Starship Asterisk*

ddale51 wrote:Boy, am I confused. Apparently the position and direction of travel of Venus as it crosses the sun varies hugely depending on the location of the observer on Earth. This photo shows Venus traveling across the sun's face in a horizontal position from roughly 10 o'clock to 2 o'clock. But from where I watched the transit--about 38 degrees latitude in the US--Venus began its transit at about the 1:00 position and was traveling "downward" toward the 5:00 position. That's about a 90 degree tangent from this photo! I just can't the visualize how these varying perspectives are possible. Is there a diagram somewhere that can explain this to this confused soul?

astro-newbie wrote:I'm a bit confused. The desription says,

"The remarkable scene looks north over the Norwegian Sea from Sortland, Norway."

Despite the fact that the sun is at its northernmost point seen in the sky, wouldn't it still be toward the SOUTH as viewed in Norway? Isn't this a picture of the SOUTHERN horizon around midnight?.

Perk Cartel wrote: ... In the State of Victoria in the south eastern part of Australia, the indigenous folk recognise six seasons ( no so called "autumn" or "fall" perhaps because indigenous vegetation here is non-deciduous. There's more here: http://home.vicnet.net.au/~herring/seasons.htm

Chris Peterson wrote:

Anthony Barreiro wrote:All definitional contention aside, I hope everyone has a joyful Solstice, whether you call it Midsummer as was the common usage in Shakespeare's time (thus "A Midsummer Night's Dream" happens on the shortest night of the year, i.e. Solstice), or the first day of Summer as is more common today, or even the first day of winter if you happen to be down under. When I was outside around noon (1:11 pm Pacific Daylight Time here in San Francisco), my shadow was pretty darn short!

Dang! With the whole state under a red flag fire warning, we can't do our ritual naked midnight bonfire dance!

Chris Peterson wrote: Dang! With the whole state under a red flag fire warning, we can't do our ritual naked midnight bonfire dance!

Anthony Barreiro wrote:All definitional contention aside, I hope everyone has a joyful Solstice, whether you call it Midsummer as was the common usage in Shakespeare's time (thus "A Midsummer Night's Dream" happens on the shortest night of the year, i.e. Solstice), or the first day of Summer as is more common today, or even the first day of winter if you happen to be down under. When I was outside around noon (1:11 pm Pacific Daylight Time here in San Francisco), my shadow was pretty darn short!

vofl wrote:Today's solstice, the ... OOPS - solstice is tomorrow ! At least in most of Europe and eastwards. In Denmark Solstice is at 1:09 21. june 2012 (MET summer time).

vofl wrote:It is difficult to understand - but todays image is KIND OF FAKE. When the midnight sun in on in Sortland, the daylight is on all day and all night. Real daylight all 24 hours. No darkness at all - The sky never gets dark and no stars visible.

ozproff wrote:"Today's solstice, the astronomical beginning of summer in the north"

No it does not!!!!!!! The solstice marks the MIDDLE of astronomical summer in the north!

I have enough trouble in my classes with this without APOD adding to the confusion.

Astronomical
The precise timing of the seasons as viewed by astronomers is determined by the exact times of transit of the sun over the tropics of Cancer and Capricorn for the solstices and the times of the sun's transit over the equator for the equinoxes. [9] For 2012 these times are:

Code: Select all

Equinoxes                Solstices 
Mar 20, 05:14 UTC        June 20, 23:09 UTC 
Sept 22, 14:49 UTC       Dec 21, 11:12 UTC 

The following diagram shows the relation between the line of solstice and the line of apsides of Earth's elliptical orbit. The orbital ellipse (with eccentricity exaggerated for effect) goes through each of the six Earth images, which are sequentially the perihelion (periapsis—nearest point to the sun) on anywhere from 2 January to 5 January, the point of March equinox on 20 or 21 March, the point of June solstice on 20 or 21 June, the aphelion (apoapsis—farthest point from the sun) on anywhere from 4 July to 7 July, the September equinox on 22 or 23 September, and the December solstice on 21 or 22 December.

In astronomical reckoning, the solstices and equinoxes ought to be the middle of the respective seasons, but, because of thermal lag, regions with a continental climate often consider these four dates to be the start of the seasons as in the diagram, with the cross-quarter days considered seasonal midpoints. The length of these seasons is not uniform because of the elliptical orbit of the earth and its different speeds along that orbit.[10]

Ed Thompson wrote:In the discussion --- "for some the Sun won't set at all, still standing just above the horizon at midnight as far south as about 66.6 degrees northern latitude." Would the sun be above the horizon, or half the sun be above the horizon?

saturno2 wrote:It¨s a strange Sun with Venus as a mole on his face

K1NS wrote:
If we didn't already know about the photograph, there'd be enough information in the image to calculate the time, date, and latitude where it was taken. I don't think it's possible to calculate the longitude, though (unless you happened to recognize the exact shape of that mountain). Anyone?