At that moment the earth is neither tilted towards or away from the sun. Most of us know this as the day and night being of equal lengths.

You can check this out visually on the Sun Map we talked about in a recent blog. At other times of the year the day/night line is a curve – at this point in time, it is a straight line.

So today is the day that everyone in the world is experiencing night and day of the same lengths. The day we experience as the same before we turn and head in opposite directions again – with our long summer days or long winter nights.

Interesting facts about equinox:

• The moments of the equinox are not fixed, but fall about six hours later every year – about one full day in four years. This gets reset by the leap year.
• On the day of an equinox, the Sun rises everywhere on Earth (except the Poles) at 06:00 in the morning and sets at 18:00 in the evening (local time). This can be altered if your country is using Daylight Saving
• One effect of the equinox is the temporary disruption of communications satellites. The effects varies but can range from a few minutes to an hour.
• At the poles, the equinox marks the start of the transition from 24 hours of nighttime to 24 hours of daylight (or vice versa). Far north of the Arctic Circle, at Longyearbyen, Svalbard, Norway, there is an additional 15 minutes more daylight every day about the time of the Spring equinox, whereas in Singapore (which is just one degree of latitude north of the Equator), the amount of daylight in each daytime varies by just a few seconds.

Our next equinox is in March 2012 – and you expect it at 5.04am UTC on the 20th.

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• Robert Scragg (associate professor at the School of Population Health at the University of Auckland) is pushing for more sun. His position is “go out in the sun, just don’t get sunburnt”.
• For its part, the Cancer Society says Scragg’s advocacy of 15 minutes at midday is “irresponsible”. Dermatologists, who deal with the effects of sun damage every day, are adamant that we can get all the vitamin D we need through incidental exposure.
• Dr Louise Reiche (represented the New Zealand Dermatological Society on the Cancer Society) says sunning yourself in winter, when vitamin D levels in the body drop, is pointless. “We get very low levels of UV in our winter, so even if you were brave enough to stand naked in the midday sun in the winter, you would not be able to generate vitamin D from the sun at all.”
• However, Richard McKenzie, principal scientist in atmospheric processes with Niwa, says this is in contention.

Given these viewpoints and the current state of research into the importance of sun protection, how do you plan to limit or extend your sun exposure this year?

ADDENDUM: Subsequent to posting this piece we were sent a copy of this video. It gives a comprehensive account of the current state of research into Vitamin D and health benefits associated with it. We highly recommend taking the time to watch it.

Related posts:

1. Sun helps to battle skin cancer?
2. Vitamin D and pain relief
3. The Sun. What it really does to you.

A research team from the University of Leeds working with the US National Institutes of Health found a high level of vitamin D – suggestive of high sun exposure – protected patients with malignant melanoma, the deadliest form of skin cancer.

Those with the lowest levels of vitamin D in their blood at diagnosis were 30 per cent more likely to suffer a recurrence of the disease after treatment than those who had the highest levels.

Patients with the highest levels of the vitamin also had the thinnest tumours at diagnosis. Results of the study, funded by Cancer Research UK and the National Institutes of Health, are published in the Journal of the National Cancer Institute.

The findings add to the growing body of evidence that boosting levels of vitamin D could protect against a wide range of diseases, or extend survival with them. The gloomy weather and long winter in countries north of 30 degrees latitude, such as the UK, means that a large part of the earth’s population is deficient in the vitamin between October and March. The weight of evidence has grown so dramatically that governments around the world are reviewing their minimum recommended limits.

In the second study, researchers led by Professor Kimmie Ng, from the Dana-Farber Cancer Institute in Boston, US, who followed more than 1000 bowel cancer patients for nine years, found those with the highest level of vitamin D were half as likely to die from the disease compared with those with the lowest levels. The results are published in the British Journal of Cancer.

Read the complete article here…

Related posts:

1. The Sun. What it really does to you.
2. Conflict Of Interest In Melanoma Study
3. What is the relationship between sunlight and breast cancer?