6 months day and 6 months night?is it true?

Question

I have heard that in North Pole and South Pole area, there is 6 months days and 6 months night. This means that for 6 months in a year there is continuous day(continuous sunlight) and six months continuously there is dark and night and no sun seen...is this true.

Answer 1

Pretty much true, but only if you are exactly on the pole. When the Sun is up at either pole, it appears to rotate around the entire sky at a constant height, during the space of 24 hours.

In actual fact, you get more than 6 months of daylight in the summer, and less than 6 months of daylight in the winter, for three reasons. First, the Sun has a finite size, and when its center is on the horizon, or even a bit below the horizon, the upper edge (called the "upper limb" by astronomers) is still above the horizon and you have daylight.

Second, atmospheric refraction allows the Sun to be visible even if it's "mathematically" below the horizon by as much as half a degree. These effects combine to give you about 3 or 4 "extra" days of sunlight at each equinox.

Then there is the effect of twilight. The sky doesn't really get dark until the Sun is 6 degrees or more below the horizon. At the pole, twilight lasts about 2 weeks around each equinox. So the bottom line is this: at the North Pole, night lasts from October 9 to March 4, a little less than 5 months. Then there's twilight from March 5 to March 17; and daylight from March 18 to September 26, a little more than six months. Then more twilight from September 27 to October 8.

At the South Pole, seasons are reversed, and winter is a bit longer because of the shape of Earth's orbit. So at the South Pole, daylight lasts from September 19 to March 24, a bit longer than 6 months. Then you have twilight from March 25 to April 5; and night lasts from April 6 to September 7, a bit more than 5 months. Finally, you have more twilight from September 8 to September 18.

Answer 2

Every point on the Earth's surface has exactly six months of the year (in total) when the sun is above the horizon and precisely the same when it's below.

At the equator it's split into 12 hour "days" and "nights". The sun rises at 0600 each morning after a very short twilight and sets 12 hours later, every day.

As you move north or south away from the equator, the sequence changes to accommodate the seasonal variations, i.e. longer summer days, longer winter nights

At the poles the sequence is six months of continuous day and night. (I don't know what Anna (above) is talking about.)

Answer 3

Not exactly true as your friend has stated it, but it is true that in any area close to the north or south pole, not just Alaska, there is darkness 24 hours a day at some point in winter and then 24 hours a day of sunlight in summer. It changes gradually from one to the other. It's because the sun is further away from the poles in winter, and closer in summer. It's the same reason why days are longer in summer and shorter in winter in much of the continental US, just a little more extreme. People cope with it by using artificial light in winter and ignoring the sun in summer.

Answer 4

Yes, Sweden is the country having six months day and six months night because it is located in the north pole. However I think that Antarctica is also having long days and long nights because it is in south pole.

Answer 5

This is exaggerated a little. In the summer, some days are completely light. But through Spring and Autumn months, there are days/nights, although they are very unusually systemed. In the winter months, some days also never become light.