When the third angel sounded its trumpet, a great star fell from heaven (Revelation 8:10), but what does this mean? First of all, a star represents kings, especially the Messiah (Numbers 27:17), but they can also represent leaders of the church (Revelation 1:16, 20), or even the nation of Israel, itself (Revelation 12:1; cf. Genesis 37:9-12). Secondly, if we consider the veil of the Temple, the significance of the star falling from heaven might impact the reader in a very unexpected manner. For example, Josephus says this about the Temple veil:
It was a Babylonian curtain, embroidered with blue, and fine linen, and scarlet, and purple, and of a contexture that was truly wonderful. Nor was this mixture of colors without its mystical interpretation, but was a kind of image of the universe; for by the scarlet there seemed to be enigmatically signified fire, by the fine flax the earth, by the blue the air, and by the purple the sea; two of them having their colors the foundation of this resemblance; but the fine flax and the purple have their own origin for that foundation, the earth producing the one, and the sea the other. This curtain had also embroidered upon it all that was mystical in the heavens, excepting that of the [twelve] signs, representing living creatures. (emphasis mine)
In other words the curtain encompassed the heavens placing the stars in their respective constellations. Only the images of the living creatures representing the constellations were lacking on the veil, but the constellations, themselves, which were embroidered on the veil, had a mystical meaning concerning the nations of the earth. For example, consider Revelation 12:1-2 where the constellation, Virgo, seems to be pointing to Israel.
In the context of Revelation 8:10, if a star fell from heaven, it may mean there was an earthquake, causing the lintel (weighing several tons) above the door of the Temple to break. As the heavy lintel fell to the floor of the Temple complex, the veil, which was attached to the lintel, would have been torn in two, casting veil and the constellations embroidered upon it to fall to the earth (cf. Matthew 27:51; Mark 15:38; Luke 23:45), perhaps one third of all the stars (Revelation 12:4). Thus, the judgment brought against the nation of the Jews by the blowing of the third trumpet, would have been predicted in the events immediately following the crucifixion of Jesus.
The great star that fell from heaven fell upon the fountain of waters. The fountain of ‘living’ waters was a title claimed by the Lord:
Jeremiah 2:13 “For my people have committed two evils; they have forsaken me the fountain of living waters, and hewed them out cisterns, broken cisterns, that can hold no water” (emphasis mine).
Proverbs 16:22 say ‘understanding’ is a fountain of life, but the instruction of fools leads to folly. Following this logic, the star (i.e. the nation of the Jews) had rejected the instruction of the Lord, which is the beginning of wisdom (Proverbs 14:27), and in the context of Jeremiah 2:13 above (compare: Jeremiah 17:13), it had become a cistern cut off from the flow of living waters. Therefore, the nation’s leadership had become a source of wickedness and violence, polluting the whole nation (Jeremiah 6:7), cutting themselves off from their Messiah, the Fountain that would cleans their sin and uncleanness (Zechariah 13:1).
Notice what the prophet, Hosea, had to say about Samaria, which may also be applied to Jerusalem:
Hosea 13:15-16 Though he be fruitful among his brethren, an east wind shall come, the wind of the LORD shall come up from the wilderness, and his spring shall become dry, and his fountain shall be dried up: he shall spoil the treasure of all pleasant vessels. (16) Samaria shall become desolate; for she hath rebelled against her God: they shall fall by the sword: their infants shall be dashed in pieces, and their women with child shall be ripped up. (emphasis mine)
Therefore, we are able to see that the king is a fountain in the sense that his wisdom guides the nation, which is life, if he fears the Lord, but his words lead to destruction, if he doesn’t regard the God of Israel (cf. Proverbs 16:22). In such a case, the “fountain shall be dried up.” The kings guidance will not lead to life, but, instead, the enemy would come and “spoil the treasure of all the pleasant vessels” (Hosea 13:15).
The star that had fallen to the earth (Revelation 8:10) was called Wormwood, meaning bitter (Revelation 8:11). The leaders of the Jews, through unbelief (Jeremiah 2:13; cf. Zechariah 13:1), had committed adultery, walked in lies and strengthened the hands of the wicked, so that none of the wicked sought to return from his evil ways (Jeremiah 23:14). Together, and probably beginning with the imprisonment of Paul in 56 AD, the Jewish leaders and wicked men increased their efforts to destroy the Gospel and those who preached it (Acts 23:12-15; 24:27; 25:1-3, 9). Therefore, the Lord gave them wormwood or poison to drink, because “godlessness had spread from the prophets of Jerusalem throughout the land” (Jeremiah 23:15), bringing death to all who would follow them (drink of their waters). In the context of Revelation 8:10 this meant that, during the ten years that preceded the breakout of the war between the Jews and Rome, Jewish leadership had been cut off from the Lord, due to their wickedness and their rejection and persecution of the Gospel. Thus, they placed themselves on the road to destruction, where they would receive no help from God.
 Josephus: Wars, 5.5.4.