Perihelion Precession
Every planet’s perihelion (closest approach to the Sun) slowly rotates around the Sun - a phenomenon called perihelion precession. This happens because of gravitational perturbations from other planets, and the rate of precession can be calculated using Lagrange-Laplace secular perturbation theory.
All Planets Have Perihelion Precession
The Holistic Universe Model calculates perihelion precession for all planets. Each planet has a PERIHELION-POINT that orbits the Sun, creating the precession we observe.
| Planet | PERIHELION-POINT Orbital Period | Direction | Arcsec/century |
|---|---|---|---|
| Mercury | ~241,141 years | Prograde | ~537 |
| Venus | ~667,776 years | Prograde | ~400 |
| Earth | ~111,296 years | Prograde | ~1,164 |
| Mars | ~185,493 years | Prograde | ~1600 |
| Jupiter | ~47,849 years | Prograde | ~1,800 |
| Saturn | ~55,648 years | Retrograde | ~-3,400 |
| Uranus | ~117,800 years | Prograde | ~1,100 |
| Neptune | ~648,000 years | Prograde | ~200 |
Note: The “PERIHELION-POINT Orbital Period” shows how long each planet’s perihelion point takes to complete one orbit around the Sun. Prograde means the same direction as orbital motion (counter-clockwise when viewed from above the North Pole). Saturn’s perihelion precession is retrograde (clockwise), moving opposite to all other planets.
The Mercury “Anomaly”
Mercury’s perihelion precession is historically significant because of a famous discrepancy that has been debated for over a century.
The Numbers
| Measurement | Value | Reference Frame |
|---|---|---|
| Observed precession | ~575 arcseconds/century | Heliocentric (from Sun) |
| Observed precession | 5,600 arcseconds/century | From Earth (against ICRF) |
| Newtonian prediction | ~535 arcseconds/century | Heliocentric |
| Discrepancy | ~40-43 arcseconds/century |
The observed value (~575 arcsec/century heliocentric) exceeds the Newtonian prediction (~535 arcsec/century) by approximately 43 arcseconds per century.
The Standard Explanation
The standard explanation for this 43 arcsecond discrepancy is Einstein’s General Relativity (1915):
- Space-time is curved near massive objects
- Mercury, being closest to the Sun, experiences the strongest curvature
- This causes an additional precession of exactly ~43 arcseconds per century
This was one of the first major confirmations of Einstein’s theory.
The Model’s Alternative Explanation
Alternative Proposal: The Holistic Universe Model proposes that the ~43 arcsecond discrepancy is NOT caused by relativistic effects, but by Earth’s reference frame motion.
Why the Reference Frame Matters
When we observe Mercury from Earth, we’re not observing from a fixed point. Earth itself is moving in multiple ways:
- Earth wobbles around the EARTH-WOBBLE-CENTER over ~25,684 years (axial precession)
- PERIHELION-OF-EARTH orbits the Sun in the opposite direction over ~111,296 years
These two motions change Earth’s orientation axis over time. When we measure Mercury’s perihelion precession from this moving reference frame, we get a different value than the “true” heliocentric rate.
The Math
The difference between the Earth-frame observation (~5,600 arcsec/century against ICRF) and the heliocentric observation (~575 arcsec/century) already shows how much Earth’s motion affects the measurement.
Similarly, the ~40-43 arcsecond “anomaly” can be explained as the effect of Earth’s wobble combined with the counter-movement of PERIHELION-OF-EARTH:
A Key Prediction
If this model is correct, the “anomaly” should change over time as Earth’s precession cycles progress:
| Period | Predicted “Anomaly” |
|---|---|
| Around 2000 AD | ~40 arcseconds/century |
| Coming century | ~34 arcseconds/century |
The standard General Relativity explanation predicts a constant ~43 arcseconds/century. The model predicts this value will decrease as axial precession increases in the coming centuries.
Testable Prediction: If the “missing” perihelion precession of Mercury decreases from ~40 to ~34 arcseconds in the coming century, it would support the Holistic Universe Model’s explanation over General Relativity for this specific phenomenon.
Planetary Contributions to Mercury’s Precession
The ~535 arcseconds/century Newtonian prediction comes from gravitational perturbations by all other planets. Since Mercury is the innermost planet, every other planet “pulls” its perihelion forward (prograde):
| Planet | Contribution | Percentage |
|---|---|---|
| Venus | ~278 arcsec/century | ~52% |
| Jupiter | ~153 arcsec/century | ~29% |
| Earth | ~85 arcsec/century | ~16% |
| Saturn | ~12 arcsec/century | ~2% |
| Mars, Uranus, Neptune | Combined less than 2% | less than 2% |
| Total (Newtonian) | ~530-535 arcsec/century | 100% |
These contributions are calculated using Lagrange-Laplace secular perturbation theory - an 18th-19th century mathematical framework that remains remarkably accurate. The theory:
- Treats gravitational interactions as averaged effects over complete orbits
- Assumes nearly circular, coplanar orbits
- Works well for the inner solar system
Data Sources
The perihelion precession data used in the model comes from WebGeocalc , NASA’s tool for calculating orbital elements.
The graph shows Mercury’s perihelion movement over 6 centuries confirming the ~575 arcseconds per century rate.
Connection to the Holistic Model
In the Holistic Universe Model:
- Every planet has a PERIHELION-POINT that orbits the Sun
- These PERIHELION-POINTS follow Kepler’s third law
- Mercury’s PERIHELION-POINT orbits in ~241,141 years (prograde)
- The observed “anomaly” is a measurement artifact from Earth’s moving reference frame
The model does not claim General Relativity is wrong as a theory - only that this particular phenomenon (Mercury’s perihelion anomaly) may have a simpler explanation based on reference frame motion.
Visualizing Planetary Perihelions
In the Interactive 3D Simulation, you can see all planetary perihelion points:
- Go to Settings → Objects show/hide
- Select all planets that mention “PERIHELION” (e.g., “PERIHELION Mercury”)
- Set “1 second equals” to “1000 years”
- Press “Run” to see the perihelion points precess around the Sun
The perihelion points form a spiral pattern that evolves over one Holistic-Year (333,888 years).
Calculate Perihelion Precession at Any Year
To calculate longitude of perihelion and related values for any year, see the Formulas page which provides the complete Excel formulas.
Summary
| Question | Answer |
|---|---|
| What is perihelion precession? | The slow rotation of a planet’s closest approach point around the Sun |
| What’s Mercury’s cycle? | ~241,141 years (prograde) |
| What’s the “anomaly”? | ~40-43 arcsec/century difference between observed and Newtonian prediction |
| Standard explanation? | General Relativity’s space-time curvature |
| Model’s alternative? | Earth’s reference frame motion (wobble + PERIHELION-OF-EARTH movement) |
| Key prediction? | The “anomaly” will decrease from ~40 to ~34 arcsec in coming century |
Key Takeaways
- All planets have perihelion precession - Mercury has a ~241,141-year prograde cycle
- The ~43 arcsecond “anomaly” has been attributed to General Relativity since 1915
- The model proposes an alternative - Earth’s reference frame motion creates the apparent anomaly
- Testable prediction - if the anomaly decreases over time, it supports the model’s explanation
- Reference frame matters - ~5,600 arcsec/century from Earth vs ~575 arcsec/century heliocentric
Return to The Model: How It Works or explore the Interactive 3D Simulation to see planetary perihelion precession visualized.