What is SIMPLE?
Aside from the literal meaning (Sub-ice Investigation of Marine and Planetary-analog Ecosystems), SIMPLE is a NASA funded project aimed to better understand the ice-ocean interface underneath ice shelves in Antarctica.
Why on Earth would we want to do that?
Turns out that underneath hundreds and even thousands of meters of ice, void of any sunlight, there is a unique ecosystem thriving at the ice-ocean boundary. This is a recent discovery and virtually nothing is known about any of the macroscopic or microscopic organisms that make up this extremophilic biosphere. Since the exploration of sub ice shelf environments is in its infancy there exists a plethora of questions that now need answering. What kind of organisms exist in this extraordinary environment? How to do they manage to live in these harsh conditions? What is it even like underneath ice shelves?
SIMPLE to the rescue!
What do you do when you have a bunch of unanswered questions about one of the most extreme places on earth? Well, we got a bunch of scientists and engineers together and came up with an explorative science mission that would make Hollywood jealous.
SIMPLE is a multi-stage approach that uses aerial scans coupled with in situ underwater vehicle measurements to study and characterize the ice-ocean environment with unprecedented detail and resolution.
Stage 1 – Aerial Mapping
Overhead measurements using Ice Penetrating Radar, laser altimetry, imaging, magnetics, and gravimetry will be mapped.
Stage 2 – Science Nonfiction
Over three field seasons (October-December 2012, 2014, & 2015), we deployed several Automated Underwater Vehicles. This task amounts to taking an incredible submersible vehicle, one of which (Icefin) is designed and constructed by our Georgia Tech engineering team, and sending them through the ice shelf via a single drill hole. After being lowered through hundreds of meters of ice, the vehicle, tethered only by a thin fiberoptic cable, will trace out a predetermined path under the ice sheet and catalogue the temperature, salinity, and current gradients as well as the topography of both the sea floor and the underside of the ice shelf, and of course take amazing pictures of never before seen environments.
But wait, there’s more!
Our hope is that the data we collect will drastically improve our understanding of the sub-ice shelf environment of Antarctica and how organisms can thrive there, but we’re also interested in how we can use these extreme environments on earth to understand environments on other astronomical bodies in our solar system and throughout the universe.
Europa – the ocean moon
Europa is one of the four largest moons orbiting Jupiter. It is a differentiated body, which means it’s composition is similar to that of Earths, with an iron core, a silicate mantle, and in Europa’s case a water shell. Typically this far away from the sun water would only be found in the ice phase (Europa’s surface temperature is around -190 degrees celsius, brisk to say the least). So why do we care about this giant ice-covered moon? In early 2000 the Galileo spacecraft detected an induced magnetic field near Europa that is indicative of the moon having a salty liquid ocean underneath its outer icy shell. A new question arises – Why doesn’t the ocean freeze? It turns out Europa can thank it’s parent planet Jupiter for this feat. Because Jupiter is so big, and Europa has a slightly non-circular orbit that happens to be very close to Jupiter, Europa gets pushed and pulled by the large planet’s gravity. Think of a sphere being squished into an egg shape and then back again every time Europa orbits Jupiter, which happens every 85 hours. Although the deformation isn’t quite that extreme, these gravitational forces are enough to keep Europa’s insides at a temperature that allows liquid water to exist.
Last question (I promise) – Why is this awesome?
Aside from a size scale (Europa ~30km ice and ~70km ocean, Earth ~1-3 km ice and ~0-5km ocean), Europa’s ice and ocean layers are a spitting image of ice shelves on Earth. With the discovery of a biosphere underneath Antarctic ice shelves, Europa’s ice-ocean interface is a smoking gun for possible extraterrestrial life. Understanding Europa’s earth analog is tantamount to figuring out how life could possibly exist under the moon’s icy exterior. Additionally, since exploring Europa is high up on NASA’s to-do list, investigating the technology needed for potential future space missions is an integral piece of the puzzle. Our submersible vehicle will be a novel and important step towards a fully autonomous vehicle that could be part of a future in situ exploratory mission of Europa’s hidden and mysterious ocean.