The following is an extract from our monthly Launchpad newsletter, in which resident space expert Leah Crane journeys through the solar system and beyond. You can sign up for Launchpad for free聽here.
2024 is going to be all about moons 鈥� there are a lot of missions to Earth鈥檚 moon, Europa Clipper is heading to Jupiter鈥檚 moon Europa and there鈥檚 even a mission to observe the asteroid moon Dimorphos. So I thought I鈥檇 put aside my long-running feud with our moon and talk a bit about why it鈥檚 important and why we鈥檙e ramping up our lunar exploration now.
Blast from the past
In the beginning, Earth floated alone in its perpetual journey around and around the sun. It continued like that for around 100 million years after the birth of the solar system, before its promenade was interrupted by a Mars-sized object called Theia. This doomed interloper slammed into Earth with extraordinary force, vaporising a large portion of the planet and leaving a huge cloud of debris. Slowly, from the debris of two worlds, the moon formed.
Advertisement
Fast forward about 4.5 billion years, and things in the solar system are much less chaotic. The moon鈥檚 nearly non-existent atmosphere and lack of geologic activity means that it has stayed pretty much the same for a large portion of those years, slowly acquiring craters as smaller objects have fallen onto it.
The moon鈥檚 history is one of the biggest reasons it鈥檚 so important to explore it now. On Earth, the mixture of tectonic and biological activity, along with flowing water, has erased a great deal of the evidence of how the solar system evolved, like a childhood video that was accidentally reused to record a TV movie. But the moon still holds a record of our solar system鈥檚 youth. And because Earth and the moon are so close together, that means it has a record of our planet鈥檚 environment in its youth, as well.
To me, that鈥檚 a convincing argument for sending lots of robots to the moon to explore, which is what NASA and many other space agencies are doing in 2024 鈥� some of the聽many upcoming missions聽will investigate and attempt to mine ice on the moon, work on how to deal with the sticky lunar dust and demonstrate a variety of new types of rover. But you may notice that those examples seem to be aimed more at preparing for human exploration than at learning the moon鈥檚 history.
That鈥檚 where I become a bit unsure 鈥� given how much more difficult it is to聽send humans to the moon聽than robots, is it really worth it? Popular arguments for crewed missions to the moon include the fact that humans are faster and more agile at doing science than robots are, more observant and better able to improvise. There鈥檚 also little doubt that seeing a person on the moon again would be incredible and inspire people. Even I, with all my general cynicism, would surely be in tears about the great things humanity can accomplish (and a bit jealous of the moon walker). It may even simply be human nature to venture as far as we can. I鈥檒l leave judgments about the value of human space exploration up to you, but regardless: huge teams are working very hard on it, and people will be walking on the moon soon.
Much of what we know about the moon now comes from the limited samples brought back to Earth by the Apollo missions in the late 1960s and early 70s, so there鈥檚 no doubt that sending humans back again and returning samples will give us a wealth of information about Earth鈥檚 nearest neighbour and the early solar system more generally. There are practical pluses too 鈥� if we want to send humans to Mars or even further afield, we need to test all the new technologies necessary for those journeys, and the moon is inarguably the best place to do a lot of that testing. And if space agencies can establish a聽permanent human presence there, the study of the moon and of how to live in space could proceed much faster, and lunar science and industry could start to become relatively routine.
