Next time you look at a bright full moon, think about this: No one knows, precisely, where the moon came from.

“We have no idea why the moon is here,” says science writer Rebecca Boyle. unexplainable – The Vox podcast that explores the big mysteries, unanswered questions and all things we Learn by diving into the unknown. “I think a lot of people [the moon] Taken for granted, it’s this kind of boring stuff, and galaxies and nebulae and stars and planets are more interesting.”

It’s true that some of the epic questions in science exist in the furthest reaches of space – how and when the first galaxies formed, what happens inside a black hole – but also epic questions are here in our celestial neighbourhood, in our own. own solar system.

To explore our solar system – the moons and planets in it – is to better understand what is possible in the farthest reaches of the universe. Anything we find or discover in our cosmic backyard will help us understand what is possible in the larger universe. If evidence of ancient life is found in a hostile world like Mars, we may better understand how common life might be in other solar systems. If we understand how a world that may have been as vibrant as Venus fell into ruin, we might understand how often similar planets around other stars die at the end of the world.

The most provocative mysteries of the solar system help us understand why we are here, how long we might have, and what we might leave behind. Here are some of the mysteries of the solar system that we encountered unexplainable.

For more puzzles, listen and follow unexplainable Wherever you are listening to podcasts.

What killed Venus?

NASA

“Hellscape” is the most appropriate word to describe the surface of Venus, the second planet from the Sun. At 900 degrees Fahrenheit, it’s the hottest planet in the solar system, thanks to an atmosphere made almost entirely of carbon dioxide, generating a powerful greenhouse effect. Clouds of highly corrosive sulfuric acid are blanketed over a volcanic region of very sharp igneous rock. The pressure on Venus’ surface is about 92 times what you feel at sea level on Earth.

However, some scientists suspect that Venus once resembled Earth, with a liquid water ocean like the one that supports life on our planet. This prompts an existential question about life on Earth.

Robin George Andrews, volcanologist and author of “Venus and Earth are Planetary Brothers” Giant volcanoes: What they reveal about Earth and the worlds beyond. “It was made at the same time and made of the same things, yet the flower is horrible and terrifying in every possible way. The earth is a paradise. So why do we have a paradise beside a lost paradise?”

There are two main hypotheses. One is that the sun cooked Venus to death. The other is that volcanoes have done it.

In-depth reading: The flower could have been heaven but it turned into hell. Earthlings, watch out.

Where did the moon come from?

HUM Images / Global Image Collection

Before the moon went down, scientists thought they knew how the moon was formed. The prevailing theory was that they formed very much like planets: bits of material left over from the Sun’s formation, clump together. But then, Apollo astronauts brought back samples from the lunar surface, and those rocks told an entirely different story.

“Geologists have discovered that the moon is covered with a special type of rock called anorthosite,” unexplainable Senior Producer Meredith Hudenot explains on the show. “Shining, bright, and reflective, this is the rock that makes the moon shine white in the night sky. At the time, it was thought that this rock could only be formed in a very specific way. Magma.”

But the magma meant that the moon must have formed in some kind of epic catastrophe. “Something that pumped so much energy into the moon that it literally melted,” Hoddinott says. Scientists aren’t quite sure how all this happened. But each scenario is a cinematic story of fiery terrible proportions.

In-depth reading: How Apollo moon rocks reveal the epic history of the universe

Is there anything alive in human waste left on the moon?

NASA

During the Apollo moon missions, astronauts went to the moon and, to save weight when returning to Earth, threw their trash behind. On all of the Apollo missions, astronauts left 96 bags of human waste on the moon, and they ask a fascinating astronomical vital question.

Human excrement – especially faeces – is teeming with microbial life. With the Apollo moon landing, we took microbial life on Earth to the most extreme environment it’s ever been in. Which means that waste on the Moon is a natural, albeit unintended, experience.

The question that experience can answer: How resilient is life in the face of the monstrous environment of the moon? In this regard, if microbes can survive on the moon, can they survive between planets or? interstellar travel? If they manage to survive, perhaps life could spread from planet to planet, riding on the backs of asteroids or other space debris.

In-depth reading: Apollo astronauts left their tube on the moon. We have to go back to this nonsense.

Was there an advanced civilization on Earth before humans?

Science Photo Libra / Getty Images

Many scientists have always wondered: Is there intelligent life in the depths of space? But climate scientist Gavin Schmidt and astrophysicist Adam Frank have a different question: Was there intelligent life deep in Earth’s history? Can we find evidence of an advanced non-human civilization that lived perhaps hundreds of millions of years ago, buried in the Earth’s crust?

This isn’t strictly a “solar system” mystery, but it is of a cosmic scale. In essence, Schmidt and Frank wonder: How likely is it that an intelligent form of life on any planet – here or in the deepest depths of space – would leave a mark, a sign of their existence? And in this regard: hundreds of millions of years from now, will some of the space explorers who have landed on Earth be able to find human footprints if we go far or away?

In-depth reading: Silurian hypothesis: Can an industrial civilization be detected in the geological record?

Can we push an asteroid out of its collision course with Earth?

Tobias Roach/Future Publishing/Getty Images

Many disasters – volcanic eruptions, earthquakes, hurricanes, tornadoes – are inevitable. Scientists are talking about when, not whether they will strike. Although humans It makes some misfortunes worseNatural disasters happened long before we were here. It is a fact of life on Earth. But one type of disaster doesn’t have to be inevitable: the collision between asteroid or comet and earth.

The problem is: We’ve never tried to distract an asteroid, and we don’t know if a plan to do so will work.

To help answer this question, last year NASA launched a program Double Asteroid Redirect Test (DART), a car-sized box with solar panels. It is currently on its way to a 160-meter-high asteroid called Dimorphos. In the fall, DART will smash into Dimorphos at 24,000 kilometers per hour (about 15,000 miles per hour) in pursuit of a big question: Could the collision push the asteroid into a slightly different orbit?

In-depth reading: The quest to avoid an asteroid disaster is going surprisingly well

Was there life on Mars?

NASA / JPL-Caltech / MSSS

Mars today is a desert, devoid of any visible signs of life. But over the years, scientists have discovered evidence of Mars lost, long ago, that may have looked a lot like Earth.

“Mars is a very different place today than it was 4 billion years ago, but you can see evidence of what it was like,” said NASA astrobiologist Lindsey Hayes. “You see things like the remains of a huge river delta, which indicates not only the flow of water, but you likely had a lot of water flowing over a long period of time that continued to deposit sediment.”

And where there was water, there could have been life. Last year, a new rover landed on Mars, and this is our best chance to answer the question “Has there ever been life on Mars?” If the answer is “yes,” it could change our understanding of how widespread life is in the universe.

The unexplainable An episode on Mars airs June 22nd.

In-depth reading: NASA’s latest probe is our best chance yet to find life on Mars

Is there a real ninth planet lurking in the dark?

NASA-JHUAPL-SWRI

In 2006, the International Astronomical Union Vote for change Define what constitutes a planet, and Pluto didn’t make the cut. There are no longer nine official planets in the solar system, but eight.

But then “we started getting these hints that something else actually existed — and a real giant planet we think still lurks far from Neptune, waiting to be found,” says astronomer Mike Brown. unexplainable. Astronomers have not yet discovered this planet, but they doubt its existence: other distant objects in the solar system seem to have been affected by its gravity.

Could these hints lead us to a real new ninth planet? Can. But it will be difficult to find.

“It’s kind of like taking a little black sand grain and throwing it on the beach,” Brown says of the research process. “It would be a bit difficult to find that in the sea among the rest of them. And that is the problem of Planet Nine.”

In-depth reading: Searching for Planet 9

If you have ideas for topics for future shows, send us an email at [email protected].