I’ll cut to the chase: “Ad Astra” is the most boring movie of 2019, ponderous and slow-moving. How slow? It makes “2001: A Space Odyssey” look like an action-filled romp.

It is so bad that I’m going to spoil parts of it and not feel one bit guilty about doing so, because you should never watch this movie. If it comes on HBO and you can’t change the channel because the batteries in your remote are dead, turn off the TV manually. If it becomes the only movie offered on Netflix, cancel your subscription before sitting through it. It will be high up on my list of the Worst Movies Of 2019.

“Ad Astra” stars Brad Pitt as a veteran astronaut sometime “in the near future.” I never know what that means. I guess next week qualifies, as do next month, next year, and a decade from now. But when science fiction says it, they usually mean later in this century but don’t want to give us a specific date. Whatever.

In the movie’s opening scene, Pitt is working on a space antenna in Earth orbit, along with other astronauts. Something goes wrong, there are explosions and flying bits of metal that knock his colleagues off, and eventually he’s in free-fall, too, headed for Earth. Now, I’m no Neil deGrasse Tyson, but I do know that if you’re outside the Earth’s atmosphere, you’re going to burn up upon re-entry unless you’re protected by a heat shield. Brad has no such shield. He’s just tumbling and falling until he miraculously stops spinning long enough to deploy his parachute. Why an astronaut in a full space suit working in that environment has a parachute is not explained — nor is much else in this movie.

Naturally, Brad lands safely back on our planet, where he’s whisked off to a top secret meeting where he’s told about a power surge that originated near Neptune, which is where his father (Tommy Lee Jones) went on a mission almost three decades ago. Everyone assumed that Dad was dead, but now it appears he may be alive — and the cause of the surge, which threatens to wipe out all life in our solar system. Brad is told he has to go to Mars, where the US has a special underground base that wasn’t affected by the surge. There, he’ll send Dad a message — by laser transmission — pleading with him to knock it off. Why he couldn’t record the audio message on Earth and have it beamed to Mars before being relayed to Neptune, oh, who the hell cares.

All of this takes forever to unfold. Meanwhile, we get cumbersome scenes of Brad remembering his father, the girlfriend who just left him (Liv Tyler), and a few minutes of Donald Sutherland as a superior officer with special knowledge about the mission who’s supposed to go with Brad, but can’t because, again, I’m guessing here, his acting contract was only for a couple of days.

And we haven’t even gotten to Neptune yet. Along the way, as if recognizing that this cumbersome plot needs some spice, director and co-writer James Gray forces Pitt’s ship to answer a distress call from another ship where bad things happen involving a primate gone wild. Don’t ask.

You also can’t ask why there’s a scene in which one crew member fires a gun on board a spaceship, leading to the bullet hitting an oxygen hose, taking out all the air for everyone except Brad Pitt, who of course is wearing his space suit and helmet. You also can’t ask whether Pitt’s character could really climb on board another spaceship (that’s now headed for Neptune) while it is taking off — as if it’s easy to access a launch site without anyone noticing and not get burned up by the fiery fury of the engines. Oy!

Almost exactly a year ago, I wrote about how the stoicism of Ryan Gosling’s Neil Armstrong did not make for a good movie in “First Man” (my review is here). The internal conflicts of Pitt’s character are similarly non-compelling. Gray must have realized how awkward it was for us to watch his hero try to act out those emotional struggles, because he added a voiceover narration by Pitt which, unfortunately, doesn’t help us understand the man or his motivations at all.

Why did I go see this crap in the first place? Because I like Brad Pitt, especially after his great performance earlier this year in “Once Upon A Time…In Hollywood.” I like Tommy Lee Jones and Donald Sutherland, although their dual presence reminded me of another astronaut stinker, Clint Eastwood’s “Space Cowboys” (2000). The completely underwritten small roles for women went to Lisa Gay Hamilton, Natasha Lyonne (who gets maybe a minute of screen time), and Liv Tyler, who has her own space stinker on the resume (“Armageddon,” 1998).

“Ad Astra” is a yawn-fest that I’d only recommend as a cure for insomnia. I’m shocked that it’s made $48 million at the box office, although I’d bet that if you asked those moviegoers whether they’d pay for it on the way out, it would have grossed about three bucks.

I give it a 1 out of 10.

One final note. When I went to see this movie Saturday night, there were a mother and father with two young boys, around 8 years old, directly in front of me. One of them fell asleep on Mom’s lap halfway through while the other was leaning heavily on Dad’s shoulder. I felt sorry for them during the movie, but even more so during the coming attractions.

Of the eight trailers we had to endure, two were for horror movies with scenes so intense they could easily give these kids nightmares — I noticed them jump in their seats a couple of times. I don’t blame the theater for showing those previews — they can only promote what the studios give them — and “Ad Astra” is rated PG-13, which should have been a tipoff to the parents not to take their kids in the first place. Blame the lack of parental guidance.

As for the boys, I wonder if their bad dreams started while they were slumbering through “Ad Astra.” I know it was a nightmare experience for me.