Review of Ad Astra (2019) by Uomoviso — 24 Dec 2019

Do you even science bro?

Ad Astra is set in the near future, but anchors itself in the technological aesthetics of the present. Spacesuits look pretty much the same as they do now, spaceships are still launched with rockets, and air locks are still a thing. In other words, it looks like it's based on real science. No Klingons here.

But apparently the film's $100 million budget didn't extend to hiring an astrophysicist to sound the alarm whenever its already tenuous connection to the truth snapped like a space elevator made from chewing gum. So what follows is an indignant review of its six most shockingly awful violations of scientific principles.

There are plenty of spoilers, but don't worry, you're not going to see the film anyway.

1. Gravity on the Moon ain't what it used to be.

The scene: Brad Pitt and Donald Sutherland arrive on the Moon. Travel bags over their shoulders, they ascend an escalator and saunter through the spaceport.

The science: gravity on Earth is 9.8m/s2, but gravity on the Moon is just 1.6m/s2. Unless Brad and Donald are both super comfortable suddenly weighing 16% of their usual weight, they would bounce their way straight into the spaceport ceiling and an unhealthy dose of brain damage.

The fix: install some handrails, Moon government.

2. You can't skid to a smoking stop in space.

The scene: Brad hitches a ride on a cargo spaceship travelling from the Moon to Mars. Halfway there, the ship's captain receives a mayday call from another spaceship orbiting a nearby asteroid.

The science: since space is a vacuum, the only way a spaceship can slow down is to fire its rockets in the opposite direction of its travel. Brad's ride is well into its journey when the mayday call arrives, so it's going very, very fast. It would therefore be impossible to stop in time to help out without turning Brad and the ship's crew into meat paste.

The fix: ignore the mayday, captain.

3. We have a stowaway.

The scene: Brad is on Mars but wants to go to Neptune to see Tommy Lee Jones. Unfortunately, Space Command doesn't want him to go. So Brad dives through a lake at the base of the spaceship that Command is preparing to launch to Neptune, climbs up the side of the ship as its rockets are firing and breaks in moments before it launches.

The science: the Martian permafrost is between 3.5-8km deep, which means there are no liquid lakes anywhere on the surface of Mars.

Bonus science: Climbing up inside the launch tube of a spaceship as its rockets are firing = instant and fiery death.

The fix: I can't even.

4. Life's pretty fine in Neptune orbit.

The scene: Tommy is living in a small spaceship orbiting Neptune, which he has called home from the past twenty years. There is no gravity on the spaceship.

The science: in zero gravity, Tommy's bones should lose 12% of their density per year. As he has lived in zero gravity for twenty years, his bone density should be negative 140%. This would make Tommy a roughly human shaped sack of jelly.

The fix: design your ship to spin along its axis, Tommy, and use centrifugal force to create the impression of gravity. Duh.

5. Surfing the rings.

The scene: Brad needs to get back to his spaceship after visiting Tommy's. Unfortunately, he forgot where he put his EVA shuttle. So he rips off a sheet of metal from Tommy's ship and jumps off it. Brad's jump is a good one, but the rings of Neptune stand between him and his ship. He uses his sheet of metal as a shield to protect him from harm.

The science: Brad's ship is 3-4km from Tommy's. Even assuming Brad has a superhuman jumping power that lends him incredible strength and accuracy, he still has to deal with the pesky rocks in Neptune's rings. The metal shield might stop the rocks from killing him, but each of the many impacts would still retard or deflect his path of travel, leaving him stranded to die.

The fix: don't lose your shuttle next time, Brad.

6. Everything can be solved with a nuclear bomb The scene: Brad makes it back to his spaceship, but doesn't have enough fuel for the return journey to Earth. Fortunately, he left a nuclear bomb on Tommy's spaceship so eyeballs the direction back to Earth, waits for the bomb to explode and rides its pressure wave all the way back home. The science: sweet baby Jesus, where do I start? First, space is a vacuum so a nuclear explosion does not create any form of pressure wave at all. Second, even assuming this isn't true, Neptune is 4.4 billion kilometres from Earth and Brad lines up his position between the explosion and Earth by eye. If Brad is even 0.1 degree out, he would miss Earth by 7.5 million kilometres, which is around twenty times the distance from the Earth to the Moon. The fix: don't fly to Neptune unless you've got the juice to get back home, Brad. I give this shockingly awful, steaming mess of a film zero stars and ask: who the hell keeps giving James Gray money? Definitely do not see it.