Rare, all-red auroras are produced by high-altitude oxygen, at heights of up to 200 miles. Nitrogen produces blue or purplish-red aurora. The connection between the Northern Lights and sunspot activity has been suspected since about 1880.
In developed countries, the average birth weight of a full-term newborn is approximately 3.4 kg (71â2 lb), and is typically in the range of 2.7â4.6 kg (6.0â10.1 lb).
(Average newborn weight is around 7 pounds.) It's difficult to determine whether a baby is truly macrosomic (literally of large body) while she's still in the womb â only a post-birth weigh-in confirms it.