EDIT 4:35 pm ET: Thank you all for your excellent questions. It’s been a lot of fun sharing our science with you. We’re signing off now. We have just published a study detailing “Steve,” an aurora-related dancing purple light first spotted – and named! – by amateur photographers. This new information about Steve comes from analyzing satellite data, all-sky cameras and additional citizen-scientist photographs. Steve’s scientific name is now Strong Thermal Emission Velocity Enhancement (which can still be shortened to STEVE). STEVE appears as a faint purple ribbon of light in the sky and is often accompanied by a short-lived, green, picket fence structure. It looks much like an aurora but occurs at lower latitudes closer to the equator. After analyzing satellite data, we learned that STEVE is the visible side of something we were already familiar with: sub auroral ion drift (SAID), a fast moving stream of extremely hot particles. SAIDs appear in areas closer to the equator (like southern Canada) than where most auroras appear. Until now, we never knew SAIDs had a visual component! Studying STEVE can help us paint a better picture of how Earth’s magnetic fields function and interact with charged particles in space. You can help us learn more about STEVE by submitting your photographs and sightings of the phenomenon to a citizen science project called Aurorasaurus (online at aurorasaurus.org or on your device as iOS and Android apps). Check here for more details about how to spot STEVE. Answering your questions today are: Liz MacDonald, space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and founder of Aurorasaurus Chris Ratzlaff, citizen scientist who first named Steve; runs the Alberta Aurora Chasers Facebook group Burcu Kosar, space scientist at NASA Goddard Matt Heavner, space scientist at the New Mexico Consortium, Los Alamos, New Mexico Bea Gallardo-Lacourt, space physicist at the University of Calgary, Canada Bill Archer, space scientist at the University of Saskatchewan, Saskatoon, Canada Megan Gillies, space scientist at the University of Calgary, Canada We are now live. @NASASun on Twitter

Edit 12:46 PM ET: We are signing off! Thanks so much for all your questions. Remember to check out eclipse2017.nasa.gov/safety to make sure you are ready to watch the eclipse safely! Happy eclipse watching! Edit 11:04 AM ET: We’re live! On Aug. 21, 2017, all of North America will have the chance to see a partial solar eclipse. Along a narrow, 70-mile-wide track called the path of totality, the Moon will totally block the Sun, revealing the Sun’s comparatively faint outer atmosphere – the corona. Total solar eclipses like this are a rare chance for solar scientists to study this region of the Sun, since we can’t ordinarily see it from the ground or with satellite instruments. The sudden blocking of light also gives Earth scientists a rare chance to track how Earth’s atmosphere responds to the Sun’s radiation. Find out more about NASA’s eclipse science (and how to watch the eclipse) at eclipse2017.nasa.gov. Noah Petro I first became interested in Geology as a student at Fox Lane High School in Bedford, NY. It was while I was a student at Bates College that I was introduced to the field of planetary geology. Following my PhD work at Brown University I came to NASA Goddard as a NASA Post-Doc. Alexa Halford I am a contractor at NASA Goddard. Throughout my education I have been lucky to work at JPL NASA looking at Uranus’s moons and study Saturn on the Cassini mission at the South West Research Institute. Today I stick a bit closer to home studying the Earth’s magnetic field and its space weather phenomena. Mitzi Adams I am a solar scientist for NASA’s Marshall Space Flight Center (MSFC), where I study the magnetic field of the Sun and how it affects the upper layer of the solar atmosphere, the corona. With a professional interest in sunspot magnetic fields and coronal bright points, friends have labelled me a “solar dermatologist”. Bill Cooke The head of NASA’s Meteoroid Environment Office, I help NASA in placing meteoroid protection on spacecraft and construct meteor shower forecasts for unmanned space vehicles and the International Space Station. While a graduate student at the University of Florida, I worked on instruments flying on board balloons, the Space Shuttle, Giotto (European mission to Halley’s Comet), and LDEF. After obtaining my PhD in Astronomy, I came to work at Marshall Space Flight Center as a member of the Space Environments Team, where I became an acknowledged expert in meteors and meteoroids. I am one of the many NASA astronomers interacting with the public on the upcoming solar eclipse. Jay Herman I am an atmospheric scientist working on several projects. Two of them are of interest to the eclipse or other atmospheric questions. 1) The Pandora Spectrometer Instrument that measures the solar spectrum and derives the amount of trace gases in the atmosphere, such as ozone, nitrogen dioxide, and formaldehyde, and 2) The DSCOVR/EPIC spacecraft instrument that observes the entire sunlit globe from sunrise to sunset from the Earth-Sun Lagrange-1 point (1 million miles from earth). We derive both atmospheric and surface properties from EPIC, and we will see the Moon’s shadow during the upcoming eclipse. Guoyong Wen I am an atmospheric scientist interested in the way radiation passes through the atmosphere. The experiment we are planning to perform is a combination of theory and measurements to see if they match. For this purpose we are using an advanced radiative transfer calculation in three dimensions and measurements from the ground and a spacecraft. Hopefully, the calculations and data will match. If not, we can learn about whatever may be missing. The result will be improved calculation capability. Edit 9:18 AM ET: Added Jay Herman’s bio Edit 11:11 AM ET: Added Guoyong Wen’s bio

EDIT, NOTE FROM THE MODS: The Spring Equinox 2017 will occur in the Northern Hemisphere at 6:28 AM EST on Monday, March 20, NOT today. The date of the AMA was moved and the headline was not updated! Apologies to anyone we’ve confused! – THANKS EVERYONE!! – We appreciate the great questions, comments and support. It’s been wonderful engaging with your enthusiastic content and we look forward to speaking with everyone again during future Reddits or any of our multitude of other NASA social media events. Our scheduled time for this event has ended, though some of us may continue to answer questions throughout the day, weekend or when our schedule allows. However, please feel free to continue to talk amongst yourselves. One great thing about our NASA fans is the depth of your combined knowledge and willingness to share it with the world. Thanks everyone and good luck with your Solar Eclipse viewing. Don’t forget to follow us on our social media channels, as we will have several opportunities to discuss the Solar Eclipse event, as well as other topics. :-) Sincerely, The NASA Goddard and NASA Marshall teams Hi reddit! We are scientists at NASA are studying heliophysics and how the sun, heliosphere and planetary environments function as a single, connected system and how elements of the system like space weather affect solar, planetary and interstellar conditions. Heliophysics is the study of the sun’s influence throughout the solar system, and its connection to the Earth and the Earth’s extended space environment. Answering your questions today: Dr. Linda Habash Krause I am a space plasma physics experimentalist at NASA Marshall’s Science and Technology Office and Project Scientist of a joint US-Brazil satellite mission entitled “Scintillation Prediction Observation Research Task” (SPORT). This mission, due to launch into low Earth orbit in 2019, will observe plasma turbulence in the ionosphere responsible for operational outages in our GPS navigation systems and some of our satellite communication systems. This is form of “space weather” that is a result of the interactions between the sun, magnetosphere, ionosphere, and upper neutral atmosphere, and I have been studying it for over 20 years. My activites have included installation of an ionospheric observatory in Nigeria, invention of space plasma instruments for satellites, and performing both scientific and mission operations duties for sounding rockets, the Space Shuttle, the ISS, tethered satellites, and free-flying satellites, and data mining and analysis of large space weather data sets. Mitzi Adams I’m a heliophysicist at NASA’s Marshall Space Flight Center and co-author of a paper published in Nature that deals with solar jets seen in solar coronal holes. I study various solar phenomena, like the jets, but also prominences, sunspots and sunspot magnetic fields, in an attempt to understand solar variability and space weather. Understanding space weather is important for protecting our satellite resources, mobile phone communications, and Earth’s power systems. Nicki Viall I’m Nicki Viall, and I’m a solar physicist at NASA Goddard. I study the solar corona, the part of the sun that we will see during the total solar eclipse in August. I also study the solar wind – the part of the solar corona that continuously flows off the sun. I primarily use data taken with NASA’s Solar Dynamics Observatory and NASA’s STEREO (Solar Terrestrial Relations Observatory). One of the instruments on STEREO is called a coronagraph and works by artificially creating an eclipse so that we can continuously observe the corona. Eric Christian I design and build instruments to study energetic sub-atomic particles in space, and use the data from these instrument to improve our understanding of the Sun, the heliosphere, and the distant galaxy. These particles give clues to the origin and evolution of our Sun and planets, and other solar systems. They are also an important part of Space Weather that can be dangerous to satellites and astronauts, and even to technology down on Earth, and can affect the habitability of planets throughout the galaxy. For more information: https://www.nasa.gov/mission_pages/sunearth/overview/index.html https://www.facebook.com/NASASunScience https://eclipse2017.nasa.gov We’ll be back at noon EST to answer your questions! AUA!

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