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).
In first world nations, the average total body length of newborns are 35.6â50.8 cm (14.0â20.0 in), although premature newborns may be much smaller. The Apgar score is a measure of a newborn's transition from the uterus during the first minutes after birth.