← Another date

Birthday · April 30, 2026

April 30, 2026

Another trip around the Sun. A whole sky of possibilities.

A little universe, just for you

Your date.
Ready to give.

Choose a greeting

Image rights and credit requirements apply when sharing or reusing imagery.

This archive entry has no available still image to save. Choose a still from another year below, or open the original APOD.

Use a still image from another year

Your celebration date stays the same. Each image keeps its actual publication date.

Change the year

Selected image source ↗ APOD published April 30, 2026. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.

Behind the original result

Waves on Titan

Original APOD · April 30, 2026 ↗

Read the original APOD for the astronomer’s explanation and full image credits. Its text is preserved in the archive as published.

Read the archived explanation

Have you ever thought about surfing on an alien world? We can now expand the search for the perfect wave from Earth to the rest of the Solar System, and beyond. Scientists have developed a new model for simulating waves on other planets. Titan is one of the 274 confirmed moons of Saturn to date, and the only object in the solar system (besides Earth) known to have liquid lakes and seas on its surface. The featured video shows a simulation of waves on Earth (right) and on Titan (left), under the same conditions (the scale marker is in meters). A light breeze would create taller, slower-moving waves on Titan than on Earth, because the lakes there are filled with light liquid hydrocarbons, and because of Titan's low gravity and higher atmospheric pressure. In a couple of years, NASA expects to launch the Dragonfly mission, which will travel for 6 years and send a rotorcraft to explore Titan and study its microbial habitability.

Watch the original video
Explore April 30 in other years · 31 APOD entries, 1996–2026

Updated · APOD entries through