i tried to find it on google image and cannot find the source. even NASA uses part of it here: http://www.nasa.gov/agency/nepa/catex.html
not sure if it is owned by NASA and if there is any copyright issue if we want to use it?
收錄日期: 2021-05-04 02:46:13
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20141011090500AAAw9GJ