Solar System: 10 Things To Know This Week

Caution: Universe Work Ahead 🚧

We only have one universe. That’s usually plenty – it’s pretty big after all! But there are some things scientists can’t do with our real universe that they can do if they build new ones using computers.

The universes they create aren’t real, but they’re important tools to help us understand the cosmos. Two teams of scientists recently created a couple of these simulations to help us learn how our Nancy Grace Roman Space Telescope sets out to unveil the universe’s distant past and give us a glimpse of possible futures.

Caution: you are now entering a cosmic construction zone (no hard hat required)!

This simulated Roman deep field image, containing hundreds of thousands of galaxies, represents just 1.3 percent of the synthetic survey, which is itself just one percent of Roman's planned survey. The full simulation is available here. The galaxies are color coded – redder ones are farther away, and whiter ones are nearer. The simulation showcases Roman’s power to conduct large, deep surveys and study the universe statistically in ways that aren’t possible with current telescopes.

One Roman simulation is helping scientists plan how to study cosmic evolution by teaming up with other telescopes, like the Vera C. Rubin Observatory. It’s based on galaxy and dark matter models combined with real data from other telescopes. It envisions a big patch of the sky Roman will survey when it launches by 2027. Scientists are exploring the simulation to make observation plans so Roman will help us learn as much as possible. It’s a sneak peek at what we could figure out about how and why our universe has changed dramatically across cosmic epochs.

This video begins by showing the most distant galaxies in the simulated deep field image in red. As it zooms out, layers of nearer (yellow and white) galaxies are added to the frame. By studying different cosmic epochs, Roman will be able to trace the universe's expansion history, study how galaxies developed over time, and much more.

As part of the real future survey, Roman will study the structure and evolution of the universe, map dark matter – an invisible substance detectable only by seeing its gravitational effects on visible matter – and discern between the leading theories that attempt to explain why the expansion of the universe is speeding up. It will do it by traveling back in time…well, sort of.

Seeing into the past

Looking way out into space is kind of like using a time machine. That’s because the light emitted by distant galaxies takes longer to reach us than light from ones that are nearby. When we look at farther galaxies, we see the universe as it was when their light was emitted. That can help us see billions of years into the past. Comparing what the universe was like at different ages will help astronomers piece together the way it has transformed over time.

This animation shows the type of science that astronomers will be able to do with future Roman deep field observations. The gravity of intervening galaxy clusters and dark matter can lens the light from farther objects, warping their appearance as shown in the animation. By studying the distorted light, astronomers can study elusive dark matter, which can only be measured indirectly through its gravitational effects on visible matter. As a bonus, this lensing also makes it easier to see the most distant galaxies whose light they magnify.

The simulation demonstrates how Roman will see even farther back in time thanks to natural magnifying glasses in space. Huge clusters of galaxies are so massive that they warp the fabric of space-time, kind of like how a bowling ball creates a well when placed on a trampoline. When light from more distant galaxies passes close to a galaxy cluster, it follows the curved space-time and bends around the cluster. That lenses the light, producing brighter, distorted images of the farther galaxies.

Roman will be sensitive enough to use this phenomenon to see how even small masses, like clumps of dark matter, warp the appearance of distant galaxies. That will help narrow down the candidates for what dark matter could be made of.

In this simulated view of the deep cosmos, each dot represents a galaxy. The three small squares show Hubble's field of view, and each reveals a different region of the synthetic universe. Roman will be able to quickly survey an area as large as the whole zoomed-out image, which will give us a glimpse of the universe’s largest structures.

Constructing the cosmos over billions of years

A separate simulation shows what Roman might expect to see across more than 10 billion years of cosmic history. It’s based on a galaxy formation model that represents our current understanding of how the universe works. That means that Roman can put that model to the test when it delivers real observations, since astronomers can compare what they expected to see with what’s really out there.

In this side view of the simulated universe, each dot represents a galaxy whose size and brightness corresponds to its mass. Slices from different epochs illustrate how Roman will be able to view the universe across cosmic history. Astronomers will use such observations to piece together how cosmic evolution led to the web-like structure we see today.

This simulation also shows how Roman will help us learn how extremely large structures in the cosmos were constructed over time. For hundreds of millions of years after the universe was born, it was filled with a sea of charged particles that was almost completely uniform. Today, billions of years later, there are galaxies and galaxy clusters glowing in clumps along invisible threads of dark matter that extend hundreds of millions of light-years. Vast “cosmic voids” are found in between all the shining strands.

Astronomers have connected some of the dots between the universe’s early days and today, but it’s been difficult to see the big picture. Roman’s broad view of space will help us quickly see the universe’s web-like structure for the first time. That’s something that would take Hubble or Webb decades to do! Scientists will also use Roman to view different slices of the universe and piece together all the snapshots in time. We’re looking forward to learning how the cosmos grew and developed to its present state and finding clues about its ultimate fate.

This image, containing millions of simulated galaxies strewn across space and time, shows the areas Hubble (white) and Roman (yellow) can capture in a single snapshot. It would take Hubble about 85 years to map the entire region shown in the image at the same depth, but Roman could do it in just 63 days. Roman’s larger view and fast survey speeds will unveil the evolving universe in ways that have never been possible before.

Roman will explore the cosmos as no telescope ever has before, combining a panoramic view of the universe with a vantage point in space. Each picture it sends back will let us see areas that are at least a hundred times larger than our Hubble or James Webb space telescopes can see at one time. Astronomers will study them to learn more about how galaxies were constructed, dark matter, and much more.

The simulations are much more than just pretty pictures – they’re important stepping stones that forecast what we can expect to see with Roman. We’ve never had a view like Roman’s before, so having a preview helps make sure we can make the most of this incredible mission when it launches.

Learn more about the exciting science this mission will investigate on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space!

Say Hello to NGC 6441

Location: In the Scorpius constellation

Distance from Earth: About 44,000 light-years

Object type: Globular star cluster

Discovered by: James Dunlop in 1826

Each tiny point of light in this image is its own star - and there are more than a million of them! This stunning image captured by the Hubble Telescope depicts NGC 6441, a globular cluster that weighs about 1.6 million times the mass of our Sun. Globular clusters like NGC 6441 are groups of old stars held together by their mutual gravitational attraction, appearing nearly spherical in shape due to the density of stars that comprises them. This particular cluster is one of the most massive and luminous in our Milky Way Galaxy. It is also home to a planetary nebula and four pulsars (rotating neutron stars that emit beams of radiation at steady intervals, detected when the beams are aimed at Earth). 

Read more information about NGC 6441 here.

Right now, the Hubble Space Telescope is delving into its #StarrySights campaign! Find more star cluster content and spectacular new images by following along on Hubble’s Twitter, Facebook, and Instagram.

Make sure to follow us on Tumblr for your regular dose of space!

What Have We Learned About Pluto?

Earlier this year on July 14, our New Horizons spacecraft successfully flew by Pluto. During this encounter, it collected more than 1,200 images of the dwarf planet and tens of gigabits of data. The intensive downlinking of this information began on Sept. 5, and will continue for around a year. With the information being returned for the duration of a year, we still have a lot more to learn about Pluto. Here are a few things we’ve discovered so far:

Pluto’s Heart

An image captured by New Horizons around 16 hours before closest approach displays Pluto’s “heart”. This stunning image of one of the planet’s most dominate features shows us that the heart’s diameter is about the same distance as from Denver to Chicago. This image also showed us that Pluto is a complex world with incredible geological diversity.

Icy Plains

Pluto’s vast icy plain, informally called Sputnik Planum, resembles frozen mud cracks on Earth. It has a broken surface of irregularly-shaped segments, bordered by what appear to be shallow troughs. In other areas, the surface appears to be etched by fields of small pits that may have formed by a process called sublimation, which is when ice turns directly from solid to gas, just as dry ice does on Earth. 

Majestic Mountains

Images from the spacecraft display chaotically jumbled mountains that only add to the complexity of Pluto’s geography. The rugged, icy mountains are as tall as 11,000 feet high.

Color Variations

This high-resolution enhanced color view of Pluto combines, blue red and infrared images taken by the New Horizons spacecraft. The surface of the dwarf planet has a remarkable range of subtle color variations. Many landforms have their own distinct colors, telling a complex geological and climatological story of the planet.

Foggy Haze and Blue Atmosphere

Images returned from the New Horizons spacecraft have also revealed that Pluto’s global atmospheric haze has many more layers than scientists realized. The haze even creates a twilight effect that softly illuminates nightside terrain near sunset, which makes them visible to the cameras aboard the spacecraft. Today, a new announcement was made about Pluto’s atmosphere after the most recent image returned from New Horizons showed that Pluto’s hazes are blue. The haze particles themselves are likely gray or red, but they way they scatter blue light has created this tint.

Water Ice

In another finding announced today, New Horizons has detected numerous small, exposed regions of water ice on Pluto. Scientists are eager to understand why water appears exactly where it does, and not in other places.

Stay updated on New Horizons findings by visiting the New Horizons page. You can also keep track of Pluto News on the New Horizons Blog. 

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

The Shakespearean Moons of Uranus

This weekend marks the 400th anniversary of Shakespeare’s death, and we’re highlighting the moons of Uranus; some of which are named after characters from his works.

While most of the moons orbiting other planets take their names from Greek mythology, Uranus’ moons are unique in bing named for Shakespearean characters, along with a couple of them being named for characters from the works of Alexander Pope.

Using the Hubble Space Telescope and improved ground-based telescopes, astronomers have discovered a total of 27 known moons around Uranus.

Here’s a sampling of some of the unique aspects of the moons:

Miranda

Shakespearean work: The Tempest

Miranda, the innermost and smallest of the five major satellites, has a surface unlike any other moon that’s been seen. It has a giant fault canyon as much as 12 times as deep as the Grand Canyon, terraced layers and surfaces that appear very old, and others that look much younger.

Ariel

Shakespearean work: The Tempest

Ariel has the brightest and possibly the youngest surface among all the moons of Uranus. It has a few large craters and many small ones, indicating that fairly recent low-impact collisions wiped out the large craters that would have been left by much earlier, bigger strikes. Intersecting valleys pitted with craters scars its surface.

Oberon

Shakespearean work: A Midsummer Night’s Dream

Oberon, the outermost of the five major moons, is old, heavily cratered and shows little signs of internal activity. Unidentified dark material appears on the floors of many of its craters.

Cordelia and Ophelia

Shakespearean works: Cordelia - King Lear; Ophelia - Hamlet

Cordelia and Ophelia are shepherd moons that keep Uranus’ thin, outermost “epsilon” ring well defined.

Between them and miranda is a swarm of eight small satellites unlike any other system of planetary moons. This region is so crowded that astronomers don’t yet understand how the little moons have managed to avoid crashing into each other. They may be shepherds for the planet’s 10 narrow rings, and scientists think there must be still more moons, interior to any known, to confine the edges of the inner rings.

Want to learn more about all of Uranus’s moons? Visit: http://solarsystem.nasa.gov/planets/uranus/moons

Check out THIS blog from our Chief Scientist Ellen Stofan, where she reflects on the life and legacy of William Shakespeare on the 400th anniversary of his death on April 23, 1616.

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

A Journey of Eight Years

We’re taking time to highlight our progress and accomplishments over the past 8 years. Join our historical journey!

Obama Visit to NASA in 2010 

President Barack Obama visited our Kennedy Space Center in Florida to deliver remarks on the bold new course the administration is charting for America’s space program. During a speech at the center, President Obama said, “I believe we can send humans to orbit Mars and return them safely to Earth. And a landing on Mars will follow. And I expect to be around to see it.” R  

Commercial Crew

Our Commercial Crew and Cargo Program is investing financial and technical resources to stimulate efforts within the private sector to develop safe, reliable and cost-effective space transportation systems. This program has allowed us to continue to reach low-Earth orbit, even after the retirement of the Space Shuttle Program. In the coming years, we will once again launch U.S. astronauts from American soil to the International Space Station through this commercial partnership.  

Revamping KSC: Vehicle Assembly Building

Our Vehicle Assembly Building (VAB) at Kennedy Space Center served through the Apollo and Space Shuttle Programs, and is now undergoing renovations to accommodate future launch vehicles…like our Space Launch System (SLS) rocket that will carry astronauts to deep space destinations, like Mars. Already, shuttle-era work platforms have been removed from the VAB to make way for our advanced heavy-lift launch vehicle, SLS.  

Revamping KSC: Pad 39B

For the first time since our Apollo-era rockets and space shuttles lifted off on missions from Launch Complex 39 at our Kennedy Space Center in Florida, one of the launch pads is undergoing extensive upgrades to support our 21st century space launch complex. At launch pad B, workers are making upgrades to support our Space Launch System (SLS) rocket and a variety of other commercial launch vehicles. .

Commercial Resupply Program

Our commercial partnerships with companies like SpaceX and Orbital ATK are allowing us to find new ways to resupply the International Space Station. Orbital ATK’s Cygnus cargo spacecraft is shown being captured using the Station’s Canadarm2 robotic arm. Packed with more than 5,100 pounds of cargo and research equipment, the vehicle made Orbital ATK's fifth commercial resupply flight to the station in October 2016.  

Pluto Flyby

After a seven-year journey, our New Horizons spacecraft arrived at dwarf planet Pluto. It captured this high-resolution enhanced color view of the planet on July 14, 2015. The image combines blue, red and infrared images taken by the craft’s imaging camera. Pluto’s surface sports a remarkable range of subtle colors, enhanced in this view to a rainbow of pale blues, yellows, oranges, and deep reds. Many land forms have their own distinct colors, which tell a complex geological and climatological story.   

Juno at Jupiter

Juno’s 2011 launch brought it into orbit around Jupiter. This composite image depicts Jupiter’s cloud formations as seen through the eyes of Juno’s Microwave Radiometer (MWR) instrument as compared to the top layer, a Cassini Imaging Science Subsystem image of the planet. The MWR can see several hundred miles (kilometers) into Jupiter’s atmosphere with its largest antenna. The belts and bands visible on the surface are also visible in modified form in each layer below.  

Orion EFT-1

As we strived to make deep-space missions a reality, on Dec. 5, 2014, a Delta IV Heavy rocket lifted off from Cape Canaveral carrying our Orion spacecraft on an unpiloted flight test to Earth orbit. During the two-orbit, four-and-a-half hour mission, engineers evaluated the systems critical to crew safety, the launch abort system, the heat shield and the parachute system.  

 Building of SLS

Meet the Space Launch System, our latest rocket system and see how it stacks up (no pun intended) to earlier generations of launch vehicles. While we engaged commercial partners to help us reach low-Earth orbit, we also were able to focus on deep-space exploration. This resulted in the creation of SLS, the world’s most powerful rocket and the one that will carry humans to deep-space destinations, like Mars.  

Small Satellite Technology

Our latest generation of small satellite technology represents a new way of advancing scientific research and reducing costs. These small sats are part of a technology demonstration that were deployed from the International Space Station in December 2016.   

Technology Development Organization

In 2013, we created a standalone technology development organization at NASA. Why? This new organization was an outgrowth of President Obama’s recognition of the critical role that space technology and innovation will play in enabling both future space missions and bettering life on Earth. The President’s most recent budget request included $4 million per year for our Centennial Challenges prizes. This program seeks innovations from diverse and non-traditional sources and competitors are not supported by government funding. Awards are only made to successful teams when the challenges are met. Throughout this administration (2009 – 2016), more than $6.5 million has been awarded to winners. 

Spinoffs

Did you know that many technologies originally designed for space exploration are now being used by the general public? Yes, there’s space in your life! We have a long history of transferring technology to the private sector, things we like to call NASA Spinoffs. From enriched baby formula, to digital camera sensors…you may be surprised where this technology came from. 

 Space Station Extended to 2024

In 2014, the Obama Administration announced that the United States would support the extension of the International Space Station to at least 2024. This gave the station a decade to continue its already fruitful microgravity research mission. This offered scientists and engineers the time they need to ensure the future of exploration, scientific discoveries and economic development.  

Year in Space Mission

Former NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko spent a year in space to help us understand the impacts of long-duration spaceflight on the human body. The studies performed throughout their stay will yield beneficial knowledge on the medical, psychological and biomedical challenges faced by astronauts that will one day travel to Mars. Scott Kelly was a particularly interesting candidate for the job, as he has a twin brother. While Scott spent a year on the International Space Station, his brother Mark spent the year on Earth. Comparing test results from both subjects will provide an even deeper understanding of the human body and how it reacts to the space environment.  

EPIC Earth Images

From one MILLION miles away, our EPIC camera on the Deep Space Climate Observatory (DSCOVR) satellite returned its first view of the entire sunlit side of Earth in 2015. Because of this spacecraft, you can now see a daily series of images of our home planet! These images are available 12 to 36 hours after they are acquired. 

James Webb Space Telescope

The James Webb Space Telescope represents a giant leap forward in our quest to understand the universe and our origins.  The successor to the Hubble Space Telescope, JWST is designed to examine every phase of cosmic history: from the first luminous glows after the Big Bang to the formation of galaxies, stars, and planets to the evolution of our own solar system. More: 

Green Aviation

Our commitment to advancing aeronautics has led to developments in today’s aviation that have made air travel safer than ever. In fact, every U.S. aircraft flying today and every U.S. air traffic control tower uses NASA-developed technology in some way. Streamlined aircraft bodies, quieter jet engines, techniques for preventing icing, drag-reducing winglets, lightweight composite structures, software tools to improve the flow of tens of thousands of aircraft through the sky, and so much more are an everyday part of flying thanks to our research that traces its origins back to the earliest days of aviation. Our green aviation technologies are dramatically reducing the environmental impact of aviation and improving its efficiency while maintaining safety in more crowded skies, and paving the way for revolutionary aircraft shapes and propulsion. 

X-Planes

History is about to repeat itself as the Quiet Supersonic Technology, or QueSST, concept  begins its design phase to become one of the newest generation of X-planes. Over the past seven decades, our nation’s best minds in aviation designed, built and flew a series of experimental airplanes to test the latest fanciful and practical ideas related to flight. Known as X-planes, we are again are preparing to put in the sky an array of new experimental aircraft, each intended to carry on the legacy of demonstrating advanced technologies that will push back the frontiers of aviation.  

Drones

Blazing the trail for safely integrating drones into the national airspace, we have been testing and researching uncrewed aircraft. The most recent “out of sight” tests are helping us solve the challenge of drones flying beyond the visual line of sight of their human operators without endangering other aircraft. 

Solar Dynamics Observatory

Our Solar Dynamics Observatory, which launched in 2010, observes the sun in unparalleled detail and is yet another mission designed to understand the space in which we live. In this image, the sun, our system’s only star seems to be sending us a message. A pair of giant filaments on the face of the sun form what appears to be an enormous arrow pointing to the right. If straightened out, each filament would be about as long as the sun’s diameter—1 million miles long. Such filaments are cooler clouds of solar material suspended above the sun's surface by powerful magnetic forces. Filaments can float for days without much change, though they can also erupt, releasing solar material in a shower that either rains back down or escapes out into space, becoming a moving cloud known as a coronal mass ejection, or CME.  

Curiosity Launch and Landing

There are selfies and there are selfies—from a world more than 33 million miles away. When the Curiosity Rover launched on Nov. 6, 2011, to begin a 10-month journey to the Red Planet, who knew it would be so photogenic. Not only has Curiosity sent back beauty shots of itself, its imagery has increased our knowledge of Mars manyfold. But it’s not just a camera; onboard are an array of scientific instruments designed to analyze the Red Planet’s soil, rocks and chemical composition. 

Astronaut Applications

On Dec. 14, 2015, we announced that astronaut applications were open on USAJOBS. The window for applications closed on Feb. 18 with a record turnout! We received more than 18,300 applications from excited individuals from around the country, all hoping to join the 2017 astronaut class. This surpassed the more than 6,100 received in 2012, and the previous record of 8,000 applicants in 1978.  

OSIRIS-REx

Asteroids are a part of our solar system and in our quest to learn more about their origins, we sent the OSIRIS-Rex, the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, to rendezvous with comet Bennu and return a sample of the comet to scientists here on Earth. Along the way, the mission will be multitasking during its two-year outbound cruise to search for elusive “Trojan” asteroids. Trojans are asteroids that are constant companions to planets in our solar system as they orbit the sun, remaining near a stable point 60 degrees in front of or behind the planet. 

 Habitable Zone Planets

In December 1995, the first exoplanet (a planet outside our solar system) was found. Since then, our Kepler mission has surveyed the Milky Way to verify 2,000+ exoplanets. On July 23, 2015, the Kepler mission confirmed the discovery of the first Earth-sized planet in the habitable zone. Not only that, but the planet orbits a sun very much like our own. 

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

Water on Mars!

Did you hear? New findings from our Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, we found hydrated minerals on slopes where mysterious streaks are seen on Mars. One thing that researchers noticed was that the darkish streaks appear to ebb and flow over time. During warm seasons, they darken and then fade in cooler seasons.

When discovered in 2010, these downhill flows known as recurring slope lineae (RSL) were thought to be related to liquid water. With the recent spectral detection of molecular water, we’re able to say it’s likely a shallow subsurface flow explains the darkening.

Mars is so cold, how could liquid water flow there? Great question! Since this liquid water is briny, the freezing point would be lower than that of pure water. Also, these saline slopes appear on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius).

The dark, narrow streaks flowing downhill in the below image are roughly the length of a football field.

So there’s water, but how much? Currently we think this area has a very small amount of water, probably just enough to wet the top layer of the surface of Mars. The streaks are around four to five meters wide and 200 to 300 meters long.

Could humans drink this water? The salts in the water appear to be perchlorates, so you probably wouldn’t want to drink the water. It would most likely be very salty and would need to be purified before human consumption.

Perchlorate...What is that? A perchlorate is a salt that absorbs water from the air. Learn more about how it’s helping us unlock the mysteries of Mars in this video:

What’s next? We want to look for more locations where brine flows may occur. We have only covered 3% of Mars at resolutions high enough to see these features.

For more information on the Mars announcement, visit our Journey to Mars landing page. There is also a full recap of the press conference HERE, and a short recap below.

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

I've been very curious about the basis on which the landing site is decided! I read that it will land in the Jerezo crater, so is there a particular reason behind choosing that place for the landing?

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

I love astrophysics and especially black holes and I want to pursue a career on them, but to be honest I'm scared to be not good enough or not clever enough. How did you decide to work on black holes? How did you become the person you are today?

Living and Working Aboard Station

 Join us on Facebook Live for a conversation with astronaut Kate Rubins and the director of the National Institutes for Health on Tuesday, October 18 at 11:15 a.m. ET.

Astronaut Kate Rubins has conducted out of this world research aboard Earth’s only orbiting laboratory. During her time aboard the International Space Station, she became the first person to sequence DNA in space. On Tuesday, she’ll be live on Facebook with National Institute of Health director Francis Collins, who led the effort to map the human genome. You can submit questions for Kate using the hashtag #SpaceChat on Twitter, or during the live event. Here’s a primer on the science this PhD astronaut has been conducting to help inspire your questions: 

Kate has a background in genomics (a branch of molecular genetics that deals with the study of genomes,specifically the identification and sequencing of their constituent genes and the application of this knowledge in medicine, pharmacy,agriculture, and other fields). When she began her tenure on the station, zero base pairs of DNA had been sequenced in space. Within just a few weeks, she and the Biomolecule Sequencer team had sequenced their one billionth base of DNA aboard the orbital platform.

“I [have a] genomics background, [so] I get really excited about that kind of stuff,” Rubins said in a downlink shortly after reaching the one billion base pairs sequenced goal.

Learn more about this achievement:

+First DNA Sequencing in Space a Game Changer

+Science in Short: One Billion Base Pairs Sequenced

Why is DNA Sequencing in Space a Big Deal?

A space-based DNA sequencer could identify microbes, diagnose diseases and understand crew member health, and potentially help detect DNA-based life elsewhere in the solar system.

+Why Sequencing DNA in Space is a Big Deal

https://youtu.be/1N0qm8HcFRI 

Miss the Reddit AMA on the subject? Here’s a transcript:

+NASA AMA: We just sequenced DNA in space for the first time. Ask us anything! 

NASA and Its Partnerships

We’re not doing this alone. Just like the DNA sequencing was a collaborative project with industry, so is the Eli Lilly Hard to Wet Surfaces investigation, which is a partnership between CASIS and Eli Lilly Co. In this experiment aboard the station, astronauts will study how certain materials used in the pharmaceutical industry dissolve in water while in microgravity. Results from this investigation could help improve the design of tablets that dissolve in the body to deliver drugs, thereby improving drug design for medicines used in space and on Earth. Learn more about what we and our partners are doing:

+Eli Lilly Hard to Wet Surfaces – been happening the last week and a half or so

Researchers to Test How Solids Dissolve in Space to Design Better Tablets and Pills on Earth

With our colleagues at the Stanford University School of Medicine, we’re also investigating the effects of spaceflight on stem cell-derived heart cells, specifically how heart muscle tissue, contracts, grows and changes  in microgravity and how those changes vary between subjects. Understanding how heart muscle cells change in space improves efforts for studying disease, screening drugs and conducting cell replacement therapy for future space missions. Learn more:

+Heart Cells

+Weekly Recap From the Expedition Lead Scientist for Aug. 18, 2016 

It’s Not Just Medicine

Kate and her crew mates have also worked on the combustion experiments.

Kate has also worked on the Bigelow Expandable Activity Module (BEAM), an experimental expandable capsule that docks with the station. As we work on our Journey to Mars, future space habitats  are a necessity. BEAM, designed for Mars or other destinations, is a lightweight and relatively simple to construct solution. Kate has recently examined BEAM, currently attached to the station, to take measurements and install sensors.

Kate recently performed a harvest of the Plant RNA Regulation experiment, by removing seed cassettes and stowing them in cold stowage.

The Plant RNA Regulation investigation studies the first steps of gene expression involved in development of roots and shoots. Scientists expect to find new molecules that play a role in how plants adapt and respond to the microgravity environment of space, which provides new insight into growing plants for food and oxygen supplies on long-duration missions. Read more about the experiment:

+Plant RNA Harvest

NASA Astronaut Kate Rubins is participating in several investigations examining changes in her body as a result of living in space. Some of these changes are similar to issues experienced by our elderly on Earth; for example, bone loss (osteoporosis), cardiovascular deconditioning, immune dysfunction, and muscle atrophy. Understanding these changes and how to prevent them in astronauts off the Earth may help improve health for all of us on the Earth. In additional, the crew aboard station is also working on more generalized studies of aging.

+ Study of the effects of aging on C. elegans, a model organism for a range of biological studies.