• by Adam Buckman , Featured Columnist, Yesterday

The outer space battle scenarios in popular sci-fi movies are physically impossible, but other scenarios for space wars that are evolving right now are all too real.

That’s the conclusion of an illuminating and disconcerting (to say the least) new episode of “Nova” coming to PBS next Wednesday.

Subtitled “Space Wars,” the episode presents a number of scenarios in which outer-space wars might be waged and the havoc they would wreak.

The scenarios are each presented with title cards such as -- “Threat Scenario: Space Lasers,” “Threat Scenario: Anti-Sat [Satellite],” “Threat Scenario: Attack Sats” and more.

The show points out, somewhat obviously, that all of us depend on satellites every day. 

So do governments and their militaries -- whose advanced Earth-bound weaponry depends on satellites, most notably for their GPS capabilities.

According to this fascinating show, there are currently 12,000 satellites -- civilian and military -- circling the earth in three orbital “regimes” ranging from the nearest (low-earth orbit) to the farthest (geosynchronous orbit), with a third one in between known as medium-earth orbit.

That 12,000 number is expected to increase rapidly to 100,000 within a decade, says one of the experts in the show.

Outside of crippling orbital battles between Earth-based superpowers, the orbital pathways in which the satellites travel are already fraught with danger, caused mainly by “space debris.”

This debris comes in all sizes. These include untold numbers of smaller pieces of out-of-commission satellites that the U.S., China, Russia and India have blown apart with lasers to test the capability of these weapons.

The debris fields also carry old satellites, rocket stages and other leavings from human space travel -- including, says an expert, a single astronaut’s glove.

Needless to say, the space junk presents obstacles that have already led to orbital collisions -- mostly small pieces damaging space stations and satellites, although none have been catastrophic -- yet.

The show reports that the superpowers have long eyed outer space as a place to park nuclear weapons.

There are none of them so far, but in the early 1960s, says the show, the U.S. and U.S.S.R. both tested -- i.e., detonated -- nuclear weapons in low-earth orbit. 

I had never heard this before, but it was known then, and even covered in newspapers.

Among other things, the blasts knocked out a few satellites and also caused an outage of streetlights in Honolulu.

The takeaway from this chilling show is this: Those outcomes were exceedingly quaint compared with what could happen now. 

“Nova: Space Wars” premieres Wednesday, October 7, at 9 p.m. Eastern on PBS.