GeoLog

Space and Planetary Science

NASA’s Juno mission reveals Jupiter’s magnetic field greatly differs from Earth’s

NASA’s Juno mission reveals Jupiter’s magnetic field greatly differs from Earth’s

NASA scientists have revealed surprising new information about Jupiter’s magnetic field from data gathered by their space probe, Juno.

Unlike earth’s magnetic field, which is symmetrical in the North and South Poles, Jupiter’s magnetic field has startlingly different magnetic signatures at the two poles.

The information has been collected as part of the Juno program, NASA’s latest mission to unravel the mysteries of the biggest planet in our solar system. The solar-powered spacecraft is made of three 8.5 metre-long solar panels angled around a central body. The probe (pictured above) cartwheels through space, travelling at speeds up to 250,000 kilometres per hour.

Measurements taken by a magnetometer mounted on the spacecraft have allowed a stunning new insight into the planet’s gigantic magnetic field. They reveal the field lines’ pathways vary greatly from the traditional ‘bar magnet’ magnetic field produced by earth.

Jupiter’s magnetic field is enormous. if magnetic radiation were visible to the naked eye, from earth, Jupiter’s magnetic field would appear bigger than the moon. Credit: NASA/JPL/SwRI

The Earth’s magnetic field is generated by the movement of fluid in its inner core called a dynamo. The dynamo produces a positive radiomagnetic field that comes out of one hemisphere and a symmetrical negative field that goes into the other.

The interior of Jupiter on the other hand, is quite different from Earth’s. The planet is made up almost entirely of hydrogen gas, meaning the whole planet is essentially a ball of moving fluid. The result is a totally unique magnetic picture. While the south pole has a negative magnetic field similar to Earth’s, the northern hemisphere is bizarrely irregular, comprised of a series of positive magnetic anomalies that look nothing like any magnetic field seen before.

“The northern hemisphere has a lot of positive flux in the northern mid latitude. It’s also the site of a lot of anomalies,” explains Juno Deputy Principal Investigator, Jack Connerney, who spoke at a press conference at the EGU General Assembly in April. “There is an extraordinary hemisphere asymmetry to the magnetic field [which] was totally unexpected.”

NASA have produced a video that illustrates the unusual magnetism, with the red spots indicating a positive magnetic field and the blue a negative field:

Before its launch in 2016, Juno was programmed to conduct 34 elliptical ‘science’ orbits, passing 4,200 kilometres above Jupiter’s atmosphere at its closest point. When all the orbits are complete, the spacecraft will undertake a final deorbit phase before impacting into Jupiter in February 2020.

So far Juno has achieved eleven science orbits, and the team analysing the data hope to learn more as it completes more passes. “In the remaining orbits we will get a finer resolution of the magnetic field, which will help us understand the dynamo and how deep the magnetic field forms” explains Scott Bolton, Principal Investigator of the mission.

The researchers’ next steps are to examine the probe’s data after its 16th and 34th passes meaning it will be a few more months before they are able to learn more of Jupiter’s mysterious magnetosphere.

By Keri McNamara, EGU 2018 General Assembly Press Assistant

Further reading

Connerney, J. E. P., Kotsiaros, S., Oliversen, R. J., Espley, J. R., Joergensen, J. L., Joergensen, P. S., et al. A new model of Jupiter’s magnetic field from Juno’s first nine orbits. Geophysical Research Letters, 45, 2590–2596. 2018

Bolton, S. J. et al. Jupiter’s interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft, Science, 356(6340), p. 821 LP-825. 2017

Guillot, T. et al. A suppression of differential rotation in Jupiter’s deep interior, Nature. Macmillan Publishers Limited, part of Springer Nature. All rights reserved., 555, p. 227. 2018

GeoTalk: Matt Taylor of ESA’s Rosetta mission

GeoTalk: Matt Taylor of ESA’s Rosetta mission

In November 2014, space exploration history was made. Millions of kilometres away, orbiting a piece of ice and rock, the European Space Agency’s (ESA) Rosetta mission sent its probe Philae to become the first spacecraft to soft-land on a comet.

rosetta_tweet1

After the tense 7-hour wait that followed the separation from the main orbiter, a tweet confirmed that the little lander had successfully completed the first part of its mission. Following a 10-year journey through space, on the back of the Rosetta spacecraft, Philae had successfully touched down on comet 67P/Churyumov–Gerasimenko.

Tweet_rosetta

The story of Rosetta and Philae will go down in the history books, like others before it, and ignite the imagination of children and adults alike, for whom space is the ultimate frontier.

These great stories of space exploration have inspired the 2016 Geosciences Information For Teachers (GIFT) workshop: The Solar System and Beyond, which took place during the EGU General Assembly in Vienna. The symposium combined presentations on current research by leading scientists with hands-on activities presented by science educators for 80 teachers from 20 different countries.

The keynote lecture was given by Matt Taylor, the Rosetta Project Scientist at ESA, who told the remarkable story of Rosetta and its companion, Philae. I was lucky to catch up with Matt during the conference and we spoke about the GIFT workshop, science fiction, and life after Rosetta (with the mission end now confirmed for September 2016).

 

Matt, thank you for talking to me today. Before we get stuck into details about the Rosetta mission and your time at the conference, could you tell our readers a bit more about your role as project scientist for the mission?

I basically act as a link between the scientific community and ESA. There are many instruments on board Rosetta and Philae, with each of their operations being coordinated by a lead scientist. With such a mix of instruments, all pointing in different directions and with different goals, it’s up to me to coordinate the work of the lead scientists and ensure that we get everything we need to do, done. I try to make sure everyone is happy, or unhappy, as the case may be!

I also provide outreach support for the mission, by giving public lectures and taking part in projects such as the GIFT workshop here at EGU 2016.

The aim of the GIFT workshops is to spread first-hand scientific information to science teachers which they can then use in the classroom to inspire their students and engage them with science. Often, outreach efforts are directed towards the students themselves, so why do you think it is important to inspire teachers about science too?

Matt Taylor speaking at the 2016 General Assembly. Credit: Laura Roberts/EGU

Matt Taylor speaking at the 2016 General Assembly. Credit: Laura Roberts/EGU

It is fundamentally important. Teachers are the ones who really engage school children with a subject. But to do that, it is important to equip them with the right tools, while at the same time trying to engage and inspire them too. That way they can take those tools back to the classroom.

Truth be told, I find it inspiring talking to teachers. After the lecture today I was struck by how motivated and engaged the teachers participating in the GIFT workshop are! One of the teachers, who teaches science at a city school, told me how good it was for them to see science in action [at the conference] and be exposed to STEM subjects.

 

And what is it about space, do you think, that captures so many people’s imagination and is such a great tool to engage the masses with science?

Space has that ‘WOW’ factor. Yet it is also relatable because you can look up and perceive it through the night sky.

Then there is that adventurous aspect to it. It’s the going out there and exploring the unknown. It makes us appreciate we are so tiny and really draws on the idea of ‘where do we come from?’

It is to do with how you package it, and science fiction helps really helps with that. Take the Star Trek films.

And pictures really help. Images allow you to put science ideas across very easily and in a very engaging way – and space gives us a lot of incredible images to work with.

Comet 67P on 14 March 2015 – taken by the NavCam. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Comet 67P on 14 March 2015 – taken by the NavCam. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

There is no doubt that the Rosetta mission caught the attention of the media and public alike! So let’s talk about it a little bit more. What about the mission, would you say is, scientifically speaking, the most exciting?

Comets are the building blocks of life. Studying them has a real connection to the bigger picture stuff: where do we come from, how did the solar system form? For me, the findings of the mission contributing to that has to be the most exciting part.

And on a personal level, what is it like working on the mission and why is it exciting?

It’s, actually, just a normal job.

Day to day the work can be quite boring. A lot of my time is spent coordinating projects, going to meetings… same as anyone else. It’s when I give talks and take part in outreach events such as the ones here at the General Assembly that I am reminded about how cool this mission really is.

Recently, I’ve been excited to work on the final trajectory scenario and deciding how are we going to ‘end’ Rosetta.

Not so cool, are the conspiracy theories and being trolled on twitter, repeatedly, about whether Philae actually ever landed on comet 67P.

You mention the end of Rosetta, what is next for the mission?

The mission will end, operationally, in September. After that we’ll be focusing 100% on the science including ensuring all the data from the mission is in the best format for future scientists. There will be findings coming out of the mission for some time yet! In fact, school students now will be able to work on Rosetta data in graduate school! That’s how important and groundbreaking this mission is.

And once the mission is over, what is next for you?

Chances are I’ll be allocated to another mission, but that will depend on what the science community are pushing for [in terms of new missions] currently and whether my expertise are a good fit.

It’s unlikely I’ll work on something as big as Rosetta again. Funding for space missions is allocated well in advance and there is nothing in the pipe-line on the scale of Rosetta.

But I’m ok with that. I’m actually looking forward to a quieter life. Working on Rosetta has meant letting a few things go by the way side and I’ll now have time to start exercising and looking after my health a little more!

Even though there won’t be another Rosetta, which upcoming missions do you think are ones to watch?

I, personally, don’t think there is anything like Rosetta coming up soon. Rosetta has lots of elements that make it so attractive: the science is exciting, it takes us to the limits of space exploration, it was the first known comet and yet before we got there we had no idea what 67P looked like….

That said there are some exciting missions coming up: JUICE – JUpiter ICy moons Explorer – which is headed to Jupiter in 2022 and will study the gas giant and three of its icy moons. It gets there in

Matt is a self-confessed metal head. Credit: Matt Taylor

Matt is a self-confessed metal head. Credit: Matt Taylor

2030 – the year I’m due to retire!

I’ll also be keeping my eye on BepiColombo, ESA’s first mission to Mercury, and the Solar Orbiter, which will make the closest approach, ever, to the Sun and study solar wind.

I thought we could finish the interview on a light note. In the past I’ve asked scientists I’ve interviewed to come up with a brand new chemical element. If you could invent an element, what would it be and what would it do?

It would have to be Limenium – after Lemmy, frontman of the rock band Motörhead. It would allow you to exude rock & roll!

[As well as being a physicist, Matt is a self-confessed metal head, so much so he was recently awarded the Spirit of the Hammer of the Golden Gods].

 

Interview by Laura Roberts Artal, EGU Communications Officer

 

Further reading:

  • The Rosetta Blog: For all the science prior to and after the comet landing.
  • Find out more about the Rosetta mission: http://rosetta.esa.int/
  • DLR, the German space agency, played a major role in building the Philae lander and runs the lander control centre.
  • The Philae Blog: to recap exciting moments of the little lander’s mission.
  • Ambition, the film: a short science fiction film that tells the story of comet-chasing spacecraft Rosetta

Mars Rocks – introducing a citizen science project

Mars Rocks – introducing a citizen science project

GeoLog followers will remember our previous report on Citizen Geoscience: the exciting possibilities it presents for the acquisition of data, whilst cautioning against the exploitation of volunteered labour. This blog presents a Citizen Science platform that goes beyond data collection to analysis, specifically for geological changes in remote sensing imagery of Mars. Jessica Wardlaw, a Postdoctoral Research Associate in Web GIS, at the Nottingham Geospatial Institute, introduces ‘iMars’ and explains 1) its scientific mission and 2) why imagery analysis is especially suitable for a crowd sourcing approach, so that you might consider where and how to apply it to your project.

Imagine, just for a moment, that the Mars Geological Survey invited you to an interview for the position of Scientist in Charge. Why and how would you reconstruct the geological past for a remote planet such as Mars? Where would you start? Earth is the “Goldilocks” planet, not only for human habitation but for geologists too, who can sample and test rock to understand the evolution of the Earth’s surface on which to base well-established theories such as plate tectonics. To understand the geological past and processes of remote planets, however, requires different approaches.

Planetary scientists investigate the climate and atmosphere, and the geological terrain, of planets to further understanding of our own place in the solar system. Mars provides a scintillating snapshot of early Earth; whilst some scientists contend that plate tectonics has historically happened on Mars, 70% of its surface dates from the moment it formed and provides a platform from which to view Earth in its infancy. In fact, despite our limited knowledge of Mars, it has already informed our understanding of Earth, inspiring James Lovelock’s Gaia theory. Imminent missions to the red planet are also already exploiting geological information to inform landing sites and routes of roving vehicles on Mars. The more information scientists have, the more likely missions are to land in suitable locations to successfully pursue scientific goals, such as understanding the ability of the Martian environment to support life and water, both now and in the past, which could further theories on the origins of the solar system, life on Earth, and Earth’s destiny.

Many will remember this summer for the astonishing images that arrived from Pluto, but 50 years ago, almost to the day, people celebrated the first successful fly-by mission to Mars. Mariner 4 took 21 images from a distance 6,000 miles, which, after the initial excitement, disappointingly revealed that Mars had a Moon-like cratered surface, and led to a long-held misconception of a dead, red planet. It was in 1976 that two Viking landers touched down on the red soil for the first time, paving the way for further Martian missions, with the first mission of the European Space Agency’s ExoMars programme launching next year.

The first Mars photograph and our first close-up of another planet. A representation of digital data radioed by the Mariner 4 spacecraft on 15th July 1965. (Credit: NASA/JPL-Caltech/Dan Goods)

The first Mars photograph and our first close-up of another planet. A representation of digital data radioed by the Mariner 4 spacecraft on 15th July 1965. (Credit: NASA/JPL-Caltech/Dan Goods)

Scientists analyse the size and density of craters from meteorite impacts to age the surface. The theory goes that smaller meteorites collide with a planet much more frequently than larger ones, and older surfaces have more craters because they have been exposed for longer. Advances in imaging technology since then now provide scientists with greater granularity than ever before and glimpses of other geologic features, recognisable from the surface of the Earth; sand dunes, dust devils, debris avalanches, gullies, canyons all appear and tell us about the planet’s climatic processes. The Planet Four website is just one example.

The images taken of Mars over the last forty years reveal changes on the surface that indicate invaluable information that help us to understand the climate and geology of the planet. Changes are visible in imagery over a variety of timescales, from rapidly-moving dust devils (much bigger that the one that once trapped me in Death Valley), seasonal fluctuations of the polar ice caps and recurring slope lineae (recently reported to indicate contemporary water activity) polar ice caps and the snail-slow shaping of sand dunes.

Three images of the same location taken at different times over one Martian year show how the seasonal fluctuation of the polar cap of condensed carbon dioxide (dry ice), between its solid and gaseous state, destabilises a Martian dune at high altitude to cause sand avalanches and ripple changes. (Credit: NASA/JPL/University of Arizona)

Three images of the same location taken at different times over one Martian year show how the seasonal fluctuation of the polar cap of condensed carbon dioxide (dry ice), between its solid and gaseous state, destabilises a Martian dune at high altitude to cause sand avalanches and ripple changes. (Credit: NASA/JPL/University of Arizona)

The quality and coverage of these images, however, varies greatly due to atmospheric conditions and tilt of the camera amongst other reasons. To create a consistent album of imagery, that we can confidently compare and use to identify geological changes in the images, requires considerable computational work. Images from across as much of the Martian surface as possible must be processed to remove those of poor quality and correct for different coordinate systems (co-registration) and terrain (ortho-rectification).

The iMars project is applying the latest Big Data mining techniques to over 400,000 images, so that they can be used to compute and classify changes in geological features. On a Citizen Science platform, Mars in Motion, volunteers will define the nature and scale of changes in surface features from ortho-rectified and co-registered images to a much greater detail. Human performance is inherently variable in ways we cannot fully control, either, in the same way that we can control the performance of an algorithm. Although we are investigating this too, this would require another blog post! For now I will describe the reasons why we are using a crowd-sourcing approach for this project so that you might consider how you could apply it to your research.

First of all, humans have evolved over millions of years to identify subtle variations in visual patterns to a more sophisticated level than computers currently can. Computers can execute repetitive tasks and store an infinite amount of information with far less impact on their performance than humans; the human mind, however, has proved to be too flexible and creative for computers to fully replicate, with the success of Citizen Science projects such as Galaxy Zoo, which has so far resulted in 48 academic publications. The slow seasonal shift of sand dunes on Mars, for example, would require a computer algorithm of inordinate intelligence to identify, as previous attempts to automatically detect impact craters, valley networks and sand dunes in images of Mars have found. Recent research has resulted in some very sophisticated algorithms for image analysis, but detection of changes in such a range of geological features over the range of spatial and temporal scales that we are looking to do is computationally complex and expensive. Without sending somebody to Mars, how do we know whether the computer is correct? Machine learning algorithms can only calculate what you ask them to, so are ill-equipped to make the sort of serendipitous discoveries of the unknown required in the detection of change. Volunteers in the Mars in Motion project will seek differences (Figure 4), rather than similarities, between the images and it is inherently challenging to program a computer to find something that you don’t even know to look for.

Mars in Motion: Spot the difference...on the surface of Mars!

Mars in Motion: Spot the difference…on the surface of Mars!

Secondly, we have so much data that scientists could not possibly do all of this themselves! In many areas of science and humanities, but especially in Earth and Planetary observation, Big Data capture is growing at an astronomical rate, far faster than resources and techniques for its analysis can keep up so that we are increasingly unable to handle it. This is where geoscientists have started to join the trend for recruiting volunteers to analyse imagery with some success; through large crowd-sourcing image analysis projects, like TomNod, citizens continually contribute interpretation of images for social and scientific purposes. The number of volunteers, however, is finite and the increase in data places more and more demand upon their time. Researchers using the Citizen Science approach must now carefully consider how their projects can utilise volunteers’ time effectively, efficiently and ethically.

Third and finally, a crowd-sourcing approach exposes the public to improvements in imaging technology and brings the dynamic nature of the Martian surface to life. This can only improve the chances of space exploration receiving further funding and entering classrooms through the way it combines many areas of Science, Technology, Engineering and Mathematics. Serendipitously, the engagement of the public also increases the number of pairs of eyes that analyse the images and, as such, the confidence with which scientists can use their classifications. As we collect more and more data, image analysis will necessarily require collaboration between humans and computers, as well as between volunteers and researchers, to manage it.

I hope this post gives you an insight into how we are applying the Citizen Science to consider how it might help your research too. There is actually no better time to try setting up a Citizen Science project with the launch of the Zooniverse project builder, which makes it easier than ever before to build your own project.

By Jessica Wardlaw, researcher at the University of Nottingham

The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under the iMars grant agreement no. 607379.

Visit www.i-mars.eu and follow @JessWardlaw for updates on iMars and Mars in Motion.