee of 351183 ft.
Guest: It really sounded like they were having a lot of fun in that 15 cubic meter cabin. Congratulations to all six crew. They just officially became astronauts. Outstanding.
Guest: Both the crew capsule and the booster are now descending.
Guest: And we'll follow the booster first for landing. That rocket is now reaching its atmospheric pierce point, returning from space and entering the atmosphere. The control surfaces of the fins are now starting to have air pressure to push against and to navigate to over the landing pad.
Guest: And that booster is now reaching its maximum reentry velocity, which is just under mach four. The booster shape costs a lot less drag than the crew capsule, so it'll win the race back down to the ground.
Guest: The wedge fins, steering fins and ring fin really earning their keep at this point in the flight.
Guest: The air brakes are deploying here. This is such a critical step in slowing the vehicle down. Velocity starts to decrease very rapidly. You can follow along on, um, the top right corner of your screen. And we just heard the sonic booms loud and clear.
Guest: Confirmed. Coming down for a nice stop. Landing.
Guest: And booster touchdown. Welcome back, New Shepard.
Guest: For a lot of us at Blue, this moment in flight is one of the main highlights as it shows off the incredible engineering required to bring a rocket back safely home from space, ready to be reused.
Guest: Our six astronauts right now, they're sitting in their capsule, enjoying the view as it slowly descends down. And here are the drugs deploying. Now these drugs will slow the capsule down in preparation for the three main shoots.
Guest: And there we have it, the three main chutes.
Guest: While those beautiful parachutes are essential in providing a gentle touchdown for the crew capsule, new Shepard also has an innovative retro thrust system on the bottom of the capsule to make the touchdown even smoother for our astronauts flying today. And as that capsule slowly descends, that retro thrust system soon will fire moments before touchdown to slow the capsule down even further. Just to one or 2 touchdown. Welcome back to Earth new Shepherd's astronauts. They just went to space and they are back.
Stuart: The Supple flight reached an Apogee of 107 km, well above the 100 kilometer Kahnman line, marking the internationally recognized official start of space. The flight had been delayed by several weeks because of a problem with one of the spacecraft's backup systems. This is space time. Still to come, ariane Space undertakes its first Ariane Five launch for 2022, and SpaceX rounds off an incredibly busy launch schedule, undertaking more than a dozen flights in just a few weeks. All that and more still to come on space time. The European Space Agency has undertaken its first Ariane Five flight for the year, placing two telecommunications satellites in a gas stationary orbit ariane space flight VA Two five seven transport of Malaysia's Miyasat Three D and the Indian Space Research Organizations GSAT 24 spacecraft. The successful launch from the Guru Spaceport and Fred Skiana also marked the fifth last mission for the current Ariane Five launch vehicle, which is being replaced by the new Ariane Six early next year. The 5600 kilogram Mirae Sat 3D is a multi mission telecommunications satellite built by Airbus Defense and Space, designed to increase high definition four K and ultimately eight K broadband satellite capacity across the Asia Pacific region. The spacecraft also carrying a separate payload for the Korean Space Agency, which is designed to improve local air traffic control operations for the South Korean Ministry of Land, Infrastructure and Transport. Meanwhile, the Indian GSAT 24 is a 4180 kilogram 24 ku Band telecommunications satellite built by the Indian Space Research Organization ISRO, uh, for new space. India. A successful flight, um, comes as Issa reorganizes many of its schedule manifests for the year in the wake of the agency's decision to cut all operational ties with Russia as a result of Moscow's ongoing attacks against Ukraine. Ariane Space originally had three levels of launch vehicle. There was the Ariane Five, soon to be replaced by the Ariane Six as the heavy launcher. The Russian Soyuz was being used as a medium lift launch vehicle. And the Vega, uh, soon to be replaced by the Vegas Sea, was designed to take care of small launch payloads missions previously scheduled to fly on contractor Roscosmos. Soyuz flights have now all been canceled, and will progressively need to be slotted into new flight schedules using either Ariane or Vega launch vehicles instead. This is Spacetime. Still to come, SpaceX rounds off a busy launch schedule with more than a dozen flights. And in July, Sky Watch planet Earth reaches its furthest orbital position from the sun. We look at the spectacular Southern Cross constellation, and we study the ticking time bomb known as Antares. All that and more still to come on Space Time. Well, it's been busy times for SpaceX and its Falcon Nine workhorse, with more than a dozen launches taking place on what seems to be a futuristic space edge production line with quite literally one launch after another. On June 21, SpaceX launched three Falcon Nines. And the space is just 36 hours. The company's 26 launches this year lasted off from the Cape Canaveral Space Force Base in Florida, carrying a new 700 kilogram telecommunications satellite for Louisianabased Global Star. Uh, that was the 9th launch for the same Falcon Nine core stage which returned safely to Earth, landing on the drone ship. Just read the instructions. Which had been prepositioned down range in the North Atlantic Ocean. It followed the launch of a new radar satellite for the German military from Space Launch Complex Four east at the Vandenberg Space Force Base in California. And just a few hours earlier, SpaceX launched 53 starlink Internet satellites aboard a Falcon Nine from Pad 39 A at the Kennedy Space Center, literally just down the road from where the global star satellite was to be launched. The starling mission marked the 100 successful launch using a previously flown and refurbished Falcon Nine core stage. And again, this core stage returned safely to the drone ship a shortfall of gravitas. Meanwhile, a week earlier, another Falcon Nine launch from Cape Canaveral delivered the Nullsat 301 satellite in geostationary transfer orbit with that core stage also successfully returning to Earth and landing on the drone ship. Just read the instructions. A few weeks earlier, SpaceX had used the same launchpad for its transport of five rideshare mission, carrying more than a dozen small CubeSats micro satellites and nano spacecraft into a range of sunsynchronous orbits. Also on board that flight were the cremated remains of 47 people who wanted to be buried in space. A week earlier, another Falcon Nine undertook a launch carrying a further 53 starlink satellites into orbit, also using Space Launch Complex 40 at the Cape. That mission, which had been delayed by stormy weather, also saw the Falcon Nine core stage return safely to Earth, landing on the drone ship. Just read the instructions. That was the 12th time the same booster had been used for a launch. Meanwhile, another Falcon Nine carrying another 53 starlink satellites blast off, uh, from the adjacent Launch Complex 39 A. The core stage of that mission also returned safely to Earth, landing on the drone ship shortfall of gravitas. And days earlier, another 53 starlink satellites were placed into orbit following successful launch from the other side of the country at the Vandenberg Space Force Base in California. Again, the Falcon Nine core stage safely returned to Earth, landing on a preposition drone ship. Another batch of 53 starlink satellites had been launched days earlier from Cape Canaveral, this one marking the second flight for the same Falcon Nine core booster which had just returned from space 21 days earlier. And it won't be the last, with the booster landing safely on the drone ship. Just read the instructions. Meanwhile, another 53 starlinks were launched in late April from the Cape with a course stage undertaking its 12th landing. Also touching down safely on the drone ship. Just read the instructions. That mission was the 43rd launch related to the Starlink project. A few days earlier, the top secret National Reconnaissance Office NROL 85 mission was launched aboard another Falcon Nine rocket from Vandenberg. The core stage returned to Earth eight and a half minutes later, touching down safely on Landing Zone Four. Uh, it was the fourth dedicated launch for the National Reconnaissance Office, which is charged with the responsibility of operating the United States fleet of spy satellites. It was also the second launch for the same booster court stage which had previously flown the NROL 87 spy satellite mission. Although the National Reconnaissance Office doesn't release details of the clandestine space flights, orbital trajectory details can be used to infer what sort of satellite was launched. And based on the latest orbital trajectory details, it suggests that this launch was of a Naval Ocean Surveillance System intruder satellite. These usually operate in pairs, scouring the Earth's oceans for radio transmissions, which they can then triangulate in order to pinpoint the exact position of naval vessels. Around the same time, SpaceX also launched two manned Dragon flights to the International Space Station. These were the Axiom one mission and NASA's Crew four astronaut transfer mission both flying off Pad 39 A at the Kennedy Space Center. Now, this incredibly intense launch schedule all began back on April 1, when the SpaceX Transport, a four mission carrying a manifest of 40 payloads including a fleet of small nano and microsatellites as well as modern CubeSats, were sent into orbit. The payloads were delivered into a series of sunsynchronous orbits. The largest spacecraft on the rideshare mission was the 980 Kilogram Environmental Mapping and Analysis Program, or Nmap, German Hyperspectral satellite, which will be used to monitor and characterize the Earth's environment. Also included in the manifest were four kiosk Space Patrol Mission satellites, four satellite, uh, updated new Set MK Four satellites, as well as the new MK Five satellite fitted with visible and infrared Earth imaging equipment. Then there was the Deorbit Ion Satellite carrier Vehicle, the Almighty Alexis, a free flying selfpropelled CubeSat transfer tug, uh, designed to host or deploy up to eight payloads into specific orbits. Um, other payloads include three CubeSats from the University of Chile, three Hawkeye 360 Hawk, four A, B and C transportation monitoring satellites, a Norwegian Defense Research Establishment satellite, and several dozen smaller microsatellites and CubeSats. The first stage of the mission returned safely to Earth, landing on the drone ship. Just read the instructions which have been prepositioned 532 km downrange in the North Atlantic Ocean. Certainly a busy launch schedule for SpaceX. This is spacetime and time now to turn our eyes to the skies and check out the celestials fear for July. Um, on Sky Watch. July is the 7th month of the year in both the Julian Angagorian calendars and it's named after the Roman Emperor Julius Caesar, who was born during the month before being called July. The month was called Quintillas, which is Latin for fifth. The addition of the month, January and February brought an end to that. On average, July is the coldest month of the year in the Southern Hemisphere, which is experiencing winter and also marks the time when Earth is at a Philip, its furthest orbital position from the sun. Of course, temperatures, or more accurately, seasons on Earth aren't dictated by the distance from the sun, but rather the length of a day, and hence the amount of sunlight a given part of the Earth receives, which is governed by the tilt of Earth's axis. Consequently, that's why July is on average the warmest month in the Northern Hemisphere, which is currently experiencing summer. During this ephelian, Earth will be 152,098,455 km from the sun. That's about 5 million km further away than during perihelion back in January this year's, Ophelion occurred at 510 in the afternoon on Monday, 4 July Australian Eastern Standard Time. That's 310 in the morning, us eastern Daylight Time and 07:10 am. Greenwich. Meantime. Over cosmic time, these dates change. That's due to variations in Earth's orbit, such as eccentricity, as well as axial tilton precession, which all follow regular cyclic patterns known as Milankovitch cycles. Eccentricity involves changes in how elliptical Earth's orbit is around the sun. None of the planets actually orbit the sun in perfect circles, although Venus and Neptune are the closest. Instead, they all have elongated orbits which vary over time. As well as that, it spins on an axis which is currently tilted at 23 four degrees compared to the ecliptic Earth's orbital plane around the sun. But this angle of tilt also changes over time, influenced by, among other things, the distribution of the Earth's mass. And just like a spinning top, the rotational axis of the Earth also changes its orientation through a process called precession, changing its position in relation to fixed background stars over a 260 year cycle. Now, all these effects impact the amount of solar radiation reaching the Earth, what time it reaches the Earth, and consequently the planet's seasonal and climatic patterns. Right now, the Southern Cross is at its highest point in the southern sky and is pointing directly towards the southern celestial pole. The Southern Cross falls within the constellation Saint Torres the Centaur, the half human, half horse of Greek mythology, and the creature is holding a bow loaded with an arrow. The Centaur's front legs are marked by the two pointer stars alfred Beders, Santoros. At 4.3 light years, Alpha Centauri is the second of the two pointer stars from the Southern Cross and is also the nearest star system to the sun. The centaur's back arches over the Southern Cross. And just above this is Amiga Centauri, a spectacular globular cluster, uh, visible with the unaided eye, uh, from dark locations. Globular clusters are tightly packed fees containing thousands to millions of stars. They're thought to have all originally been born at the same time from the same molecular gas and dust cloud.
Stuart: They're the cause of small galaxies which have been consumed by bigger galaxies through galactic cannibalism. Amiga Centauri is about 160 light years away. A light year is about 10 trillion. Distance of photon can travel in a year at 300,000 speed of light in a vacuum. And the ultimate speed limit of the universe Amiga. Centauri is one of the largest and brightest of the 150 or so globular clusters known to orbit around our Milky Way galaxy. Centaurus was one of the 48 constellations listed by the second century astronomer Ptolemae and it remains one of the 88 modern day constellations. Turning to the right or west and you'll see the constellation Leo the lion just above the western horizon. Its brightest star is Regulus, or The Little King located about 79 light years away. Regulus, designated Alpha Leone's is actually a five star uh system organized into two pairs. Regulus A is a spectroscopic binary comprising a spectral type B blue white main sequence star uh some four times the mass and 288 times the luminosity of the sun and a faint companion star thought to be a white dwarf the stellar corpse of a Sunlike. Star spectroscopic binaries are stars that can't be resolved by optical telescopes into two separate objects and can only be separated by observing their individual spectroscopic doppler shifts as they orbit each other. Astronomers describe stars in terms of spectral types a classification system based on temperature and characteristics. The hottest, most massive, and most luminous stars are known as spectral type A blue stars. They're followed by spectral type B blue white stars then special type A white stars special type F white and yellow stars special type G yellow stars. That's where our sun fits in. Spectral type K. Orange stars. And the coolest and least massive known stars are special type M, red dwarf stars. Each special classification is also subdivided using a numeric digit to represent temperature with zero being the hottest and nine the coolest and a Roman numeral to represent luminosity. So put all that together and our sun is a spectrotype G two V or G 25 yellow dwarf star uh also included in the stellar classification system a spectraltypes Lt and Y which are assigned to failed stars known as brown dwarfs some of which were actually born as spectraltype M red dwarf stars but became brown dwarves after losing some of their mass. Brown dwarves fit into a category between the largest planets which can be about 13 times the mass of Jupiter and the smaller, specialty type M red dwarf stars which can be 75 to 80 times the mass of Jupiter or 0.8 solar masses. Located further away, a Regulus, BC and D, which had been main sequence stars. At the opposite end of the constellation from Regulus is the Star Beat Leone's or Dinner Bola the horse's tail. It's also a luminous bluewhite star uh about half as bright as regulars and the third brightest star in the constellation Leo. Beta Leones has about 1.8 times the Sun's mass and about 15 times the Sun's luminosity. It's suspected of being a dwarf Cepheit or Delta Scooti type variable star uh meaning its luminosity varies slightly over a period of several hours due to pulsations on its surface algebra. Or Gamma Lioness is a binary system with a visible third component. The two primary stars are located about 126 light years away and can be resolved in small backyard telescopes. Both are yellow giants orbiting each other every 600 Earth days. The unrelated Tertiary star, named 40 Leones, is a yellow tin start that can be seen through binoculars. The star's traditional name algebra means Forehead, daughter Leones, or Zozma, is the blue white star 58 lightyears from Earth. Epsilon Leonez is a yellow giant some 251 light years from Earth, and Zhao Ledis is an optical triple star. The brightest component is a white giant about 260 light years from Earth, while the second brightest star, 39 Leone, is widely spaced and located to the south of the primary. The third and faintest star in the system, 35 Leones, is to the north. Lord Leoneus is a binary star system visible in medium sized backyard telescopes located some 79 light years away. Load, early onus appears to be a yellow tin star with two components orbiting each other every 183 Earth years. Finally, in Leo uh, let's look at tallyoneus. Visible as a double star through binoculars, it includes a yellow giant located some 621 light years from Earth, and binary secondary star uh, 54 Lyonus, which is actually a pair of blue white stars divisible in small telescopes and located some 289 light years away. The constellation Leo also contains many galaxies, including the spiral galaxy Messier 66, as well as Messi 65 and NGC 36 28, which are known as the Leo Triplet. Located some 37 million lightyears away, the Leo Triplet is a somewhat distorted shape due to gravitational interactions between Messiers 66 and the other two galaxies, which are Cannibalizing stars from messy S 66. Eventually, the atomos stars may well form a dwarf galaxy orbiting M 66. Both M 65 and M 66 are visible in large binoculars or small backyard telescopes, but their concentrated nuclei and elongation are only visible in larger instruments. Other bright, well known deep sky galaxies in Leo include Messiah 95, messiah 96 and Messiah 105. Messiah 95 and Messiah 96 are both spiral galaxies, each about 20 million lightyears from Earth. Both look like fuzzy objects in small telescopes, but display their spectacular structures in larger instruments. M 95 is a bad spiral. Another bad spiral, NGC 29 Three, is thought to be similar in size and structure to our own Milky Way galaxy. It was discovered by William Herschel in 1084, close to the Mninety Five. M 96 pair is the elliptical galaxy M 105, which is also about 20 million lightyears away. The constellation also contains the Leo uh ring, a cloud of hydrogen and helium gas orbiting two of the galaxies in the constellation. A gravitationally lensed object known as the Cosmic Horseshoe is also found in Leo uh. Above Leo uh, you'll find the constellation Virgo, the Greek and Roman goddess of wheat and agriculture. Virgo's brightest star spiker is visible above the western horizon. It's located some 250 light years away. Spiker is lightened for ear of wheat which Virgo is holding in a hand. Spiker, or Alpha Vaginas is the 16th brightest star in the night sky and he's both a spectroscopic binary and a rotating Epsiloidal variable a close binary system whose stars are not eclipsing but cause apparent fluctuations in brightness because of changes in the amount of light emitting area visible to the observer. Spikers. Two main stars orbit each other once every four Earth days and are so close their egg shape rather than spherical and can only be separated by their spectra. The primary is the blue giant variable Betacephiad star. It undergoes small, rapid variations in brightness. These are caused by pulsations of the star's surface thought to be caused by the unusual properties of iron at temperatures of 200,000 degrees in the stellar interior it has about ten times the Sun's mass and about seven times its diameter. The secondary star in spiker is smaller than the primary but it's still some seven times more massive than the sun and has 3.6 times the Sun's diameter. Uh, turning to the north now and the constellation Beaurties the Herdsman, or Ploughman. There you'll see the bright orange red star Arcturus or Alpha Botes just above the northern horizon. It's a red giant located just 36 light years away a bloated aging star, uh, some 7.1 billion years old nearing the end of its life. Although not much more massive than the sun it's now expanded out to some 25 times the Sun's diameter uh, and will soon puff off its outer gaseous envelope as a planetary nebula uh, revealing its white hot stellar core a white dwarf which will then slowly cool over the eons of time. Another bright, reddish looking star this time in the east is the red supergiant Antares meaning the rival of Mars because of its appearance and location in the sky which appears to be opposite of Mars in the sky antara's is one of the biggest known stars in the universe. It's enormous 18 times the Sun's mass 10,000 times its luminosity and 883 times the Sun's radius. As we mentioned in last month's sky Watch where it placed at the center of our solar system its surface would extend out close to the orbit of Jupiter. Despite being some 550 light years away antares is still the 15th brightest star in the night sky. Unlike the sun or octorus uh, the death of Antares will be far more spectacular. Antares is destined to explode as a core collapse or type two supernova. Uh, when it does so, sometime in the next few hundred thousand years it will appear as bright in the Earth's sky as the full Moon and be quite visible even in daytime. Um, Antares has a companion star, Antari's B a special type bluewhite main sequence star more than seven times the Sun's mass and five times its diameter. Antares is the heart of the scorpion in the constellation Scorpius. Below Scorpius is the constellation SAGITTARIUS the Archer which points the way to the center of the Milky Way Galaxy. SAGITTARIUS is commonly represented as a wing centaur pulling back on a bow which is aimed at Arcturus, the center of the Milky Way galaxy and its supermassive black hole. SAGITTARIUS a star, uh, lie at the westernmost part of SAGITTARIUS. SAGITTARIUS a star, is about 270 lightyears away and has some four 3 million times the mass of our sun. It was in July, back in 2016, that the solar system's Barry Center moved outside the sun, where it will remain until 2027. A barrier center is the gravitational center of mass of a celestial system. For example, in our Earth Moon system, the Earth and Moon actually orbit each other around a common center of gravity a barrier center. Because the Earth is so much more massive than the Moon the barrier center is always inside the Earth's radius. If it were outside the Earth's radius, the Earth and Moon would instead have been classified as a binary planetary system. Like Pluto and Sharon, the solar system center of gravity, or Barry Center, is usually located inside the Sun's radius. After all, the sun contains over 99% of all the solar system's mass. But actually, the mass of the solar system is orbiting around the solar system's barrier center, which means the sun also has a very slight spiraling twelve year orbit around the barrier center. And every now and then, when the planet's orbital positions are just right especially when Jupiter and Saturn are nearest to each other their combined gravitational interactions move the solar system's barrier center ever so slightly outside the Sun's radius. And because Jupiter and Saturn reach this alignment every eleven years some scientists have speculated whether this could trigger the Sun's eleven year solar cycle. And before you ask, the Barry Center isn't named after some guy in a Bay safari suit called Barry, but rather it's the ancient Greek word for heavy or center of mass. We also have two meteor showers, both of which peak in late July. There's the Southern Delta, acknowledged which are visible from mid July to mid August each year with peak activity on July 20, 829. The shower originated either from the breakup of what are now the Marsden and Cracked Sungazing comets or from the parent comet P 96 Malcolm. The Delta Aquarids get their name because the radio appears to lie in the constellation Aquarius either one of the constellation's brightest stars. Delta Aquari. There are two branches to the Delta Acrids meteor shower the southern and northern. The southern Delta Acrids are considered a strong shower with an average between 15 and 20 meteors an hour between midnight and dawn. Listeners in the Southern Hemisphere usually get the better show because the radiant is higher in the southern sky. Since the radiant is above the southern horizon for Northern Hemisphere listeners, meteors will be seen to fan out in all directions. East north and west with few meteors heading southwards unless they're really short. Near the Radiance, the northern delta accurate are the weakest shower peaking later in mid August with an average peak rate of about 10 meters/hour. Meanwhile, the nearby slow and bright Alpha Capricorn its meteor shower will take place from as early as July 15 and continue until around August 10. The meteor shower has infrequent but relatively bright meteors and even some fireballs it's generated as the Earth passes through a debris trail left by the comet 169 PNET which was originally identified as the asteroid 2002 Ex One Two. However, it was shown to be weekly active during perihelion and was then reclassified as a comet. The meteor shower was created about 3500 to 5000 years ago when about half of the parent body disintegrated and fell into dust. The cloud eventually evolved into Earth's orbit causing a shower with peak rates of about 5 meters an hour and some outbursts of bright flaring comets radiating out from the constellation Capricorn towards the south. The bulk of the comet's debris won't be in Earth's path until the 24th century by which time the Alpha Capricorn is expected to become a major annual meteor storm stronger than any current annual shower. Jonathan Ali, the editor of Australian Sky and Telescope magazine joins us now for the rest of our tour of the July 9 skies.
Guest: Gay Stuart yeah, well, it's winter time. Middle of winter. Here we are in the southern half of the planet and it's, uh, cold. It's cold. But where I live at least the skies are usually pretty nice and clear this time of year. So it's really good for stargazing if you get out and rug up. And we've got some of the best southern constellations up nice and high in the sky this time of the year in the early evening when you can get out and do some stargazing. So we've got the Milky Way, which is our galaxy seen from the inside. It's stretching all the way from the east to the west across the sky from where the sun comes up to where it goes down. That's east to west. And that's in the middle evening or early evening and it's got stacks and stacks of things in there to see. So right in the middle of that stretch of the Milky Way and basically high in the south, we've got the Southern Cross. Southern Cross. Famous Southern Cross. Very small constellation, but a very prominent constellation. It's at its highest point in the sky at this time of year. So if you haven't seen the Southern Cross yet you want to try to identify it. Now is the time to get outside and have a look because six months from now it's going to be down very low in the sky and you might not be able to see it at all. So winter is a good time to see the Southern Cross just to its left we've got two bright stars, and they're known informally as the two pointers, because if you draw a line between them and you extend the line further, it basically points directly towards the Southern Cross. Those two stars are called Alpha and Beta Centauri, and listeners of the right age will remember that Alpha Centaurie was the destination of Stewart. What was the destination of danger, will Robinson? You babbling booby. Yes. The Jupiter Two spacecraft and the TV show Lost in Space or the Pain.
Stuart: The Pain.
Guest: No, they don't make them like that anymore, do they? Probably couldn't make them like that anymore. Anyway. They must have really become lost in Lost in Space, because the Alpha Centauri star system, of course, is the nearest star system to our solar system, and there's nothing in between. So how on Earth they got lost between here and there and there's nothing in between? There must be. Oh, that's why they got thrown off course, didn't they? Because it was stowaway. And then how many series did they get out of that? Uh, it seemed like it went on forever when I was a kid, but it was a really good show.
Stuart: According to Google, lost in space at only three series. Uh, roughly 29, 30 and 24 episodes in those three series, 1965 to 68. What else do we need to know?
Guest: Well, that's quite a few episodes per series. That probably is the reason why it just seemed to go forever, because it was always on telly. And then, of course, as soon as the series finished, they just kept repeating it, repeating it, repeating it.
Stuart: But you know what? They never had a proper ending. What I liked about Star Trek is that there was an ending to the genre. When each of the series finished, there was a final episode for The Next Generation and for Deep Space Nine, and also for Voyager, but we never had that with Lost in Space. It just ended in mid air or.
Guest: Midspace I guess that's the thing with Lost in Space. It was the suspense. The suspense of not knowing what was going to happen next. That was the whole point of being lost.
Stuart: Whereas they should have had a conclusion. They should have reached the.
Guest: No, the sickly, clawing Star Trek nonsense I'm not a Star Trek fan where, um, they have to wrap up everything nicely and everyone's lovely. W whatever. Whereas lost his face is more reality. Half of them hate each other's guts and didn't trust each other, and, uh, it all went wrong. And that's life, isn't it? Basically. Anyway, Alpha Centauri, so that's down in the south, alpha is the third brightest star in the night sky, actually beat us. And Torre, just next to it, is the 11th brightest star in the sky, the Southern Cross I mentioned, two of those stars are very bright as well. One is the 12th brightest, and the other is the 20th brightest in the night sky. Now, rising high in the eastern half of the sky this time of year we've got the constellation SAGITTARIUS and the region around it and it's neighboring constellation Scorpius. And both of these constellations are full of great stuff to see with the telescope or even just binoculars. You've got star clouds and star clusters and you've got nebulae and it's just superb. And the reason for this is that when we're looking in this direction in space we're looking right into the middle bulk of our galaxy where most of the stuff of our galaxy is. There's lots of stars and things in there. So the center of the Milky Way, in fact, is located in the direction of SAGITTARIUS. So that's starting to come up now in the eastern half of the sky. So we've got months and months and months to have a look at all that right down low, actually, in the southeast at, uh, this time of the year there's the second brightest star in the sky, like Canopus. But you have to be quick to see it because, uh, it sinks down below the horizon by about 09:00 P.m.. So if you see a bright star down on the southern horizon and you go out seven or 08:00 when it gets dark, that's the Stark And Opus the second brightest star in the sky. Up in the northern half of the sky we've got a few bright stars. We've got one called Arcturus and another one called Altar. Another one called Vega. Arcturus is the fourth brightest star. Altar is 13th and Vega is the fifth brightest star in the whole night sky. Now, all of these brightness rankings are just how we see them from Earth. Uh, their actual intrinsic brightnesses are actually different. How we see them just depends on how far away they are. So Vegas, for instance, which I said is the fifth brightest star it appears to be brighter than the star in the Southern Cross called Mimosa. But in fact, Mimosa is far brighter star. It's just further away. So Vega is only eight light years away whereas Mimosa is 350 light years away. So the difference between what astronomers call apparent brightness how bright it appears to us and intrinsic brightness how bright something would appear if it was seen from a standard distance. That's the two measurements of brightness that astronomers use. Now let's take a look at the rich planets we can see. And just like last month, actually, all the bright planets will be stretching across the morning sky. So if you go out before sunrise, about 30 minutes before sunrise you should be able to spot Mercury if you've got a good clear horizon very low down on the east northeast of the horizon from where we are. Uh, just a little bright star looking thing probably in a bit of a dawn glow already. And then above it and to its left, Venus. You can't miss Venus. It's the biggest and brightest thing in the sky other than the sun and the moon. Go up a little higher and more to the north and you'll find Mars, which can be identified quite easily because it's got a quite a distinct reddish sort of color, higher still and a bit around a bit west of north, you'll spot Jupiter, which is big and bright, although not quite as bright as being that's pretty bright. And then further around towards the west and about the same height above the horizon as Jupiter, you'll see Saturn, which you can tell because it's got a slightly yellowish tinge.
Stuart: That's Jonathan Alley, the editor of Australian Sky Telescope magazine. And that's the show for now. Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts, itunes, Stitcher, Google Podcasts, Pocket Casts, Spotify, Acast, Amazon Music, Bytescom, SoundCloud, YouTube, your favorite podcast download provider and From Spacetime with Stuart Garycom. Spacetime is also broadcast through the National Science Foundation on science owned radio, and on both iHeartRadio and Tune In radio. And you can help to support our show by visiting the Spacetime Store for a range of promotional merchandising goodies. Or by becoming a Spacetime patron, which gives you access to triple episode, commercial free versions of the show, as well as lots of bonus audio content which doesn't go to air, access to our exclusive Facebook group and other rewards. Just go to spacetime with Stewart Garycom for full details. And if you want more space time, please check out our blog, where you'll find all the stuff we couldn't fit in the show, as well as heaps of images, news stories, loads of videos and things on the web I find interesting or amusing. Just go to spacetime with Stuartgarry Tumblrcom. That's all one word and that's Tumblr without the e. You can also follow us through at stuartgary, on Twitter, at Spacetime with Stuartgarry, on Instagram, through our Spacetime YouTube channel and on Facebook. Just go to Facebook.com um SpaceTime with Stuart Gary and SpaceTime is brought to you in collaboration with Australian Sky and Telescope magazine Your Window on the Universe. You've been listening to SpaceTime
Stuart: with Stuart Gary. This has been another quality podcast production from Bitesz.com