Investigating the Formation of the Moon Through a Hypothetical Planet Between Earth and Mars
(2025) FYSK04 20251Department of Physics
Astrophysics
- Abstract
- The Moon’s origin is an exciting topic that many scientists believe started with a colossal collision between early Earth and a Mars-sized body. In this study, we examine the possibility that Theia, a body known to have existed, may have formed in a stable orbit between Earth and Mars, and eventually collided with our planet due to orbital changes over time. To explore this event, we use the REBOUND N-body simulation framework, where we experiment with Theia’s mass, semi-major axis, eccentricity, and inclination, and perform simulations with different models of the early solar system. The goal with these simulations is to uncover the conditions that could lead to collisions, ensure long-term stability, or even result in Theia being ejected... (More)
- The Moon’s origin is an exciting topic that many scientists believe started with a colossal collision between early Earth and a Mars-sized body. In this study, we examine the possibility that Theia, a body known to have existed, may have formed in a stable orbit between Earth and Mars, and eventually collided with our planet due to orbital changes over time. To explore this event, we use the REBOUND N-body simulation framework, where we experiment with Theia’s mass, semi-major axis, eccentricity, and inclination, and perform simulations with different models of the early solar system. The goal with these simulations is to uncover the conditions that could lead to collisions, ensure long-term stability, or even result in Theia being ejected from the system. We closely monitor how Theia’s orbit changes over time, study the angular momentum before and after any collisions, and evaluate various impact scenarios. By doing this, we gain valuable insights into how Theia may have formed and evolved as part of the natural dynamics of our planetary system, helping us better understand the origins of the Earth-Moon system. (Less)
- Popular Abstract
- Look up at the night sky, and there it is- the Moon, our silent companion, glowing softly above. It has been inspiring poetry, myths, and music for millennia. But there is one big question that scientists are still trying to answer: Where did the Moon come from?
The leading theory is dramatic: about 4.5 billion years ago, a Mars-sized planet, nicknamed Theia, slammed into the early Earth. The aftermath of this cosmic collision threw debris into space, which eventually clumped and formed the Moon. It is called the giant impact hypothesis, and it explains many of the characteristics of the Moon. But there is a problem: we have never
found Theia.
What if Theia wasn’t just a random wandering object from deep space? What if it was a real... (More) - Look up at the night sky, and there it is- the Moon, our silent companion, glowing softly above. It has been inspiring poetry, myths, and music for millennia. But there is one big question that scientists are still trying to answer: Where did the Moon come from?
The leading theory is dramatic: about 4.5 billion years ago, a Mars-sized planet, nicknamed Theia, slammed into the early Earth. The aftermath of this cosmic collision threw debris into space, which eventually clumped and formed the Moon. It is called the giant impact hypothesis, and it explains many of the characteristics of the Moon. But there is a problem: we have never
found Theia.
What if Theia wasn’t just a random wandering object from deep space? What if it was a real planet with its own orbit, once circling the Sun between Earth and Mars? That’s the question that I am exploring in my Bachelor’s thesis in astrophysics.
Using a powerful simulation tool called Rebound, I create virtual solar systems that include Theia, Earth, Mars, Jupiter, Saturn, and the Sun. I change Theia’s orbit and mass, then run these cosmic simulations for millions of years to see what might happen. Does Theia crash into Earth? Does it get flung out into space by Jupiter’s gravity? Or does it quietly settle into a stable orbit, never causing the impact we think happened?
By running 96 simulations, each with different setups, I am trying to find the ’Goldilocks’ conditions: the sweet spot where Theia’s orbit makes a collision with Earth likely, but not inevitable. These simulations help us to understand not just whether Theia could have existed but how its fate- and Moon formation- depends on the delicate balance of forces in our early solar system.
This kind of research is exciting because it touches on the bigger story of how planets form, evolve, and sometimes collide. It’s not just about the Moon; it’s about the chaotic beginnings of our cosmic neighborhood. Giant impacts like the one we think created the Moon could happen in other solar systems, too. Studying them helps us understand how unique or common our Earth-Moon system might be.
And beyond science, there is something deeply human about trying to explain the Moon. It connects us to our past, to stories told around fires thousands of years ago. But now, instead of myths, we have physics, computers, and orbital mechanics to tell the story.
In the end, my project is about tracing the cosmic footsteps of a lost planet, one that may have helped us not just to get the Moon, but the conditions for life on Earth. Theia might be gone, but its legacy lights up our sky every night. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9211069
- author
- Shukla, Rishabh LU
- supervisor
- organization
- course
- FYSK04 20251
- year
- 2025
- type
- M2 - Bachelor Degree
- subject
- keywords
- Moon Formation, Theia, REBOUND
- report number
- 2025–EXA251
- other publication id
- 2025–EXA251
- language
- English
- id
- 9211069
- date added to LUP
- 2025-08-29 13:14:19
- date last changed
- 2025-08-29 13:14:19
@misc{9211069,
abstract = {{The Moon’s origin is an exciting topic that many scientists believe started with a colossal collision between early Earth and a Mars-sized body. In this study, we examine the possibility that Theia, a body known to have existed, may have formed in a stable orbit between Earth and Mars, and eventually collided with our planet due to orbital changes over time. To explore this event, we use the REBOUND N-body simulation framework, where we experiment with Theia’s mass, semi-major axis, eccentricity, and inclination, and perform simulations with different models of the early solar system. The goal with these simulations is to uncover the conditions that could lead to collisions, ensure long-term stability, or even result in Theia being ejected from the system. We closely monitor how Theia’s orbit changes over time, study the angular momentum before and after any collisions, and evaluate various impact scenarios. By doing this, we gain valuable insights into how Theia may have formed and evolved as part of the natural dynamics of our planetary system, helping us better understand the origins of the Earth-Moon system.}},
author = {{Shukla, Rishabh}},
language = {{eng}},
note = {{Student Paper}},
title = {{Investigating the Formation of the Moon Through a Hypothetical Planet Between Earth and Mars}},
year = {{2025}},
}