Tag Archive for: planets

September

• 1st Saturn is approaching  Opposition  on the 8th September and is rising at ( closest position to Earth, which was on 8th September and is a stunning evening object at Magnitude o.6, distance 1296.3 million km,  72.07 light minutes away. The image above is Saturn at 20:hrs AEST on the 1st September at an altitude of 17 degrees 31 min.
• 6th  Moon at Apogee, furthest point from Earth this month, 0:53hrs AEST,  distance from Earth 406,209.2 km.
• 21st Introduction to Astronomy Course 17:15 – 19:15hrs Inquiries 0419 103 213 Viewing of Saturn and other objects if clear afterwards, BYO Telescope and Binoculars if you have them but they are not necessary.
• 22nd Southward Equinox 22:44hrs AEST.
• 27th C/203 A3  Tsuchinshan-Atlas closest to Sun, a morning object just before sunrise.

• 28th Moon at Perigee, Closest point to Earth this month, 23:26hrs AEST, distance from Earth 357,285.7km.
• 6th Oct Daylight Savings begins. AEDT Time.
• 13th Oct
• C/203 A3  Tsuchinshan-Atlas closest to Earth, an evening object setting just after the Sun.

• Universal Nomenclature of the      Equinoxes and Solstices Each celestial object has coordinates similar to a street directory to locate its’ position in the heavens.Celestial Sphere – An imaginary sphere surrounding the Earth on which the celestial bodies appear to lie.Celestial Longitude (CLong) – coordinateon the Celestial Sphere that corresponds tothe longitude on Earth and is measuredfrom 00.00h. Measured in hours, minutes, seconds or sometimes given as degrees,minutes seconds corresponding to degreesin a circle, ie 360 degrees. Celestial Latitude (CLat)– corresponds to latitude on Earth’s surface and is measured

  in degrees, minutes, seconds. Up to 90

  degrees North (Nth) or South (Sth) of the Celestial Equator.

  + for the Northern Hemisphere,

  – for the Southern Hemisphere.

   

  Celestial Equator – directly above the

  Equator on the Earth’s surface.

   

  Northward Equinox – Day & Time the

  Sun crosses the Celestial Equator travelling into the northern Hemisphere. 00.00h CLong

   

  North Solstice   – Date and Time Sun reaches its’ furthest northern position ~ 23.5 degrees Nth. of the Celestial Equator. The Tropic of

  Cancer on the Earth’s surface, northern limit

  of Sun overhead.

                     

  Southward Equinox – Day and Time

  Sun crosses the Celestial Equator travelling into the Southern Hemisphere.

   

  South Solstice – Date and Time the Sun

  reaches its furthest southern position ~ 23.5 degrees Sth. of the Celestial Equator.

  The Tropic of Capricorn on the Earth’s

  Surface, southern limit of Sun overhead.

   

  The preceeding 4 terms indicate:

  1.Direction of the Earth’s Poles

  relative to the Sun.

  2.Extent of the Nth/Sth movement

  of the Sun overhead

  3.Direction of seasonal change of the

  position of the Sun due to the angle of the

  Earth’s axis of rotation,  ~ 23.5  degrees.

  

  Ecliptic – Path of the Sun against the background of the stars.

   SCP – South Celestial Pole

  NCP -North Celestial Pole

  Both directly above the Earth’s Poles.

   

  The Point of Northward Precession –

   The point the Sun crosses  the Celestial Equator travelling  into the Northern Hemisphere. The point is actually moving 1/7 sec/day. It is linked  to Celestial Longitude as the point slowly  slips along the Celestial Equator.

   

  Epoch   For a printed map the stars positions are fixed and so the Epoch date needs to be stated, ie Current Epoch is 2000.  Printed star maps are good for about 50 years, then the next epoch data is required for astronomers, ie next epoch will be 2050.

   

  Tropical Year – Time for the Sun to travel from one Northward Equinox to next,

  365.2422 days.

   

  Siderial Year – Time taken for the Earth to complete one orbit relative to the fixed stars, 365.2564 days.

   

  The difference between the Tropical and Siderial years is due to the effects of

  precession, a gradual westward drift in the ecliptic. The gravitational pull of the Sun and Moon on the Earth’s equatorial bulge cause

  the Earth’s axis to trace out  a circle on the sky every 25,800yrs.

   

  Judith Bailey – Ballarat Municipal Observatory & Museum

  E:  info@ballaratobservatory.org.au 0429 199 312

   

March

• 5th Moon at it’s highest altitude, 29 degrees South.
• 10th Moon at Perigee 16:04hrs AEDT, 356,893.9 km. A super Moon is when the Moon is less than 360,000km from Earth.
• 11th 5.30amAEDT ONLINE Watch Comet 12P/Pons-Brooks is putting on a show now in the NORTHERN HEMISPHERE ONLY, soon after sunset: the Virtual Telescope Project will share the view live, online.  The live feed will start on 10 Mar. 2024, at 18:30 UTC,  05:30hrs AEDT in Ballarat. See April What’s in the Sky for a small window of time for possible viewing from Ballarat.
  

• 18th Luna lowest altitude 28 degrees North.
• 12th The Large Magellanic Cloud  (LMC) reaches highest altitude about 9.00pm AEDT at magnitude 0.28. The LMC is a spiral galaxy in Dorado at a distance of 160kly and a diameter of 29.7kly in diameter.  The Tarantula Nebula, NGC 2070 is located in this area and is magnitude 5. it is 1,833ly in diameter. The Small Magellanic Cloud (SMC) located nearby is a spiral Galaxy in Tucana and 200kly in distance and 17.5kly in diameter. visual magnitude is 2.29. These two irregular dwarf are members of our local group and are orbiting the Milky Way Galaxy.
• Kourtchin (Boorong) refer to the Magellanic Clouds as the male (LMC) and female (SMC), Brolgas. Each cloud resembles the colour and pitted shell of the Brolga egg. Brolgas breed from October to April , when the clouds are at their highest, extending into nearby stars the larger one is trumpeting and the smaller one displaying, but dancing as a pair towards each other.

• 20th Northward Equinox, 14:07hrs AEDT. The Sun crosses the Celestial Equator and moves into the Northern Hemisphere Sky.

• A healthy 100-foot-tall tree has about 200,000 leaves. A tree this size can take 11,000 gallons of water from the soil and release it into the air again as oxygen and water vapor in a single growing season.
  * Native tree species support natural ecosystems by providing habitat and food for birds, mammals, and insects.
  * The planting of trees improves water quality. Tree’s complex root network reduces runoff and erosion. This allows more recharging of the ground water supply. Wooded areas help prevent the transport of sediment and chemicals into streams. Studies show up to 88 percent of nitrate and 76 percent of phosphorus is reduced after agricultural runoff passes through a forested streamside buffer.
  * In addition to all these things, forested streamside buffers also filter sediment from streams, stabilize streambanks, shade and modify stream temperatures, sequester carbon to help mitigate greenhouse gas emissions, and reduce downstream flooding. And the presence of mature trees in a buffer makes the stream wider.
  * A mature tree absorbs carbon dioxide at a rate of 48 pounds per year. In one year, an acre of forest can absorb twice the CO2 produced by the average car’s annual mileage.
  NONE of THE ABOVE OCCURS ON MARS OR ANY OTHER PLANET WE KNOW OF.
• 24th Luna Apogee, 2nd for this month, furthest distance from Earth for the month 02:43hr AEDT 406,259.2km.
• 25th Partial Eclipse of the Moon Image is at 7.55pm AEDT.
• 

Image: Geminids 13th December, 02:00 hrs AEDT Local Time.

December

• 6th Earliest Sunrise for the year.
• 8th Mars is rising 05:18hrs AEDT in Ophiuchus,  Mag. +1.4  Dist. 366.9 milion km, 20.40 light min.. Tilt of North pole towards Earth is 14.0413 degrees, 97.78% illuminated.
• 17th Moon at Apogee 05:42hrs AEDT, Dist. 404,347.0km.
• 8th Saturn at mag. 1.0 setting at 00:26hrs AEDT, Dist. 1,486.7 million km.
• 8th Jupiter is a beautiful evening object setting at 04:02hrs AEDT,  mag. -2.8, dist. 6.520 million km, Red spot transits  Fri Dec 8th 19:19hrsAEDT.
• 9th Red Spot on Jupiter transit 05:15hrs AEDT.
• 9th One of the GREAT COMETS, Comet 1P/Halley, reaches it’s furthest point from the Sun on the 9th December 2023 and begins the journey back to reach perihelion on Saturday September 17th, 2061.
• 8th Mercury sets at 22:46hrs AEDt, Dist. 139.6 million km Mag. -0.3.
• 4th-17th  Geminids Meteor Shower  Maximum: December 14, 19h UT (15th  06hrs AEDT);  ZHR = 150; Velocity = 35 km/s.
  

The best and most reliable of the major annual showers presently observable reaches its broad moon-free maximum on December 14 centred at 19h UT. Well north of the equator, the radiant rises about sunset, reaching a usable elevation from the local evening hours onwards. In the southern hemisphere, the radiant appears only around local midnight or so. It culminates near 02h local time. During high activity, observers
should report their count data for short intervals (no longer than 15 minutes).
Remember that there may be activity related to comet 46P/Wirtanen* on December 12, perhaps from two different radiants. While counting is the best method to record the major GEM activity, notes are advised about the apparent trails and angular velocities of possible “Wirtanen-meteors”.

*12th December ~ 22:20hrs AEDT – Possible Meteor shower

Just before the Geminid maximum there is a chance to observe meteors released from comet
46P/Wirtanen (the initial target of the Rosetta comet exploring mission) on December 12,
around 11h20mUT (λ = 260 .◦11). Vaubaillon writes: this is the first time I see a trail of this
comet crossing the Earth’s orbit. The 1974 trail is quite young and we have no clue concerning
the flux density. Most interestingly, the radiant is split in two very different regions in the sky
– something requiring detailed data and analysis. Most of the activity should be related to a
radiant at about 10◦ north of α Phoenicis in Sculptor, the other radiant is
at between α Pegasi and γ Piscium. Meteors should be very slow with
V∞ = 10km/s and V∞ = 13km/s, respectively. The described activity is expected shortly before
the Geminid maximum. While the Geminid meteors are preferably counted, we recommend to
note to which of the two radiants potential meteors are associated (Scl or Psc). Of course, video
data will provide complete data sets to investigate the radiant structure. Source: IMO

• 17th Moon at Perigee 05:55hrs AEDT  Perigee distance 367,901.4km.
• 22nd South Solstice  (or Summer Solstice in Southern Hemisphere) 13:28 AEDT.  The Sun is at it’s Southern most position, -23  26′ 15.07″
• 27th Moon lowest 28 degrees Nth and is at full Moon.

• MOON’s 18.6 year cycle

The mystery emerged in 2015, when nearly 10 percent of the seemingly healthy mangrove forest along northern Australia’s Gulf of Carpentaria suddenly died. Scientists initially blamed this crucial ecosystem’s die-off solely on an unusually strong El Niño, a weather pattern that periodically siphons water away from the western Pacific and lowers local tides. But a new study published in Science Advances reveals that El Niño had a stealthy accomplice: the moon.

Researchers analyzed more than 30 years of national satellite data to narrow down the suspect list. “It was just the most phenomenal data set,” says the study’s lead author Neil Saintilan, a biogeographer at Macquarie University in Australia. A pattern quickly emerged—about every 18 to 19 years, mangrove tree cover along the Gulf of Carpentaria thinned out significantly before bouncing back to normal within a couple of years. And roughly nine years after each such die-off, the mangrove canopies became unusually dense.

That regularity gave the researchers an important clue. “Nature’s usually pretty chaotic,” Saintilan says. “If something is superregular, it’s probably some kind of orbital cycle.”

“The 18.6-year cycle is essentially driven by what we call a ‘wobble’” in the moon’s orbit, says climate dynamics researcher Sophie Wilmes, who studies tides at Bangor University in Wales and was not involved in the mangrove investigation. Lunar gravity affects daily ocean tides worldwide. As the moon’s orbit oscillates, or wobbles, over 18.6 years, it creates regular, sustained periods of unusually high or low tides in certain places. This effect is especially strong in the Gulf of Carpentaria; its low tides can drop by an average of 40 centimeters because of its location relative to the equator and the shape of Australia’s coastline.

Indeed, the researchers found that Australia’s 2015 mangrove die-off fell 18 and a half years after the previous one. And because of the 2015 El Niño, the trees were hit with a low-tide double whammy: El Niño decreased tides an additional 40 centimeters, a fatal blow to water-loving mangroves.

Although the orbital mechanics of the moon’s wobble have been studied extensively, “there hasn’t been much work that looks at its impact on ecology,” Wilmes says, “so it’s a really cool paper.” In the future, Saintilan and his colleagues hope to look at whether this phenomenon affects mangrove forests in other parts of the world. They also want to study how sea-level rise driven by climate change will alter this natural ecological pattern. A moderate rise might mitigate some of the tidal drop, helping to preserve mangrove forests, but an extreme rise could drown the trees at the cycle’s highest tidal point. “We might be able to anticipate when—or if—we’ll start to see some big problems in terms of mangroves coping,” Saintilan says.

This article was originally published with the title “Mangrove Moon” in Scientific American 327, 6, 22 (December 2022)doi:10.1038/scientificamerican1222-22b