Editing 2561: Moonfall

[[Megan]] asks [[Cueball]] if he is excited for the release of the movie ''Moonfall''.

''{{w|Moonfall (film)|Moonfall}}'' was released in February 2022, a couple of months after this comic. Its director, {{w|Roland Emmerich}}, is known for blowing up things in his movies (see for instance [https://www.gq.com/video/watch/explosions-the-roland-emmerich-supercut the Roland Emmerich Supercut]), as well as for factual inaccuracies in his work (mainly the scientific implausibility of his many disaster movies like ''{{w|Independence Day (1996 film)|Independence Day}}'', ''{{w|The Day After Tomorrow}}'' and ''{{w|2012 (film)|2012}}'').

The [https://www.imdb.com/title/tt5834426/plotsummary basic premise] of ''Moonfall'' is that a mysterious force manages to knock the moon out of its orbit, leaving it on a collision course with the Earth. This is scientifically preposterous (see [[#Realistic analysis of the scenario|analysis]] below), making it potentially 'cringe-worthy' for someone who prefers {{w|hard science fiction}} where things are more grounded in established scientific facts and theories. Cueball states that a story based on good science can potentially serve as a novel window into what the real world may look like someday—or, as he puts it, "expand our ideas of what's possible."

But Cueball then goes on to imply that he's still looking forward to the movie because his less critical side is still excited by things like cool spaceship noises and smashing moons into things. Sometimes you just want to [[311: Action Movies|get lost in mindless action]], even if it's less 'mature' than a well-thought-out meaningful plot. Megan then sums things up by playing off Cueball's wording from the previous panel, saying she's excited to "expand our ideas on how much stuff can explode at once." Given the scale of ''Moonfall'''s premise involving a potential planetary-scale collision, as well as the director's tendency to use gratuitous visual effects and explosions in his movies, it seems reasonable to conclude that the movie will likely contain quite a lot of stuff exploding at once.

In the title text Cueball continues by explaining that while novel ideas and cool explosions are good, what he really wants from a movie is novel ideas about cool explosions. So new ways to explode things, or ideas about exploding more things at once. Or both!

[[1536: The Martian]] contains a similar discussion of an (at the time) upcoming movie, in particular ''{{w|The Martian (film)|The Martian}}''. In that case, however, the subject of the comic was the movie's high scientific accuracy and lack of huge explosions, rather than the other way around.

===Realistic analysis of the scenario===

For the moon to fall from the sky, it would have to stop orbiting. Most forces applied it to will simply change the way in which it is orbiting, making the orbit more elliptical, larger or smaller. To stop it from orbiting entirely, a 'braking' force would need to be applied in the opposite direction of its travel, to halt it.

 

The moon's mass is about 7.34767×10²² kg and its speed about 1.022 km/s, so the energy needed to stop it is ½''mv''² or about 3.8364×10²⁸ joules. That's about the energy of 1 trillion large nuclear explosions, centered on the leading-most point of the moon's surface. A precisely-oriented stellar body could strike the moon to do this, like a billiard ball colliding with tons of interstellar moon shrapnel instead of dust.

 

Less counteractive energy could make the Moon change orbit to one with a {{w|perigee}} below the surface of the Earth, close enough to (partially) enter the atmosphere or merely bring it down beneath the applicable {{w|Roche limit}}. These scenarios would be only technically less catastrophic, and whether the Moon fragments from the initially applied force, the stresses of its nearest (non-contact) distance to Earth or actually survives largely intact until there is a more direct physical interaction, the precise degree of the effect might be practically academic.

:[Cueball and Megan walking to the right]

:[Closeup on Cueball]