Celestial Magnetic Ropes

NASA satellites have uncovered giant 'magnetic ropes' linking the Earth's atmosphere to the Sun. These channel solar energy to create the spectacular northern and southern lights.

"The satellites have found evidence of magnetic ropes connecting Earth's upper atmosphere directly to the Sun," said David Sibeck, project scientist at NASA's Goddard Space Flight centre in Maryland.

"We believe that solar wind particles flow in along these ropes, providing energy for geomagnetic storms and auroras," he told the annual meeting of the American Geophysical Union in San Francisco.

Enormous burst of energy
The discovery is among a series of revelations made by the U.S. space agency's Time History of Events and Macroscale Interactions during Substorms mission (THEMIS) launched earlier this year.

A 'magnetic rope' is a twisted bundle of magnetic fields much like a rope made of hemp, and although previous spacecraft have seen glimpses of them, none had been able to map their structure. But the THEMIS's five identical micro-satellites could.

THEMIS encountered its first magnetic rope on May 20. It was very large, about as wide as Earth, and located approximately 65,000 km above Earth's surface in a region called the magnetopause.

This is the region where solar wind hurtles into the Earth's magnetic fields, and magnetic ropes are formed and unfurled in just a few minutes allowing solar wind to be briefly conducted along them.

This enormous burst of energy helps explain the phenomenon of aurora borealis (and its southern hemisphere equivalent, the aurora australis) also known as substorms, said Sibeck.

A substorm, which erupted over Alaska and Canada on March 23, provided a stunning show of auroras for more than two hours. They were photographed from below while satellites measured the particles and fields above, and showed a series of 10-minute outbursts.

Speedy substorms
The mission's principal investigator Vassilis Angelopoulos said the storm behaved very unexpectedly. "The auroras surged westward twice as fast as anyone thought possible, crossing 15 degrees of longitude in less than one minute… The storm traversed an entire polar time zone, or 400 miles, in 60 seconds flat."

The total energy required for such a two-hour show was about five hundred thousand billion Joules, or the equivalent of a 5.5 magnitude earthquake, Angelopoulos said.

The THEMIS mission also witnessed small explosions on the outskirts of the Earth's magnetic field in an area known as the bow shock.

"The bow shock is like the bow wave in front of a boat," said Sibeck. "It is where the solar wind first feels the effects of Earth's magnetic field. Sometimes a burst of electrical current within the solar wind will hit the bow shock and 'Bang!' we get an explosion."

THEMIS is a two-year mission being coordinated by the University of Berkeley in California, with several countries contributing.

Every four days the five THEMIS satellites line up along the Earth's magnetic field to follow disturbances in the magnetopause region. This allows the storms to be observed from five different angles simultaneously, helping scientists to learn about the origins of the storms and their evolutions.
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Saturn Ringed by Electric Doughnut by Dave Mosher @ LiveScience
Part of Milky Way rotates in Opposite direction - from SPACEcom
Ultra High Energy Cosmic Rays by Charles Daney @ Science & Reason
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Space Tsunami

The image to the left is the typical appearance of the aurora before a magnetic substorm. During a substorm, the single auroral ribbon may split into several ribbons (centre) or even break into clusters that race north and south (right). Credits: Jan Curtis

Cluster provides new insights into the working of a ‘space tsunami’ that plays a role in disrupting the calm and beautiful aurora, or northern lights, creating patterns of auroral dances in the sky.

Generally seen in high-latitude regions such as Scandinavia or Canada, aurorae are colourful curtains of light that appear in the sky. Caused by the interaction of high-energy particles brought by the solar wind with Earth’s magnetic field, they appear in many different shapes.

Early in the evening, the aurora often forms a motionless green arc that stretches across the sky in the east-west direction. Colourful dancing auroral forms are the results of disturbances known as ‘substorms’ taking place in Earth’s magnetosphere.

These perturbations can affect our daily lives, in particular by affecting the reception of GPS signals. Thus, understanding the physical processes involved is important to our routine life and security.
[+/-] Click here to expand

These substorms typically last one to two hours and are three-dimensional physical phenomena spread over altitudes from 100 to 150 000 kilometres.

Currently, there are two competing theoretical models to describe these substorms or space tsunamis. The first one is called the ‘Current-Disruption’ model, while the second one is the ‘Near Earth Neutral Line Model’. Using data from the four Cluster spacecraft, a group of scientists from both sides of the Atlantic were able to confirm that the behaviour of some substorms is consistent with the Current Disruption model.

In the late stage of substorm development, auroral disturbances move towards the poles, suggesting that the energy source for auroras and substorms moves away from Earth.

Previous satellite observations have found that, during this late stage, the flows of plasma (a gas of charged particles populating Earth’s magnetosphere) in the magnetotail exhibit a reversal in direction. In recent years it was generally thought that a flow reversal region is where magnetic reconnection takes place, that is where the energy of the magnetic field is converted into particle energy (dissipation effect), resulting in high-speed plasma flows that hurl towards Earth, like space tsunamis.

By comparing the directions of the electric current and the electric field in the magnetosphere it is possible to understand whether the cause of the flow reversal is a dissipation effect (where magnetic field energy converted to particle energy) or a dynamo effect (where particle energy is converted to magnetic field energy). For this case study, the Cluster scientists observed that features associated with flow reversal are actually very complex, consisting of both dissipation and dynamo effects in localised sites.

Read more: Cluster sees tsunamis in space from ESA

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ESA invites proposals

ESA's Aurora Space Exploration Programme invites proposals for the Next Exploration Science and Technology (NEXT) mission.

The Aurora Programme is composed of two main elements: a Core Programme, which aims to establish the ability of Europe to participate as a recognised partner in future international space exploration endeavours, and an Exploration Robotic Missions component with a first mission, ExoMars, which is now being implemented for launch in 2013.

As an intermediate step, after ExoMars and before the international context will allow the initiation of a Mars Sample Return (MSR) mission, the Executive considers proposing to the next Ministerial Council an 'ExoMars class' mission.

Envisaged for launch in the period 2015-2018, the technological goal of NEXT is to demonstrate key enabling capabilities, such as descent and precision landing, as needed for a future Mars Sample Return mission.


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To this end the Core Programme has initiated an MSR Phase A2 System Study, building on the results of two previous Phase A1 studies. In this frame Entry, Descent and Soft/Precision Landing on the one hand, and Autonomous Rendezvous and Docking/Capture on the other, were identified as key elements of interest for Europe.

Such a mission would demonstrate in particular key MSR technologies and achieve a step change in the European capabilities over and above present possible contributions to the MSR mission, whilst also providing an opportunity for scientific investigations. Ideas that would include aspects relevant to the human exploration scenario are welcome.

NEXT exploration mission - call for ideas
Proposals and suggestions are sought from Industry, Technical Centres and the Scientific Community for mission concepts that would combine, in the spirit of exploration, technology development with first class science.

Ideas should be submitted electronically to:
explorationcall@esa.int not later than 13 April 2007.
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Solar Sail Mission to an Asteroid by Centauri Dreams
Solar Power at Play - Observing the Spin-Up of an Asteroid ESO
Sensor Being Developed To Check For Life On Mars from Science Daily
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Polar Lights

In an old television tube (not the recent LCD or plasma TV screens), accelerated electrons hit a phosphorescent screen and cause the phosphor to glow. The acceleration region generating the aurora works similarly.

Electrons in the atmosphere get accelerated in an 'acceleration region' between about 5000 and 8000 kilometres altitude, and rush down to the Earth's ionosphere – a region of the upper atmosphere. They finally crash into ionospheric atoms and molecules, transferring to them some of the energy and cause them to glow, creating aurorae.

Giant electrical circuits power the magical open-air light show of the auroras, forming arcs in high-latitude regions like Scandinavia. New results obtained thanks to ESA's Cluster satellites provide a new insight into the source of the difference between the two types of electrical circuits currently known to be associated to the auroral arcs.



Auroras form in high latitude regions of Earth, and appear in many different shapes.

The aurora in the early evening sky forms a green arc that stretches across the sky in an east-west direction. The longitudinal extent (length) of an auroral arc can be as large as several thousands kilometres, but its width can be as small as 100 metres.
The deep mechanisms that rule the creation of such beutiful natural light displays (also called polar lights), have been the subject of studies that have been keeping solar and plasma scientists busy for years, with more to come. While early rockets and ground-observations have already provided a few important clues for the understanding of these phenomena, the real break-throughs in our knowledge have started with dedicated auroral satellites, such as S3-3, Dynamics Explorer, Viking, Freja and FAST, and have now come to full fruition with ESA's multi-point mission Cluster.

Photo Credits: Jan Curtis, Fairbanks, Alaska



Artistic view of electrons, responsible for aurora, spiralling down magnetic field lines. The U-shaped potential structure illustrates the region where electrons get accelerated on their way down to the upper atmosphere. Here they are stopped by collisions with neutral atoms and molecules, primarily oxygen and nitrogen, at altitudes of a few hundreds kilometres down to 80 kilometres. Each collision transfers part of the electron energy to these atmospheric particles. In turn, they get rid of this energy excess by emitting visible emissions in specific wavelength (or colours) such as green (oxygen) or purple (nitrogen).

It has been observed that these electric potential structures are mainly of two types - symmetric (U-shaped) or asymmetric (S-shaped), and typically occur at the boundaries between magnetospheric regions with different properties.

The former type (U-shaped) was found at a plasma boundary between the so-called ‘central plasma sheet’, situated in the magnetotail at equatorial latitudes, and the ‘plasma sheet boundary layer’, an adjacent area located at higher latitudes. The latter type (S-shaped) was found at the boundary between the ‘plasma sheet boundary layer’ and the polar cap, further up in latitude.

Image Credits: ESA
Read more Cluster – new insights into the electric circuits of polar lights
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Auroras: Paintings in the sky from Exploratorium
Looking at exoplanet atmospheres from Centauri Dreams
Magnetic Explosions In The Distant Universe from Science Daily
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ESA - Earth to Mars

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Consultations were hosted by the European Space Agency (ESA) and the British National Space Centre (BNSC) in Edinburgh 8/9th January 2007.

Representatives from the UK and other European political, industrial and scientific sectors, together with members of the general public, the various stakeholder groups in Europe with colleagues from across the world, debated the future long-term exploration of the solar system and beyond.

The UK has a vibrant space science and industrial community that already makes a significant contribution to our knowledge economy. Its experience in developing innovative space technology will continue to ensure the UK plays a leading role in both European and global space exploration in the future.

MoonLITE Credit: SSTL
MoonLITE equipped with missile-shaped penetrators carrying seismometers to investigate the lunar interior and a telecommunications capability to demonstrate high data rate telecoms at the Moon.



Moonraker Credit: SSTL
MoonRaker, a small propulsive Lander to provide in-situ geological dating.
These mission options exemplify the UK's expertise in small satellites, robotics and miniaturised instruments and MoonLITE's telecoms capability could provide a vital contribution to NASA's ambition of establishing a Moon base by 2020.

The UK is already the second largest European contributor to ESA's Aurora programme of planetary exploration and is currently involved in developing an ambitious Mars Rover project that will fly onboard Europe's ExoMars mission to the Red Planet slated for launch in 2013.


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ESA's Aurora Mission

From the dawn of humankind the need to explore has driven expansion across our planet. Today this expansion continues towards other planets in the solar system by means of robotic spacecraft - virtual explorers. But will human expansion continue? In the public consciousness this is only a matter of time. By 2025 an international human mission to Mars may be a reality. It may use the Moon as a way station and to prepare for the great leap. The feasibility of such a mission is being assessed, however, the necessary technology and capability still need to be developed.

Over the next 20 years robotic missions will prepare for human missions, by collecting as much scientific and engineering data as possible, without human scientists in situ. These robotic missions will contribute and demonstrate the technologies needed to put humans on Mars and return them safely to our planet.

Some of the key technologies for a human mission are also very important to the search for life in situ on the red planet and on other solar systems, planets and moons. Soft and precision landing, drilling and sample return, will not just be demonstrated for the sake of technology. These missions will carry sophisticated exobiology payloads and provide answers to some key questions on the origin of life in the solar system and possible causes for its extinction.

A challenging and complex return mission to collect a sample on Mars might also involve our first attempt at interplanetary exploitation. Instead of lugging propellant for the return trip all the way from Earth, the lander systems could include technology that would generate rocket fuel from Martian resources.

Ultimately, though, Mars exploration plans should result in an even greater adventure - a human mission. Astronauts are vastly more capable than even the smartest robot, but they are also vastly more difficult and expensive to transport. Unlike robots, they eat and breath; and if their environment is too uncomfortable, they can become tetchy and depressed. For a human Mars expedition to be possible, new technologies will have to be developed and tested: not only soft-landing methods and in-situ fuel processing, but life-support engineering for a long haul far from home and perhaps entirely new rocket systems, possibly based on new types of propulsion, which will reduce the time spent coasting through space.

By 2025 A human Mars mission, perhaps with the Moon as a first target or even as a way station to the Red Planet, would represent the culmination of the programme's efforts. And just incidentally, it would also guarantee that there was life on Mars: human life.

Read more European workshop on space exploration from ESA
Europe forges long-term strategy for Space Exploration by PPARC
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ESA's Aurora

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Credits: ESA - P.Carril

ESA's Aurora Programme aims to prepare Europe to play a key role in the future human exploration of Mars and in the exploration of the solar system.

ESA polls governments & stakeholders on long-term exploration strategy
On 8 and 9 January, in the historic city of Edinburgh, ESA and BNSC are to hold a workshop to kick off the first in a series of consultations with key stakeholders. The aim is to define European long-term strategy for space exploration and set the scene for the decisions to be taken at the ESA Council meeting at ministerial level scheduled for 2008.

ESA has been working on the Aurora programme as a framework for space exploration for several years, and aims to make space exploration a global and societal project. It would be global insofar as it would rally, in a coordinated manner, as many nations as possible behind space exploration goals and objectives whose value and benefits would be there for the whole of humankind. It would be societal in that the European drivers and priorities would be defined following consultation with, and the commitment of, four stakeholder communities: scientific; political and institutional; industrial and innovation-related; and the general public and youth.

Representatives of these four groups, from all around Europe and worldwide, will gather in Edinburgh. They will be given a presentation of the current and future ESA plans and discuss a compelling rationale for Europe to play a significant role in the global space exploration endeavour.

Further to NASA's unveiling of its lunar exploration architecture on 4 December, ESA will define a broader scenario that will include the Moon as an important exploration target and an unavoidable stepping-stone for the human exploration of further destinations. European space exploration architectures will be derived from these scenarios, taking into account the industrial, scientific and societal interests expressed by the stakeholders in consultations like the one in Edinburgh.

Based on these architectures and driven by the main European priorities, ESA will be participating with other international partners in this decades-long undertaking of robotic and human exploration of the Solar System.

The outcomes will be presented to the Media on Wednesday 1oth at
the Franklin Theatre Institute of Physics, 76 Portland Place, London.
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3D simulated Map of Dark Matter [+/-] Click here to expand

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Credits: NASA, ESA and R. Massey (California Institute of Technology)

This three-dimensional map offers a first look at the web-like large-scale distribution of dark matter, an invisible form of matter that accounts for most of the Universe’s mass, as mapped with Hubble Space Telescope’s largest ever survey of the Universe, the Cosmic Evolution Survey (“COSMOS”).

Read more First 3D map of the Universe’s dark matter - 07 January 2007

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Famous Quotes: You must be the change
you wish to see in the world. Mohandas Gandhi
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