Magical back-to-school children, riding on pencil t-shirt

Magical back-to-school t-shirt design featuring two young children, a boy and a girl, riding on a giant pencil rocket through a beautiful starry galaxy. The pencil should be designed like a rocket ship with the eraser end as the rocket booster with flames/smoke trail. Include swirling galaxies, twinkling stars, colorful nebulas, and planets in the cosmic background. The children should look excited and adventurous, wearing backpacks and school clothes, with happy expressions as they soar through space. Add the text "Exploring galaxies: Back to school dreams" in dreamy, space-themed typography with star decorations. Use vibrant cosmic colors - deep blues, purples, pinks, and bright yellows for stars. Create an inspiring, imaginative design that combines education and space adventure. Transparent background for t-shirt printing. Child-friendly cartoon style with magical, dreamy atmosphere.