Solar Activity Teamwork: IBEX and TWINS Observe a Solar Storm

The highly elliptical orbit of TWINS offers a good view of the ring current - a hula hoop of charged particles that encircles Earth.

Credit: J. Goldstein/SWRI.

On April 5, 2010, the sun spewed a two million-mile-per-hour stream of charged particles toward the invisible magnetic fields surrounding Earth, known as the magnetosphere.

As the particles interacted with the magnetic fields, the incoming stream of energy caused stormy conditions near Earth.

Some scientists believe that it was this solar storm that interfered with commands to a communications satellite, Galaxy-15, which subsequently foundered and drifted, taking almost a year to return to its station.

To better understand how to protect satellites from intense bursts of energy from the sun, scientists study the full chain of space weather events from first eruptions on the sun to how the magnetic fields around Earth compress and change shape in response.

During the April 5 storm, two NASA Heliophysics System Observatory missions - the Interstellar Boundary Explorer (IBEX) and two spacecraft called the Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) - were perfectly positioned to view the storm from complementary viewpoints.

The three sets of instruments have been used together to paint a more complete picture of what happens during a solar storm, from initial impact of solar energy through to the particles that ultimately slide down into Earth's atmosphere near the poles.

These results were published online on March 27, 2012 in the Journal of Geophysical Research.

"One spacecraft can only take recurring measurements along its own flight path," says Natalia Buzulukova, one of the authors on this paper and a geospace scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. and at the University of Maryland in College Park.

"But this is not always enough to understand the whole event. With several spacecraft at once we have a unique opportunity to observe more of the magnetosphere simultaneously."

The two TWINS spacecraft and IBEX orbit Earth in very different paths. TWINS travels along a highly elliptical orbit around Earth through the magnetosphere. IBEX, too, circles Earth, but generally lies outside the magnetosphere allowing it to map the very edges of the solar system.

Together, they offer glimpses from the inside and outside of the magnetosphere, including the side that faces the sun, the side that extends long away from the sun - the magnetotail - and an electric current that sometimes appears around Earth like a giant hula hoop called the ring current.

"This imaging gives us a better global picture of the evolution of the magnetosphere - especially of the processes by which the sun injects energy into the magnetosphere - than has ever been available before," says David McComas, a space scientist at Southwest Research Institute in San Antonio, Texas, who is first author on this paper and also the principal investigator for the IBEX and TWINS missions.

IBEX and TWINS both have instruments to study what's called energetic neutral atoms or ENAs. These fast moving particles are produced during particle collisions between charged and neutral particles.

Crucially, they move in a straight line from their point of origin, unmolested by the magnetic fields that would constrain charged particles in their travels. Thus they can provide an "image" to decode and map out the structure of a far away charged particle system, such as occurs in the magnetosphere and ring current.

The ENA images from IBEX were taken from a distance of around 180,000 miles above the magnetosphere. They show that the magnetosphere immediately compressed under the impact of the charged particles from the solar wind.

Minutes later, one of the TWINS spacecraft observed changes in the inner magnetosphere from a much-closer 28,000 miles: the ring current began to trap incoming charged particles.

About 15 minutes after impact, these trapped particles gyrated down magnetic field lines into Earth's atmosphere, a process known as "precipitation."

The time delay between the onset of trapped particles and losing them to the atmosphere points to a fairly slow set of internal processes carrying the region from storm impact through compression to precipitation.

"The solar storm directly causes the ring current activity, but the other effects, including particles precipitating down toward the atmosphere, are triggered by something called a substorm, a process that releases energy form the magnetotail," says Buzulukova.

"These two triggers have different physics and different manifestations. This analysis opens the door to understanding how these different effects are connected."

The paper also paves the way to more sophisticated modeling techniques of the entire magnetosphere. To produce the new images, the team developed a series of techniques to process the imaging data, including improved procedures for differential background subtraction, "statistical smoothing" of images, and comprehensive modeling of the ring current.

"Understanding how solar events develop and impact satellites is like understanding the processes that cause extreme weather events on Earth to develop and destroy homes and businesses," says McComas.

"Engineers use weather data to know where and how they need to strengthen buildings against various types of weather threats. The more we know about the processes occurring in space, the better engineers can design satellites to protect them from space weather hazards, which is increasingly important in our highly technological world."

Solar Eruptions Cause Sunquakes

A study led by UCL's Mullard Space Science Laboratory has shown for the first time that sunquakes can be produced during eruptions of magnetic field and charged particles, as the immense magnetic structure blasts off into the Solar System. 

The results were presented by Dr Sergei Zharkov at the National Astronomy Meeting 2012 in Manchester on Friday 30th March 2012.

The first observation of a sunquake was reported by Kosovichev and Zharkova in the late 1990s. During the last decade it has become well established that explosions in the Sun's atmosphere, known as solar flares, can create sunquakes through the impact of powerful beams of particles which travel into the Sun.

This new study shows that eruptions of material known as coronal mass ejections are also able to produce sunquakes.

The authors studied an eruption that took place on 15 February 2011 and found that sunquakes 1000 times more powerful than the Great East Japan Earthquake (and subsequent tsunami), March 2011, were triggered at the two ends of the erupting rope of magnetic field.

This indicates that the sudden expansion of the magnetic field that takes place as the eruption occurs is likely to play an important role in generating the quakes.

The eruption raced through the Solar System with an average speed of 600 km/s and was Earth directed, driving a geomagnetic storm and a beautiful display of the aurora when it reached us.

"Sunquakes were first predicted in 1972 by Wolff and are seen at the Sun's surface as circular ripples emanating outward, looking much like those produced as a stone is dropped into to a pond. (Wolff referred to them as like 'trapped sound waves')

"However, they are actually caused by sudden a release of energy below the solar surface that produces sound waves which bend and travel up to the surface of the Sun, lifting it and producing the ripples," said Zharkov.

These spectacular events are helping scientists understand how energy and momentum are transported from the Sun's atmosphere down to the surface and into the interior.

With solar activity currently increasing, and due to peak in 2013, more sunquakes will be observed helping unravel the mechanisms that cause them.

Aurora Australis from Space Station - Video

ESA Astronaut, André Kuipers took this video of Aurora Australis from the European Cupola module in the Space Station.

The beautiful phenomenon is caused by bursts of particles from the Sun pouring down Earth’s magnetic field into the atmosphere.

NASA TWINS/IBEX spacecraft observed impact of powerful solar storm

These energetic neutral atom (ENA) panels show IBEX observations before (left) and after (right) the solar wind impacted the Earth's magnetosphere on April 5, 2010, and increased from one- to two-million miles-per-hour. 

The magnetosphere, which is modeled in both panels, becomes compressed after the impact and shows a significant rise in the production of energetic neutral atoms (indicated by red).

For the first time, instrumentation aboard two NASA missions operating from complementary vantage points watched as a powerful solar storm spewed a two million-mile-per-hour stream of charged particles and interacted with the invisible magnetic field surrounding Earth, according to a paper published today in the Journal of Geophysical Research.

The spacecraft, NASA's Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) and Interstellar Boundary Explorer (IBEX), observed the impact from inside and outside the Earth's magnetosphere, respectively.

The energetic neutral atom (ENA) cameras aboard each spacecraft enabled global imaging of the magnetosphere, the invisible bubble that protects Earth from the majority of charged particles from the Sun, as it compressed in response to sharply faster solar wind.

The storm, observed April 5, 2010, also is thought to have caused an important communications satellite, Galaxy-15, to founder and drift, taking almost a year to return to its station.

These integrated images show energetic neutral atom (ENA) emissions as seen by TWINS. 

Each circle represents five minutes of activity, with the start times listed at the top of the graph. 

Each row shows a different energy band. The images in the last two columns (in red boxes) were taken roughly 20 minutes and one hour after the solar wind impact.

"Many satellites above Earth are in geosynchronous orbit. Like heavy traffic on a Los Angeles freeway, they have to stay in their lanes because they could, theoretically, collide," says Dr. David McComas, assistant vice president of the Space Science and Engineering Division at Southwest Research Institute, and principal investigator of the IBEX and TWINS missions.

"More likely, however, is that they will get too close together and their radio frequencies will interfere with the operation of nearby satellites, which could hamper activities on Earth."

The IBEX images (taken from a distance of around 180,000 miles) show an immediate compression of the magnetosphere as it was impacted by charged particles from the solar wind.

ENA global imaging enabled the team to determine the precise timing of the compression, to within ±9 seconds.

Minutes later, one of the TWINS spacecraft, carrying identical ENA sensors that provide stereoscopic imaging, observed changes in the inner magnetosphere (from a much-closer 28,000 miles).

A magnetospheric structure called the "ring current" traps charged particles that gyrate around magnetic field lines.

About 15 minutes after impact, the trapped particles propagated down the field lines toward the poles and into Earth's atmosphere, where they produced additional ENAs.

The brief time delay in losing particles to the atmosphere suggests that internal magnetospheric processes take some time after compression from the initial impact.

Solar Flares Solution to Vanishing Electrons

Researchers from the University of California, Los Angeles (UCLA) have solved the mystery behind vanishing electrons on Earth. The scientists conducted an experiment which suggested solar flares were the major reason behind the mystery.

During the experiment, the researchers installed three networks of orbiting spacecrafts, positioned at different distances from Earth to catch escaping electrons in the act. The data shows that a majority of the electrons were stripped away from the radiation belt by solar wind particles, when the solar flare reached Earth.

According to the researchers, when flares erupt on the Sun's atmosphere, parts of the magnetized outer layers of the Sun's atmosphere crash onto Earth's magnetic field, thereby triggering geomagnetic storms that are capable of damaging satellites and affecting electrons present on Earth.

The fact that these electrons were missing was discovered back in the early 1960s. Initial hypothesis suggested they were lost to the Earth's atmosphere, while others said they were not permanently lost merely drained of energy (temporarily) so they appeared absent. The mystery has now been solved.

"During the onset of a geomagnetic storm, nearly all the electrons trapped within the radiation belt vanish, only to come back with a vengeance a few hours later," said Vassilis Angelopoulos, a Professor at the UCLA, "It's a puzzling effect."

"This is an important milestone in understanding Earth's space environment," said Drew Turner, an Assistant Researcher at UCLA, "We are one step closer towards understanding and predicting space weather phenomena."

ESA BepiColombo Mercury Magnetospheric Orbiter: Structural model

The four components of the Mercury Composite Spacecraft together for the first time in the 'Rosetta' cleanroom at ESA's European Space Research and Technology Centre in Noordwijk, the Netherlands on 14 November 2011. 

Front right, on its ground multi-purpose trolley - the Mercury Planetary Orbiter (MPO) Structural and Thermal Model. 

Front left, on its handling trolley - the Mercury Magnetospheric Orbiter (MMO) Structural Model. 

Rear left, on its multi-purpose trolley - the Mercury Transfer Module (MTM) Structural and Thermal Model. 

Rear right - Magnetospheric Orbiter Sunshade and Interface Structure (MOSIF) Proto-Flight Model, in two parts - the sunshade (left, on the floor) and the interface adapter (right, on the vertical integration stand).

The BepiColombo Mercury Magnetospheric Orbiter Structural Model arrived at ESA's European Space Research and Technology Centre in the Netherlands on 7 November 2011, having been flown from Japan.

In the coming weeks, the four components that make up the Mercury Composite Spacecraft will be prepared for integration into their launch configuration in preparation for an acoustic and mechanical test campaign.

The BepiColombo Mercury Magnetospheric Orbiter (MMO) Structural Model (SM) arrived at ESA's European Space Research and Technology Centre (ESTEC) in Noordwijk, the Netherlands, on 7 November 2011, having travelled by road from Amsterdam Airport Schiphol.

The spacecraft, which is being developed and built by the Japan Aerospace Exploration Agency (JAXA), was flown from their facility at Sagamihara, Japan.

Once the transport container had been cleaned and transferred to the 'XMM' cleanroom in the ESTEC Test Centre, it was left overnight to reach thermal equilibrium with its surroundings.

On 8 November, the transport container was opened and the MMO's internal shock recorders were inspected to ensure that the dynamic environment experienced by the spacecraft during transport had remained within specifications.

An overhead crane and lifting device were used to move the MMO from its transport container base onto its handling trolley, after which it was moved to the 'Rosetta' cleanroom to join the other components of the Mercury Composite Spacecraft (MCS).

In parallel with the unpacking of the MMO, the Mercury Planetary Orbiter (MPO) was undergoing alignment checks after completion of its thermal balance test and the removal of its thermal blankets.

In the coming weeks, the MMO, the MPO, the Mercury Transfer Module (MTM) and the Magnetospheric Orbiter Sunshade and Interface Structure (MOSIF) will be prepared for integration to form the MCS, the configuration in which they will be launched and travel to Mercury.

The BepiColombo Mission
BepiColombo is Europe's first mission to Mercury. It is scheduled to launch in 2014 and arrive at Mercury in late 2020. It will endure temperatures in excess of 350C and gather data during a one-year nominal mission, with a possible one-year extension.

The mission comprises two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). During the journey to Mercury, the MMO will be shielded from the Sun by the Magnetospheric Orbiter Sunshield and Interface Structure (MOSIF), which also provides the interface between the MMO and the MPO.

The fourth component of the composite spacecraft stack is the Mercury Transfer Module (MTM), whose primary task is to provide solar-electric propulsion for the journey to Mercury.

BepiColombo is a joint mission by ESA and the Japan Aerospace Exploration Agency (JAXA), executed under ESA leadership. The Prime Contractor for BepiColombo is Astrium GmbH.

Skywatcher: Stunning Image of Aurora Borealis

Skywatcher Kwon, O Chul of The World At Night (TWAN), shot this image of the Northern Lights at Yellowknife in northern Canada.

CREDIT: (c)Kwon O Chul / TWAN

It took a collision of charged particles from Earth’s magnetosphere and one veteran landscape astrophotographer from Seoul, Korea to deliver this green spectacle.

Skywatcher Kwon, O Chul of The World At Night (TWAN), traveled to Yellowknife in northern Canada with a Canon 5d mark II + 24mm lens to capture this image of the Northern Lights.

The northern and southern lights — also known as the aurora — are mostly witnessed in polar latitudes. A clash of charged particles from Earth's magnetosphere with atoms and molecules of Earth's atmosphere (at altitudes above 50 miles, or 80 km) cause these lights. Solar wind from the sun carries these particles to Earth.

Kwon often uses several medium-format and panorama-format film cameras in his exhibitions. The skywatcher “looks for the harmony between celestial motion and star trails, ancient relics, and Korean beautiful landscapes,” according to the TWAN website. 

Mystery of Moon's Lost Magnetism

This illustration shows one suggested mechanism for creating an ancient magnetic field on the moon. In this scenario, impacting space rocks on the moon would create instability in the moon's core that could lead to a dynamo that creates a magnetic field.

CREDIT: M.-H. Deproost, ORB, Belgique

One of the abiding mysteries of our moon is why it apparently once had a magnetic field.

Now two teams of scientists have offered two separate, but potentially complementary, explanations.

When Apollo astronauts brought back samples of moon rocks from their lunar landing missions in the 1960s and '70s, some of them shocked scientists by being magnetic.

That means that individual rocks might have a magnetic north and south pole and a small magnetic field of their own.

This can happen to rocks with the right minerals inside them, if they cool in the presence of a magnetic field.

The problem is, scientists had no idea that the moon had ever had a magnetic field, and were at a loss to explain how that might have happened.

A magnetic field is generated by what's called a dynamo, which is caused by the fluid motion of a conducting material, such as liquid iron.

In the case of the Earth's magnetic field, this motion occurs in the planet's outer core, and is caused by the convection of heat.

ESA: The origin of ultrafast substorm auroras

This animation depicts the sequence of events that give rise to ultrafast substorm auroras.

A magnetic reconnection event occurs far out in the magnetotail, at a distance of around 125 000 - 200 000 km.

Energy from this event is transported by kinetic Alfvén waves (KAW) - which carry electrons - towards Earth at speeds of several thousand kilometres per second.

These KAW can reach Earth quickly enough, and carry sufficient energy, to produce intense auroras.

In reality, the reconnection process is persistent and less bursty, continuously emitting energy via the KAWs to the aurora.

ESA Science & Technology: The origin of ultrafast substorm auroras

Magnetic Anomalies Shield The Moon

Scientists have discovered a new type of solar wind interaction with airless bodies in our solar system.

Magnetised regions called magnetic anomalies, mostly on the far side of the Moon, were found to strongly deflect the solar wind, shielding the Moon's surface.

This will help understand the solar wind behaviour near the lunar surface and how water may be generated in its upper layer.

Observational evidence for these findings will be presented by Dr. Yoshifumi Futaana and Dr. Martin Wieser at the European Planetary Science Congress in Rome, on Friday 24th September.

Atmosphere-less bodies interact with the solar wind quite differently than the Earth. Their surfaces are exposed without any shielding by a dense atmosphere or magnetosphere. This causes them to be heavily weathered by meteoroids or the solar wind, forming a very rough and chaotic surface called regolith.

Previously, the solar wind was thought to be completely absorbed by the regolith. However, recent explorations of the Earth's moon by the Chang'E-1, Kaguya and Chandrayaan-1 spacecrafts have revealed that this interaction is not that simple.

A significant flux of high energy particles was found to originate from the lunar surface, most probably due to the solar wind directly reflected off the Moon's regolith.

"These results may change dramatically the way we understood the solar wind-regolith interaction so far," says Dr. Futaana of the Swedish Institute of Space Physics.