Ragweed compounds could protect nerve cells from Alzheimer's

As spring arrives in the northern hemisphere, many people are cursing ragweed, a primary culprit in seasonal allergies. But scientists might have discovered a promising new use for some substances produced by the pesky weed. ...

Image: SOHO's equinox sun

Last Wednesday, all locations on our planet enjoyed roughly the same number of hours of day and night. This event, called an equinox, takes place twice a year – around 20 March and then again around 23 September.

page 1 from 23

Northern Hemisphere

Coordinates: 45°0′0″N 0°0′0″E / 45°N 0°E / 45; 0

The Northern Hemisphere is the half of a planet that is north of the equator—the word hemisphere literally means 'half sphere'. It is also that half of the celestial sphere north of the celestial equator. Earth's northern hemisphere contains most of its land area and most of its human population (about 90%).

This text uses material from Wikipedia, licensed under CC BY-SA