Lettuce. Lettuce is a fairly hardy, cool-weather vegetable that thrives when the average daily temperature is between 60 and 70Â°F. It should be planted in early spring or late summer. At high temperatures, growth is stunted, the leaves may be bitter and the seedstalk forms and elongates rapidly.ipburn is a physiological condition that causes lettuce to die back at the edges of the leaves. It results from a change in the moisture relationship between the soil and the plant. Clip off any brown leaf tissue and use the remainder of the leaf.
chromosphere. A layer of gas that lies above the photosphere of a star, such as the Sun. Thesaurus Antonyms Related Words Synonyms Legend: Switch to new thesaurus . Noun: 1. chromosphere - a gaseous layer of the sun's atmosphere (extending from the photosphere to the corona) that is visible during a total eclipse of the sun layer - a relatively thin sheetlike expanse or region lying over or under another
1 The Sun in the center of our solar system is a star. 2  There are around 200 billion stars in the Milky Way alone. 3  VY Canis Majoris is the largest known star in our galaxy, if this star was in the center of our solar system its outer atmosphere would reach the orbit of Saturn.hen a star is in its main sequence it is fusing hydrogen atoms in its core which creates energy. Stars in their main sequence are referred to as 'dwarfs', the sun being an example of a dwarf star, all stars will spend the majority of their lifespan in this state before they exhaust their supply of hydrogen.