Forget physics: love makes the world go 'round. This is a gallery of our favourite images of love from the natural world, from rocks to landscapes to the far reaches of space.
If the natural universe of love is calling out for you to print a photo as your Valentine's Day card, click on the image credit to get the highest-resolution images available.
Top image: The heart-shaped Small Aral Sea in Central Asia is slowly evaporating, leaving behind the vast salt plains of the Aralkum Desert. Credit: USGS
The W5 star-forming region seen in infrared is a glorious tribute to love everlasting with cool, old blue stars, and hot, pink stars in the dense dusty star-forming pillars. Image credit: NASA/JPL-Caltech/Harvard-Smithsonian
Love is in the spaces between: erosion exposes a heart in the Écrins mountains, France. Image credit: Yann Forget
Through the passage of time, love is revealed in the plains of Mars. Image credit: NASA/JPL/Malin Space Science Systems
The Heart and Soul nebula in infrared requires a bit more of a flexible approach to spotting symbols, but you know its love has lasted for at least 7,500 years. Image credit: NASA/JPL-Caltech/UCLA
Love the concept, but don't want to come up with your own cutesy phrasing? NASA dove through their archive to make you a collection of fully-formatted cards for your sending pleasure that you can customize with the name of your intended! Bonus: The Orion spacecraft and the Space Launch System have something to say for soulmates.
Do you need even more geektastic Valentine's ideas? io9 created original ideas for the shows that own your heart, Symmetry magazine has an entire collection of Valentine's and Anti-Valentine's, and while the European Space Agency has an entire gallery of space-love. Or of course, you could always skip cute for something a bit more direct.
Have a favourite earth and space science image perfect for Valentine's Day that we missed? Share it with us!