According to the law of universal gravitation, the mass of the earth is about 5.965 × 1024kg。 Does the total mass of the earth change every year? Some experts gave the answer. According to foreign media reports, experts from the Langley Research Center (LRC), a research institution under the National Aeronautics and Space Administration (NASA), said that from the current estimated results, the earth's mass is decreasing every year. Guillaume gronoff, an expert on atmospheric escape at Langley Research Center, said that the earth, as a planet, faced a problem when it was formed - atmospheric escape, which will also lead to its smaller and smaller mass. By analyzing satellite data, scientists can conclude that the mass of atmospheric escape each year is about 75000 metric tons. At the same time, a large number of asteroids impact the earth every year, adding about 15000 metric tons of mass every year. According to this calculation, the earth will lose about 60000 metric tons of mass every year. Although it sounds like 60000 metric tons, it is almost negligible for the earth. According to the atmospheric escape data established in the past 100 years, gronov estimated that even if the atmosphere decreases at the rate of 60000 metric tons per year, it will take 5 billion years to completely lose the atmosphere. In addition, the atmosphere is not a unilateral reduction. Plant photosynthesis, respiration and volcanic eruptions will continue to supplement the atmosphere every year. If the quality of these supplements is included, it will take about 15.4 trillion years for the atmosphere to completely disappear. (Xinhua News Agency)