‘Lost in Space': Would Will Robinson’s Magnesium Idea Really Work to Melt Ice?

Will Robinson uses his chemistry knowledge to formulate an anti-ice plan in the first episode of “Lost in Space,” but is the science sound?

Last Updated: April 15, 2018 @ 7:02 PM

(Note: This post contains spoilers for the first episode of Netflix’s “Lost in Space.”)

Netflix’s reimagining of the classic 1960s sci-fi TV show “Lost in Space” sees the Robinson family marooned on a distant alien planet and encountering all kinds of dangerous hazards. One of the marks of the new series is its more realistic take on space travel, and some spiffy uses of science to solve those life-threatening space problems.

In the first episode, the Robinsons confront one such life-threatening space problem when they crash-land on an alien planet and their ship, the Jupiter 2, melts its way into a glacier.

Judy (Taylor Russell) dives in, hoping to retrieve a battery from the crash, but it’s so cold that the water quickly freezes, and Judy is trapped in the ice in her space suit.

Young Will (Maxwell Jenkins) comes up with a potential solution as time runs out for Judy: use magnesium spotted near the crash site to melt the ice. He also notes that ice makes magnesium burn hotter. The cool thing is, “Lost in Space” is pretty much on point on these facts — finding magnesium really would be a potential solution to saving Judy from the ice.

In the show, Will and his dad, John (Toby Stephens), gather flakes of magnesium to burn and use a torch to light it. Magnesium is highly flammable in small flakes or strips and burns very hot. It’s possible for magnesium fires to hit 5,100 degrees Fahrenheit — definitely hot enough to help get Judy out of her ice jam.

When it burns, magnesium reacts with lots of different chemicals and compounds, and those reactions can also increase the temperature of the magnesium fire. Water is among the compounds that reacts with magnesium when it burns, increasing the reaction and turning magnesium and water into hydrogen and magnesium oxide.

It means that, effectively, you can’t stop a magnesium fire with water. Magnesium fire bombs were used by the Nazis during World War II, and dousing the flames they created required dumping sand on them. Using water would only cause the fires to burn stronger and hotter. Magnesium also reacts with carbon dioxide, which means if you use a fire extinguisher on a magnesium fire, you’ll only make it worse in the same way as water.

On our planet, a form of magnesium is used to melt ice, albeit with a lot less in the way of flames. Magnesium combined with chlorine creates magnesium chloride, which is used on streets and sidewalks, and in other situations, as an ice melt. Magnesium chloride works a lot like salt to melt ice on your driveway, but it’s less corrosive and damaging than salt, and it stays effective at colder temperatures — as low as -5 degrees Fahrenheit.

So Will’s quick thinking to save Judy in the first episode of “Lost in Space” is, in fact, scientifically sound. But that doesn’t mean everything about the show could pass scientific muster with, say, NASA.

For instance, the Robinsons’ decision to immediately remove their helmets on their alien planet just because they realized the air wasn’t toxic isn’t really a great idea. The helmet decision doesn’t account for microbes or other potential threats that might be in the air.

We also see the water of the glacier freeze at an extremely fast rate, suggesting temperatures are incredibly low. A few minutes later, rainfall takes away the Robinsons’ ability to keep burning magnesium, even though snow, sleet or hail are more likely weather events.

Still, “Lost in Space” is definitely bringing at least some useful scientific info to its sci-fi adventure.