62554
Within the Milky Way , molecular gas clouds account for less than one percent of the volume of the interstellar medium ( ISM ) , yet it is also the densest part of the medium , comprising roughly half of the total gas mass interior to the Sun 's galactic orbit .
 Milky Way, Sun
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Milky Way, Sun