(via Voyager 2 Is Gathering Science Data Again After Recovering From A Glitch In Interstellar Space |

May the Four Forces Be With You!

May the force be with you? Much to learn you still have, padawan. In our universe it would be more appropriate to say, “May the four forces be with you.”

There are four fundamental forces that bind our universe and its building blocks together. Two of them are easy to spot — gravity keeps your feet on the ground while electromagnetism keeps your devices running. The other two are a little harder to see directly in everyday life, but without them, our universe would look a lot different!

Let’s explore these forces in a little more detail.

Gravity: Bringing the universe together

If you jump up, gravity brings you back down to Earth. It also keeps the solar system together … and our galaxy, and our local group of galaxies and our supercluster of galaxies.

Gravity pulls everything together. Everything, from the bright centers of the universe to the planets farthest from them. In fact, you (yes, you!) even exert a gravitational force on a galaxy far, far away. A tiny gravitational force, but a force nonetheless.

Credit: NASA and the Advanced Visualization Laboratory at the National Center for Supercomputing and B. O'Shea, M. Norman

Despite its well-known reputation, gravity is actually the weakest of the four forces. Its strength increases with the mass of the two objects involved. And its range is infinite, but the strength drops off as the square of the distance. If you and a friend measured your gravitational tug on each other and then doubled the distance between you, your new gravitational attraction would just be a quarter of what it was. So, you have to be really close together, or really big, or both, to exert a lot of gravity.

Even so, because its range is infinite, gravity is responsible for the formation of the largest structures in our universe! Planetary systems, galaxies and clusters of galaxies all formed because gravity brought them together.

Gravity truly surrounds us and binds us together.

Electromagnetism: Lighting the way

You know that shock you get on a dry day after shuffling across the carpet? The electricity that powers your television? The light that illuminates your room on a dark night? Those are all the work of electromagnetism. As the name implies, electromagnetism is the force that includes both electricity and magnetism.

Electromagnetism keeps electrons orbiting the nucleus at the center of atoms and allows chemical compounds to form (you know, the stuff that makes up us and everything around us). Electromagnetic waves are also known as light. Once started, an electromagnetic wave will travel at the speed of light until it interacts with something (like your eye) — so it will be there to light up the dark places.

Like gravity, electromagnetism works at infinite distances. And, also like gravity, the electromagnetic force between two objects falls as the square of their distance. However, unlike gravity, electromagnetism doesn’t just attract. Whether it attracts or repels depends on the electric charge of the objects involved. Two negative charges or two positive charges repel each other; one of each, and they attract each other. Plus. Minus. A balance.

This is what happens with common household magnets. If you hold them with the same “poles” together, they resist each other. On the other hand, if you hold a magnet with opposite poles together — snap! — they’ll attract each other.

Electromagnetism might just explain the relationship between a certain scruffy-looking nerf-herder and a princess.

Strong Force: Building the building blocks

Credit: Lawrence Livermore National Laboratory

The strong force is where things get really small. So small, that you can’t see it at work directly. But don’t let your eyes deceive you. Despite acting only on short distances, the strong force holds together the building blocks of the atoms, which are, in turn, the building blocks of everything we see around us.

Like gravity, the strong force always attracts, but that’s really where their similarities end. As the name implies, the force is strong with the strong force. It is the strongest of the four forces. It brings together protons and neutrons to form the nucleus of atoms — it has to be stronger than electromagnetism to do it, since all those protons are positively charged. But not only that, the strong force holds together the quarks — even tinier particles — to form those very protons and neutrons.

However, the strong force only works on very, very, very small distances. How small? About the scale of a medium-sized atom’s nucleus. For those of you who like the numbers, that’s about 10-15 meters, or 0.000000000000001 meters. That’s about a hundred billion times smaller than the width of a human hair! Whew.

Its tiny scale is why you don’t directly see the strong force in your day-to-day life. Judge a force by its physical size, do you? 

Weak Force: Keeping us in sunshine

If you thought it was hard to see the strong force, the weak force works on even smaller scales — 1,000 times smaller. But it, too, is extremely important for life as we know it. In fact, the weak force plays a key role in keeping our Sun shining.

But what does the weak force do? Well … that requires getting a little into the weeds of particle physics. Here goes nothing! We mentioned quarks earlier — these are tiny particles that, among other things, make up protons and neutrons. There are six types of quarks, but the two that make up protons and neutrons are called up and down quarks. The weak force changes one quark type into another. This causes neutrons to decay into protons (or the other way around) while releasing electrons and ghostly particles called neutrinos.

So for example, the weak force can turn a down quark in a neutron into an up quark, which will turn that neutron into a proton. If that neutron is in an atom’s nucleus, the electric charge of the nucleus changes. That tiny change turns the atom into a different element! Such reactions are happening all the time in our Sun, giving it the energy to shine.

The weak force might just help to keep you in the (sun)light.

All four of these forces run strong in the universe. They flow between all things and keep our universe in balance. Without them, we’d be doomed. But these forces will be with you. Always.

You can learn more about gravity from NASA’s Space Place and follow NASAUniverse on Twitter or Facebook to learn about some of the cool cosmic objects we study with light.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Hubble Hooks a One-Arm Galaxy via NASA https://ift.tt/3bGuO2f

M83, Southern Pinwheel

UGC 12591: The Fastest Rotating Galaxy Known via NASA https://ift.tt/326jqJe

NGC 253: The Silver Coin Galaxy via NASA https://ift.tt/2yYJ2NM

NGC 253 is one of the brightest spiral galaxies visible, but also one of the dustiest. Dubbed the Silver Coin for its appearance in smalltelescopes, it is more formally known as the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. Discovered in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 10 million light-years away. About 70 thousand light-years across, NGC 253, pictured, is the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group of galaxies. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions in this sharp color image. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy’s center. Take a trip through extragalactic space in this short video flyby of NGC 253.

(Published April 14, 2020)

Who Was Mary W. Jackson?

On June 24, 2020, NASA announced the agency’s headquarters building in Washington, D.C., was to be named after Mary W. Jackson, the first African American female engineer at NASA.

Jackson’s story — along with those of her colleagues Katherine Johnson, Dorothy Vaughan, and Christine Darden — was popularized with the release of the “Hidden Figures” movie, based on Margot Lee Shetterly’s book by the same name.

Today, as the accomplishments of these women are brought to light, we celebrate them as Modern Figures — hidden no longer. Despite their recent recognition, we cannot forget the challenges that women and BIPOC faced and continue to face in the STEM fields.

Background

Jackson showed talent for math and science at an early age. She was born in 1921 in Hampton, Virginia, and attended the all-Black George P. Phenix Training School where she graduated with honors. She graduated from Hampton Institute (now Hampton University) in 1942 with a bachelor of science degree in both mathematics and physical sciences.

Jackson worked several jobs before arriving at the National Advisory Committee on Aeronautics (NACA), the precursor organization to NASA. She was a teacher, a receptionist, and a bookkeeper — in addition to becoming a mother — before accepting a position with the NACA Langley Aeronautical Laboratory’s segregated West Area Computers in 1951, where her supervisor was Dorothy Vaughan.

Accomplishments 

After two years in West Computing, Jackson was offered a computing position to work in the 4-foot by 4-foot Supersonic Pressure Tunnel. She was also encouraged to enter a training program that would put her on track to become an engineer — however, she needed special permission from the City of Hampton to take classes in math and physics at then-segregated Hampton High School.

She completed the courses, earned the promotion, and in 1958 became NASA’s first African-American female engineer. That same year, she co-authored her first report, “Effects of Nose Angle and Mach Number on Transition on Cones at Supersonic Speeds.” By 1975, she had authored or co-authored 12 NACA and NASA technical publications — most focused on the behavior of the boundary layer of air around an airplane.

Legacy

Jackson eventually became frustrated with the lack of management opportunities for women in her field. In 1979, she left engineering to become NASA Langley’s Federal Women’s Program Manager to increase the hiring and promotion of NASA’s female mathematicians, engineers, and scientists.

Not only was she devoted to her career, Jackson was also committed to the advancement of her community. In the 1970s, she helped the students in the Hampton King Street Community Center build their own wind tunnel and run experiments. She and her husband Levi took in young professionals in need of guidance. She was also a Girl Scout troop leader for more than three decades.  

Jackson retired from Langley in 1985. Never accepting the status quo, she dedicated her life to breaking barriers for minorities in her field. Her legacy reminds us that inclusion and diversity are needed to live up to NASA’s core values of teamwork and excellence.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

2020 March 1

A Hole in Mars Image Credit: NASA, JPL, U. Arizona

Explanation: What created this unusual hole in Mars? The hole was discovered by chance in 2011 on images of the dusty slopes of Mars’ Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole, shown in representative color, appears to be an opening to an underground cavern, partly illuminated on the image right. Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation, as is the full extent of the underlying cavern. Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life. These pits are therefore prime targets for possible future spacecraft, robots, and even human interplanetary explorers.

∞ Source: apod.nasa.gov/apod/ap200301.html

May Ms. Johnson forever rest in peace knowing she helped forward humanity to the stars.

Mathematician. Leader. Heroine. Remembering Hidden Figure Katherine Johnson

Tonight, count the stars and remember a trailblazer. 

We’re saddened by the passing of celebrated #HiddenFigures mathematician Katherine Johnson. She passed away at 101 years old. 

An America hero, Johnson’s legacy of excellence broke down racial and social barriers while helping get our space agency off the ground.

Once a “human computer”, she famously calculated the flight trajectory for Alan Shepard, the first American in space.

And when we began to use electronic computers for calculations, astronaut John Glenn said that he’d trust the computers only after Johnson personally checked the math.

As a girl, Katherine Johnson counted everything. As a mathematician, her calculations proved critical to our early successes in space travel.

With slide rules and pencils, Katherine Johnson’s brilliant mind helped launch our nation into space. No longer a Hidden Figure, her bravery and commitment to excellence leaves an eternal legacy for us all.

“We will always have STEM with us. Some things will drop out of the public eye and will go away, but there will always be science, engineering and technology. And there will always, always be mathematics.” - Katherine Johnson 1918 -2020 

May she rest in peace, and may her powerful legacy inspire generations to come! What does Katherine Johnson’s legacy mean to you? Share in the comments. 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com