A quarter-century ago, the Solar and Heliospheric Observatory (SOHO) launched to space. Its 25 years of data have changed the way we think about the Sun — illuminating everything from the Sun’s inner workings to the constant changes in its outermost atmosphere.
SOHO — a joint mission of the European Space Agency and NASA — carries 12 instruments to study different aspects of the Sun. One of the gamechangers was SOHO’s coronagraph, a type of instrument that uses a solid disk to block out the bright face of the Sun and reveal the relatively faint outer atmosphere, the corona. With SOHO’s coronagraph, scientists could image giant eruptions of solar material and magnetic fields, called coronal mass ejections, or CMEs. SOHO’s images revealed shape and structure of CMEs in breathtaking detail.
These solar storms can impact robotic spacecraft in their path, or — when intense and aimed at Earth — threaten astronauts on spacewalks and even disrupt power grids on the ground. SOHO is particularly useful in viewing Earth-bound storms, called halo CMEs — so called because when a CME barrels toward us on Earth, it appears circular, surrounding the Sun, much like watching a balloon inflate by looking down on it.
Before SOHO, the scientific community debated whether or not it was even possible to witness a CME coming straight toward us. Today, SOHO images are the backbone of space weather prediction models, regularly used in forecasting the impacts of space weather events traveling toward Earth.
Beyond the day-to-day monitoring of space weather, SOHO has been able to provide insight about our dynamic Sun on longer timescales as well. With 25 years under its belt, SOHO has observed a full magnetic cycle — when the Sun’s magnetic poles switch places and then flip back again, a process that takes about 22 years in total. This trove of data has led to revolutions in solar science: from revelations about the behavior of the solar core to new insight into space weather events that explode from the Sun and travel throughout the solar system.
Data from SOHO, sonified by the Stanford Experimental Physics Lab, captures the Sun’s natural vibrations and provides scientists with a concrete representation of its dynamic movements.
The legacy of SOHO’s instruments — such as the extreme ultraviolet imager, the first of its kind to fly in orbit — also paved the way for the next generation of NASA solar satellites, like the Solar Dynamics Observatory and STEREO. Even with these newer instruments now in orbit, SOHO’s data remains an invaluable part of solar science, producing nearly 200 scientific papers every year.
Relatively early in its mission, SOHO had a brush with catastrophe. During a routine calibration procedure in June 1998, the operations team lost contact with the spacecraft. With the help of a radio telescope in Arecibo, the team eventually located SOHO and brought it back online by November of that year. But luck only held out so long: Complications from the near loss emerged just weeks later, when all three gyroscopes — which help the spacecraft point in the right direction — failed. The spacecraft was no longer stabilized. Undaunted, the team’s software engineers developed a new program that would stabilize the spacecraft without the gyroscopes. SOHO resumed normal operations in February 1999, becoming the first spacecraft of its kind to function without gyroscopes.
SOHO’s coronagraph have also helped the Sun-studying mission become the greatest comet finder of all time. The mission’s data has revealed more than 4,000 comets to date, many of which were found by citizen scientists. SOHO’s online data during the early days of the mission made it possible for anyone to carefully scrutinize a image and potentially spot a comet heading toward the Sun. Amateur astronomers from across the globe joined the hunt and began sending their findings to the SOHO team. To ease the burden on their inboxes, the team created the SOHO Sungrazer Project, where citizen scientists could share their findings.
Keep up with the latest SOHO findings at nasa.gov/soho, and follow along with @NASASun on Twitter and facebook.com/NASASunScience.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Shirakawa village,Gifu Prefecture(白川郷,岐阜県) by Kinhaku on Flickr.
石川恋
Former NASA astronaut and Girl Scout alumna Jan Davis eating Girl Scout Cookies inside the shuttle Endeavour on Sept. 12, 1992. Image credit: NASA
Leadership, service, being prepared and doing your best – these qualities are exemplified by our astronauts, but are also shared by the Girl Scouts! Our astronaut corps has many scout alumnae, and over the years they’ve been breaking barriers and making names for themselves at NASA.
Today marks the 108th birthday of Girl Scouts in the United States, which has been inspiring generations of girls through leadership and STEM (science, technology, engineering and mathematics) activities to empower the explorers of today and tomorrow. To celebrate, we’re highlighting some of our Girl Scout alumnae over the years!
NASA astronaut and Girl Scout alumna Sunita Williams, who served as an International Space Station commander and spent 322 days in space during two spaceflight expeditions.
From left: Susan Helms, the first female International Space Station crew member; Eileen Collins, the first woman to pilot and command a space shuttle; and Dr. Kathy Sullivan, the first American woman to perform a spacewalk.
Former Girl Scouts flew on more than one-third of the space shuttle missions and were pioneering forces as women began making their mark on human spaceflight. The first female crew member to serve on the International Space Station, the first to pilot and command a space shuttle and the first American woman to spacewalk were all Scout alumnae.
NASA astronaut Christina Koch smiles for a selfie while completing tasks during a spacewalk outside the International Space Station.
Koch went on to seal her name in the record books by surpassing Peggy Whitson’s record for the longest single spaceflight in history by a woman!
Understanding how the human body adjusts to things like weightlessness, radiation and bone-density loss is crucial as we look forward to embarking on long-duration spaceflights to the Moon and Mars. Thanks to former astronaut Scott Kelly’s Year in Space mission, we’ve been able to observe these changes on a biological male. Now, thanks to Christina’s mission, we are able to observe these changes on a biological female.
From left: NASA astronauts Kayla Barron, Jessica Watkins and Loral O’Hara
On January 10, 2020 we welcomed 11 new astronauts to our ranks – including three Girl Scout alumnae! As part of the first-ever class of astronauts under our Artemis lunar exploration program, Kayla Barron, Jessica Watkins and Loral O’Hara are now qualified for assignments including long-duration missions to the International Space Station, the Moon and Mars.
Q: A question from the Girl Scouts: What inspires you?
A: “Being a part of an awesome team has always been what inspires me. Whether it’s your Girl Scout troop, a sports team, your class – I think for me always the people around me who push me to succeed and support me when I make mistakes and help me become my best self is what inspires me to show up and do my best.” - NASA astronaut Kayla Barron
Q: How has being a Girl Scout helped you in becoming an astronaut?
A: “Being in the Girl Scouts when I was younger was really cool because, well, first it was just a group of my friends who got to do a lot of different things together. But it really gave us the opportunity to be exposed to a lot of different areas. Like we’d get to go camping. We’d get to ride horses and learn all of these different skills, and so that variety of skill set I think is very applicable to being an astronaut.” - NASA astronaut Loral O’Hara
Q: What would your advice be for the next generation of Girl Scout astronauts?
A: “My advice would be to find something that you’re passionate about. Ideally something in the STEM fields: Science, Technology, Engineering or Mathematics, and to pursue that thing that you’re interested in. Pursue that passion, whatever it is. And don’t give up on your dreams, and continue to follow them until you arrive where you want to be.” - NASA astronaut Jessica Watkins
To all the Girl Scouts out there, keep reaching for the stars because the sky is no longer the limit!
Astronaut applications are OPEN until March 31 for the next class of Artemis generation astronauts who will embark on missions to the International Space Station, the Moon and Mars. If you’re interested in applying to #BeAnAstronaut or just want to learn more, click HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Here are astronauts Richard Truly & Guion Bluford of Space Transport System 8 (STS-8) grabbing some shut-eye before the wrap up of their mission. This mission had:
The first African American, Guion Bluford, to fly in space
The first night launch and landing during the Space Shuttle Program
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
“The best preparation for tomorrow is doing your best today.”
— H. Jackson Brown