A magnetosphere is that area of space, around a planet, that is controlled by the planet’s magnetic field. The shape of the Earth’s magnetosphere is the direct result of being blasted by solar wind. The solar wind compresses its sunward side to a distance of only 6 to 10 times the radius of the Earth.
A supersonic shock wave is created sunward of Earth called the bow shock. Most of the solar wind particles are heated and slowed at the bow shock and detour around the Earth in the magnetosheath. The solar wind drags out the night-side magnetosphere to possibly 1000 times Earth’s radius; its exact length is not known. This extension of the magnetosphere is known as the magnetotail. The outer boundary of Earth’s confined geomagnetic field is called the magnetopause. The Earth’s magnetosphere is a highly dynamic structure that responds dramatically to solar variations.
Also residing within the magnetosphere are areas of trapped charged particles; the inner and outer Van Allen Radiation Belts, the plasmasphere, and the plasmasheet.
The Sun and its atmosphere consist of several zones or layers. From the inside out, the solar interior consists of:
The Core – the central region where nuclear reactions consume hydrogen to form helium. These reactions release the energy that ultimately leaves the surface as visible light.
The Radiative Zone – extends outward from the outer edge of the core to base of the convection zone, characterized by the method of energy transport – radiation.
The Convection Zone – the outermost layer of the solar interior extending from a depth of about 200,000 km to the visible surface where its motion is seen as granules and supergranules.
The solar atmosphere is made up of:
The Photosphere – the visible surface of the Sun.
The Chromosphere – an irregular layer above the photosphere where the temperature rises from 6000°C to about 20,000°C.
A Transition Region – a thin and very irregular layer of the Sun’s atmosphere that separates the hot corona from the much cooler chromosphere.
The Corona – the Sun’s outer atmosphere.
Beyond the corona is the solar wind, which is actually an outward flow of coronal gas. The Sun’s magnetic fields rise through the convection zone and erupt through the photosphere into the chromosphere and corona. The eruptions lead to solar activity, which includes such phenomena as sunspots, flares, prominences, and coronal mass ejections.
UPDATED Aug. 4, 2023: NASA has reestablished full communications with Voyager 2.
The agency’s Deep Space Network facility in Canberra, Australia, sent the equivalent of an interstellar “shout” more than 12.3 billion miles (19.9 billion kilometers) to Voyager 2, instructing the spacecraft to reorient itself and turn its antenna back to Earth. With a one-way light time of 18.5 hours for the command to reach Voyager, it took 37 hours for mission controllers to learn whether the command worked. At 12:29 a.m. EDT on Aug. 4, 2023, the spacecraft began returning science and telemetry data, indicating it is operating normally and that it remains on its expected trajectory.
A series of planned commands sent to NASA’s Voyager 2 spacecraft on July 21 inadvertently caused the antenna to point 2 degrees away from Earth. As a result, Voyager 2 is currently unable to receive commands or transmit data back to Earth.
Voyager 2 is located almost 12.4 billion miles (19.9 billion kilometers) from Earth and this change has interrupted communication between Voyager 2 and the ground antennas of the Deep Space Network (DSN). Data being sent by the spacecraft is no longer reaching the DSN, and the spacecraft is not receiving commands from ground controllers.
Voyager 2 is programmed to reset its orientation multiple times each year to keep its antenna pointing at Earth; the next reset will occur on Oct. 15, which should enable communication to resume. The mission team expects Voyager 2 to remain on its planned trajectory during the quiet period.
Voyager 1, which is almost 15 billion miles (24 billion kilometers) from Earth, continues to operate normally.
Five researchers supported by NASA’s Living With a Star Program will join the 2023-2024 class of NASA’s Jack Eddy Postdoctoral Fellowship.
The early career PhDs, selected by the University Corporation for Atmospheric Research (UCAR)’s Cooperative Program for the Advancement of Earth System Science (CPAESS), will research interdisciplinary projects contributing to the field of heliophysics at a host institution for the next two years.
The Jack Eddy Postdoctoral Fellowship was founded in 2009 in honor of pioneering solar researcher John A. “Jack” Eddy. The program matches the fellows with experienced scientists at the host institutions to train the next generation of Sun-Earth researchers.
2023 NASA Jack Eddy Postdoctoral Fellowship Awardees
Peijin Zhang Host: Dr. Bin Chen of New Jersey Institute of Technology, Newark, NJ
PhD Institution: University of Science and Technology of China (USTC)
Proposal: Radio Imaging Spectroscopy for CMEs and CME-driven Shocks
Charlotte Waterfall Host: Dr. Georgia deNolfo of NASA’s Goddard Space Flight Center
PhD Institution: University of Manchester
Proposal: Bad News Travels Fast: Energetic Particle Transport in the Heliosphere
Robert Jarolim Host: Dr. Matthias Rempel at National Center for Atmospheric Research | High Altitude Observatory
PhD Institution: University of Graz
Proposal: Physics-informed Neural Networks for the Simulation of Solar Magnetic Fields
Devojyoti Kansabanik Host: Dr. Angelos Vourlidas at The Johns Hopkins University Applied Physics Laboratory
PhD Institution: National Centre for Radio Astrophysics, Tata Institute of Fundamental Research
Proposal: Remote Sensing of CME-entrained Magnetic Fields
Mei-Yun Lin Host: Dr. Andrew R. Poppe at the University of California, Berkeley
PhD Institution: University of Illinois, Urbana-Champaign
Proposal: From Ionosphere or Moon? A Comprehensive Study of Metallic Ions in the Magnetosphere
As Earth spins around the Sun, our planet’s slight tilt creates seasons. Now, research from two NASA space missions has found how the same tilt also influences seasonal differences in space weather – conditions in space produced by the Sun’s activity.
Space weather events produce the beautiful glow of the northern and southern lights, but, if intense enough, they can also endanger spacecraft and astronauts, disrupt radio communications, and even cause large electrical blackouts. Since space weather is created by particles and energy sent from the Sun, it varies with the Sun’s 11-year cycle of activity – the solar cycle. But space weather also varies on shorter timescales, such as seasonally and daily.
The new results, published in the journal Nature Communications, found that the seasonal differences are caused by a phenomenon known as the Kelvin-Helmholtz instability. This instability forms curling waves at the boundary between two regions – such as different layers of the atmosphere or between air and water – flowing at different speeds. These waves sometimes occur in Earth’s atmosphere, resulting in unique cloud formations that look like a series of crashing ocean waves. In space, these waves are composed of charged particles that are energized and pushed toward Earth, resulting in enhanced space weather effects.
The new findings confirm that Kelvin-Helmholtz waves are more commonly produced during the spring and fall equinoxes. During the equinoxes, Earth is not tilted toward or away from the Sun. As a result, the orientation of the Sun’s and Earth’s magnetic fields is ideal for forming Kelvin-Helmholtz waves. When Earth’s magnetic field is tilted at extremes toward or away from the Sun – such as during the summer and winter solstices – few Kelvin-Helmholtz waves are created.
“We have discovered that Kelvin-Helmholtz waves in the space around Earth are seasonal, which explains an important factor in the seasonal variation of space weather,” said the lead author on the new study, Shiva Kavosi, a researcher at Embry–Riddle Aeronautical University in Daytona Beach, Florida. “These waves are ubiquitous and can be found roughly 20 percent of the time around Earth, but after monitoring over an entire solar cycle, we now know there are more chances observing them during certain times of the year.”
To make the discovery, scientists used 11 years of data from NASA’s Time History of Events and Macroscale Interactions during Substorms, or THEMIS, mission, as well as four years of data from the Magnetospheric Multiscale, or MMS, mission. “The unique orbits and long period of observations by THEMIS made this discovery – which was first theorized in the 1970s – possible,” Kavosi said.
By better understanding how Kelvin-Helmholtz waves form due to Earth’s seasonal tilt, researchers can better forecast its effects and plan accordingly to ensure spacecraft and astronaut safety. “Additionally, space weather forecasters can now add this component to their models for better forecasting,” Kavosi said.
After more than 15 years of scientific discoveries, NASA’s Aeronomy of Ice in the Mesosphere, or AIM, spacecraft is no longer supporting operations after experiencing issues with its battery.
AIM’s batteries initially started to decline in 2019, but the Earth-studying spacecraft continued to return a significant amount of data. Now, with further decline in the battery power, the spacecraft currently is not able to receive commands or collect data.
Launched in 2007, AIM has studied polar mesospheric clouds, also known as night-shining or noctilucent clouds, from its orbit 312 miles above Earth. Its data have changed scientists’ understanding of the causes and formation of the clouds, leading to 379 peer-reviewed scientific papers. AIM – originally slated to operate for two years – completed its primary mission in 2009 and has been in extended operations status since then.
The AIM team will continue to monitor AIM’s communication for two weeks in case the spacecraft is able to reboot and transmit a signal.
By Mara Johnson-Groh NASA Goddard Space Flight Center, Greenbelt, Md
A massive eruption of solar material, known as a coronal mass ejection or CME, was detected escaping from the Sun at 11:36 p.m. EDT on March 12, 2023.
The CME erupted from the side of the Sun opposite Earth. While resarchers are still gathering data to determine the source of the eruption, it is currently believed that the CME came from former active region AR3234. This active region was on the Earth-facing side of the Sun from late February through early March, when it unleashed fifteen moderately intense M-class flares and one powerful X-class flare.
Based on an analysis by NASA’s Moon to Mars Space Weather Office, the CME was clocked in traveling at an unusually fast 2,127 kilometers (1,321 miles) per second, earning it a speed-based classification of a R (rare) type CME.
A simulation of the CME below shows the blast erupting from the Sun (located at the middle of the central white dot) and passing over Mercury (orange dot). Earth is a yellow circle located at the 3 o’clock position.
The eruption is likely to have hit NASA’s Parker Solar Probe head-on. The spacecraft is currently nearing its 15th closest approach of the Sun (or perihelion), flying within 5.3 million miles (8.5 million kilometers) of the Sun on March 17. On March 13, the spacecraft sent a green beacon tone showing the spacecraft is in its nominal operational mode. The scientists and engineers are awaiting the next data download from the spacecraft, which will occur after the close approach, to learn more about this CME event and any potential impacts.
The eruption is known as a halo CME because it appears to spread out evenly from the Sun in a halo, or ring, around the Sun. Halo CMEs depend on the observer’s position, occurring when the solar eruption is aligned either directly towards Earth, or as in this case, directly away from Earth. This expanding ring is apparent in the view from NASA/ESA’s Solar and Heliospheric Observatory, or SOHO, spacecraft shown below. SOHO observes the Sun from a location about 1 million miles closer to the Sun along the Sun-Earth line. In SOHO’s view, the Sun’s bright surface is blocked to reveal the much fainter solar atmosphere and erupting solar material around it. The bright dot on the lower right side of the image is Mercury.
Even though the CME erupted from the opposite side of the Sun, its impacts were felt at Earth. As CMEs blast through space, they create a shockwave that can accelerate particles along the CME’s path to incredible speeds, much the way surfers are pushed along by an incoming ocean wave. Known as solar energetic particles, or SEPs, these speedy particles can make the 93-million-mile journey from the Sun to Earth in around 30 minutes.
Though SEPs are commonly observed after Earth-facing solar eruptions, they are less common for eruptions on the far side of the Sun. Nonetheless, spacecraft orbiting Earth detected SEPs from the eruption starting at midnight on March 12, meaning the CME was powerful enough to set off a broad cascade of collisions that managed to reach our side of the Sun. NASA’s space weather scientists are still analyzing the event to learn more about how it achieved this impressive and far-reaching effect.
NASA’s Interstellar Boundary Explorer (IBEX) is fully operational after the mission team successfully reset the spacecraft on March 2.
To take the spacecraft out of a contingency mode it entered last month, the mission team performed a firecode reset (which is an external reset of the spacecraft) instead of waiting for the spacecraft to perform an autonomous reset and power cycle on March 4. The decision took advantage of a favorable communications environment around IBEX’s perigee – the point in the spacecraft’s orbit where it is closest to Earth.
After the firecode reset, command capability was restored. IBEX telemetry shows that the spacecraft is fully operational and functioning normally.
Launched on Oct. 19, 2008, IBEX is a small explorer NASA mission tasked with mapping the boundary where winds from the Sun interact with winds from other stars. IBEX, the size of a bus tire, uses instruments that look toward the interstellar boundary from a nine-day orbit around Earth.
NASA’s Interstellar Boundary Explorer (IBEX) experienced a flight computer reset during a planned contact and the spacecraft went into contingency mode on Feb. 18.
While fight computer resets have happened before, this time the team lost the ability to command the spacecraft during the subsequent reset recovery. The team also was unsuccessful in regaining command capability by resetting ground systems hardware and software.
Flight software still is running, and the spacecraft systems appear to be functional. However, while uplink signals are reaching the spacecraft, commands are not processing.
If the mission team’s efforts to find and remedy the loss of command capability remain unsuccessful, IBEX will perform an autonomous reset and power cycle on March 4.
NASA will provide additional information on IBEX following the reset unless the agency is able to find a solution before.
The CubeSat to Study Solar Particles (CuSP) launched as an Artemis I payload on 1:47 AM EST on Nov. 16, 2022. CuSP was deployed from its canister about eight hours after launch. Approximately two hours after deployment, CuSP transmissions were received by an Open Loop Receiver (OLR) operated by NASA’s Jet Propulsion Laboratory’s Radio Science Systems Group. The OLR recorded approximately 60 minutes of transmission from CuSP. Unfortunately, the CuSP team has not re-established contact with the CubeSat after the initial contact.
In the initial OLR contact (which was listening mode only) CuSP was operating mostly as expected. The solar arrays deployed, and they were stable and pointing at the Sun. However, anomalous software resets and temperature readings were reported during the contact.
NASA’s Deep Space Network (DSN) provided the mission team a downlink-only pass eight hours after deployment as well as a contact with CuSP 11 hours after deployment. CuSP radio transmissions were not detected during either of these DSN opportunities. No further radio transmissions have been received from CuSP during subsequent scheduled DSN contacts.
During the initial OLR contact period, CuSP experienced three software reboots. One ended during the start of the data collection period, one occurred in the middle of the data collection, and one occurred at the end. However, the OLR signal indicated that CuSP remained powered on after the last reboot.
An unexplained battery anomaly also occurred at the end of the initial data collection period. Two minutes prior to the end of the data collection period, one of the battery cells suddenly experienced a temperature spike – jumping from 34 degrees Celsius to more than 168 degrees Celsius in under a minute. The temperature of the anomalous cell subsequently increased from approximately 34 degrees Celsius to about 80 degrees Celsius before loss of contact.
The CuSP team is investigating the cause of the sudden battery temperature increase and working to find a solution. The team is also working to regain contact with the spacecraft.
CuSP was designed to be one of the first CubeSats to explore interplanetary space, the region around the Sun and planets of our solar system. This CubeSat’s objective is to study the solar wind particles and magnetic fields that stream from the Sun and the relationship of this solar wind to more energetic particles generated by solar activity.