Marinus Anthony van der Sluijs (back to homepage)

November 2003, last updated February 2005



Surveys of the history of modern catastrophism tend to overlook the work of the German scholar Johann Gottlieb Radlof. This omission is regrettable because Radlof's ideas actually formed the missing link between the antiquated cometary theories of Burton, Whiston and Halley, rooted in Renaissance thinking, and the post-Darwinian forms of catastrophism. While Radlof on one hand retained the cometary ingredients of his predecessors, he also planted the seeds for a movement one might call 'planetary catastrophism'.


Radlof's theory, embodied in a thin booklet printed in Gothic letters and published in 1823, essentially boils down to four strands of theory, all of which recur throughout the entire subsequent history of catastrophism. The first idea was that of the exploded planet: in 1802, Olbers had proposed that the recently discovered bodies Ceres, Pallas, Juno and Vesta in the asteroid belt must have been the last remnants of a former giant planet that once orbited between Mars and Jupiter.[1] In this hypothetical body, Radlof saw the original referent of the myths of Phaethon, Isaiah's 'morning star', Typhon, and others.[2] The link with Phaethon was justified by reference to the following passage from Nonnus, in which Hermes addressed Phaethon as follows:


Then you will shine in the sky like the sun god next to Ares, scattering that thick invisible darkness far away; a miracle unheard of in the course of the ages …[3]


If Phaethon really stood "next to Ares", Radlof naively argued, he could have been the missing planet, that formerly revolved between Mars and Jupiter.[4]


The mythical death of both Phaethon and Typhon at the hands of Zeus was now interpreted as the disruption of the former planet. In keeping with Nonnus' statement that Zeus discharged a comet towards Typhon, Radlof supposed that the former planet 'Phaethon' splintered to pieces after collision with a comet – and this is the second component of his theory:


Perhaps this displacement happened as the result of a collision with what used to be called a dragon star or a comet …[5]


Unperturbed by Nonnus' late date, Radlof then complained that Nonnus ought to have given more attention to the comet than he actually did:


The moving power of that enormous water mountain that rose from the sea and moved forth over the earth is obviously Jupiter's comet, and it is actually surprising that our poet allows him only a marginal role[6]


The third element of Radlof's theory is that of planets on different orbits than today. Radlof uniquely speculated that the planet Venus was one of the fragments of the exploded planet, that settled into its present orbit in the immediate aftermath of the explosion, after some close encounters with Mars. These views were motivated by the desire to accommodate Varro's statement regarding Venus' changed appearance[7] and possibly also Phaethon's links to Venus. In defence of the view that Venus had once been a constituent of a bigger planet, Radlof pointed to Venus' 'tiny size'.[8] His bold ideas about the origins of Venus qualify Radlof as possibly the first modern 'planetary catastrophist' on record.


The explosion of the planet 'Phaethon' would also have had repercussions for our own planet. The fourth element in Radlof's theory was the tilting of the rotational axis of the earth, that had originally pointed towards the zenith:


And the Aethiopians may indeed really have turned black on that occasion, because the hot zone ran over their heads when the earth axis was disrupted by that event.[9]


The tilted position of the earth axis with respect to its poles had already led old-Greek researchers to assume that our earthly star had been hurled from its former, straight position by some external body; in fact, Anaxagoras taught that the stars had originally revolved straight in the celestial firmament, so that the pole stood exactly on top of the zenith of the earth. The earth's point of gravity must have been disrupted by the collisions of the two disturbed heavenly bodies Hesperus and Phaethon, and especially by the former's change of orbit and all subsequent radical changes in the internal equilibrium equations of the planets in our solar realm, and its former position with respect to the pole had to be altered twice.[10]


For the connection of the tilting of the axis to the myth of Phaethon, Radlof relied on two ancient passages in which Phaethon's fire disturbed Atlas, standing at the pole of heaven. The passages in case came from Ovid, falsely identified as Hesiod, and Nonnus:


The fire already threatens the pole of heaven and Atlas can hardly go on to carry the glowing firmament, when Jupiter … with his lightning hurls the rider from his chariot and with dreadful fire quenches the all-fire. With burning hair Phaethon comes down from the high sky like a star that seems to fall and is absorbed, far from his home, by the waves of the great Eridanus … an entire day went by without sun.[11]


Even the axis of the sky is twisted by the swirling ether, and the bent Atlas can hardly continue to bear the circling pole of the stars … and all animals of the circle turn inimical towards each other; even the planets clash: Venus clashes with Jupiter, Mars with Saturn; and the Pleiad, thrown of its orbit, approaches Mercury, mixing its cognate light with that of the Pleiades …[12]


Shrinking back from the extraordinary claim of a full-on disruption of all planetary orbits, Radlof hastened to add the following laconic remark to the latter part of Nonnus' quote:


Whether those disturbances in the solar domain during the fall of that radiant earth star had really been so far-reaching or whether the poet rather painted it in the way it appeared to the eye, easily misled, that may the actual astronomer investigate for himself.[13]


Quite apart from the shifting of the axis, the explosion of the planet 'Phaethon' wreaked more havoc on earth. Ahead of his time, Radlof speculated that the catastrophe caused by the comet impact must have incurred a bundle of disastrous events on earth, including the flood, "great earthquakes" and "eruptions of fire".[14] In a remarkable display of prescience, Radlof envisaged the 'cosmic winter' as a universal deposit of snow in the wake of the event. This prediction was based on Nonnus' report that an endless rain of snow covered the entire earth until the sky, "so that Thessaly's highest pinnacle of rocks and the tops of Parnassus, close to the clouds, swung in the icy flood".[15] And the equivalent of a veil of darkness induced by the fall-out of cosmic debris was Solinus' account of an uninterrupted night holding sway over the earth for nine months during the flood of Ogyges.[16]


Despite these accurate 'predictions', however, and for all its genius, Radlof's work is rather poorly documented by modern standards. No compelling evidence is brought into court at all for the identification of the mythical protagonist with the missing planet in the solar system. A major flaw is the unclarity regarding the dates and the exact number of catastrophes believed to have happened. Radlof cited classical sources distinguishing between at least four catastrophes – those of Ogyges, Inachus, Dardanus, and Deucalion respectively, beside the flood of Noah and the fall of Phaethon – but failed to elucidate how many of these could have been identical, and especially to which one the shattering of the planet Phaethon and the fall of Hesperus or Venus would belong. That said, however, Radlof definitely ranks among the pioneers of early catastrophism and may indeed be the first planetary catastrophist in modern scholarship. Immanuel Velikovsky would have done well to credit Radlof as such.




Clube, V. & B. Napier, The cosmic winter (Oxford: Basil Blackwell, 1990)

Radlof, J. G., Zertrümmerung der großen Planeten Hesperus und Phaëthon, und die darauf folgenden Zerstörungen und Ueberflutungen auf der Erde; nebst neuen Ausschlüssen über die Mythensprache der alten Völker (Berlin: G. Kelmer, 1823)

Warmington, E. H. (tr.), Saint Augustine: The city of God against the pagans (I-VII; 'Loeb Classical Library'; London: William Heinemann, 1972)

[1] Radlof1823: 55; compare Clube 1990: 123, 125, 196, 319

[2] Radlof 1823: 23

[3] "Dann wirst noch du, jene dichte unsichtbare Finsterniss fern verscheuchend, neben dem Ares gleich dem Sonnengotte am Himmel erglänzen; ein Wunder, noch nie im Laufe der Zeiten erhört …", Nonnus, Dionysiaca, 38. 971ff., in Radlof 1823: 70

[4] Even the slightest acquaintance with classical astronomy would have convinced Radlof that this is not what Nonnus meant. From the Hellenistic period onward, the prevailing astronomical theory located the sun in the orbit between Venus and Mars. Phaethon's aspiration to replace the sun would thus have seen him in that orbit, directly above Venus and below Mars.

[5] "Vielleicht geschah diese Verrückung durch Zustammenstoß mit einem vormals sogenannten Drachensterne oder Kometen …", Radlof 1823: 25, 27 note 1

[6] "Die Bewegkraft jenes ungeheuern Wasserberges, welcher vom Meere aufsteigend über die Erde dahinzog, ist offenbar der Jupiterskomet, und es könnte befremden, dass unser Dichter ihm nur eine Nebenrolle zutheilt …", Radlof 1823: 101ff.

[7] " There is a passage in the treatise of M. Varro entitled The Race of the Roman People, which I shall quote in his exact words: 'In the sky,' he says, 'appeared a marvellous portent. For in the splendid star Venus, which Plautus calls 'Vesperugo', and Homer 'Hesperos' with the epithet 'most beautiful', Castor writes that a portent occurred when the star changed its colour, size, shape and course, a thing which has never happened before or since. The well-known astronomers Adrastus of Cyzicus and Dion of Naples said that this happened in the reign of Ogygus.' As great a writer as Varro would surely not call this a portent unless it seemed contrary to nature …" Augustine, De civitate Dei, 21. 8, tr. Warmington VII 1972: 48-51. The relevant phrase in Latin is ut mutaret colorem, magnitudinem, figuram, cursum.

[8] Radlof 1823: 25, 27 note 1

[9] "Wol mögen indess die Aethiopen damals wirklich geschwärzt worden seyn, weil seit der, durch jenes Eräugnis verrückten Erdachse, die heiße Zone über ihre Häupter lief", Radlof 1823: 69

[10] "Die schiefe Stellung der Erdachse gegen ihre Pole hatte schon alt-griechische Forscher auf die Vermuthung geleitet, dass unser Erdstern durch irgend einen auswärtigen Welt-körper aus seiner frühern geraden Stellung geworfen worden; ja Anaxagoras lehre, dass die Gestirne sich anfangs gerade im Himmelsgewölbe herumgedreht hätten, so dass der Pol mitten ober dem Gipfel der Erde gewesen sey. Durch die Aufstürzungen der zwey zerstörten Weltkörper Hesperus und Phaëthon, besonders aber durch die Bahn-veränderung des erstern, und die dadurch gänzlich veränderten Gleichgewichtsverhältnisse aller Planeten unseres Sonnenthumes untereinander, musste auch der Schwerpunkt unserer Erde verrückt, und ihre frühere Stellung gegen die Pole zweymal verändert werden", Radlof 1823: 112f. The two erratic bodies involved were Venus as 'Hesperus' and the exploded planet as 'Phaethon'.

[11] "Schon bedrohet der Brand die Pole des Himmels, und Atlas vermag noch kaum das glühende Gewölbe zu tragen, als Jupiter … mit seinem Blitze den Fahrmann dem Wagen entschmettert, und durch grause Feuer den Allbrand erstillt. Mit brennendem Haare stürzt Phaëthon gleich einem zu fallen scheinenden Sterne hochab durch die Lüfte, und wird, fern der' Heimat, von den Wellen des großen Eridanus aufgenommen … ein ganzer Tag gieng ohne Sonne vorüber", in Ovid, Metamorphoses, 2. 320, in Radlof 1823: 64f.

[12] "Von dem umwirbelnden Aether wird selbst des Himmels Achse gekrümmt, und der gebückte Atlas erträgt noch kaum den umkreisenden Pol der Gestirne … und alle Thiere des Kreises gerathen feindlich wider einander; selbst die Planeten stoßen alle zusammen: Venus stößt wider den Jupiter, Mars wider den Saturn; der' lenzlichen Plejade aber nähert sich, aus der Bahn geworfen, Merkur, sein verwandtes Licht mischend mit dem Siebengestirn …", in Nonnus, Dionysiaca, 38. 348-409, in Radlof 1823: 72

[13] "Ob nun jene Störungen im Sonnenbezirke bey dem Falle jenes leuchtenden Erdsternes wirklich so allgemein gewesen, oder ob der Dichter vielmehr dieselbe so schildert, wie sie dem täuschbaren Auge erschienen, mag der eigentliche Gestirnforscher untersuchen", Radlof 1823: 73

[14] "große Erdbeben" and "Feuer-ausbrüche", in Radlof 1823: 37

[15] "... so dass Thessaliens höchste Felsengipfel, und die Spitzen des wolken-nahen Parnassus in der eisigen Flut wogten", Nonnus, Dionysiaca, 3. 17 or 97, in Radlof 1823: 28, 49

[16] Solinus, Collectanea rerum memorabilium, 11, in Radlof 1823: 28