We’re off the moons of Jupiter…in 2022

I’ve been waiting a long time for this and I’m pretty sure all planetary scientists have been waiting a long time for this too. It’s regarded as the most important destination(s) in the solar system. That’s right, we’re finally off to the moons of Jupiter. Well we will be in 2022 anyway.

After a brief competition with two other space mission proposals JUICE (JUpiter ICy moons Explorer) will head off to Jupiter in 2022 and arrive in 2030 and spent a minimum of 3 years studying Jupiter’s moons. And it’s a European mission too!

JUICE and the Jupiter System

Why the moons of Jupiter? Well, the moons here are exceedingly interesting. Io, first of all, is the most volcanic object in the solar system (although Io won’t be studied much with this mission). The other 3 main moons are the really exciting ones though. Callisto is a fairly large moon and its surface is incredibly old, peppered with craters. It’s holding clues as to the formation of the Jupiter system some 4.5 billion years ago. Europa, the most famous of the moons, has a liquid ocean beneath it’s icy surface, and a very bizarre looking surface. Could there be life in the ocean? It’s a distinct possibility. The mission is mainly focusing on Ganymede though, the largest moon in the solar system, so large it’s bigger than Mercury! It generates it’s own magnetic field. How? Through a salty sub-surface ocean or a molten iron core?

Ganymede

The spacecraft itself looks quite interesting too. It’s going to be operating at the limits of what’s possible. It’ll be using solar power where there isn’t much solar power. Previous missions have used nuclear generators which are far more efficient this far out, but there’s a shortage of the plutonium required for such endeavours at the moment. We’re likely to get an advancement in solar power technology through the efforts of this mission though.

In my opinion NASA have really mucked up. With all their budget cuts they’re not planning a mission to launch to study Jupiter’s moons until well into the 2030’s despite having been told it is the utmost priority of planetary science at the moment. There’s a possibility they’ll add some hardware to the JUICE mission, but we’ll have to really wait and see. What we’d like to see is a Europa lander and ocean explorer (as outlined in NASA’s JIMO mission, now cancelled).

There’s one certainty though, we’re going to find out some truly exciting stuff and we’re going to be surprised with what we find!


Related articles

Advertisements

Smooth Moves at 17,500mph

This is a beautiful image of ATV-3 ‘Edoardo Arnaldi’ docking at the International Space Station the other day. You can see the green haze of the atmosphere, the great stars of the galaxy and the bright lights of ATV-3. I think this will be my new desktop wallpaper!

ATV-3 Docking at the ISS

ATV-3 is the third ‘Automated Transfer Vehicle‘, an unmanned supply capsule, created by the European Space Agency, used to deliver food, water, clothes and experiments to the space station. It holds a lot more than the more regular Russian Progress resupply ships. After a few months docked to the station the astronauts will fill it with rubbish and it will burn up in the atmosphere.

Book Review: My Life on Mars

My Life on Mars: The Beagle 2 Diaries - Click image to be redirected to Amazon

My Life on Mars: The Beagle 2 Diaries by Prof Colin Pillinger.

First of all, please bear in mind that it has taken me quite a while to read this book – I’ve been rather busy over the last few months with OU studies and so on.

I was 13 on Christmas Day 2003, when Beagle 2 was due to land on Mars. I had got up extra early to pop and the news and see what had happened. It wasn’t good news.

Since then though I have always been astonished that we actually sent a mission to land on Mars, we the British people had made a lander to look for the signs of life on another world. I needed to know how it was done – finally Colin’s book came out.

It’s quite an intense book, there’s a lot of information, a lot of names to follow. I found at times that this made it slightly difficult to read, having to head back a few pages to figure out which person was being discussed now. I understand that in a project as grand as this a lot of people are involved, and at the end of the day the story needs to be told.

In this book we learn about Colin’s family history, his youth, how he became interested in science and eventually how he sent a lander to Mars. I had no idea how difficult it could be. The meetings, the letters, the phone calls, the arguments. I was very surprised about the European Space Agency, this book has changed my opinion of them, and not in a good way. Infact near the end I quite liked this quote regarding ESA ‘The way things are going the Universe will end before ESA arrives on Mars’, this referring to their Aurora programme.

If you’re interested in space exploration and want to understand how a space mission works and is put together this is a must read. It had me laughing and gasping in shock, you’ll enjoy it.

It’s 4 out of 5 from me!

Next book – The God Delusion by Prof Richard Dawkins (finally!)

Water: Where did it come from?

I haven’t done a proper science post for a while and I’m sorry for that. I saw a news story pop up on Twitter from the ESA Science Team (@esascience) about the origin of Earth’s water. Just where did it come from?

This is an area that really interests me, in fact I get rather too excited about it. We had a long and detailed question on it pop up in S283 (an OU planetary science course) and I thoroughly enjoyed researching and developing my answer. I leapt at this chance to discuss it further.

The origin of Earth's water?

The origin of Earth’s water?

It’s pretty obvious surely? Comets right? They’re mainly composed of water ice, we know the planets were pummeled by them in the late heavy bombardment about 4 billion years ago, its got to be them hasn’t it?

There has been no way to test this hypothesis until very recently. You need to send a spacecraft to a comet to test it – a very expensive but totally worthwhile test.

Now we’ve finally managed to study 4 comets in detail and the results are interesting. What we need to study is what’s called the deuterium/hydrogen isotope ratio. Deuterium is just basically a slightly heavier version of hydrogen, it has an extra neutron (technically not an extra one because hydrogen doesn’t have any neutrons).

If comets are the origin of the Earth’s water we’d expect there to be a very similar ratio of hydrogen and deuterium to the ratio of these isotopes in ocean water. From the comets that have been studied it turns out that this probably isn’t the case. Comets appear to have twice as much deuterium than ocean water, meaning that comets are an unlikely cause for our waters origins. As we’ve said already though, only a few comets have been analysed in detail. They might not be representative of all comets.

Another theory states that water-bearing grains are responsible. The distance from the Sun at which the Earth formed though casts doubt on this. It would have been so warm that water couldn’t have existed here. Not if they were incorporated within hydrated minerals though. As the planet formed (and after) these hydrated minerals would, over time, degas out into the atmosphere via volcanic eruptions. Eventually, enough was degassed  to form today’s oceans. This has been held as the most plausible explanation.

A spanner seems to have been thrown in the works though, the debate has been reignited. The Herschel infrared space observatory has been looking at comet Hartley 2 and has found that its deuterium/hydrogen ratio is pretty much exactly the same as Earth’s oceans. This comet is suspected to originally have been a trans-Neptunian object flung into the inner solar system have a gravitational tug of war. These comets, forming under different conditions to those that formed between Jupiter and Saturn, probably have slightly different compositions, specifically the deuterium/hydrogen ratio.

A recent study shows that there was likely a 5th giant planet in the solar system, but after gravitational encounters with other planets was flung out of the solar system, stirring up all the trans-Neptunian comets on its way. Is this the reason for the late heavy bombardment? It lends weight to comets being the origin of Earth’s water.

I’m still sceptical though. This is only one comet. We’re going to need to study many, many more before we reach a definitive conclusion. From what I’ve studied, hydrated minerals seem to fit best with the available evidence, but as more comes in I’m willing to change my mind.

The report from the ESA science can be read here
The report on a possible 5th giant/ice giant can be read here