Astroblog

The great sign appearing in the sky in September, This once in 7,000 year celestial event shows "a woman clothed with the sun, with the moon under her feet, and on her head a crown of 12 stars. She was with child and wailed aloud in pain as she labored to give birth … She gave birth to a son, a male child, destined to rule all the nations with an iron rod", the beginning of tribulations described in Revelations 12...

Oh, I'm sorry, that's the line up in 1827.. (Hmm, the earth has not ended in the intervening century).

Well, September 23, the date, according to numerologist David Meade, of the great sign of Revelation 12, where the spiritual beginnings of the apocalypse will occur, to be followed up by the impact of the imaginary Planet Nibiru on or Earth, has come and gone.

The crescent Moon, Jupiter and Spica on the evening of September 23, 2017 (click to embiggen)

So, what happened, we had the Solstice (spring in the Southern Hemisphere, Autumn in the North), a  very nice day here, warn and blue skied, and  nice evening line-up of Spica, Jupiter and the Moon (which will still be nice tonight), although the Moon will be further away.

And that was it. Nibiru failed to appear.   David Meade has suspended the apocalypse until some unspecified date in the future.

But we all knew this would happen, didn't we. We survived the end of the earth in 2012, the end of the Earth from Comet ISON and the end of the Earth from comet Elenin. Some simple simple astronomical knowledge heled usalong.

Assuming that we can trust the interpretation of the "woman clothed with the sun" as being the astrological constellation of Virgo when the suns is in it, the occurs EVERY September. The Moon will be at Virgo's feet at least once every september too. Jupiter, which is supposed to be the "male child" in the prophecy, is currently in Virgo not far from Spica, and will move out of Virgo over the coming Months (the "giving birth" thing). Jupiter have an orbit of roughly 12 years, so reoughly every 12 years of so we will have a  woman clothed with the sun, with the moon under her feet, giving bith to a child. Hardly the 7,000 year unqiue line up.

WHat about the crown of 12 stars, This si particularly arbitray (there are any number of stars above the "Head" of Virgo). There are 13 unaided eye visible stars in Leo, and you can add in the planets as well. Theses line-ups with the added Planets are rarer, EarthSky found at least 4 others in 1827, 1483, 1293, and 1056. I've illustrated the 1827 one above.

Notably, the world did not end after the 1827 Revelation sign, despite months and years passing. The same will happen with this revelation sign.

What about Nibiru. It is a figment of the imagination. In the same peoid that this supposed bigger than Jupiter palent was supposed to come close to us, amateur and professional astronomers tracked a tiny space probe, found a new Dwarf Planet, multiple new asteroids and generally failed to see anything as obvious as a mega Jupiter heading towards us (it would be the brightest object in the sky, other than the Sun and Moon, for many months before it came close to us, even if it was pitch black).

Because it isn't there.

So next time someone tries to scare you with an astronomical doomsday, just say no. You've survived at least four, you are not scared any more.

Labels: Astronomy, Pseudoscience, science communicators

Coming Events in 2013
Significant Astronomical events that can be seen with the unaided eye or minimal equipment in 2013 in Australia (and to some degree elsewhere in the Southern Hemisphere, ocultations and eclipses are very region specific). Special events are bolded.


6 January 2013; Occultation of Spica
7 January 2013; Moon Near Saturn
10-11 January 2013; Moon Near Venus
13 January 2013; Moon Near Mars
18-22 January 2013; Comet C/2012 F6 Lemmon in the Southern Cross
20 January 2013; Comet Lemmon near the Jewel Box Cluster
22 January 2013; Moon Near Jupiter
1-28 February 2013; Comet Lemmon visible to the unaided eye
3 February 2013; Moon near Saturn
9-28 February 2013; Comet PanSTARRS visible in evening twilight
9 February 2013; Venus near Moon in morning twilight
18 February 2013; Occultation of Jupiter
1-14 March 2013; Comet PanSTARRS visible in evening twilight
2 March 2013; Moon close to Saturn
11 March 2013; Moon close to Mercury
18 March 2013; Moon close to Jupiter
29 March 2013; Moon close to Saturn
8 April 2013, Moon close to Mercury
14 April 2013, Moon close to Jupiter
26 April 2013, Partial Lunar Eclipse
28 April 2013, Saturn at opposition
5 May 2013; Eta Aquarid meter shower.
10 May 2013; Annular eclipse of the Sun
23 May 2013, Moon and Saturn close.
26 May 2013, Venus, Mercury and Jupiter close together.
29 May 2013, Venus, Mercury and Jupiter close together.
7 June 2013, Crescent Moon and Mars close together.
10 June 2013, Crescent Moon, Venus and Mercury close together.
19 June 2013, Moon and Saturn close.
21 June 2013, Mercury and Venus close.
30 June 2013, "Blue" first quarter Moon.
6 July 2013, Crescent Moon and Mars close.
7 July 2013, Crescent Moon and Jupiter close.
10 July 2013, Venus and crescent Moon close.
17 July 2013, Saturn and Moon close.
22 July 2013, Evening, Venus and Regulus closee.
22 July 2013, Morning, Mars and Jupiter close.
4 August 2013, Jupiter and thin crescent Moon close.
5 August 2013, Mars, Mercury and thin crescent Moon close.
10 August 2013, Venus and crescent Moon close.
13 August 2013, Staurn and Moon close.
1 September 2013, Crescent Moon close to Jupiter.
2 September 2013, Crescent Moon close to Mars.
6 September 2013, Crescent Moon close to Mercury.
6 September 2013, Venus and Spica close.
8 September 2013, Crescent Moon close to Venus.
25 September 2013, Mercury and Spica close.
1 October 2013, Crescent Moon and Mars close.
7 October 2013, Mercury, Saturn and Crescent Moon close.
8 October 2013, Venus close to crescent Moon.
16 October 2013, Mars close to Regulus.
17 October 2013, Venus close to Antares.
21 October 2013, Orionid meteor shower.
22 October 2013, Orionid meteor shower.
26 October 2013, Jupiter close to Moon.
7 November 2013, Crescent Moon close to Venus.
10-20 November 2013, Venus crosses Sagittarius.
17 November 2013, Leonid Meteor Shower.
22 November 2013, Moon close to Jupiter.
26 November 2013, Saturn and Mercury close.
28 November 2013, Crescent Moon close to Mars.
1 December 2013, Crescent Moon close to Saturn.
2 December 2013, Crescent Moon close to Mercury.
6 December 2013, Crescent Moon close to Venus.
13 December 2013, Geminid Meteor shower.
26 December 2013, Mars and Moon close.
29 December 2013, Saturn and Crescent Moon close.

Labels: Astronomy, comets, eclipse, Occultation, unaided eye

The International Space Station shoots between the Saturn and Mars (closest to Saturn though), then zooms through alpha and Beta Centauri, the pointers to the Southern Cross below' The sequence was taken at 7:02 pm ACST on 11 September 2012 from Adelaide. Ten x 6 second exposures at 400 ASA taken with canon IXUS (click to embiggen). The bight line bottom left is a plane.

My animation of all 10 images is below (images stacked and converted to AVI with ImageJ.

Labels: animation, Astronomy, astrophotography, ISS, Mars, Satellite, Saturn

Labels: Astronomy, Public Lecture

The Adelaide Planetarium at the University of South Australia is presenting, as part of their 40th Anniversary celebrations, "Aboriginal Skies" with Paul Curnow. You can see Paul talking about Aboriginal skies here.

From their email to me:

"Come and learn how to find the different constellations (stellar patterns) as seen by indigenous groups around Australia. Hear about the Dreaming stories that relate to the night sky. Learn about how constellations like the Southern Cross and Orion are seen by Aboriginal Australians. The evening is strictly designed for the adult beginner, with little or no astronomical knowledge who would like to know more about the night sky and the constellations, as seen by the Aboriginal Peoples of Australia."

Seats are running out fast: Saturday 30th of June 2012 at 7:30pm – 9:30pm
Adelaide Planetarium,
Building P
Mawson Lakes Campus,
University of South Australia

Cost $30.00 per person. Enrolments are subject to the seating capacity of the planetarium. To make a booking or for further information phone 8302 3138 or email the planetarium at [email protected].

Labels: Astronomy, miscelaneous

You may, or may not, have heard of Laneway Learning. In a Melbourne laneway cafe people come together for relatively informal learning sessions. Learning with Lattes if you like.

Well, my mate and fellow iTelescoper Peter Lake has a laneway learning session. He will be doing citizen science, and teaching astronomy by tracking asteroids with remote telescopes.

If you live in Melbourne and have a hankering for Astronomy, why not try this session?

Labels: Astronomy, citizen science, iTelescope, Public Lecture

Artist's impression of the SKA dishes. Credit: SKA Organisation/TDP/DRAO/Swinburne Astronomy Productions.

In case you haven't hear the news, the site of the Square Kilometre Array, a massive synthetic aperture radio telescope that will greatly advance our understanding if the universe, has been awarded to BOTH South Africa and Australia.

This is a great outcome for both our countries, and science. We get the low resolution* frequency and Survey scopes, South Africa gets the mid resolution frequency scopes. Construction begins in 2016.

Of course, The Australian sees this result as a snub, not a win.

*Sorry, I wrote this at about 1 am, so I misunderstood what was going on. Australia basically gets to probe the very beginning of the Universe. Astroswanny has a much better article explaining what it means here.

Labels: Astronomy, miscelaneous, Radio Astronomy

While we are on the subject of the Moon, here is another wonderful Citizen Science project you can be a part of.

CosmoQuest.org is a group of astronomers who have created a series of citizen science projects for people who would like to contribute to astronomical science.

MoonMappers is a project where you identify and measure craters using high resolution images from the Lunar Reconnaissance Orbiter. You will need to register first but this is quick and easy. Once you are registered go to the Moonmappers home page and start mapping to your hearts content.

CosmoQuest has issued a Million Crater Challenge, to get 1,000,000 craters identified by this full Moon, which is just two days away. Why not join up now and help them along.

You can follow the mapping progress here.

Labels: Astronomy, Moon

This week is (14-20 April) is International Dark Sky Week, part of Global Astronomy Month. Don't forget to fill out a light pollution survey for Globe at Night, follow the Australian GAM facebook page, or visit the IceInSpace GAM page. Also check out what your local astronomy club is doing.

Labels: Astronomy, globe at night, science communicators

There is a combined footpath bicycle path that runs behind the dunes of the local beach. A little while ago the city council put in viewing platforms where people could stop, rest and look out at the view.

As well, they put in some wooden pillars with information plaques on the history, plants and animals of the area ... and the constellations. The Natural History and history information is fairly accurate and fascinating, but the constellations ... not so much.

To start with, the initial panel shows an apparent polar region of the sky with completely imaginary stars. How hard would it have been to use real star positions?

Then there is Orion, one of the classic constellations. I've contrasted their illustration of Orion with the actual constellation below. They used the correct southern hemisphere orientation for Orion, which is a good start, then it gets a bit sad.

Now, I am quite aware that there are a variety of design issues that would prevent a realistic portrayal of the constellation, but the artist left out Alnilam, the brightest star in Orions' Belt!

It probably wouldn't matter so much, but the "saucepan", formed by the belt and the stars of Orions' sword, is a classic Australian asterism, the second most recognised asterism after the Southern Cross. The artist put a lot of effort into Orions' shield (although the location of Tabit is wrong, it should be the leftmost star), how much effort would be needed to get Orions' belt right?

Then there is the constellation layout of the platforms themselves. According to the information plaque, each platform is laid out in a pattern of an easily recognised constellation. Except they aren't.

I suppose the Orion platform could be representing Orions belt, but they left the sword off. It certainly doesn't look like the "saucepan" we know and love. The platform for the Southern Cross has at least the major stars in the right position, but what is with the minor stars? They are nowhere near where the should be. The plaques could at least be re-drawn to show the stars more correctly, but the stars on the platforms are concreted in and can't be moved.

I think this kind of outreach is fantastic, and the Council and their artists, and information people did a great job with the natural history and the history. We always take visitors to the platforms when we take them down the beach. Why- oh-why couldn't they get the astronomy right? Couldn't they at least have had an astronomer eyeball the designs before they started laying them down?

Labels: Astronomy, science communicators

Pluto as seen from Nix

The current passion for astronomical doomsday, as exemplified by unwarranted concern about comet C/2010 X1 Elenin and the mythical planet Nibiru, is sad, given the wealth of real, interesting but non-threatening astronomical events happening. However, we can use this interest as a “teachable moment” to give people a better understanding of the sky and the people who watch it.

I was recently forwarded an email from someone who was puzzled as to why amateur astronomers had not detected Nibiru, and what he could do to search for himself. Firstly, how do you go about finding an unknown object?

At this very moment, hundreds of amateur astronomers are scanning the sky looking for a glimpse of an as-yet undiscovered comet or asteroid (as well as the supernova hunters). Similarly, robotic telescopes such as LINEAR are also scanning the sky, looking for asteroids that have the potential to come threateningly close to Earth.

By definition, we don’t know where these objects are, but we can make educated guesses. Asteroids are mostly found in roughly the same plane as Earths’ orbit, so asteroid surveys tend to be around the ecliptic. Comets can come from any direction in the sky, so we have to cover most of the sky when looking for them. Generally, most amateurs work systematically, regularly observing a broad swath of sky repeatedly over a number of days. In these days of CCD cameras, multiple wide field images are taken, and the images inspected for points of light that move between successive exposures. Then comes the task of deciding if these moving points are instrument glitches, a known object, or a real discovery.

Pluto imaged by myself with the Global-rent-a-scope GRAS05 instrument, a typical serious amateur instrument.

What are the limits of the objects that amateurs can detect? With modern CCD cameras and instruments, a reasonably well equipped amateur can see objects between magnitude 14 (how bright Pluto is at the moment) and magnitude 18 (the discovery magnitude of some recent comets). So what sort of objects could amateurs be expected to detect? Quite small faint ones; for example, if Earth was at the distance of Pluto, it would be around magnitude 12, readily visible by the majority of amateur comet hunters.

So what about Nibiru? What do we know of its properties? Well, it is claimed to have an orbit which takes 3600 years to complete. At the moment, it is claimed to be close to the Earths’ orbit around November/December 2012 (there have been other dates, Nibiru was originally predicted to turn up in 2003). From Kepler’s laws we can calculate that the diameter of the orbit must be 496 astronomical Units (AU, the distance of Erath to the Sun http://www.2012hoax.org/nibiru) (see also here http://arxiv.org/abs/1009.1374) compare this with Pluto’s orbit of 39.6 AU. From this we can also work out its orbital velocity (http://www.sjsu.edu/faculty/watkins/orbital.htm) which turns out to be 3.8 x 10⁸ Kilometres per year (or roughly 2.5 AU a year). Working backwards, we find that right now, today, Nibiru should be about 4.2 AU away, closer to us than Jupiter is. How bright would such an object be?

It depends on the size of the object and how reflective it is. The Moon isn’t very reflective, its surface is quite dark, but it is very bright because it is close to us. There is a formula to work out how bright any given object is (http://space.wikia.com/wiki/Absolute_magnitude). The formula is a little messy, depending on the angle of illumination of the object, but any object outside Earths’ orbit will be at least 2/3 illuminated. If we assume that the object is the size of Earth, and is as reflective as Pluto (a good assumption for an object allegedly coming from the outer solar system), then it will have a magnitude of around 4, faint but easily visible to the unaided eye in all but the most light polluted skies. At the very least the supernova hunters would have noticed it, let alone the comet and asteroid hunters, months ago. If it was at the orbit of Saturn, about a year ago, then it would be around magnitude 6, easily visible in binoculars.

That is for an Earth-sized object, but Nibiru is claimed to be larger. The size given for Nibiru is varied, but usually runs from Jupiter sized, to many multiples of Jupiter’s size (from Brown Dwarf stars to Red Dwarfs). A Jupiter sized planet at the calculated current distance of Nibiru would have a magnitude of -1 to -2. That is it would be outshining most stars and really, really obvious.

Is there a way for Nibiru to remain invisible? One person maintains that Nibiru is already in the inner solar system, just inside the orbit of Venus only 69 x 10⁶ kilometres away. It is not visible because it is too close to the Sun. However, to have crossed the inner solar system in the first place it would be highly visible. The only way it could be hidden is to have a highly unlikely orbit, where Nibiru precisely tracks Earths orbit around the Sun, from when Nibiru is magnitude 12. This is amazingly, astoundingly unlikely.

But that only hides it incompletely from Earth. As people know, I spend a lot of time looking for Venus in the daylight. An Earth sized object would be visible in daylight to a reasonable distance from the Sun (just like Venus). A Jupiter sized object just inside Venus’s orbit would be magnitude -10. It would be a crescent phase, but still very bright and easily visible in daylight even quite close to the Sun, as well as readily visible just after Sunset. Even if Nibiru was as black as coal it would be bright from the reflected light of the Sun.

Nibiru can't hide from the STEREO satellites.

And let’s not forget the satellites, the STEREO and SOHO instruments are watching the Sun from different angles to Earth, an Earth sized object would be painfully obvious in either of the STEREO instruments (either ahead or behind), as well as the SOHO instruments.

The dedicated bands of comet hunters who peruse the raw STEREO and SOHO images looking for comets would notice something immediately.

So an Earth-sized, unknown astronomical object would be picked up by the amateur astronomical community in the outer solar system, any such an object would be visible to the unaided eye by the time it reached Jupiter’s orbit. Anything of Jupiter sized or bigger would be painfully obvious by the time it reached Jupiter’s orbit. It couldn’t be hidden by anybody.

You yourself can go out this afternoon or evening and confirm that there is no Nibiru, using just your eyes.

Nibiru and Google Sky (http://bbs.keyhole.com/ubb/ubbthreads.php?ubb=showflat&Number=1360179&page=all)

Labels: Astronomy, Pseudoscience, science communicators

The Australian Science Communicators have a free public lecture on Friday 16 April 6:30 pm at the Swinburne University (Melbourne, Victoria). It's about the Cosmic Dark AGes, those early moments of the Universe before it became transparent to light. Details are here. You will need to RSVP.

Labels: Astronomy, science, science communicators

Being the well connected, on-top-of-it all guy that I an, I've totally missed out on the fact that it's Global Astronomy Month. See the Astronomers without Borders page for more information, there's the Global Astronomy Month Picture of the Day, a Messier Marathon, and "Revenge of the Merds" meets "American Idol" as well as more events. Now is not too late to join in.

Labels: Astronomy, International Year of Astronomy

Space is big, very, very big. And the stars are very far away. Even though the stars are all different distances from the earth, they are so far away that they all look as if they are painted on a dome.

The get the same sort of change in perspective that we would get looking at ordinary objects if we moved just one meter, you need to move light years.

To demonstrate this, with the aid of Celestia, I've made a cross-eyed stereo image of Crux, the Southern Cross (the red-green anaglyph didn't give a strong stereo effect). Stare at the picture and cross your eyes until the x of Crux aligns, and the stereo version will pop out at you (you can click on the image to embiggen and get a higher definition view).

I made this by taking an image of Crux as seen from Earth using Celestia, then moved to Alpha Centuari A, 4 light years away, for the second image of Crux. Then I cropped and assembled the images in the Gimp for optimal stereo effect.

4 ligt years. For most objects, you can get perspective effets by hopping from one foot to the other, hopping 4 light years is a bit more difficult.

Labels: Astronomy, stereograms

The Moon in daylight. Left image, standard photo, right image, photo through polaroid glasses.

As long time readers of this blog know, I'm very enthusiastic about getting people to see Venus and Jupiter in the daylight. But did you know you can see the Moon in the daylight?

Now the dedicated astronomer types here will be going "What do you mean? Of course you you can see the Moon in daylight". Some others of you will remember a nearly full Moon rising just before sunset.

But many people have never noticed the Moon in the daytime sky. The Moon is a lot paler in the daytime sky, and can often be easily missed or or its pale aspect mistaken for a cloud. Also, for most of us living in suburban and urban settings , the sky is often a narrow band broken up by buildings or other obstructions, so seeing anything in the sky is a bit haphazard if you don't know where to look.

And of course there is clouds, we won't talk about clouds.

As well, when the Moon is at is largest, near full, it is only in the daytime sky for a short time, low to the horizon. Even today, as I write, the nearly last quarter Moon is low in the daytime sky, two hours after sunrise. Still, overall the Moon is visible in the daytime sky for a fair amount of time between full and three days before new Moon. You can actually see the crescent Moon two days before new, but it is very close to the Sun, and much care is needed (and often binoculars). In the past, I've had to use daylight Venus to help me find the thin crescent!

To find the Moon in the daylight it helps to have a good idea of where it is at night. After full it is relatively easy, you can see where the Moon is just before Sunrise, and can keep an eye on it after Sunrise. In the daylight, a lot of the moons features are easier to see with the unaided eye, as they are not lost in the glare of the Moons brightness. You can use polaroid glasses or filters to help see the Moon. Unlike Venus, whose light is strongly polarised, using polaroid filters cam increase the contrast between the Moon and the sky quite significantly (the images above don't do the actual increase justice).

Before full, you can use a newspapers Moon rise and set times (often up the back) or set of astronomical tables (or tide time tables) to find when the Moon rises, and scan the sky (wearing polaroid glasses if you like) for the Moon. Or you could see where the Moon is the previous night just after sunset, then, remembering that the Moon is around two hand spans further on each night, look in the approximate position the Moon was the next day (but two hand spans over).

We often think that astronomical activities cease when the Sun rises, but for the Moon and bright planets, it's not really over. Happy Moon hunting!

This is the fifth of a planned series of posts on looking at the sky and how to find your way around it as a beginner.

First post: The Dark Adapted Eye.
Second post: Let the Moon be Your Guide
Third Post: Seeing the Emu.
Fourth Post: Cloudy, Cloudy Sky

Labels: Astronomy, Daylight, Moon, unaided eye observation, where to look

Starbirth in the Eta Carina Nebula. Image Credit Hubble- NASA.

So, if you have been living under a rock, in a cave, with earmuffs on, you will not know that NASA have released amazing images from the refurbished Hubble telescope. The Bad Astronomer has interesting details and pictures, Tom has his favourite shot, and Starts with a Bang has a nice paean to the Hubble instrumentation.

Labels: Astronomy, astrophotography, hubble

The Big Aussie Starhunt is over, and the results are in. First up, the "What constellation would you rename" competition was won by Madison Hunt, who wanted to rename Ara Echidna. Go to the competition website to find out why, and who the Schools winner was. Want to know what the skies around Australia are like, see the results site and find out who your city/town/region compares. Some weod places turn out bright, like Strathalban, way out in the country, had a limiting sky magnitude of 5!

Labels: Astronomy, light pollution

IceInSpace, an Australian Astronomical Community website, turns 5 on September 13th, 2009. There's a competition, so why not drop in and have a look?

Labels: Astronomy, miscelaneous

If you are shopping in or around Rundle Mall this coming Friday (28 August, 6:00-9:00pm) the Astronomical Society of South Australia will be setting up telescopes in Rundle Mall.Have a view of the Moon for Science Week while you are out and about!

Science Week: Stockport Star Party, Saturday 29 August, 8:00pm

Although Jupiter is past opposition, it is still a fantastic sight in a telescope of almost any size. If the weather is fine, you can view the Moon and Jupiter through the ASSA 0.5 metre telescope and other telescopes and binoculars (if the horrible weather and gale force winds go away) at the ASSA Stockport Observatory. A slide show, sausage sizzle and refreshments will be available throughout the evening. Admission is only $7 for adults and $3 for children. There is no need to book - just turn up on the night at pay at the gate. Details of the Stockport observatory location are here.

Labels: Astronomy, Observational Astronomy, science

The Big Aussie Starhunt has been extended to August 30, due to the inclement weather that has plagued us. Just a reminder, The Big Aussie Starhunt is a Australia wide event to get people more familiar with our wonderful night sky, and to raise awareness of light pollution so it's well worth participating. All you have to do is count how many stars you can see in Scorpius using very simple star-charts! Use SkippySky to get cloud cover predictions so you can choose a clear night.

As well as the starhunt, there is a wealth of information and resources on our skies and how to observe them.

Labels: Astronomy, International Year of Astronomy, Observational Astronomy, science, science matters