Europa is one of the four Galilean moons that orbit the Solar System’s largest planet, Jupiter, discovered in 1610 by Italian astronomer Galileo Galilei. Underneath its icy, scarred surface could lie a salty ocean – just like those that make up 71 per cent of Earth’s surface. Europa is tidally locked to Jupiter, meaning the same face of the moon is pointing at the Jovian giant at all times, much like the Moon and Earth. Europa has an equatorial diameter of 3,100 kilometres (1,940 miles), which is 90 per cent of the Moon’s diameter. If you were to replace the Moon with Europa in our sky, to the naked eye they would both seem about the same size. However, Europa would be much brighter on account of its surface ice reflecting 5.5 times more sunlight than the Moon, giving it a higher albedo.
The process behind the creation of Jupiter’s largest moons is still hotly debated, but astronomers largely agree that they formed from leftover debris from the formation of Jupiter roughly 4.5 billion years ago. Fast-forward to today and Europa is a water-ice ball with fractures criss-crossing all over the surface. The number of craters currently found across its cracked terrain indicate that the moon is no older than 90 million years old, suggesting there is likely to be some form of surface replenishment that also brings salts and sulphur compounds to the outer layer. Surrounding the icy world is a thin atmosphere composed of molecular oxygen.
This story is from the Issue 134 edition of All About Space UK.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the Issue 134 edition of All About Space UK.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
LONG AGO, A LAKE ON MARS MAY HAVE BEEN SPRAWLING WITH MICROBES
Curiosity discovered manganese oxide in bedrock in a Martian region that may have been a shoreline billions of years ago
MOON TOUR HELL
Finding this fascinating crater isnt as hard as its name suggests...
THIS MONTH'S PLANETS
Most of the planets are tricky targets this month, but our guide will help you locate them
UNIVERSE BEFORE TIME
Could the existence of a mirror-image cosmos before the Big Bang solve some of the biggest mysteries in astronomy?
CLIMATE CHANGE IN THE SOLAR SYSTEM
Alongside Earth, our planetary neighbourhood is changing, but it’s not for the better…
Stars give tiny planets a gravitational 'squeeze' to strip away their atmospheres
A scientist has learned more about the violent processes that rip atmospheres away from planets, finding that squashing and squeezing by a parent star can contribute to this process.
The Milky Way's halo is filled with ‘magnetic doughnuts' as wide as 100,000 light years
The outer halo of the Milky Way is filled with magnetic fields that take the shape of vast doughnuts with diameters ranging from 12,000 to 100,000 light years, with the heart of our galaxy at their centre.
The Pentagon wants the commercial space reserve to support military satellites in orbit
The US Department of Defense is developing a plan to use the ever-growing American commercial space industry for national security purposes.
DOES A COSMIC 'GLITCH' IN GRAVITY CHALLENGE ALBERT EINSTEIN'S GREATEST THEORY?
Gravity changes once you reach a cosmic scale
DEEP SKY CHALLENGE : STELLAR TREASURES OF THE ARCHER AND SCORPION
Summer skies are stuffed full of amazing objects for your telescope - if you're prepared to stay up late