Acorn is a methuselah found by Charles Corderman. It was discovered no later than 1971, though its exact year of discovery is unknown. Its maximum population, 1057, occurs in generation 4408. Also, it is composed of 2 or 3 sparks, depending on how the left side is looked at. Despite this, 4 gliders are required for synthesis. The left spark can be flipped to create another isomer that evolves the same way, and the left spark can also be changed into a V spark.
The stable pattern that results from the acorn has 633 cells and covers an area of 215 by 168 cells; it consists of 41 blinkers (including four traffic lights), 34 blocks, 30 beehives (including one honey farm), 13 gliders, eight boats, five loaves, three ships, two barges, two ponds and a mango. An eater 1 is temporarily formed at the north side in generation 2661, but does not survive after generation 3925.
The name was coined by Robert Wainwright "after seeing its final census", which he called "oak tree", apparently alluding to the proverb "From little acorns mighty oaks do grow".