# How Many Black Holes Are In The Solar System?

Source: https://www.youtube.com/watch?v=wh75ubECL8I
Recap page: https://rapidrecap.app/video/wh75ubECL8I
Generated: 2025-07-22T03:05:04.076+00:00

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## Quick Overview

Dark matter, a mysterious invisible substance making up over 80% of the universe's mass, has eluded direct detection for decades. Scientists now propose that asteroid-mass primordial black holes (PBHs), formed in the early universe, could account for all dark matter. The Solar System, particularly the precise tracking of Mars's orbit, can serve as a giant detector for these PBHs, revealing their gravitational influence through minute shifts in planetary positions over time.

**Key Points:**
- Dark matter, comprising over 80% of the universe's mass, remains undetected despite decades of searching with advanced colliders and detectors.
- The most promising unexplored mass range for compact dark matter objects is between 10^17 and 10^23 grams, roughly the mass of asteroids.
- Primordial black holes (PBHs), formed in the early universe, are viable dark matter candidates within this asteroid-mass range, unlike regular asteroids or stellar black holes.
- The Solar System can act as a giant PBH detector, with asteroid-mass PBHs potentially passing through the inner Solar System as frequently as once per month to decade.
- Precise tracking of planetary orbits, particularly Mars, can reveal minute, meter-scale gravitational shifts caused by passing PBHs over years.
- Distinguishing PBH gravitational effects from those of known solar system objects or interstellar asteroids is possible due to their distinct trajectories and speeds.
- If observed orbital anomalies cannot be explained by known objects and the source is invisible to telescopes, it would provide strong evidence for asteroid-mass PBHs as dark matter.

![Screenshot at 0:39: A pie chart illustrating the energy distribution of the universe, showing 69% dark energy and 31% total matter, with the total matter further broken down into 80% dark matter and 20% regular matter.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-00-39.png)

**Context:** Dark matter, an invisible and mysterious substance, makes up the vast majority of the universe's mass but has never been directly observed. Scientists have explored various candidates for dark matter, from exotic particles to non-luminous celestial bodies. However, direct detection experiments and astronomical observations have largely ruled out many of these possibilities, leaving a significant gap in our understanding of the cosmos. This video explores a compelling hypothesis: that dark matter could be composed of primordial black holes (PBHs) formed in the very early universe, and proposes a novel method to detect them using our own Solar System.

## Detailed Analysis

Dark matter, an invisible and unseeable substance, constitutes over 80% of the universe's total mass, yet remains undetected by advanced particle colliders and underground detectors. Early hypotheses suggested dark matter might be non-shining regular matter like brown dwarfs, neutron stars, or black holes, but these candidates have largely been ruled out for most mass ranges. The remaining unexplored mass range for compact objects, roughly 10^17 to 10^23 grams (asteroid-mass), is a promising candidate for primordial black holes (PBHs). These PBHs could have formed directly from density variations in the very early universe, unlike stellar black holes which form from collapsing stars. If PBHs in this asteroid-mass range constitute dark matter, they would pass through the inner Solar System frequently, potentially one per month to decade. While direct observation of these tiny black holes is impossible due to their subatomic to microscopic event horizons, their gravitational influence on planetary orbits could be detectable. Recent studies suggest the Solar System can act as a giant PBH detector. By precisely tracking the positions of planets like Mars using existing spacecraft data and future missions, scientists could detect minute, meter-scale shifts in their orbits caused by passing PBHs. Distinguishing these gravitational kicks from those caused by known solar system objects or interstellar asteroids is crucial, as PBHs would exhibit distinct trajectories and speeds. The ability to predict and measure planetary positions with extreme precision, combined with sophisticated computer simulations to account for all known gravitational influences, makes this detection feasible. If such orbital anomalies are found and cannot be attributed to known objects, it would provide strong evidence for asteroid-mass PBHs as dark matter, solving a long-standing cosmic mystery.

### The Dark Matter Problem

- Over 80% of the universe's mass is dark matter, a mysterious invisible substance that has eluded detection by advanced particle colliders and underground detectors for decades
- Early candidates like brown dwarfs, neutron stars, and stellar black holes have been largely ruled out for most mass ranges due to insufficient abundance or formation constraints
- The remaining unexplored mass range for compact objects, from 10^17 to 10^23 grams (asteroid-mass), is a promising 'pocket' for dark matter candidates.

### Primordial Black Holes (PBHs)

- PBHs are black holes that could have formed directly from tiny density variations in the hyper-dense early universe, shortly after the Big Bang, unlike stellar black holes which form from collapsing stars
- PBHs can have a wide range of masses depending on early universe conditions, and if Big Bang parameters are tuned correctly, enough PBHs in the asteroid-mass range could account for all dark matter
- These PBHs would be truly invisible, with event horizons ranging from subatomic to microscopic sizes, making direct telescopic observation impossible.

### The Solar System as a PBH Detector

- If dark matter consists of asteroid-mass PBHs, they would frequently pass through the inner Solar System (e.g., one per month to decade for certain mass ranges)
- While direct impacts on planets are rare, passing PBHs would leave faint but detectable gravitational signatures on planetary orbits
- The entire Solar System can serve as a giant PBH detector, with precise measurements of planetary positions revealing these gravitational perturbations.

### Detecting PBH Signatures

- Astronomers can precisely predict and measure planetary positions with clockwork precision, even down to the centimeter, using techniques like timing the round trip of light from Earth to Mars via orbiting satellites
- A passing PBH would cause a tiny, parts-per-trillion change in a planet's position, which, over years, could accumulate to a measurable offset (e.g., 1 meter for a 10^21 gram PBH over a decade for Mars)
- Sophisticated computer simulations are required to map the space of possible orbital evolutions and separate the subtle PBH signal from the gravitational influences of all known and unknown solar system objects.

### Distinguishing PBHs from Asteroids

- PBH flybys would have distinct trajectories and speeds compared to solar system asteroids, which orbit close to the ecliptic plane and are gravitationally bound to the Sun
- PBHs would move much faster and could come in at any angle, causing different types of orbital perturbations (e.g., tweaking speed vs. altering orbital inclination)
- If numerous such gravitational 'kicks' are observed in planetary data that cannot be explained by known asteroids, it would strongly suggest the presence of PBHs; if the source is then not visible via telescope, it confirms a black hole.

### Current and Future Experiments

- Current data from Mars orbiters (20+ years of precision data) can be analyzed to look for past PBH flybys, though the object itself would be long gone
- Future monitoring of Mars's position can allow for detection of gravitational disruptions within a few years, potentially allowing tracking of the offending source as it leaves the Solar System
- This approach offers a unique way to solve the dark matter mystery by observing minuscule shifts in planetary paths through spacetime, leveraging existing and future astronomical data.

![Screenshot at 0:43: Pie charts showing the energy and matter distribution of the universe, highlighting dark energy, total matter, dark matter, and regular matter percentages.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-00-43.png)
![Screenshot at 1:58: A horizontal line graph illustrating the 'under-explored compact object mass range' from 10^17 to 10^23 grams, with an asteroid image in the middle.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-01-58.png)
![Screenshot at 2:48: A 3D simulation showing tiny density variations in the early universe, represented by fluctuating grey and colored blobs within a cube.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-02-48.png)
![Screenshot at 3:37: An animation of the Solar System with the Sun and planets orbiting, showing a black hole \(small black dot\) passing through on a hyperbolic trajectory.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-03-37.png)
![Screenshot at 4:45: An image of the Milky Way galaxy with a text overlay indicating the dark matter density at the Sun's location as ~7 x 10^-25 g/cm^3.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-04-45.png)
![Screenshot at 5:59: An animation demonstrating gravitational microlensing, where a foreground black hole briefly brightens a distant star as its light is focused towards the observer.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-05-59.png)
![Screenshot at 8:33: A top-down view of the Solar System showing planetary orbits, with a red line illustrating the chaotic and devastating trajectory of a stellar black hole passing through.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-08-33.png)
![Screenshot at 9:29: An overhead view of two cars on a highway, one slightly pulling ahead of the other due to a tiny speed difference, illustrating how small changes accumulate over time.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-09-29.png)
![Screenshot at 9:49: A top-down view of the Solar System with a red line showing a primordial black hole's trajectory passing just outside Mars's orbit.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-09-49.png)
![Screenshot at 11:54: A close-up view of a lunar retroreflector on the Moon's surface, used for precise Earth-Moon distance measurements via laser ranging.](https://ss.rapidrecap.app/screens/wh75ubECL8I/00-11-54.png)