Sparse universal graphs for planarity

We show that for every integer $n\geq 1$ there exists a graph $G_n$ with $n^{1 + o(1)}$ edges such that every $n$-vertex planar graph is isomorphic to a subgraph of $G_n$. The best previous bound on the number of edges was $O(n^{3/2})$, proved by Babai, Erd\H{o}s, Chung, Graham, and Spencer in 1982.