Astral Comet

Reaching into the sky with a light bolt of lightning, causing the clouds to swirl before a flash of light strikes down at a target location within range. The comet creates an earth-shattering boom that can be easily heard from anyone that is less than 300ft. away.  Creatures struck take 8d6 fire damage and knocked prone. A successful Dexterity saves halves the damage and is not knocked prone. The blast creates a creator twice the initial impact size, causing it to become difficult terrain.

The Astral Comet sets fire to combustibles and damages objects in the area. It cannot melt metals with low melting points, such as lead, gold, copper, silver, and bronze. the spell deals double damage to barriers, If the damage caused to an interposing barrier shatters or breaks through it, the Astral Comet may continue beyond the barrier if the area permits; otherwise, it stops at the barrier just as any other spell effect does.

    "Before the more efficient Fire Ball spell, this was the go-to for armed conflict, which lead to Fire Balls' widespread adoption over Astral Comet. A more robust spell with a little bit more of a cost." -Eviren, FeaDragon-

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the radius of the blast increases by 5ft. for each slot level above 4th.