The next time you look at a bright full moon, think about this: no one knows exactly where the moon came from.
“We have no idea why the moon is here,” says science writer Rebecca Boyle Inexplicable – The Vox podcast that explores great mysteries, unanswered questions and all things we learn by diving into the unknown. “I think for many people [the moon] it’s taken for granted, it’s this monotonous kind of thing, and galaxies and nebulae, stars and planets are more intriguing.
It’s true that some of science’s most epic questions lie in the farthest corners of space – how and when the first galaxies formed, what happens inside a black hole – but equally epic questions exist right here in our celestial neighborhood. , in our own solar system.
Exploring our solar system – the moons and planets it contains – means better understanding what is possible in the farthest reaches of the universe. Everything we find or discover in our cosmic courtyard will help us understand what is possible in the larger universe. If evidence of ancient life is found on a hostile world like Mars, we may better understand what common life might be like in other solar systems. If we understand how a possibly once vibrant world like Venus has gone into ruin, we might understand how often similar planets around other stars die in an apocalypse.
The solar system’s most challenging mysteries help us understand why we are here, how long we may have left, and what we may be leaving behind. Here are some of the solar system mysteries we’ve stumbled upon Inexplicable.
For other mysteries, listen and follow Inexplicable wherever you listen to podcasts.
What killed Venus?
“Hellscape” is the most appropriate word to describe the surface of Venus, the second planet from the sun. At 900 degrees Fahrenheit, it is the hottest planet in the solar system, thanks to an atmosphere almost entirely made up of carbon dioxide, which generates a very strong greenhouse effect. Clouds made of highly corrosive sulfuric acid are draped over a volcanic landscape of razor-sharp volcanic rock. The pressure on the surface of Venus is about 92 times what you would feel at sea level on Earth.
Yet some scientists suspect that Venus was once very similar to Earth, with an ocean of liquid water like those that support life on our planet. This raises an existential question for life on Earth.
“Venus and Earth are planetary brothers,” says Robin George Andrews, volcanologist and author of Super volcanoes: what they reveal about Earth and the worlds beyond. “They were made at the same time and made of the same matter, yet Venus is apocalyptic and terrible in every possible way. The earth is a paradise. So why do we have a paradise next to a lost paradise? “
There are two basic assumptions. One is that the sun caused Venus to die. The other is that the volcanoes did.
Further reading: Venus could have been a paradise but it turned into hell. Grounders, be careful.
Where the hell did the moon come from?
Before the moon landing, scientists thought they knew how the moon was formed. The prevailing theory was that it formed much like planets: fragments of material left over from the formation of the sun, clustered together. But then, the Apollo astronauts brought back samples from the lunar surface and those rocks told a completely different story.
“Geologists had discovered that the moon was covered with a special type of rock called anorthosite”, Inexplicable Senior producer Meradith Hoddinott explains on the show. “Shimmering, luminous and reflective, this is the rock that makes the moon shine white in the night sky. And at the time, it was thought, this rock could only be formed in a very specific way. Magma.”
But magma means the moon must have formed in some sort of epic cataclysm. “Something that poured so much energy into the moon that it literally melted,” says Hoddinott. Scientists aren’t exactly sure how it all turned out. But each scenario is a cinematic story of fiery apocalyptic proportions.
Further reading: How the Apollo moon rocks reveal the epic story of the cosmos
Is there anything alive in the human poop left on the moon?
During the Apollo lunar missions, the astronauts went to the moon and, to save weight to return to Earth, dumped their waste behind them. In all Apollo missions, the astronauts are gone 96 bags of human waste on the moon, and pose a fascinating astrobiological question.
Human waste – and especially feces – teems with microbial life. With the Apollo moon landings, we have brought microbial life on Earth to the most extreme environment it has ever been in. Which means that the waste on the moon is a natural, if unintended experiment.
The question the experiment might answer: How resilient is life in the face of the moon’s brutal environment? And for the rest, if microbes can survive on the moon, they can survive interplanetary or interstellar travel? If they manage to survive, then perhaps it is possible that life could spread from one planet to another, riding on the backs of asteroids or other similar space debris.
Further reading: Apollo astronauts left poop on the moon. We have to go back for that shit.
Was there an advanced civilization on Earth before humans?
Many scientists have long 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 in the depths of Earth’s history? Could 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 is not strictly a “solar system” mystery, but it is cosmic in scope. At the center, Schmidt and Frank ask: How likely is it that an intelligent life form on any planet – here or in the depths of space – will leave a mark, a mark of its existence? And after all: in hundreds of millions of years, will some alien explorers landing on Earth be able to find traces of humans if we are away for a long, long time?
Further reading: The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological documentation?
Can we push an asteroid off the collision course with Earth?
Many disasters – volcanic eruptions, earthquakes, hurricanes, tornadoes – are inevitable. Scientists talk about when, not if, they will strike. Although humans make some calamities worse, natural disasters have been happening long before we were here. They are a fact on Earth. But one kind of disaster need not be inevitable: a collision between an asteroid or comet and the Earth.
The problem is: we have never tried to deflect an asteroid and we don’t know if a plan to do so would work.
To help answer this question, NASA last year launched the Double Asteroid Redirection Test (DART), which is a car-sized box equipped with solar panels. It is currently on its way to a 160-meter asteroid called Dimorphos. In the fall, DART will crash into Dimorphos at 24,000 kilometers per hour (about 15,000 miles per hour) in search of the big question: Could the collision push the asteroid into a slightly different orbit?
Further reading: The quest to avoid an asteroid apocalypse is going surprisingly well
Was there ever life on Mars?
Mars today is a desert, devoid of obvious signs of life. But over the years, scientists have uncovered evidence of a long-lost Mars that could have looked a lot more 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,” says NASA astrobiologist Lindsay Hays. “You see things like the remnants of a huge river delta, which indicates that not only was there water flowing, but there was probably a lot of water flowing over a long period of time that continued to deposit sediment.”
And where there was water, there could be life. Last year, a new rover landed on Mars and it’s our best chance to answer the question “was there ever life on Mars?” If the answer is “yes”, it could change our understanding of what common life is like in the universe.
The Inexplicable episode on Mars airs on June 22.
Further reading: NASA’s latest rover is our best chance to find life on Mars
Is there a true ninth planet lurking in the dark?
In 2006, the International Astronomical Union voted to change the definition of what constitutes a planet and Pluto didn’t make the cut. There were no longer nine official planets in the solar system, but eight.
But then “we started getting these hints that there really is something else out there – and a real giant planet that we think is still lurking far beyond Neptune, waiting to be found,” says astronomer Mike Brown. Inexplicable. Astronomers have yet to detect this planet, but they suspect it is there: other distant objects in the solar system appear to be affected by its gravity.
Could these suggestions lead us to a true, new ninth planet? Perhaps. But it will be difficult to find.
“It’s kind of like taking a grain of black sand and throwing it on the beach,” Brown says of the research. “It would be a little hard to find the one in everyone else’s sea. And that’s the problem with Planet Nine. “
Further reading: The hunt for the planet 9
If you have topic ideas for future shows, please email us at [email protected]