3 ms·http://www.explainxkcd.com/2010/12/27/explorers/ http://www.explainxkcd.com/2010/12/27/explorers/by ph0rque 16y agohttp://www.explainxkcd.com/2010/12/27/explorers/ http://www.explainxkcd.com/2010/12/27/explorers/