There’s no shortage of candidates for the cause of the mass extinctions of prehistory. But experts have found flaws in every one.
Asteroid impact at Chicxulub, Yucatan clearly played a role in the Cretaceous-Paleogene (K-Pg) extinction that wiped out the non-flying dinosaurs 66,000,000 years ago, though scientists point to the serious disruptions that had begun hundreds of thousands of years before with the basalt flows of the Deccan Traps.1 Giant basalt lava flows that poisoned the atmosphere and oceans played a role in four or perhaps all five major extinctions. But other enormous basalt flows have not caused extinctions, nor did they cause the tsunamis associated with various extinctions.2 Researchers have suggested many other mechanisms, but there’s no consensus at all.
Lurking in the background, however, is a quite plausible cause, one that would have possessed the power to set off the volcanic activity, air pollution, mass wasting, sea level shifts, loss of oxygen in oceans, climate changes, and other phenomena associated with the extinctions.
The Martian Theory
originally formed a single planet outside the orbit of Jupiter. Then, 
In his Worlds in Collision (New York: Macmillan, 1950), Immanuel Velikovsky argued that Venus emerged as a red-hot comet from Jupiter and passed Earth every 52 years, causing the Bronze Age catastrophes, before settling into its current orbit. His claim set off a controversy in which his theory was rejected and stigmatized. But over the years, new findings have changed the picture. Here are eight new reasons to accept a Revised Venus Theory, based on the evidence and reinterpretation in The Knowable Past (2nd edition, Washington, D.C.: Scientia Press, 2019).
A new theory of the origin of the terrestrial planets—that Jupiter’s gravity pulled them inward from the outer solar system—solves longstanding scientific riddles and offers a rich agenda for further investigation.