In the late 20th century, more “scientific” explanations have been advanced for disastrous consequences of planetary alignments.
The tidal influence of the planets (especially the giant planets) is supposed to affect the solar wind, usually by increasing the flow of particles from the sun.
- See the article “Tidal Forces on May 5, 2000” by Donald Olson and Thomas Lytle in the May 2000 Sky & Telescope
The increased solar wind is supposed to affect the rotation of the earth, indirectly causing atmospheric disturbances and possibly earthquakes.