May the 4th be with you – happy Star Wars day! And happy Science Wednesday as well!
In Star Wars Episode V: The Empire Strikes Back, the icy planet of Hoth hosts a temporary Rebel base where the heroes have to defeat Imperial walkers in order to escape. How could Rebel Alliance scientists and engineers have explored and exploited this icy terrain? For starters, ice-penetrating radar would have been helpful for determining the thickness and properties of Hothian ice and snow, which, in turn, would have been useful for creating icy infrastructure like fortifications and ice-roads that either avoid or exploit crevasses. However, Rebel airspeeders travel too fast to be an ideal airborne platform for ice-penetrating radar, so you’d probably have to go orbital for large-scale surveys and then use tauntaun-pulled sleds for very local fine-scale studies.
After escaping Hoth, Han Solo attempts to navigate an asteroid field that surrounds the planet, eventually landing on one of the rocks, which happens to be home to a giant space slug. Hmmm…. First off, asteroids are not as close to each other as depicted in this scene. In the asteroid belt in our solar system, the average distance between two asteroids is 600,000 miles. That’s 2.5 times the distance between the Earth and the Moon! Space is vast. It’s claimed that this asteroid field was formed by the collision of two rocky planets. In reality, these types of planetary collisions primarily happen at the beginning of a solar system’s lifetime, and the resulting debris would either coalesce to reform into a new planet or be gravitationally disturbed and ejected to other parts of the solar system. Our asteroid belt is made up of many, many smaller planetary bodies that were gravitationally “herded” into their current position – mostly by the gravitational forcing of giant gas planets like Jupiter – and is not related to the breakup of a single planetary body. If the Star Wars asteroid field was real, the objects hitting Hoth would vaporize upon impact. If the rocks were large enough or impacts occurred frequently enough, they could pose a serious threat to life forms living on Hoth.
As for life on an asteroid? The largest object in our own asteroid belt (Ceres) is only about the size of Texas (sorry, Texas, you’re big, but not that big). Its gravity is much too low to allow it to hold onto an atmosphere, which is vital to make liquid water stable at the surface. Tiny bacteria could possibly survive on Ceres, buried deep underground but it’s unlikely they would thrive and evolve into a large organism because the environment is so inhospitable. Microscopic tardigrades (also known as waterbears) on Earth are possibly the only multicellular animal that could survive such conditions (if they somehow got delivered there), but they would be in a dormant hibernation state until exposed to liquid water, and also not likely to evolve into a giant space slug!
So there you have it – some science on Star Wars Day…
photo: Ulyana Horodyskyj Peña, on a flight to Alaska