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).
As the child grows, the lateral diameter increases. The circumference of a newbornâs thorax is usually 30 to 36 cm and is approximately 2 cm smaller than the infantâs head circumference until 2 years of age. The chest wall is thin with very little musculature, and the ribs and the xiphoid process are quite prominent.