Did Terra have rings in the past?

Our planet may have had rings similar to Saturn in the past, says a team of researchers from Monash University in Melbourne.

They believe that the planetary rings, which would have formed about 466 million years ago, a relatively recent period compared to the 4.6 billion-year-old Earth, would be the only plausible explanation for several geological oddities discovered .

First of all, there are numerous craters in the equatorial zone, formed in a relatively short period of time in the Ordovician (488.3 – 443.7 million years ago), very close to each other. All 21 in the same area, given that this region is not conducive to the preservation of craters created by meteorites, compared to areas located at higher latitudes.

Moreover, calcareous deposits from the same period contain a high level of meteorite debris, which shows less exposure to cosmic radiation.

In addition to all this, there is geological evidence of an intensification of tsunamis during the mentioned period. The authors of the study published by the journal Earth and Planetary Science Letters are convinced that a connection exists between these unusual phenomena that happened in a short time.

Rings like Earth’s or Saturn’s can form when a celestial body smaller than a moon or a planet, an asteroid, for example, is pulled by a planet’s gravitational pull.

Having reached the so-called Roche limit, the theoretical distance below which a celestial body begins to dislocate under the action of tidal forces caused by the celestial body around which it orbits, the asteroid fragments.

All these fragments give rise to a ring that orbits around the planet’s equatorial line. Over time, the material in the ring is pulled by the gravitational pull of the larger celestial body and ends up collapsing onto it. And the impact marks will be visible in the area of ​​the Equator.

Basically, if Earth captured and destroyed at least one such gigantic asteroid about 466 million years ago, that would also explain the presence of craters, and tsunamis, and the reduced exposure to cosmic radiation of sedimentary debris, writes Science Alert .

Another evidence for the existence of rings is related to the drastic decrease in temperatures recorded in the Ordovician.

A ring located in the equatorial zone would have cast a massive shadow cone on the Earth’s surface. And since solar radiation that normally reaches Earth would have been blocked, one effect would have been significant global cooling.

Not by chance, about 465-445 million years ago, Earth experienced the coldest period in the last half a billion years.

Scientists also note that the rings formed around the planets are not permanent. In the case of the most well-known ones, those of the planet Saturn, the data obtained so far indicate their origin located about 10 to 100 million years ago.