Frequency Atlas

Mercury Orbit (Cosmic Octave)

141.27 Hz

Nearest note: C♯3, 33 cents above standard tuning

A tone calculated from a measured cycle, by doubling its frequency 30 times. It is calculated, not recorded.

How well is this supported?

DerivedOctave of an astronomical cycle

Calculated from a measured value by a stated method. You can check the arithmetic. What the result means is a matter of interpretation.

The cycle is measured. The tone is calculated from it by doubling, so that it can be heard. Nothing in space makes this sound.

What the four labels meanChecked against sources September 27, 2026

The button plays a plain tone. Start with the volume low. Phone and laptop speakers play low notes quietly; headphones or a speaker help.

Where this number comes from

Mercury goes around the Sun in 87.969 days. 1 ÷ 7,600,522 seconds, doubled 30 times, is 141.27 Hz. That is a C♯, about 33 cents above standard tuning.

  1. Step 1. Start with the length of the cycle

    Mercury orbit around the Sun: 87.969 days.

  2. Step 2. Turn it into a frequency

    One divided by that many seconds is 1.32 × 10⁻⁷ Hz. That is far too slow to hear.

  3. Step 3. Double it 30 times

    Doubling a frequency raises it by one octave: the same note, higher. After 30 doublings it is 141.27 Hz.

  4. Step 4. Name the note

    141.27 Hz is a C♯, 33 cents above standard tuning. A cent is one hundredth of the step between two neighboring piano keys. To play in tune with this tone, an instrument sets its A to 448.51 Hz instead of 440.

  5. Step 5. Keep doubling and the number lands in the range of light

    42 more doublings give the frequency of light with a wavelength of 483 nm, which is blue-green. This is arithmetic. It pairs a tone with a color; it does not show that the two are connected.

The method is Hans Cousto’s. Planet gongs explained walks through it and says what it does and does not show.

Facts

Frequency
141.27 Hz
One cycle takes
87.97 days
Wavelength in air (20 °C)
2.43 m
Nearest note
C♯3, 33 cents above standard tuning
Kind of statement
Octave of an astronomical cycle
Filed under
Planets

Tuning Data

The row for this tone in Hans Cousto’s tables, with the tempo and pendulum length that follow from it.

Cycle
Mercury orbit around the Sun
Length of the cycle
87.969 days
Octaves up
30
Concert pitch (A)
448.51 Hz
Difference from A = 440 Hz
+33.17 cents
Tempo
66.22 beats per minute
Pendulum length
20.4 cm / 8.03 in
Color by octave
Blue-Green (483 nm)
Tempo and pendulum length, octave by octave
OctaveFrequencyOne cycleTempoPendulum
23tempo1.10 Hz906.07 ms66.22 BPM20.4 cm
242.21 Hz453.03 ms132.44 BPM5.1 cm
254.41 Hz226.52 ms264.88 BPM1.3 cm
268.83 Hz113.26 msToo fast to countToo short to build
2717.66 Hz56.63 msToo fast to countToo short to build
2835.32 Hz28.31 msToo fast to countToo short to build
2970.64 Hz14.16 msToo fast to countToo short to build
30tone141.27 Hz7.08 msToo fast to countToo short to build
Intervals built on this tone
RatioIntervalFrequencyNoteConcert ACents from 440
1/1Perfect unison141.27 HzC#3448.50 Hz+33.14
81/80Syntonic comma143.04 HzD3428.62 Hz-45.35
531441/524288Pythagorean comma143.20 HzD3429.11 Hz-43.40
128/125Diesis144.66 HzD3433.49 Hz-25.80
648/625Greater diesis146.47 HzD3438.91 Hz-4.29
25/24Chroma147.16 HzD3440.97 Hz+3.81
16/15Diatonic semitone150.69 HzD3451.55 Hz+44.87
10/9Minor whole tone156.97 HzD#3443.97 Hz+15.55
9/8Major whole tone158.93 HzD#3449.52 Hz+37.05
8/7Septimal whole tone161.45 HzE3431.02 Hz-35.68
6/5Minor third169.52 HzE3452.57 Hz+48.78
5/4Major third176.59 HzF3444.97 Hz+19.46
4/3Perfect fourth188.36 HzF#3448.00 Hz+31.19
3/2Perfect fifth211.91 HzG#3449.01 Hz+35.10
8/5Minor sixth226.03 HzA3452.06 Hz+46.83
5/3Major sixth235.45 HzA#3444.47 Hz+17.50
7/4Natural seventh247.22 HzB3440.50 Hz+1.97
16/9Pythagorean minor seventh251.15 HzB3447.49 Hz+29.23
9/5Just minor seventh254.29 HzC4427.66 Hz-49.26
15/8Major seventh264.88 HzC4445.48 Hz+21.41
2/1Octave282.54 HzC#4448.50 Hz+33.14

Source notes

Mercury’s sidereal orbit is measured relative to the fixed stars with the Sun as the observational base.

Source: Hans Cousto — Tuning Data / Sun Earth Moon Planets. View the source PDF.

License: CC BY-NC-ND 4.0, as stated in Stimmdaten.pdf (German edition), page 2.

Values are reproduced from Cousto’s tables. Tempo, pendulum length and interval tables are calculated by this site from those values.

See every tone in the tables: Open the tuning data reference.

Sources

More about the pitch

The same note in every octave

Each step doubles or halves the frequency. Tap one to hear it.

Entries close in pitch

Within 35 cents of this tone, in any octave. A cent is one hundredth of the step between two neighboring piano keys. Being close in pitch does not mean two things are connected.

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