Can an Area of Effect spell be cast without a target?

@JeremyECrawford can an AOE spell be cast without a target ? IE: Fireball

— Amphieuss (@Amphieuss) November 28, 2015

Fireball and many other area spells require the caster to choose a point in space, not a creature or object. #DnD https://t.co/TaJ23tfkMk

— Jeremy Crawford (@JeremyECrawford) November 28, 2015