Celestial Valentine’s Day Cards

Earth’s Land Ice by the Numbers

“At a glacial pace” used to mean moving so slowly the movement is almost imperceptible. Lately though, glaciers are moving faster. Ice on land is melting and flowing, sending water to the oceans, where it raises sea levels.

In 2018, we launched the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) to continue a global record of ice elevation. Now, the results are in. Using millions of measurements from a laser in space and quite a bit of math, researchers have confirmed that Earth is rapidly losing ice.

16 Years 

ICESat-2 was a follow-up mission to the original ICESat, which launched in 2003 and took measurements until 2009. Comparing the two records tells us how much ice sheets have melted over 16 years.

½ Inch

During those 16 years, melting ice from Antarctica and Greenland was responsible for just over a half-inch of sea level rise. When ice on land melts, it eventually finds its way to the ocean. The rapid melt at the poles is no exception.

400,000 Olympic Swimming Pools

One gigaton of ice holds enough water to fill 400,000 Olympic swimming pools. It’s also enough ice to cover Central Park in New York in more than 1,000 feet of ice.

200 Gigatons

Between 2003 and 2019, Greenland lost 200 gigatons of ice per year. That’s 80 million Olympic swimming pools reaching the ocean every year, just from Greenland alone.

118 Gigatons

During the same time period, Antarctica lost 118 gigatons of ice per year. That’s another 47 million Olympic swimming pools every year. While there has been some elevation gain in the continent’s center from increased snowfall, it’s nowhere near enough to make up for how much ice is lost to the sea from coastal glaciers.

10,000 Pulses

ICESat-2 sends out 10,000 pulses of laser light a second down to Earth’s surface and times how long it takes them to return to the satellite, down to a billionth of a second. That’s how we get such precise measurements of height and changing elevation.

These numbers confirm what scientists have been finding in most previous studies and continue a long record of data showing how Earth’s polar ice is melting. ICESat-2 is a key tool in our toolbox to track how our planet is changing.

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100th Anniversary of Einstein’s Theory of Relativity

One hundred years ago this month, Albert Einstein published his theory of general relativity (GR), one of the most important scientific achievements in the last century.

A key result of Einstein’s theory is that matter warps space-time, and thus a massive object can cause an observable bending of light from a background object. The first success of the theory was the observation, during a solar eclipse, that light from a distant background star was deflected by the predicted amount as it passed near the sun.

When Einstein developed the general theory of relativity, he was trying to improve our understanding of how the universe works. At the time, Newtonian gravity was more than sufficient for any practical gravity calculations. However, as often happens in physics, general relativity has applications that would not have been foreseen by Einstein or his contemporaries.

How many of us have used a smartphone to get directions? Or to tag our location on social media? Or to find a recommendation for a nearby restaurant? These activities depend on GPS. GPS uses radio signals from a network of satellites orbiting Earth at an altitude of 20,000 km to pinpoint the location of a GPS receiver. The accuracy of GPS positioning depends on precision in time measurements of billionths of a second. To achieve such timing precision, however, relativity must be taken into account.

Our Gravity Probe B (GP-B) mission has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test. The experiment, launched in 2004, and measured the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates.

Scientists continue to look for cracks in the theory, testing general relativity predictions using laboratory experiments and astronomical observations. For the past century, Einstein’s theory of gravity has passed every hurdle.

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Any advice for young girls going into the sciences?

You seem to have spent a lot of time in some pretty isolated locations during your career, what are some challenges to that? Was there anything you enjoyed about it?

What is an upcoming project/mission you're most excited for?

It is likely that I’ll be assigned a mission to the International Space Station (ISS) within the next few years.  We’ve had a continuous presence on the Space Station for 17 years now, along with our international partners (Russian Space Agency, European Space Agency, Japanese Space Agency, and Canadian Space Agency).  Missions on the ISS typically last 6 months.  I’m incredibly excited to contribute to the impressive array of scientific experiments that we are conducting every day on ISS (I am a scientist after all!), and very much look forward to the potential of going for a spacewalk and gaining that perspective of gazing down on the fragile blue ball that is our home from above.  Beyond that, being part of test missions on the Orion spacecraft (currently under construction at NASA!) would be an extraordinary opportunity.  The current NASA plan is to send astronauts in Orion in a mission that will go 40,000 miles beyond the Moon in the early 2020s, reaching a distance further than that ever travelled by humans.  I’d certainly be game for that! 

Last Glacier Standing in Venezuela

In 1910, glaciers covered at least 4 square miles (10 square km) of the mountainous region of northwestern Venezuela. Today, less than one percent of that ice remains, and all of it is locked up in one glacier. The ongoing retreat of Humboldt Glacier—Venezuela’s last patch of perennial ice—means that the country could soon be glacier-free.

The glacier is in the highest part of the Andes Mountains, on a slope at nearly 16,000 feet. A cold and snowy climate at high elevations is key for glaciers to exist in the tropics. Most of Earth’s tropical glaciers are found in the Andes, which runs through Venezuela, Colombia, Ecuador, Peru and Bolivia. But warming air temperatures have contributed to their decline, including Humboldt Glacier.

The relatively recent changes to Humboldt are evident in these images, acquired on Jan. 20, 1988, by the United States Geological Survey’s Landsat 5 and on Jan. 6, 2015, by Landsat 8. The images are false-color to better differentiate between areas of snow and ice (blue), land (brown) and vegetation (green).

Scientists are trying to understand how long Humboldt will remain. One said: “Let’s call it no more than 10 to 20 years.”

Read more: https://go.nasa.gov/2NuYcg6

More than Just Dust in the Wind

From space, we can see a swirling brown mass making its way across the Atlantic – dust from the Sahara Desert – the largest hot desert in the world. It’s a normal phenomenon. Every year, winds carry millions of tons of dust from North Africa, usually during spring and summer in the Northern Hemisphere.

June 2020 has seen a massive plume of dust crossing the ocean. It’s so large it’s visible from one million miles away in space.

Dust clouds this large can affect air quality in regions where the dust arrives. The particles can also scatter the Sun’s light, making sunrises and sunsets more vibrant.

Dust particles in the air are also known as aerosols. We can measure aerosols, including dust, sea salt and smoke, from satellites and also use computer models to study how they move with the wind.

Following the transport of dust from space shows us how one of the driest places on Earth plays a role in fertilizing the Amazon rainforest. There are minerals in Saharan dust, like phosphorous, that exist in commercial fertilizers, helping seed the rainforest.

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The National Space Council

October 5 marks the first meeting of the National Space Council since 1993. But what is it and why does it matter? Let us explain by taking a trip back in history… We’ve teleported back to 1958…President Dwight Eisenhower is in office and the National Aeronautics and Space Council was created with the signing of the Space Act that year. President Eisenhower chaired the first National Aeronautics and Space Council (NASC). That council continued during the Kennedy, Johnson and Nixon Administrations during which we put an American in outer space with John Glenn in 1962 and put humans on the moon starting in 1969. That Council was disbanded in 1973.

In 1989, President George H.W. Bush’s Administration reinstated what was known as the National Space Council, which was designed to help chart national space policy and the roles of multiple federal agencies such as NASA. The Space Council disbanded again in 1993.

On June 30, 2017, President Trump signed an executive order reestablishing the National Space Council – which brings us to today. The current National Space Council will bring a unified national perspective on space policy to the Administration by coordinating the views of the civilian, commercial and national security sectors.

So now that you have a bit of the history…why does this matter?

With the Oct. 5 meeting, titled “Leading the Next Frontier: An Event with the National Space Council,” Vice President Mike Pence will convene this council and have participation from acting NASA Administrator Robert Lightfoot, as well as a number of Trump Administration cabinet members and senior officials, and aerospace industry leaders.

During the council’s first meeting, we will hear from experts who represent various parts of the space industry: Civil Space, Commercial Space and National Security Space.

You can watch the first meeting of the National Space Council starting at 10 a.m. EDT HERE.

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Why do scientists think there could have been life on Mars?

A Spacecraft's Second Life: Our K2 mission

A critical failure that ended one mission has borne an unexpected and an exciting new science opportunity. The Kepler spacecraft, known for finding thousands of planets orbiting other stars, has a new job as the K2 mission.

Like its predecessor, K2 detects the tiny, telltale dips in the brightness of a star as an object passes or transits it, to possibly reveal the presence of a planet. Searching close neighboring stars for near-Earth-sized planets, K2 is finding planets ripe for follow-up studies on their atmospheres and to see what the planet is made of. A step up from its predecessor, K2 is revealing new info on comets, asteroids, dwarf planets, ice giants and moons. It will also provide new insight into areas as diverse as the birth of new stars, how stars explode into spectacular supernovae, and even the evolution of black holes.

K2 is expanding the planet-hunting legacy and has ushered in entirely new opportunities in astrophysics research, yet this is only the beginning.

Searching Nearby for Signs of Life

Image credit: ESO/L. Calçada

Scientists are excited about nearby multi-planet system known as K2-3. This planetary system, discovered by K2, is made of three super-Earth-sized planets orbiting a cool M-star (or red dwarf) 135 light-years away, which is relatively close in astronomical terms. To put that distance into perspective, if the Milky Way galaxy was scaled down to the size of the continental U.S. it would be the equivalent of walking the three-mile long Golden Gate Park in San Francisco, California. At this distance, our other powerful space-investigators – the Hubble Space Telescope and the forthcoming James Webb Space Telescope (JWST) – could study the atmospheres of these worlds in search of chemical fingerprints that could be indicative of life. K2 expects to find a few hundred of these close-by, near-Earth-sized neighbors.

K2 won’t be alone in searching for nearby planets outside our solar system. Revving up for launch around 2017-2018, our Transiting Exoplanet Survey Satellite (TESS) plans to monitor 200,000 close stars for planets, with a focus on finding Earth and Super-Earth-sized planets.

The above image is an artist rendering of Gliese 581, a planetary system representative of K2-3.

Neptune's Moon Dance

Movie credit: NASA Ames/SETI Institute/J. Rowe

Spying on our neighbors in our own solar system, K2 caught Neptune in a dance with its moons Triton and Nereid. On day 15 (day counter located in the top right-hand corner of the green frame) of the sped-up movie, Neptune appears, followed by its moon Triton, which looks small and faint. Keen-eyed observers can also spot Neptune's tiny moon Nereid at day 24. Neptune is not moving backward but appears to do so because of the changing position of the Kepler spacecraft as it orbits around the sun. A few fast-moving asteroids make cameo appearances in the movie, showing up as streaks across the K2 field of view. The red dots are a few of the stars K2 examines in its search for transiting planets outside of our solar system. An international team of astronomers is using these data to track Neptune’s weather and probe the planet’s internal structure by studying subtle brightness fluctuations that can only be observed with K2.

Dead Star Devours Planet

Image credit: CfA/Mark A. Garlick

K2 also caught a white dwarf – the dead core of an exploded star –vaporizing a nearby tiny rocky planet. Slowly the planet will disintegrate, leaving a dusting of metals on the surface of the star. This trail of debris blocks a tiny fraction of starlight from the vantage point of the spacecraft producing an unusual, but vaguely familiar pattern in the data. Recognizing the pattern, scientists further investigated the dwarf’s atmosphere to confirm their find. This discovery has helped validate a long-held theory that white dwarfs are capable of cannibalizing possible remnant planets that have survived within its solar system.

Searching for Far Out Worlds

NASA/JPL-Caltech

In April, spaced-based K2 and ground-based observatories on five continents will participate in a global experiment in exoplanet observation and simultaneously monitor the same region of sky towards the center of our galaxy to search for small planets, such as the size of Earth, orbiting very far from their host star or, in some cases, orbiting no star at all. For this experiment, scientists will use gravitational microlensing – the phenomenon that occurs when the gravity of a foreground object focuses and magnifies the light from a distant background star.

The animation demonstrates the principles of microlensing. The observer on Earth sees the source (distant) star when the lens (closer) star and planet pass through the center of the image. The inset shows what may be seen through a ground-based telescope. The image brightens twice, indicating when the star and planet pass through the observatory's line of sight to the distant star.

Full microlensing animation available HERE.

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