From Thinkgeek:

Exclusive glow-in-the-dark TARDIS in space design on a black, 100% cotton shirt. Design features the TARDIS, with some wibbly-wobbly timey-wimey motion lines around it, against a starfield when viewed in the light. The stars, TARDIS roof light, “Police Public Call Box” sign, and windows glow in the dark.

[Doctor Who Glowing TARDIS in Space T-Shirt]