If a medium-sized asteroid smacked into deep ocean waters here on Earth, what are the consequences?

Elisabetta Pierazzo, a senior scientist at the Planetary Science Institute (PSI) in Tucson, has some bad news.

An asteroid crashing into the deep ocean could have dramatic worldwide environmental effects including depleting the Earth’s protective ozone layer for several years. In the past, the interest in the effects of oceanic impacts of medium sized asteroids has focused on the danger of regional tsunami.

But Pierazzo’s new approach, published recently in Earth and Planetary Science Letters, has used computer modeling scenarios to look at the effects such a strike would have on the atmospheric ozone.

“The results suggest that mid-latitude oceanic impact of one kilometer asteroids can produce significant global perturbation of upper atmospheric chemistry, including multi-year global ozone depletion comparable to record ozone holes recorded in the mid 1990s,” Pierazzo said in a press statement.

The researcher has found that rapidly ejected seawater, included as water vapor and compounds like chloride and bromide that hasten the destruction of the ozone, would affect atmospheric chemistry.

Indeed the removal of a significant amount of ozone in the upper atmosphere for an extended period of time can have important biological repercussions at the Earth’s surface – such as an increase in ultraviolet rays that reach terra firma.

The research was funded by a NASA Exobiology grant.

Meanwhile, how best to deal with global coordination and response in the event that an asteroid or other object is found to pose an impact threat to Earth?

That’s the issue being taken up later this week during a three-day workshop of experts, hosted by the European Space Agency (ESA) at the European Space Operations Centre in Darmstadt, Germany.

Workshop participants include officials from ESA, NASA, as well as the Russian Space Agency. They are gathering this week to review the latest information and findings from asteroid and Near Earth Object (NEO) research worldwide.

During the workshop, those attending will also consider two theoretical — but plausible impact scenarios — and analyze them in detail in order to identify the best strategy for global response.

By LD/CSE