The Path of the Sun: Museum Victoria

The Path of the Sun

The diagram below shows the path of the Sun across the sky in Melbourne for four important dates:

The Autumn Equinox, usually on March 21, is when the Sun rises exactly east, sets exactly west and we have approximately equal day and night.
The Winter Solstice, usually on June 22, is when the Sun is furthest north and we have our shortest day; and longest night.
The Spring Equinox, usually on September 23, is identical to that of March 21, except that the Sun rises 16 minutes earlier on September 23.
The Summer Solstice, usually on December 22, is when the Sun is furthest south and we have our longest day and shortest night.

The outer circle on the diagram represents the horizon and the inner circles are lines of constant elevation, drawn at 15° intervals. The radial lines are lines of constant azimuth drawn at 15° intervals also.

The position of the Sun at each hour of the day is marked and the time indicated. All times are Australian Eastern Standard Time. Add one hour for daylight savings.

Comments (41)

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we want/need the program to take the diagram

cold you give more info you relly need hlep with star info

Hi there Suradi - thanks for your question. According to the Museum's Planetarium Presenters, these days a Sun Path can be got using any good astronomy program or planetarium software such as Starry Night or Stellarium. Please note, if you would like to use our diagram for anything other than private use then MV copyright acknowledgement would be expected.

Hi I live in the UK and am used to the "apparent" path of the sun rising roughly east, travelling across the south and setting roughly west. Does it do this just the same in the southern hemisphere

Hi there John. As in the Northern Hemisphere the Sun rises in the East and sets in West (due to Earth’s rotation from west to east), but its path as seen from the Southern Hemisphere is across the northern sky. You might find this link and this one useful.

Hi Mel, the Tropic of Capricorn is technically an infinitesimally thin line, although the uncertainty in the measurement of the Earth's obliquity corresponds to an error in positioning of the Tropic of about 3cm. We can't locate the Tropic any better than this, so this is a kind of width.

At the moment the Tropic is at 23°26'16.7" S. But the obliquity of the Earth varies and is decreasing around a half a second of arc per year, so the Tropic is moving slowly northwards at the same rate. This corresponds to something like 13m per year. So depending on what kind a timeframe you want to look at this also puts limits on how precisely you can locate the tropic. Within a decade, for example, we can't locate the Tropic more precisely than a 133m band.

What is the relationship between the latitude of a point on the planet and the angle between the horizon and the plane of the suns motion across the sky's hemisphere.

Thanks for this site MV, and for the links to stellarium. I'm downloading it now and as I travel around our Country/continent I'm sure I'll enjoy a better understanding of what I'm seeing in the sky around the camp fire

hey, does anyone know how to do calculations for the longest and shortest day of a town (eg. Ballarat, Victoria?? Thanks :)

Hi, Fernando. The "Time and Date" website gives information about the length of days for several locations in regional Victoria, including Ballarat. Hope this helps!

lol, fernando I think your doing the same assignment as me...

Hi, I am wanting to know what seats get the most shade at the MCG for the cricket this summer. If I am interpretting the diagram correctly, would I be best to get seats at the northern end of the ground?

Hi Matt,

For advice about seating, you would probably be best to check with MCG staff directly - MCG contact details can be found here.

when we set our clocks ahead in Australia, would a country in the northern hemisphere on the same longitude line set their clocks forward or backward? Would the time on the the same longitude line be the same, or different by 2 hours?

i want to know sun path diagram for 11th of august from 6am to 6pm

Hi Muhamad - If you have a look at the first couple of comments, you'll find our recommendations for programs that can be used to generate sun paths.

Why does the sun rise and set earlier in sydney than in melbourne -- I have seen live telecasts from melboune showing it is still dark or light there when the opposite is true in Sydney

Hi Georgina - Several factors effect sunrise and set times, such as surrounding buildings or mountains, elevation above sea level, etc; however the main reason in this case is because Sydney is much further east than Melbourne, by approximately 700 km.

Hope that helps

When the sun sets in one place it would be a sun rise at another. My question is when the sun sets in Melbourne in which place does it rise? (at the same time). Is there a way to compute the two places where the sun sets and rises at the same time? For example when the sun rises in London where does it set?

Hi M G, there are quite a number of web sites that display this information. This site does give you the option of setting your own times, and also has a lot of other good information.

DOES THE EARTH GO AROUND THE SUN?, OR THE SUN GO AROUND THE EARTH? AND CAN WE SEE THE SOUTHERN CROSS 24/7 ALL YEAR ROUND, USING THE MODERN TELESCOPES?

Hi Steve - Earth orbits the sun. The Southern Cross never disappears below the horizon when viewed from Southern Australia. It never sets below the horizon, but traces a circle in the sky. The position of the sun relative to the South Celestial Pole isn't a relevant factor, what is relevant is that the Southern Cross is close to the South Celestial Pole from our vantage point, and is therefore visible from Southern Australia. Obviously it is not visible to our eyes during the day time, as daylight from the sun makes it diffult to see the constellations, however it is still there.

HAS THIS ALWAYS BEEN THE VEIW OF ASTRONOMY?

Hello Steve

The link to this section of the NASA website gives a brief insight to the history of the evolution of the theory of the planets movement around the sun.

WE READ THIS AND IT IS NOT CORRECT OR TRUE? IF WE SPIN AROUND THE SUN?,THEN HALF THE TIME WE COULD NOT SEE THE SOUTHERN CROSS WHEN WE TURN AWAY FROM THE CROSS OR WHEN WHERE ON THE OPPOSITE SIDE OF THE GALAXY/SUN! ARISTOTLE IS CORRECT AND RIGHT! THE SUN ORBITS THE EARTH AND IT CAN BE PROVEN?

Hi Steve - The Sun is at the centre of our Solar System, and all planets revolve about the Sun. The Sun at the centre of our Solar System, is in our galaxy called the Milky Way Galaxy amongst about 400 billion other stars. All the stars that can be seen with the naked eye are in our galaxy. It's important to remember at this point that our sun is not at the centre of the galaxy.

Because we revolve about the Sun, which is very close to us, all the other stars which are much further away, do not appear to move as we move around the Sun. So the constellations, such as The Southern Cross, look the same wherever we are. As the axis of the Earth is tilted, the south pole axis points towards the Southern Cross, so that constellation is always visible in the lower latitudes such as Victoria.

Hope that helps

I enjoy this coments page Steve, it informative and a bit of comedy as well.

NO.IT DOES NOT MAKE SENSE ! IF YOU SPIN A BALL THE OTHER SIDE CANT BE VEIWED ? SO IF I WERE PRETENDING TO BE ON THE SOUTHERN CROSS AND VEIWED MELBOURNE AND THEN THE EARTH SPUN AROUND I WOULD"NT AND COULD"NT SEE MELBOURNE WHEN IT FACED AWAY FROM THE CROSS ? YOUR ANSWER DOES"NT MAKE ANY SENSE ! ARISTOTLE MUST BE RIGHT

Steve,

Try to think of it this way - If you were “on” the Southern Cross and looked towards Earth with a theoretical, highly powerful telescope, then Melbourne would always be visible, because the bottom of the Earth is pointing towards the Southern Cross. As the Earth spins on its axis, Melbourne would appear to rotate around the globe. As go further north from Melbourne, say to Sydney, then as the Earth spins, an observer on the Southern Cross would see Sydney disappear briefly on each rotation. The further you travel north the less time you will be able to see the Southern Cross, until you can never see the Southern Cross.

It is like that the Sun is at the centre of a globe of stars, and the Earth always points to one spot in the sky which is close to the Southern Cross. In reality this is not so, but the concept is true.

I hope this may clarify it a bit more for you.

When is the suns arc at its lowest in the sky causing long shadows from buildings (Melbourne area)? Is this the equinox (22/03/12 this month) l read in another area of the web site?

Hi Casper, the Sun’s path is at its lowest in the sky on the Winter Solstice – 21st June, see here for more information.

HiI am building a house and I am trying to work out the angle of the sun on the 1st of march so that I can ensure that my eaves are wide enough to shade the windows thru summer and then begin to allow the sun into the windows from march the 1st onwards. I live in anglesea victoria and the latitude is 38 degrees south.

Hi John,
There are two websites that may help you determine the angle of the sun at your house on a particular date. The Rise and Set Times on the Planetarium website provides a calendar for the visibility of the sun in Melbourne. There is also an online resource about how to make your own Sun Angle Calculator.

Hi Jim, if you were at one of the poles during a summer equinox the Sun continues to make a circle in the sky, but now it would dip below the horizon for a while. It may appear to be an ellipse, but in actual fact it is still a circle. This YouTube clip, http://www.youtube.com/watch?v=ZZcafg-meJA shows what it would look like a little further away from the pole. This web link may also be helpful.

NO WHAT HAPPENS WHEN WE ARE ON THE OTHER SIDE OF THE SUN ?????

Hi again Steve - The sun is not at any point directly 'between' earth and the Southern Cross. An important point to consider here is that unlike Earth, the Sothern Cross does not revolve around our Sun.

If you look at the diagram at the top of this page, you can see the path of the sun as it appears to us here in Melbourne throughout the year. If we were to factor into this diagram the relatively static position of the Southern Cross, it would be close to the southern horizon. Notice that the southern most path of the sun (in the Summer Solstice) does not intersect with the position of the Southern Cross.

This means the Sun does not obstruct our view of the Southern Cross - so, we are never on 'the other side of the sun' to the Southern Cross. As we've explained previously, the Sothern Cross may not be visible during the day due to brightness of the Sun, but it is still there.

In Australia (due to ease or laziness) we say that seasons start on the first of the month. I understand that this is to make collecting data and statistics easier? Let's work with Summer..... Summer 'starts' Dec-1. The solstice is Dec-21. Officially this is the start of summer (that's what my Northern Hemisphere wife says - and I've never been able to convince her she is wrong about anything). If the solstice is the start of summer, then why was 'midsummer' around this date. If seasons are 13 weeks long, summer presumably 'starts' 6 weeks prior to mid summer, hence should technically be 'starting' around the Nov-9. I once heard also, that the 'seasons were moving' - is this correct? Or am I totally confused?????

Hello Cool - we ran this past our experts in the Planetarium, and their response is as follows:

In Australia, seasons begin on the first day of a particular calendar month – March for autumn, June for winter, September for spring and December for summer. This is also the convention followed internationally by meteorologists. One idea for Australia following this rule, is that during the early years of Australia’s white settlement soldiers would change from their summer to winter uniforms on the first of the month.

Indigenous Australians have a more tactile view of the seasons. They link the seasons to the local conditions and environment, and also to the activities of the birds, plants and animals around them. With such a diverse climate across Australia, it’s no surprise that the seasons vary greatly across Indigenous groups. Some regions have five seasons and others only three as the Bureau of Meteorology explains.

In other countries, such as Britain and the USA, the seasons are said to begin on the equinoxes and solstices – Spring Equinox, Summer Solstice, Autumn Equinox and Winter Solstice. These are the times when Earth reaches a particular point along its orbit around the Sun.

I hope this helps

My house is oriented east-west (according to the title and also Google Earth!), but late afternoon yesterday the sun fully lit up the south side of my house and the sun set well 'below' east. How can this happen? I live close to 32° South.

Hi Cam,

The only time that the Sun rises due east and sets due west is at the Spring and Autumn Equinoxes, 21^st March and 21^st September. After the Spring equinox the Sun gradually rises and sets further south until the solstice on 21^st December, then starts moving northwards. So for your house to have the Sun shining on the south facing side, it needs to be between these two equinoxes. After the Autumn equinox the Sun rises and sets northwards of east and west, so no Sun on your south wall.

For more information, please see the following link: http://museumvictoria.com.au/discoverycentre/infosheets/planets/the-path-of-the-sun/

I have been puzzled as to why the sun is setting in the south-west at the moment in Melbourne. I always thought that it set due west in the summer solstice. Your diagram and explanation make perfect sense - thanks!

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The Path of the Sun

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