menu Home chevron_right
SCIENCE

What If Earth Was the Only Planet in the Solar System?

What If | October 17, 2025



With your support we can make our show better! Join our Patreon community: http://bit.ly/whatif-patreon

Imagine never being able to dream of landing on Mars or traveling to Saturn.
Not because it’s impossible to get there, but because they didn’t exist. Because Earth was the only planet in our solar system. What would the night sky look like? Where would Earth be located? And how would humanity evolve?

Watch more what-if scenarios:
Planet Earth: https://www.youtube.com/watch?v=_-HhCwYD7rc&list=PLZdXRHYAVxTJCzxwmCq0NNpYq9N9wyb2l
The Cosmos: https://www.youtube.com/watch?v=gfuJyVkMH_g&list=PLZdXRHYAVxTJno6oFF9nLGuwXNGYHmE8U
Technology: https://www.youtube.com/watch?v=CS3bBO05fpU&list=PLZdXRHYAVxTIeRY3JtgXgoGqSEB7kDdKO
Your Body: https://www.youtube.com/watch?v=QmXR46TrbA8&list=PLZdXRHYAVxTJNsV9FFeNAKl2ySsHj8GZO
Humanity: https://www.youtube.com/watch?v=fdCDQIyXGnw&list=PLZdXRHYAVxTIFnvmOeWbv-Mt8zFxSCSvZ

Tweet us your what-if question to suggest an episode: https://twitter.com/WhatIfScience

What If elsewhere:
Instagram: https://www.instagram.com/whatif.show/
Twitter: https://twitter.com/WhatIfScience
Facebook: https://www.facebook.com/What.If.science

Suggest an episode (detailed): http://bit.ly/suggest-whatif
T-shirts and merch: http://bit.ly/whatifstore

Feedback and inquiries: https://underknown.com/contact/

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 — grounded in scientific theory — through time, space and chance, as we ask what if some of the most fundamental aspects of our existence were different.

Written by What If

Comments

This post currently has 48 comments.

  1. @discworldfan

    October 17, 2025 at 5:10 am

    All planets and you did include moons and dwarf planets. you also need to include asteroids as well since they are sort of "corpses" of planets. so no danger from them.. but we got surely alot of other things to worry about.

  2. @mospeada1152

    October 17, 2025 at 5:10 am

    Actually, the waters wouldn't be totally still, as they would be affected by the Sun.
    Also, we could have still had the Moon to explore, but other than that, local space would be pretty boring!

  3. @jcs1025

    October 17, 2025 at 5:10 am

    There are a lot of factual inconsistencies in this video. For example, the Goldilocks zone only refers to the presence of liquid water. It does not mean that the planet could have life.

  4. @thuphuongnguyen6331

    October 17, 2025 at 5:10 am

    Earth would be in the same place. You're being silly just like my mom. My mom would be a kid. You would be a kid genius. My mom knows nothing about geo facts. I'm used to teach her geo facts.

  5. @golden2662

    October 17, 2025 at 5:10 am

    Creation is by intelligent devine design. We are not here by "luck" or "accident". Genesis 1:1 In the beginning God created the heavens and the earth.

  6. @matthewbittenbender9191

    October 17, 2025 at 5:10 am

    It's an interesting thought experiment that has very quantifiable consequences as all planets and the moon affect life on Earth. However, this video sort of mixes the effects of no other celestial bodies both at the beginning and today if they all just disappeared. These are 2 totally different things as life today would likely cease but also may never have formed in either scenario. It also doesn't account for Theia which was hypothesized to have been absorbed by Earth in the solar system's wait years giving rose to the active core AND the Moon which is proposed to have been the coalesced debris from that collision. But without Theia Earth my have stayed a lifeless rock devoid of enough resources to keep any intelligent lifeform in the stone age.

    But for the sake of argument, suppose the earth was in the Goldilocks zone all by itself in the configuration it is to have the possibility to sustain life. Without the moon there would be no tides. In fact, there is evidence that even Venus and Mars affect our deep currents. All land formations would be different even if the active core was present. Lifeforms would have had to evolve differently and may have had better living conditions in the oceans. Chances are it would be totally synchronous tidally locked without Theia which caused the spin. Assuming it Theia did hit causing spin and not the moon, life could still form but it would be different. Nights would be darker and no organizing would have that light (like sea turtles) to use for mating or migration.

    Other planets still exert gravity. Without them we wouldn't have the shielding from meteors and comets. Earth's chances of being hit dramatically go up though it is still a tiny target. There have been a few extinction level events from the big ones that aren't diverted or absorbed by our gas giants. On the either hand if nothing else existed in the solar system then, neither does the asteroid ring and perhaps even the Oort Cloud which then makes Earth much safer. So while it's chances of an interstellar object colliding with it goes up which is infinitesimal or it greatly increases if all the planetary material instead is situated at a minimum of 2000AUs away.

    There is much more to add but I'll leave it here. It would be a vastly different world if it started that way and life would likely have formed very differently if ever at all and less likely not forming into intelligent beings.

Comments are closed.




This area can contain widgets, menus, shortcodes and custom content. You can manage it from the Customizer, in the Second layer section.

 

 

 

  • play_circle_filled

    92.9 : The Torch

  • play_circle_filled

    AGGRO
    'Til Deaf Do Us Part...

  • play_circle_filled

    SLACK!
    The Music That Made Gen-X

  • play_circle_filled

    KUDZU
    The Northwoods' Alt-Country & Americana

  • play_circle_filled

    BOOZHOO
    Indigenous Radio

  • play_circle_filled

    THE FLOW
    The Northwoods' Hip Hop and R&B

play_arrow skip_previous skip_next volume_down
playlist_play