The more scientists study the Red Planet, the more they find unusual objects and patterns scattered across Mars' surface. Here are some of the most baffling.

An open "travel book", A "teddy bear's face", Frozen "mineral flowers", A bushel of "blueberries", Ruins of an "Inca City", A rock with an, er … crack

As one of Earth's closest neighbors in space, Mars has long captivated humans with the prospect of alien life located just a short rocket trip away. No such life has been found. But now, as NASA and other space agencies have begun to explore the skies and surface of the Red Planet using robotic technology, images of strange features and formations continue to inflame skywatchers' hopes, fears and curiosities.

Here are some of our favorite objects on Mars that look like they don't belong on a dead and dusty planet. Many of these are a result of pareidolia — the tendency for humans to seek familiar patterns and shapes in inanimate objects. However, some of them may even lead scientists to the long-sought evidence of past Martian life.

An open "travel book"

Perhaps weary from hunting for evidence of ancient water, NASA's Curiosity rover took a short break in April 2023 to leaf through the pages of an old Martian hardback lying in the dust of Gediz Vallis. While the strange object may look like a book with a single page frozen mid-turn, it is in fact just a rock — and a small one at that. The charming little book-rock measures just 1 inch (2.5 centimeters) wide, according to NASA. Hey, at least it's travel-size!

A "teddy bear's face"

In an image shared in January 2023 by the University of Arizona (UA), what appears to be the face of an enormous Martian teddy bear — complete with two beady eyes, a button nose and an upturned mouth — grins at the camera of NASA's Mars Reconnaissance Orbiter. According to UA, the cuddly-wuddly formation is likely just a broken-up hill in the center of an ancient crater. But as far as we're concerned, it's the cutest pile of rubble in the known universe.

Frozen "mineral flowers"

Branching outward like a tiny coral, this delicate mineral flower is about the closest thing to greenery one can find on the Red Planet today. Mineral deposits like these are common sights across Mars and result from ancient water mixing with ancient rock. Still, it's rare to see a deposit that's so perfectly flower-like, NASA researchers said. You'll notice two slightly less impressive, circular rocks of the same type to the right of the coral. Curiosity spotted this floral feature in February 2022.

A bushel of "blueberries"

Blueberries are not a significant source of iron when consumed on Earth — but these geological "blueberries" discovered by NASA's Opportunity rover on Mars in 2004 are built differently. The iron-rich spheres, polished smooth by plentiful amounts of water billions of years ago, are some of the earliest evidence scientists have of Mars once being an incredibly wet world. Whether they also taste good on cheesecake is a question for future generations to grapple with.

Ruins of an "Inca City"

Near the Martian south pole are curious structures that look like the ruins of a vast and ancient city. Dubbed the "Inca City" for its resemblance to actual ruins discovered in South America, the bizarre rock formation may be made of elevated sand dunes that turned to stone over time, according to ESA. However, its exact origins remain a mystery. The labyrinthine formation appears to curve, forming part of a giant circle 53 miles (86 km) in diameter, leading scientists to suspect it may be part of a much larger impact crater from a meteor strike ages ago.

A rock with an, er … crack

Try not to laugh at this rock snapped by NASA's Perseverance rover in 2021. The cracked boulder became the butt of more than a few jokes after its close-up was first released to the public. There's really not much to see, though — the Red Planet is full of cracked rocks, albeit not quite as plump as this one. Perseverance spotted this rock in dusty Jezero Crater, on its 102nd day on Mars.