Eureeka! It’s Europa!
Updated: Nov 6
Our solar system is found in the spiral arm shape of the Milky Way galaxy, known to be one of the estimated 100 billion galaxies in the observable universe. To say that Earth is a small piece in the observable universe is not shy from reality, and as humans, we are a spec.
To break down our solar system, is to find our star, also known as the Sun, and everything that is bound to it by the law of gravity: the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids.
Our planet, Earth, is approximately 3.5 million times larger than the size of an average human (about 5 to 6 feet in inches). This is an extraordinary fact, but Earth is surely not the largest planet in our solar system. In fact, the largest planet in our solar system is planet Jupiter. With a radius of 43,440.7 miles (69,911 kilometers), Jupiter is 11 times wider than Earth. Let us put this into an easier comparison for perspective: if Earth were the size of a nickel coin, Jupiter would be about as big as a basketball!
Jupiter’s large size contains familiar stripes and swirls that are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium. However, despite its unique structure and size, this is not all that the planet has to offer. One of its main features that have scientists exploring is one of its moons, known as Europa. Europa is one of Jupiter's largest of 90 moons, and is considered one of the most intriguing bodies in our solar system. Perhaps you may have never heard of Europa and are curious why such a moon is special. Let us dive into this!
To explore Europa, we must first look at its size, surface and composition. Europa is slightly smaller than Earth's Moon, with a diameter of about 3,100 kilometers (1,900 miles). It is primarily composed of silicate rock and has a water-ice crust and probably an iron-nickel core. It has a very thin atmosphere, composed mostly of oxygen. Europa's surface is also marked by a complex network of cracks, ridges, and fractures. These features suggest that the icy crust is actively shifting and resurfacing, likely due to the tidal forces exerted by Jupiter. Some areas on Europa show geologic activity, such as the occasional eruption of water vapor and icy material from the surface.
With years of studies and research, scientists have collected evidence and are almost certain that hidden beneath the icy surface of Europa is a saltwater ocean with about twice as much water as Earth’s global ocean. This global ocean is estimated to contain two to three times the amount of water found on Earth and is kept in a liquid state due to tidal heating caused by Jupiter's gravitational influence.
With the potential of a subsurface ocean, Europa may be one of the most promising places in our solar system to find present-day environments suitable for some forms of life beyond those found on Earth, making it a true target in the search for extraterrestrial life as well. The combination of liquid water, essential chemical elements, and a stable environment makes Europa a potential habitat for microbial life or even more complex organisms.
To further investigate Europa's potential habitability for other life species, NASA has announced its Europa Clipper mission. According to NASA’s website, the Europa Clipper mission “will conduct detailed reconnaissance of Jupiter's moon Europa and investigate whether the icy moon could harbor conditions suitable for life”.
This mission, set to take launch in late 2020’s, will place a spacecraft in orbit around planet Jupiter in order to perform a detailed investigation of Europa -- which shows strong evidence for an ocean of liquid water beneath its icy crust and that could potentially host conditions favorable for life. Mission Europa Clipper will send a highly capable, radiation-tolerant spacecraft into a long, looping orbit around Jupiter to perform repeated close flybys of the moon in order to study its surface, subsurface ocean, and geology using a suite of scientific instruments.
Studying Europa can provide insights into the conditions necessary for life to emerge and thrive beyond its icy moon, Jupiter, our planet Earth, or the potential of life in other icy ocean worlds within our solar system and beyond.
It's important to note that our knowledge of Europa is still limited, and many questions remain unsolved and unanswered. Future missions and scientific advancements will play a crucial role in unraveling the mysteries of this fascinating moon and determining its potential for hosting extraterrestrial life!