Astronomy forums are buzzing with speculation about newly-discovered Comet C/2012 S1 (ISON). Currently located beyond the orbit of Jupiter, Comet ISON is heading for a very close encounter with the sun next year. In Nov. 2013, it will pass less than 0.012 AU (1.8 million km) from the solar surface. The fierce heating it experiences then could turn the comet into a bright naked-eye object. (continued below)

Comet ISON photographed by E. Guido, G. Sostero & N. Howes on Sept. 24. [more]

Much about this comet–and its ultimate fate–remains unknown. “At this stage we’re just throwing darts at the board,” says Karl Battams of the NASA-supported Sungrazer Comet Project, who lays out two possibilities:

“In the best case, the comet is big, bright, and skirts the sun next November. It would be extremely bright — negative magnitudes maybe — and naked-eye visible for observers in the Northern Hemisphere for at least a couple of months.”

“Alternately, comets can and often do fizzle out! Comet Elenin springs to mind as a recent example, but there are more famous examples of comets that got the astronomy community seriously worked up, only to fizzle. This is quite possibly a ‘new’ comet coming in from the Oort cloud, meaning this could be its first-ever encounter with the Sun. If so, with all those icy volatiles intact and never having been truly stressed (thermally and gravitationally), the comet could well disrupt and dissipate weeks or months before reaching the sun.”

“Either of the above scenarios is possible, as is anything in between,” Battams says. “There’s no doubt that Comet ISON will be closely watched. Because the comet is so far away, however, our knowledge probably won’t develop much for at least a few more months.”

Meanwhile, noted comet researcher John Bortle has pointed out a curious similarity between the orbit of Comet ISON and that of the Great Comet of 1680. “Purely as speculation,” he says, “perhaps the two bodies could have been one a few revolutions ago.” — News and information about meteor showers, solar flares, auroras, and near-Earth asteroids.

What’s in the Sky – October 2012

What’s in the Sky – October 2012


Mercury, the solar system’s innermost planet, returned to the evening sky on September 10, after its most recent superior conjunction and will remain an evening object until November 17th.  By the second half of October Mercury will be set about 2 hours after the Sun. Mercury starts the month in Virgo then moving through Libra before ending the month in Scorpius. Low in the western evening sky just after sunset at the beginning of October, Mercury begins the month in Virgo just over one degree to the north of Virgo’s brightest star, Spica.

Oct 1st:             Mercury and Saturn will be close.

Oct 6th:            Mercury and Saturn, both of which are currently in the constellation of Virgo, will be at conjunction after sunset. Mercury will be being the brightest at magnitude -0.3 with Saturn to its right will be at magnitude 0.7. The bright star, Spica will be just below forming the point of a small triangle.

Oct 8th: Mercury at aphelion

Oct 16th:          Mercury will be close to Zubenelgenubi the second brightest star in Libra

Oct 17th:          Mercury and Zubenelgenubi will be just below the two day old crescent Moon at around 7pm

Oct 26th:          Mercury will reach its greatest eastern (evening) elongation from the Sun and will be at its highest point in the sky.

Venus is the ‘morning star’ at present and will remain visible in the morning skies until January 2013. In a telescope, Venus will show about 60% gibbous phase and will have a magnitude of -4.1. Venus will move in to the constellation of Virgo by the 23rd October. It rises about ninety minutes before the Sun at the beginning of the month.

Oct 3rd & 4th:             Venus pass less than half of a degree from Leo’s brightest star, Regulus

Oct 12th:          Venus, waning crescent Moon and Regulus will form a right angle triangle in the sky

Oct 31st:        Venus at perihelion



The red planet can easily be found low in the western evening sky after sunset. Situated among the stars of Libra at the beginning of the month. It crossed into Scorpius on the 7th, passing through the jaws of the Scorpion on the 11th and on into Ophiuchus on the 19th.

Oct 1st:          Mars 0.1 degree from minor planet 7 Iris

Oct 18th:          3 day old waxing Moon will be close to Mars

Oct 19th:        Mars, the star Antares and the crescent Moon make a temporary triangle in the early evening sky

Oct 22nd                    Mars will be 3.5 degrees to the north of Antares. The colour resemblance between these two objects can be quite striking, both exhibiting a slightly orange tint with Antares being the slightly brighter of the two. The name Antares actually means “rival of Mars”.


On the night of 5/6 October, the moon is near Jupiter, and occults it as seen from South Western Australia at sunrise, and along Australia’s southern coast in daylight. The giant planet rises just after 11.00pm at the beginning of the month and by the end of the month at around 10pm. Jupiter spends the entire month in Taurus where it is close to the waning gibbous Moon on the 6th. Its four Galilean satellites will appear to the west of the planet on the 11th of the month and to the east of the planet in the early evening on the 21st.

Oct 4th:           Jupiter stationary (Midnight)

Oct 5th:           Gibbous Moon, the star Aldebaran and Jupiter make a temporary triangle in the morning sky

Oct 6th:           Gibbous Moon and Jupiter close in the morning sky.


Saturn starts the month low in the Western sky setting around 7pm. Saturn goes round the far side of the Sun on 25 October, and towards the end of the month, emerges back out into the morning sky. Low in the western evening twilight at the beginning of the month, Saturn is very quickly heading towards its conjunction with the Sun on the 25th. It will be lost from view until it appears in the early morning twilight next month.

Oct 6th:           Mercury, Saturn and the star Spica make a temporary triangle low above the Western horizon in the early evening twilight. Difficult and will require a clear horizon.

Oct 16th:        Slim crescent Moon located to left of and above Saturn, low above the Western horizon in the evening twilight could be difficult to see.

Oct 25th:        Saturn at conjunction 7pm

 Uranus is a particularly good target this month particularly after midnight. It should be visible in binoculars.

It rises after sunset and sets before sunrise throughout the month. It is in Pisces this month. You may be able to recognize Uranus just by its hue, which most people find faintly blue or green. I can see the colour even with my 10×50 binoculars. In a dark sky you can pick it naked eye if you have a good finder scope.

 Neptune is currently in the constellation of Aquarius, sets after 3am at the start of October and just after 1am at the end of the month. Neptune varies from magnitude 7.8 to 8.0, about two magnitudes fainter than Uranus. It’s visible in steadily supported binoculars, but only if you look quite carefully. The planet disk can be resolved in a 4inch (100mm) aperture telescope but only in really good conditions. In a 6 inch the disk can be plainly visible.

Name That Asteroid Contest

Students worldwide have an opportunity to name an asteroid from which an upcoming NASA mission will return samples to Earth.

Scheduled to launch in 2016, the mission is called the Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, or OSIRIS-REx. Samples returned from the primitive surface of the near-Earth asteroid currently called (101955) 1999 RQ36 could hold clues to the origin of the solar system and organic molecules that may have seeded life on Earth. NASA also is planning a crewed mission to an asteroid by 2025. A closer scientific study of asteroids will provide context and help inform this mission.

The competition is open to students under age 18 from anywhere in the world. Each contestant can submit one name, up to 16 characters long. Entries must include a short explanation and rationale for the name. Submissions must be made by an adult on behalf of the student. The contest deadline is Dec. 2, 2012.

The contest is a partnership with The Planetary Society in Pasadena, Calif., the Massachusetts Institute of Technology’s, or MIT, Lincoln Laboratory in Lexington and the University of Arizona in Tucson.

A panel will review proposed asteroid names. First prize will be awarded to the student who recommends a name that is approved by the International Astronomical Union Committee for Small-Body Nomenclature.

The asteroid was discovered in 1999 by the Lincoln Near Earth Asteroid Research, or LINEAR, survey at MIT’s Lincoln Laboratory. LINEAR is part of NASA’s Near Earth Observation Program in Washington, which detects and catalogs near-Earth asteroids and comets. The asteroid has an average diameter of approximately one-third of a mile (500 meters).

To review contest rules and guidelines, visit
To see a video explanation about the contest, visit
For information about the OSIRIS-REx mission, visit
Questions about this contest should be directed to

Astronomy Events in Coonabarabran – October 5th-6th 2012.

Annual Science in the Pub

This entertaining event starts the weekend off on Friday October 5th, 2012 from 6.30pm. This annual debate is definitely entertaining and can be thoroughly outrageous at times as a group of astronomers from various backgrounds debate a topic of astronomical interest at the Royal Hotel, John Street Coonabarabran. This event has an entry fee of $5 and provides entry into the drawer for a variety of prizes on the night. Food is available for sale on the night. Bookings would be appreciated. Vegetarian meals are also available. Enjoy Dr Fred Watson, Dr Amanda Bauer and Dr Bradley Schaeffer debating the topic; “The End is nigh.. or is it? Come along join in  and be a part of the fun!
Siding Spring Open Day

On Saturday October 6th, the Annual Siding Spring Open Day will be held here at Siding Spring Observatory. A number of the telescopes will be open during the day to the public.
There will be a BBQ lunch available; a shuttle bus on site to help you move around and see all there is to see. You will have the opportunity to talk to astronomers and learn about what science is carried out here.
Solar observing will also be available and there will be talks in the Exploratory lecture theatre throughout the day.
The Exploratory cafe will be opened for a well deserved cuppa or Devonshire tea or try a light lunch from their International Men.

Entry to the event is free.

The Open Day will start at 10am and run until 4pm. Visit the various telescopes and listen to astronomers talk about the research they do.
Take part in the trivia treasure hunt to win prizes on the day.

Annual Bok Lecture
Saturday evening will culminate with the annual Bok lecture. This is a free lecture, held at the Coonabarabran Primary School in George Street, Coonabarabran.
The Bok Lecture is a light hearted look at astronomy and is accessible to even the most non-science mind. Dr Scott Croom from the University of Sydney will be speaking on the topic: “big Bangs, Big Crunches and Big Rips”.

This night is open to everyone and is free. The event starts at 7pm.
For more information on all these events or to make a booking please contact Donna Burton at Siding Spring Observatory on 02 6842 6255 or by email