Manicouagan Reservoir breakup and subsequent impact of an asteroid or comet, similar to the well observed string of impacts of Comet Shoemaker–Levy 9 on Jupiter in 1994. The Manicouagan Reservoir as it exists today was created in the 1960s, by flooding the earlier Lake Mushalagan (Mouchalagan) to the west of the central plateau and then-smaller Manicouagan to the east, by construction of the Daniel-Johnson Dam. The works were part of the massive Manicouagan or Manic series of hydroelectric projects undertaken by Hydro-Québec, the provincial electrical utility. The complex of dams is also called the Manic-Outardes Project because the rivers involved are the
Comet Shoemaker–Levy 9 Despite published predictions, astronomers had not expected to see the fireballs from the impacts and did not have any idea in advance how visible the other atmospheric effects of the impacts would be from Earth. Observers soon saw a huge dark spot after the first impact. The spot was visible even in very small telescopes, and was about (one Earth radius) across. This and subsequent dark spots were thought to have been caused by debris from the impacts, and were markedly asymmetric, forming crescent shapes in front of the direction of impact. Over the next six days, 21 distinct impacts