https://www.instagram.com/jiyeoomi/p/BmyXt49hYl0/
As our planet warms, sea levels are rising around the world – and are doing so at an accelerating rate. Currently, global sea level is rising about an eighth of an inch every year.
That may seem insignificant, but it’s 30% more than when NASA launched its first satellite mission to measure ocean heights in 1992 – less than 30 years ago. And people already feel the impacts, as seemingly small increments of sea level rise become big problems along coastlines worldwide.
Higher global temperatures cause our seas to rise, but how? And why are seas rising at a faster and faster rate? There are two main reasons: melting ice and warming waters.
The Ice We See Is Getting Pretty Thin
About two-thirds of global sea level rise comes from melting glaciers and ice sheets, the vast expanses of ice that cover Antarctica and Greenland. In Greenland, most of that ice melt is caused by warmer air temperatures that melt the upper surface of ice sheets, and when giant chunks of ice crack off of the ends of glaciers, adding to the ocean.
In Antarctica – where temperatures stay low year-round – most of the ice loss happens at the edges of glaciers. Warmer ocean water and warmer air meet at the glaciers’ edges, eating away at the floating ice sheets there.
NASA can measure these changes from space. With data from the Ice, Cloud and land Elevation Satellite-2, or ICESat-2, scientists can measure the height of ice sheets to within a fraction of an inch. Since 2006, an average of 318 gigatons of ice per year has melted from Greenland and Antarctica’s ice sheets. To get a sense of how big that is: just one gigaton is enough to cover New York City’s Central Park in ice 1,000 feet deep – almost as tall as the Chrysler Building.
With the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission – a partnership with the German Research Centre for Geosciences – scientists can calculate the mass of ice lost from these vast expanses across Greenland and Antarctica.
It’s not just glaciers in Antarctica and Greenland that are melting, though. Nearly all glaciers have been melting in the last decade, including those in Alaska, High Mountain Asia, South America, and the Canadian Arctic. Because these smaller glaciers are melting quickly, they contribute about the same amount to sea level rise as meltwater from massive ice sheets.
The Water’s Getting Warm
As seawater warms, it takes up more space. When water molecules get warmer, the atoms in those molecules vibrate faster, expanding the volume they take up. This phenomenon is called thermal expansion. It’s an incredibly tiny change in the size of a single water molecule, but added across all the water molecules in all of Earth’s oceans – a single drop contains well over a billion billion molecules – it accounts for about a third of global sea level rise.
So Much to See
While sea level is rising globally, it’s not the same across the planet. Sea levels are rising about an eighth of an inch per year on average worldwide. But some areas may see triple that rate, some may not observe any changes, and some may even experience a drop in sea level. These differences are due to ocean currents, mixing, upwelling of cold water from the deep ocean, winds, movements of heat and freshwater, and Earth’s gravitational pull moving water around. When ice melts from Greenland, for example, the drop in mass decreases the gravitational pull from the ice sheet, causing water to slosh to the shores of South America.
That’s where our view from space comes in. We’re launching Sentinel-6 Michael Freilich, an international partnership satellite, to continue our decades-long record of global sea level rise.
The Apollo 11 Moon landing was a feat for the ages. With the help of the NASA History Office, we’ve identified some of the most frequently asked questions surrounding the first time humans walked on the surface of another world. Click here to check out our post from last week.
Believe it or not, yes! The Apollo guidance computer not only had less computing power than a smartphone, it had less computing power than the calculator you use in your algebra class. The computer, designed by MIT, had a fixed memory of 36 kilobytes and an erasable memory of 2 kilobytes. That’s fairly advanced for the time!
A substantial portion of the Apollo 11 crew’s checklist was taking photographs. Taking closeup shots of the "very fine” moon dust was a critical component of mission objectives and helped scientists better understand the surface makeup of the Moon.
Armstrong and Aldrin wore lunar overboots over their main spacesuit boots to protect them from ultraviolet radiation and hazardous rocks. To make room for the nearly 50 pounds (22 kilograms) of lunar samples, the crew left all their pairs of boots on the Moon. But don’t worry; they wouldn’t get charged an overweight baggage fee anyway.
That’s somewhat subject to interpretation. Once the Lunar Module’s footpads touched the surface, Buzz Aldrin called out “Contact Light” to Mission Control. After the engine shut down, he said “ACA out of detent,” simply meaning that the Eagle’s Attitude Control Assembly, or control stick, was moved from its center position.
But the first words heard by the entire world after Apollo 11 touched down were delivered by Neil Armstrong: "Houston, Tranquility Base here. The Eagle has landed.” More than six hours later, Armstrong stepped off the Eagle’s footpad and delivered the most famous words ever spoken from the surface of another world: "That’s one small step for [a] man, one giant leap for mankind." And although we have a hard time hearing it in the recording, Armstrong clarified in a post-flight interview that he actually said, “That’s one small step for a man…”
We can’t say for sure what our next moonwalkers will decide to say, but perhaps the better question is: What would be your first words if you were to land on the Moon? There’s no doubt that the astronauts of the Artemis Generation will inspire a new crop of explorers the way Apollo Generation astronauts did 50 years ago. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
We judge ourselves by what we feel capable of doing, while others judge us by what we have already done.
Henry Wadsworth Longfellow (via quotemadness)
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
When the first Apollo astronauts returned from the Moon in 1969, the Moon’s surface was thought to be completely dry. Over the last 20 years, orbital and impactor missions confirmed water ice is present inside dark, permanently shadowed craters around the poles. But could water survive in the Moon’s sunnier regions? Using SOFIA, the world’s largest flying observatory, we found water on a sunlit lunar surface for the first time. The discovery suggests water may be distributed across the Moon’s surface, which is a whopping 14.6 million square miles. Scientists think the water could be stored inside glass beadlike structures within the soil that can be smaller than the tip of a pencil. The amount of water detected is equivalent to about a 12-ounce bottle trapped in a cubic meter volume of soil. While that amount is 100 times less than what’s found in the Sahara Desert, discovering even small amounts raises new questions about how this precious resource is created and persists on the harsh, airless lunar surface. Learn more about the discovery:
We are eager to learn all we can about the presence of water in advance of sending the first woman and next man to the lunar surface in 2024 under our Artemis program. What we learn on and around the Moon will help us take the next giant leap – sending astronauts to Mars.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
The Butterfly Nebula, created by a dying star, was captured by the Hubble Space Telescope in this spectacular image. Observations were taken over a more complete spectrum of light, helping researchers better understand the “wings'' of gas bursting out from its center. The nebula’s dying central star has become exceptionally hot, shining ultraviolet light brightly over the butterfly’s wings and causing the gas to glow.
Learn more about Hubble’s celebration of Nebula November and see new nebula images, here.
You can also keep up with Hubble on Twitter, Instagram, Facebook, and Flickr!
Image credits: NASA, ESA, and J. Kastner (RIT)
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
No matter what happens in life, be good to people.
Being good to people is a wonderful legacy to leave behind.
[ Taylor Swift ]
Bruna Lirio