A £1.4bn probe will blast into space on Thursday lunchtime on a mission to search for signs of life around Jupiter.
In what some scientists regard as the best chance of finding extra-terrestrial life in our solar system, the spacecraft will give relatively nearby Mars a miss and instead head to the icy moons of distant Jupiter, much deeper into space.
It will take eight years to get there but the data it will send from 2031 is hoped to provide “spectacular” insights into how life reached the solar system.
The Jupiter Icy Moons Explorer – or Juice – will explore the vast reserves of water in the planet’s three ocean-bearing moons to see if they are habitable.
These are thought to contain more liquid water than Earth’s oceans, regarded as the key ingredient for life on this planet.
The mission to Jupiter, which on average is 444 million miles from Earth, is due to take off from French Guiana and is run by the European Space Agency.
Scientists in the UK are playing an important role, leading the development of one of the 10 instruments on the spacecraft.
Experts from Imperial College London led the development of the magnetometer, known as J-MAG, which will measure the characteristics of the magnetic fields of Jupiter and its largest moon, Ganymede.
It will also play a key role in detecting moving salts in the oceans beneath the icy crusts of Ganymede as well as exploring Jupiter’s other moons, Europa and Callisto.
The data will help characterise the depth and salt content of Ganymede’s ocean, to see if it may hold the conditions for life.
“With our instrument’s measurements, we are almost looking inside these worlds,” said Professor Michele Dougherty, of Imperial College London and principal investigator for J-MAG.
“What we’re doing however is extremely difficult, as the signals we’re trying to detect are extremely small.
“It’s like trying to find lots of needles in a haystack, and those needles are changing shape and colour all the time. But we think the results are going to be spectacular.”
Professor Dougherty said patience is very much a virtue in this project – which is about to hit and exciting milestone but still has some way left to run.
“Space missions are long and slow, so launch only marks the halfway point of this one – because we first started thinking about it 15 years ago, and we’ll be getting the last data in 15 years’ time. But I can’t wait for launch to happen because that’s the next milestone for us – we’ll be on our way to Jupiter.”
The idea that the best chance of finding ET life in ice-coated moons around Jupiter would have seemed highly unlikely a few decades ago. At that point, Venus and Mars were considered the best hopes for finding life in the solar system away from Earth.
But since then, Venus has been found to have a surface temperature of 475°C, while Mars was found to have lost its atmosphere and surface water billions of years ago. Efforts to find surviving underground supplies on the Red Planet have so far been unsuccessful.
Three of Jupiter’s main moons – Ganymede, Callisto and Europa – contain vast oceans of liquid water, the one prerequisite needed for the existence of life on Earth. The water is beneath ice but could still harbour life.
Professor Dougherty and her team will be collaborating with experts from the University of Leicester and the University College London (UCL).
Professor Emma Bunce, director of the Institute for Space at the University of Leicester and co-investigator on J-MAG, said: “After many years of hard work from science, engineering, and industry teams, we are so excited that the Juice mission is finally ready to launch and start its long journey to the Jupiter system.
“We will patiently await the incredible data that we expect to receive from 2031, and we are confident that it will absolutely be worth the wait.”
As well as J-MAG, Leicester’s scientists will also collaborate with other experts on two other instruments on Juice: MAJIS (the Moons and Jupiter Imaging Spectrometer) – which will observe cloud features and atmospheric constituents on Jupiter; and UVS (UV imaging spectrograph) – which will characterise the composition and dynamics of the exospheres of the icy moons.
The UCL’s Mullard Space Science Laboratory (MSSL) has also provided particle detectors for Juice’s PEP (Particle Environment Package) instrument, which will gather data on “the ‘soup’ of ions, electrons, and atoms surrounding Jupiter and its moons”.
Professor Geraint Jones, of MSSL and a co-investigator on the PEP instrument, said: “This data will help us, for instance, to understand how particles around Jupiter reach such high energies – energies that could be fatal for an astronaut.
