Lots of people are posting Valentine's Day images with the heart-shaped island Galesnjak on Earth or this 3D anaglyph heart from the Moon or a splotch on Mars, but longtime readers will know I hate to do what everyone else is doing. So I dug around and found something unique: this cool heart-shaped feature on Mars -- my Valentine to you all!
I can't take credit for discovering this feature; credit for noticing it goes to Malin Space Science Systems, who used to post lots of photos of funny-cool things from Mars while Mars Global Surveyor was active. Here's the a MOC image containing the heart. Knowing how much of Mars has now been imaged by the Context Camera (CTX) on Mars Reconnaissance Orbiter (well over half), I figured that a little searching on ASU's Global Mars Data website would lead me to the feature, and it did; so the image above is from CTX and has a resolution of 6 meters per pixel. How did the heart form? To answer that, let's pull back and look at the context (something that CTX -- as you can tell from its name -- was designed for):
There is a lot of interesting geology going on in this picture. The heart and the circular pits that occur within Acheron Catena are all collapse pits, which formed when the ground literally opened up beneath the surface, part of extensive extensional faulting that you can see all around the flanks of Alba Patera, one of Mars' great big volcanoes. Underneath that extensional faulting you can see lots and lots of volcanic landforms -- the lobate fronts of lava flows, and sinuous channels that once contained molten rock but which are now just full of dust. So, Happy Valentine's Day! And it's not too late to buy a Valentine's gift through our Facebook Cause, which nets the Planetary Society $10 for every purchase.