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What If the Moon Was Bigger Than Earth?

What If | March 26, 2026



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00:00 What If Earth and Moon Switched Sizes?
14:04 What If All the Planets Doubled in Size?
22:11 What If Earth Was the Size of Jupiter?
27:27 What If We Swapped Our Moon With Other Moons?
48:16 What If Earth Was As Big As These Planets?
57:12 What If Earth Was As Big As the Sun?
1:02:58 What If The Sun Was Smaller Than The Earth?
1:06:07 What If Earth Was As Small as Pluto?
1:11:59 What If You Shrunk 1cm Every Second?

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What If is a mini-documentary web series that takes you on an epic journey through hypothetical worlds and possibilities. Join us on an imaginary adventure through time, space and chance while we (hopefully) boil down complex subjects in a fun and entertaining way.

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Comments

This post currently has 37 comments.

  2. @Powerack

    March 26, 2026 at 10:40 pm

    These videos just recycling the same "facts" and visuals again and again and again. It's soooo boring to "learn" things that doesn't even make any sense…

  5. @droneworld2312

    March 26, 2026 at 10:40 pm

    Oh shut up about climate change its a natural part of nature, the world.has gone through ice ages and very high temps going back to the ladt ice age dis man make it cool no, virtual signaller

  7. @Into-The-Unknown-xxx

    March 26, 2026 at 10:40 pm

    The way you weave in knowledge about 'massive tides' that could wipe out coastal cities, or how humans would have to face solar radiation, truly kept me glued to the screen. The content is both highly educational and a great spark for the imagination. Thank you to the team for always creating such high-quality and scientifically grounded 'What If' scenarios! I'm eagerly looking forward to future episodes about other planets in our Solar System. 🚀🔭👏

  9. @RestoryBuild

    March 26, 2026 at 10:40 pm

    This video from "What If" explores several hypothetical scenarios involving changes in the size of Earth, the Moon, and other celestial bodies, examining the catastrophic and sometimes surprising consequences of such alterations.

    Here are the key "What If" scenarios discussed:

    Earth and Moon Switch Sizes (0:05–14:03): If Earth shrunk to the size of the Moon and the Moon expanded to Earth's size, "Little Earth" would lose its atmosphere, magnetic field, and all liquid water, making it uninhabitable. It would eventually become tidally locked to the "Big Moon," effectively becoming its moon.
    All Planets Doubled in Size (14:04–22:10): This segment discusses the impact of planets doubling in size. For instance, a doubled Mars could potentially become more Earth-like with a renewed magnetic field, while a doubled Jupiter would significantly shift the solar system's barycenter.
    Earth Was the Size of Jupiter (22:11–27:26): If Earth were as large as Jupiter, its increased gravity would make human movement and even breathing nearly impossible. It would also lead to extreme atmospheric pressure, higher boiling temperatures for water, and could even tear the Moon apart.
    Swapping Our Moon With Other Moons (27:27–48:15): The video explores the effects of replacing Earth's Moon with various moons from other planets:
    Titan (30:14): Moving Titan to Earth's orbit would cause its methane lakes to evaporate, revealing a subsurface ocean, but it would eventually dry out.
    Ganymede (31:29): Ganymede, being icy and reflective, would shine brightly, cause mega tides, earthquakes, and volcanic eruptions, but it would also stabilize Earth's axial tilt and become a potentially habitable world as its ice melts.
    Io (34:53): Io, known for its extreme volcanic activity, would initially be spectacular to watch, but without Jupiter's tidal forces, it would cool down and its volcanoes would go dormant.
    Europa (38:22): Europa, a mysterious ocean world, would become easily accessible for exploration, and while its subsurface ocean might eventually freeze without Jupiter, we might discover life.
    Earth Was As Big As These Planets (48:16–57:11): This section delves into various exoplanets and their characteristics, from tiny ones like Kepler 37b to super Earths like Kepler 452b and Kepler 22b (which might be a super ocean world), and even massive gas giants like TOI 3757b and WASP 12b. The segment highlights the diversity and extreme conditions of these distant worlds.
    Earth Was As Big As the Sun (57:12–1:02:57): If Earth were the size and mass of the Sun, continents and oceans would spread out, making water shallower and more susceptible to evaporation. The immense mass would also disrupt the entire solar system.
    The Sun Was Smaller Than the Earth (1:02:58–1:06:06): If the Sun were smaller than Earth, it would lose the mass required for thermonuclear fusion, causing it to burn out. This would send all planets, including Earth, adrift in space.
    Earth Was As Small as Pluto (1:06:07–1:11:58): If Earth shrank to Pluto's size, it would become a cold, airless, and geologically inactive world with minimal gravity.
    You Shrunk 1cm Every Second (1:11:59–1:26:02): This thought experiment tracks the shrinking of a human, detailing the changes in perception, physical abilities, and the appearance of the environment as one descends to microscopic and even atomic scales.

  28. @JamesSmith-fz7qk

    March 26, 2026 at 10:40 pm

    Fun series. Reminds of the What If? Marvel comic book. But If Mars doubled in size, it could hold water and an atmosphere if it had a magnetic field also. But that water, and that atmosphere has long ago evaporated into space. It wouldn’t come back.

  29. @StoriesForSleep-Channel

    March 26, 2026 at 10:40 pm

    Imagine waking up on a tiny Earth, weighing only 19kg [04:06] and being able to fly from New York to Paris in under 2 hours [04:32]—that’s a traveler's dream! ✈ But seeing the massive tsunamis caused by the Big Moon [06:45], I’d rather stay a bit heavy on a peaceful Earth. Would you guys choose to weigh 70kg or live on 'Little Earth'?

  34. @LadyCatFelineTheSeventh

    March 26, 2026 at 10:40 pm

    Quit blaming forest fires on climate change. That has been disproven over and over. Fire is a natural occurrence in forests and many trees only release seeds in a fire. Also, fires clear the forest floor, preventing future fires from getting out of hand. When you don't allow fires to burn, the forest floor builds up with debris and the fires are worse and do unnecessary damage.

Comments are closed.

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