GeoLog

National American Space Agency

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

Union-wide events at EGU 2018

Union-wide events at EGU 2018

Wondering what to expect at the General Assembly this year? Here are some of the highlights:

Union Symposia (US)

For events which will have general appeal, regardless of your field of research, look no further than the Union Symposia. The very first session, organized in collaboration with the European and American space agencies (ESA and NASA) will highlight observation missions focused on Earth and other planetary bodies, as well as discuss the challenges of organising future missions in an international framework.

Following this session will be Union Symposia 1: Past achievements and future challenges for the Geosciences, co-sponsored by the American Geophysical Union. The Union Symposia on Wednesday will reflect on the fifty years of international ocean drilling. Thursday’s session will then feature reports on the Cassini mission and future perspectives for the exploration of the outer solar system.

And finally, Union Symposia 5 on Friday will cover Scientific research in a changing European Union: where we stand and what we aim for. Panelists will explore some of the challenges and potential threats to academics in the EU and how these issues can be addressed and overcome. The session will also outline some of the advantages of the EU, funding programmes that are currently provided and how the European Union can continue to develop and nurture its researchers.

Great Debates (GDB)
This year we’re holding four Great Debates! The topics covered this year are varied, from Natural versus anthropogenic threats for life on Earth to Low-risk geo-engineering: are techniques available now? The role of scientists in policy-making is another hot topic on the Great Debate agenda, with one debate dedicated to the subject on whether to be hands on or hands off in the political sphere. Continuing with the success of last year’s Early Career Scientist (ECS) Great Debate, the 2018 General Assembly invites participants to join a round-table discussion where everyone will be given the opportunity to discuss this year’s chosen topic: “Should early career scientists use time developing transferrable skills?” Whether you are in Vienna or elsewhere, be sure to follow and join in the debates using #EGU18GDB on twitter.

Educational & Outreach Symposia (EOS)
Educational and Outreach Symposia are sessions dedicated to all things education and outreach, and include the Geosciences Information for Teachers (GIFT) workshop, a long-running event for high school teachers that helps shorten the time between discovery and textbook.

Medal Lectures and Lectures organized by related scientific societies (ML, LRS)
There will be 3 lectures organized by related scientific societies as well as a grand total of 46 Medal Lectures this year!

Meet EGU (EGU)
Meet EGU does exactly what it says on the tin – these sessions are a great opportunity to get to know your division president and early career representative, put faces to names and find out what’s going on in the Union.

Townhall and Splinter Meetings (TSM)
Townhall Meetings allow participants to take part in a lot of open discussion. This year’s meetings cover a huge variety of topics, from a general discussion of the use of preprints and preprint servers like EarthArXiv, through to a talk on how geoscientists should address urbanisation. Like Townhall Meetings, Splinter Meetings are organised by participants, but they are typically smaller and can be either public or by invitation only.

The EGU General Assembly is taking place in Vienna, Austria from 8 to 13 April. Check out the full session programme on the General Assembly website.

Union-wide events at EGU 2017

Union-wide events at EGU 2017

Wondering what to expect at the General Assembly this year? Here are some of the highlights:

Union Symposia (US)

For events which will have general appeal, regardless of your field of research, look no further than the Union Symposia.  In particular, if you want to stand up for science at a time when (some) politics seems at odds with science, come along to Union Symposia 3, Make Facts Great Again. An impressive panel composed of Christine McEntee (AGU Executive Director), Sir David King (Chief Scientific Adviser to the UK Government 2000–2007), Christiana Figueres (Executive Secretary of the United Nations Framework Convention on Climate Change 2010–2016) and Heike Langenberg (Nature Geoscience Chief Editor) will discuss what can scientists do to further the progress of scientific research and ensure mainstream scientific views are accepted and taken seriously by policymakers and the public.

The very first of the Union Symposia, organized in collaboration with the European and maerica space agencies (ESA and NASA) will highlight Earth observation missions and there will be talks on ESA’s and NASA’s planetary and space programmers. On Wednesday, scientists from different fields will come together to explore the key role plants play in the climate system in Union Symposia 1: Vegetation-climate interactions across time scales Finally, there’s the EGU Awards Ceremony – set to celebrate excellent research and achievement in the Earth, planetary and space sciences.

Great Debates (GDB)
This year we’re holding not one, not two, but six Great Debates! The topics covered this year are varied, from: Arctic environmental change: global opportunities and threats (organized with AGU), through to whether 2 degrees is possible without relying on carbon storage and capture? Scientific publishing is also hot on the Great Debate agenda, with two debates dedicated to the subject, including the very first early career scientist (ECS) specific Great Debate: Should early career scientists be judged by their publication record? A set of group debates.  Discussions also explore the Earth’s deep past (Great Debate on Great Extinctions) and the planet’s future (transition to next generation cities and planet Earth future).  Whether you are in Vienna or elsewhere, be sure to follow and join in the debates using #EGU17GDB on twitter.

Educational & Outreach Symposia (EOS)
Educational and Outreach Symposia are sessions dedicated to all things education and outreach, and include the Geosciences Information for Teachers (GIFT) workshop, a long-running event for high school teachers that helps shorten the time between discovery and textbook.

Medal Lectures and Lectures organized by related scientific societies (ML, LRS)
There will be five Lectures organized by related scientific societies as well as a grand total of 45 Medal Lectures this year!

Meet EGU (EGU)
Meet EGU does exactly what it says on the tin – these sessions are a great opportunity to get to know your division president and early career representative, put faces to names and find out what’s going on in the Union.

Townhall Meetings (TM)
Townhall Meetings allow participants to take part in a lot of open discussion. This year’s meetings cover a huge variety of topics, from a discussion, moderated by ESA’s Director of Earth Observation Programmes, on how space data impacts EGU participants, through to questioning the formalizatin of the “Anthropocene” and how the interconnection between Open Access, Open Data and Free Open Source Software can be improved to develop the Open Science movement.

Splinter Meetings (SPM)
Like Townhall Meetings, Splinter Meetings are organised by participants, but they are typically smaller and can be either public or by invitation only.

The EGU General Assembly is taking place in Vienna, Austria from 23 to 28 April. Check out the full session programme on the General Assembly website.