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Show Know The Weather What is the process by which the sun keeps the earth warm, both day and night? THE SUN'S rays reach the earth in daytime as solar (short) rays. These are absorbed ab-sorbed by various things on earth and' when they are reradiated they are heat (long) rays. Since long rays are more easily blocked (by the glass of a greenhouse, for example, or by moisture in the atmosphere) at-mosphere) much of the sun's heat is retained on earth or in the earth's atmosphere. THAT RETAINED in the atmosphere helps warm the earth's surface at night. To avoid skin damage in the day, especially harmful to pregnant preg-nant women, new skin preparations which block out solar radiation are now available. Most sun-tan creams and lotions, however, do not accomplish ac-complish this so check the label or ask to be sure. |