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News Archive 2008 December 17 , 2008: As of Dec 15, 2008, THEMIS has entered its second tail season: the probes have started to line up in the tail. Four out of five of the THEMIS probes (satellites) have already captured the first substorm of the new season, on Dec 15, 09:15UT (precursor) and 09:40UT (onset). Four day conjunctions occur on Dec 17 and 4 days thereafter through mid-March, on 00:30 - 12:30 UT. See http://themis.ssl.berkeley.edu for details. New predicted orbits are now available at http://sscweb.gsfc.nasa.gov. December 16, 2008: Researchers on the THEMIS team have discovered that 20 times more solar particles can enter the Earth's magnetosphere when the solar wind's magnetic field near Earth is pointing north than when the solar wind's magnetic field is pointing south. Computer simulations show that this affect is due to the solar wind's magnetic field merging with Earth's magnetic field at two points - far above Earth's arctic and anarctic regions. This merging allows the solar wind's magnetic field to essentially become Earth's magnetic field, bringing with it the solar wind particles that flow along the solar wind's magnetic fields (these particles - plasma - are 'stuck' to magnetic fields.) This discovery leads researchers to the conclusion that when the solar wind's magnetic field in a solar storm is northward for a long time and then turns southward, there are many more particles in Earth's magnetosphere that can be energized by the southward magnetic field. This leads to large geomagnetic storms, electrical blackouts in cities and beautiful northern and southern lights (auroras.) This newly THEMIS discovered effect is analogous to lighting a gas stove. Turning the gas on is like turning the solar wind magnetic field (IMF) northward. The gas is the solar wind plasma. And the fire to ignite the gas is the solar wind magnetic field (IMF) turning southward. If you turn on the gas on your stove just briefly and then quickly ignite the gas, the gas simply burns in a controlled fashion. This is analogous to the solar wind magnetic field turning northward just briefly and then turning southward and energizing the small amount of plasma from the solar wind in a controlled fashion (not much effect geomagnetically.) If, however, you turn on the gas on your gas stove for a long time and then ignite the gas, you can get a big explosion. This is analogous to the solar wind magnetic field turning northward and staying northward for a long time and then turning southward, energizing the huge amount of plasma very rapidly leading to a huge geomagnetic storm. October 30, 2008: Researchers on the THEMIS team have discovered 'magnetic portals' forming high above Earth that can briefly connect our planet to the Sun. Not only are the portals common, one space physicist contends they form twice as often as anyone had previously imagined. July 24, 2008: THEMIS has determined that a substorm has been initiated 1/3 of the way to the moon's orbit in a region of magnetic reconnection. This is the first time five satellites have been aligned in just the right place and at just the right time to see the timing of events from this substorm initiation leading to the initiation of a dancing and dynamic aurora. The satellites showed how plasmas and magnetic fields moved both towards Earth and away from Earth. The bubble of plasma moving toward Earth caused a disruption in the normal electrical current much closer to Earth than the substorm initiation and then caused the auroral substorm. Learn more about this event from the NASA Press Release, "NASA Satellites Discover What Powers Northern Lights." The THEMIS media page for this press release has some excellent graphics. And you can learn more about the THEMIS mission science from the very basics on auroras and substorms on this website under "Mission Science" July 13-15 , 2008: Twelve THEMIS teachers from across the country came together for a teacher professional development workshop in Boulder, CO. They shared with each other the lessons they have been doing in their classes using the THEMIS ground-based magnetometer data located in many of their schools. Dr. Peticolas modeled lessons with the teachers from the new THEMIS teacher's guide that is a revised version of the "Space Weather" guide. And they heard from scientists, Drs. Mark Moldwin and Sten Odenwald, about the THEMIS mission and the Super Storm of 1859. The teachers are looking forward to continuing to be a integral part of the THEMIS mission - a part of which is to bring THEMIS science to students across the Northern United States. If you are interested in bringing THEMIS science to your classroom, including some of the THEMIS data, see the "In the Classroom" part of this website for more information. May 23 , 2008: Despite being a rather quiet week operationally (remember: quiet is good!) we've received some excellent news from NASA headquarters. On the basis of our success so far and the high quality of science THEMIS continues to collect, NASA has agreed to extend the THEMIS mission until fiscal 2012. Part of the THEMIS proposal for the extended mission was to use remaining propellant on the two outermost probes (satellites) to send them out to the moon, and this was also provisionally accepted (pending one more technical review). Unlike the Apollo missions of the late 60's, THEMIS does not have a big enough rocket engine to shoot the two probes directly to the moon in a matter of days. Instead, the probes will use their thrusters to slowly (over the course of many months) raise the high point of Probes 1 and 2's orbit -- currently in a 4 and 2 day long orbits respectively -- until the moon's gravity is strong enough to pull them away from earth. Even once that happens, the path to the moon is not direct. The probes will get pulled out in a large arc that eventually loops back to the moon. The whole process will take approximately a year to complete, and will be more intensive and more complicated than the maneuver planning the THEMIS mission operation center (MOC) team has ever done to date. For these two outer probes, Earth departure will be in October 2009. The MOC team already started working to improve the automation of the flight dynamics planning process to ensure we can keep up with the complexity of the maneuvers. May 13 , 2008: The THEMIS mission team received a Goddard Space Flight Center (GSFC) Group Achievement Award for the team's accomplishments. May 12 , 2008: We have been finished with the THEMIS tail season for over a month, that is when the THEMIS probes aligned within Earth's magnetotail. And now the 'Dusk Phase' season starts in order to study the radiation belts surrounding Earth. In this phase, the satellites align with one another when they pass above the 'place' where sunset (dusk) occurs for a person on Earth, hence the terminology 'Dusk Phase.' See the THEMIS science orbits page for more on this and other orbit phases. Last week, late Wednesday night and Thursday during the day, the Mission Operations Center (MOC) team completed the last of the maneuvers which fine tune the entire THEMIS constellation so it will be ready for "day side science" this summer. In this phase, the constellation is a mirror image of the tail season alignment we had last winter. This time, the apogees (farthest point of the orbit from the earth) are in the sun direction. Instead of taking measurements inside or very near the stretched out magneto-tail, we'll be collecting science in the "bow shock" region (just imagine the wave in front of the bow of a ship). This is where the solar wind slams into the earth's magnetic field and starts to warp it back. Probe 1, which is in the most elongated orbit, can actually travel far enough away from the earth to punch through this bow shock and measure the solar wind before it has gotten a chance to be disturbed by the Earth's magnetic field. May 8 , 2008: NASA Administrator Michael Griffin bestowed upon the THEMIS team a Group Achievement Award for the successful delivery, launch and operations of the THEMIS probes. March 5 , 2008: At the all-day monthly THEMIS science meeting last week, Tuesday, many scientists came together to look at the February substorms. Although one person argued for a near-earth neutral line model (reconnection first, current disruption next, then aurora), most scientists were not ready to sign up to one interpretation of the data. As with most scientific endeavors, the answers are not as simple as one might initially hope, leading to deeper understanding of the physics and new discoveries. With multiple spacecraft available to address the question of where does the onset of substorm begin, the signatures in the particle and magnetic field data demonstrate that the magnetosphere is a very complex and dynamic system. With more than a dozen substorms collected with the THEMIS probes in just the right place and together with computer modeling of the magnetospheric system, it is clear that the upcoming analysis will lead to significant discoveries regarding substorm onsets. February 26, 2008: The company that evaluates our education and public outreach program, Cornerstone Evaluation Associates LLC (Cornerstone), has provided us with a report summarizing findings from our teacher professional development workshops over Fiscal Year 2007 (FY07) - from October 1, 2006 through September 30, 2007. The report also contains a summary of relevant statistics about the use of this website over the Fiscal Year 2006 (FY06) from October 1, 2005 through September 30, 2006 and Fiscal Year 2007 (FY07) from October 1, 2006 through September 30, 2007. You can read the report here. To find out more about our teacher PD workshops, visit the THEMIS GEONS page and the Center for Science Education teacher PD workshop page. February 20, 2008: PBS NOVA Science NOW came on February 5th to film several of the THEMIS scientists and engineers for a short NOVA piece about THEMIS. You can view a photograph of our own Manfred Bester, Director of the Missions Operations Center at UC Berkeley, with Neil deGrasse Tyson, the host of NOVA Science NOW, an astrophysicist and the director of the Hayden Planetarium at the American Museum of Natural History in New York City. We will share information here about when the NOVA show will air when we find out the schedule for this program. February 17, 2008: Today is the first anniversary of THEMIS in orbit. The past year has been filled with discoveries. See the Articles Section to read about some of these discoveries, such as the first detection of a flux transfer event, when the magnetosphere combines with the solar wind in a rope-like fashion, peeling pieces of the magnetosphere off its front-side. We will provide news about some of the other science discoveries when the special THEMIS issue of the Geophysical Research Letters is published. February 12, 2008: There were substorms throughout last week, including a substorm on Feb. 2nd, the THEMIS wedding day. See Feb. 1st news for a definition of wedding day. Due to technical difficulties, the satellite data was insufficient to tell us which model was at work for this particular substorm. Fortunately, however, there was another substorm on February 6, when the satellites were aligned with each other and close to the Sun-Earth line. The data from this day are currently being analyzed and we have high hopes that we’ll soon be getting some answers to the THEMIS substorm mystery! To provide an idea of what a substorm look like from the all-sky imager data, here are two images (click to enlarge) showing the imager data as a mosaic across Canada and Alaska. The circles represent the field of view of the camera and the bright lines in those field of view are aurora. These images are 1 minute apart and show the substorm onset brightening right in the middle at 7:39:06 UT on Feb. 2nd. The colored dots represent how the five satellites are connected to the upper atmosphere by way of Earth's magnetic field.  
So, tomorrow is one of the best opportunities to really answer the question of what are the timing of the events that cause the sudden release of energy in the magnetotail and start the auroras a-dancin'! And thus, it is dubbed the "wedding day." Will a substorm happen tomorrow? We sure hope it will. Even if it doesn't, though, we still have many more chances in the coming month. Then we may finally have an answer whether this release of energy occurs in the "magnetic reconnection" region or in the "current disruption" region. Of course this will lead to all sorts of new questions, like "What is the physics in this main region that allows for the energy release?" and "How does the energy flow from one region to the other?" Some of these questions THEMIS can answer and others will have to be answered by future missions your students or children are a part of. January 14, 2008: Two days ago, the THEMIS Electric Fields Instrument (EFI) and Mission Operations Center (MOC) team successfully rolled out, or deployed, the spin-plane Electric Fields Instrument (EFI) to their full extent (40.4 and 46.4 meters tip-to-tip) on the "spare" probe, THEMIS A (or TH-A; Probe 5, P-5). Note that the statue of liberty is 46 meters tall - so these booms really extend very far out into space. See the past two News and Events posts to learn more about this deployment. And the axial EFI booms were deployed successfully this morning. The axial booms are a bit shorter (6.7 meters tip-to-tip) and stiff since they do not have the rotation of the probes to keep them extended. All in all, this deployment took about a week and was very successful. Congratulations to the THEMIS team! January 10, 2008: The THEMIS Electric Fields Instrument (EFI) and Mission Operations Center (MOC) team successfully rolled out, or deployed, the spin-plane Electric Fields Instrument (EFI) to 10 meters on the "spare" probe, THEMIS A (or TH-A; Probe 5, P-5). An additional 3 meters of very thin wire was also deployed that connects the preamplifier (housed in about a one inch cylinder) to the actual sensor, which is a black ball about the size of an extra-large softball. The preamplifier is used to carefully process the signal from the electric field sensor. The thicker wire connects the preamplifier with the THEMIS probe. This deployment means that the spin-plane booms are deployed a total length of 26-m tip-to-tip on both axes! To get a sense of this scale, see this 85 foot tall (26 meter tall) tree in Illinois next to a house. See May 16th, 2007 for a diagram of the EFI booms (not-to-scale). January 8, 2008: It's another blistery day in Berkeley, CA but the THEMIS mission operation center (MOC) team operating out of UC Berkeley communicated successfully with the "spare" probe, THEMIS A (or TH-A; Probe 5, P-5) to start to roll out, or deploy, the Electric Fields Instrument (EFI). The spin-plane EFI sensors were rolled out to 5 meters and then the spacecraft spun back up to its original spin rate. This is necessary because of angular momentum - just as a figure skater spinning stretches out her arms to slow down her spin rate, the EFI instruments as they move out will slow down the spin rate of the probe. So boosters have to be used to spin it back up again. See May 16th, 2007 for a diagram of the EFI booms deployed on a THEMIS probe. The EFI deployment has been done on all the other probes so this is the final deployment. It will take several "satellite passes" over about a week. A satellite pass is when the satellite is in the right place to be able to send electromagnetic (or light) signals back and forth with a ground-based antenna. Luckily the strong winds didn't cause a problem with the Berkeley antenna and thus with the communication opportunities. January 4, 2008: Happy New Year! THEMIS is officially in its "tail" season and ready to solve the mystery of substorm onset. Will we find that it starts with magnetic reconnection or current disruption? The over 30-year debate will finally be settled this coming year. Stay tuned for this exciting THEMIS science news. The mission operations center (MOC) here at the University of California at Berkeley will start ramping back up to full staffing next week. The MOC team will finish the last major hurdle: to unfurl the EFI (electric fields instrument) on THEMIS A, which has been a "spare" probe, ready to take over if any of the other four hadn't made it into their intended orbits. In the mean time, Northern California is getting hammered by a severe winter storm, and the winds here in the Berkeley hills are so high that the MOC team had to cancel all the communications passes with our antenna, and install special locking pins to keep the wind from damaging it. The rain has been coming in sideways through our entry doors! We hope you all are safe and warm during this winter season.
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February 1st, 2008: Tomorrow, Feb. 2nd, 2008, is "wedding day" for THEMIS. This is the day when all the satellites will align with each other and at the same time, the line they form will align with the magnetotail. This orbital configuration is shown in the diagram above with the perspective looking down on Earth's North Pole. So far the satellites have aligned with each other but not exactly in this line connecting the Sun and Earth, where the magnetotail blows out like a wind sock. They have lined up on the dawn side (top side of image) of the magnetosphere. And after this day, they will no longer line up directly downstream of Earth in the length of the magnetotail. They will drift to the dusk side (bottom side of the image.) For more information on the THEMIS orbits, vist the 
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