In Bhagavad-gītā (10.21) Kṛṣṇa says, nakṣatrāṇām ahaṁ śaśī: “Of stars I am the moon.” This indicates that the moon is similar to the other stars. The Vedic literature informs us that within this universe there is one sun, which is moving. The Western theory that all the luminaries in the sky are different suns is not confirmed in the Vedic literature. Nor can we assume that these luminaries are the suns of other universes, for each universe is covered by various layers of material elements, and therefore although the universes are clustered together, we cannot see from one universe to another. In other words, whatever we see is within this one universe. In each universe there is one Lord Brahmā, and there are other demigods on other planets, but there is only one sun.