【参考資料】
■ESA”How many stars are there in the Universe?”
https://www.esa.int/Science_Exploration/Space_Science/Herschel/How_many_stars_are_there_in_the_Universe
■Science”New calculations say there are more living cells than grains of sand or stars in the sky”
https://www.science.org/content/article/new-calculations-say-there-are-more-living-cells-grains-sand-or-stars-sky
■ESA”How many stars are there in the Universe?”
https://www.esa.int/Science_Exploration/Space_Science/Herschel/How_many_stars_are_there_in_the_Universe
■Science”New calculations say there are more living cells than grains of sand or stars in the sky”
https://www.science.org/content/article/new-calculations-say-there-are-more-living-cells-grains-sand-or-stars-sky
