Ways NASA Studies The Ocean

Soaring through the skies! This view looks from the window of our F-18 support aircraft during a 2016 Orbital ATK air-launch of its Pegasus rocket. 

The CYGNSS mission, led by the University of Michigan, will use eight micro-satellite observatories to measure wind speeds over Earth’s oceans, increasing the ability of scientists to understand and predict hurricanes. 

CYGNSS launched at 8:37 a.m. EST on Thursday, Dec. 15, 2016 from our Kennedy Space Center in Florida. CYGNSS launched aboard an Orbital ATK Pegasus XL rocket, deployed from Orbital’s “Stargazer” L-1011 carrier aircraft.

Pegasus is a winged, three-stage solid propellant rocket that can launch a satellite into low Earth orbit. How does it work? Great question!

After takeoff, the aircraft (which looks like a commercial airplane..but with some special quirks) flies to about 39,000 feet over the ocean and releases the rocket. 

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Celebrating Thanksgiving in Space!

Part of the appeal of Thanksgiving is how easily we settle into the familiar: cherished foods, friends and family, and favorite activities like football, puzzles or board games. As anyone who has spent Thanksgiving with someone else’s traditions knows, those familiar things can take on seemingly unusual forms. That’s especially true when you’re 200 miles up in space.

Holidays in space weren’t very common early in the program, but as astronauts start the 20th year of continuous habitation they will also be celebrating the 20th consecutive Thanksgiving in orbit. As it turns out, everything’s the same, but different.

Food

Early in the space program, astronauts didn’t have much choice about their meals. A turkey dinner with all the trimmings was as much a pipe dream in the early 1960s as space travel had been a few decades earlier. Food had to be able to stay fresh, or at least edible, from the time it was packed until the end of the mission, which might be several weeks. It couldn’t be bulky or heavy, but it had to contain all the nutrition an astronaut would need. It had to be easily contained, so crumbs or droplets wouldn’t escape the container and get into the spacecraft instrumentation. For the first flights, that meant a lot of food in tubes or in small bite-sized pieces.

Examples of food from the Mercury program

Chores first, then dinner

Maybe you rake leaves to start the day or straighten up the house for guests. Perhaps you’re the cook. Just like you, astronauts sometimes have to earn their Thanksgiving dinner. In 1974, two members of the Skylab 4 crew started their day with a six-and-a-half hour spacewalk, replacing film canisters mounted outside the spacecraft and deploying an experiment package.

After the spacewalk, the crew could at least “sit down” for a meal together that included food they didn’t have to eat directly from a bag, tube or pouch. In the spacecraft’s “ward room”, a station held three trays of food selected for the astronauts. The trays themselves kept the food warm.

A food tray similar to the ones astronauts used aboard Skylab, showing food, utensils and clean wipes. The tray itself warmed the food.

The ward room aboard Skylab showing the warming trays in use. The Skylab 4 crew ate Thanksgiving dinner there in 1974.

Fresh food

It can’t be all mashed potatoes and pie. There have to be some greens. NASA has that covered with VEGGIE, the ongoing experiment to raise food crops aboard the space station. Though the current crop won’t necessarily be on the Thanksgiving menu, astronauts have already harvested and eaten “space lettuce”. Researchers hope to be growing peppers aboard the space station in 2020.

Astronaut Kjell Lindgren enjoys lettuce grown and harvested aboard the International Space Station.

Football

Space station crews have been able to watch football on Thanksgiving thanks to live feeds from Mission Control. Unfortunately their choices of activities can be limited by their location. That long walk around the neighborhood to shake off the turkey coma? Not happening.

Football in space. It’s a thing.

Be Prepared for the Unplanned

No matter how you plan, there’s a chance something’s going to go wrong, perhaps badly. It happened aboard the Space Shuttle on Thanksgiving 1989. Flight Director Wayne Hale tells of plumbing problem that left Commander Fred Gregory indisposed and vacuum-suctioned to a particular seat aboard the spacecraft.

 This is not the seat from which the mission commander flies the Space Shuttle.

Hungry for More?

If you can’t get enough of space food, tune into this episode of “Houston, We Have a Podcast” and explore the delicious science of astronaut mealtime.

And whether you’re eating like a king or one of our astronauts currently living and working in space, we wish everybody a happy and safe Thanksgiving!

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Stars Make Firework Supplies!

The next time you see fireworks, take a moment to celebrate the cosmic pyrotechnics that made them possible. From the oxygen and potassium that help fireworks burn to the aluminum that makes sparklers sparkle, most of the elements in the universe wouldn’t be here without stars.

From the time the universe was only a few minutes old until it was about 400 million years old, the cosmos was made of just hydrogen, helium and a teensy bit of lithium. It took some stellar activity to produce the rest of the elements!

Stars are element factories

Even after more than 13 billion years, the hydrogen and helium that formed soon after the big bang still make up over 90 percent of the atoms in the cosmos. Most of the other elements come from stars.

Stars began popping into the universe about 400 million years after the big bang. That sounds like a long time, but it’s only about 3% of the universe’s current age!

Our Nancy Grace Roman Space Telescope will study the universe’s early days to help us learn more about how we went from a hot, soupy sea of atoms to the bigger cosmic structures we see today. We know hydrogen and helium atoms gravitated together to form stars, where atoms could fuse together to make new elements, but we're not sure when it began happening. Roman will help us find out.

The central parts of atoms, called nuclei, are super antisocial – it takes a lot of heat and pressure to force them close together. Strong gravity in the fiery cores of the first stars provided just the right conditions for hydrogen and helium atoms to combine to form more elements and generate energy. The same process continues today in stars like our Sun and provides some special firework supplies.

Carbon makes fireworks explode, helps launch them into the sky, and is even an ingredient in the “black snakes” that seem to grow out of tiny pellets. Fireworks glow pink with help from the element lithium. Both of these elements are created by average, Sun-like stars as they cycle from normal stars to red giants to white dwarfs.

Eventually stars release their elements into the cosmos, where they can be recycled into later generations of stars and planets. Sometimes they encounter cosmic rays, which are nuclei that have been boosted to high speed by the most energetic events in the universe. When cosmic rays collide with atoms, the impact can break them apart, forming simpler elements. That’s how we get boron, which can make fireworks green, and beryllium, which can make them silver or white!

Since massive stars have even stronger gravity in their cores, they can fuse more elements – all the way up to iron. (The process stops there because instead of producing energy, fusing iron is so hard to do that it uses up energy.)

That means the sodium that makes fireworks yellow, the aluminum that produces silver sparks (like in sparklers), and even the oxygen that helps fireworks ignite were all first made in stars, too! A lot of these more complex elements that we take for granted are actually pretty rare throughout the cosmos, adding up to less than 10 percent of the atoms in the universe combined!

Fusion in stars only got us through iron on the periodic table, so where do the rest of our elements come from? It’s what happens next in massive stars that produces some of the even more exotic elements.

Dying stars make elements too!

Once a star many times the Sun’s mass burns through its fuel, gravity is no longer held in check, and its core collapses under its own weight. There, atoms are crushed extremely close together – and they don’t like that! Eventually it reaches a breaking point and the star explodes as a brilliant supernova. Talk about fireworks! These exploding stars make elements like copper, which makes fireworks blue, and zinc, which creates a smoky effect.

Something similar can happen when a white dwarf star – the small, dense core left behind after a Sun-like star runs out of fuel – steals material from a neighboring star. These white dwarfs can explode as supernovae too, spewing elements like the calcium that makes fireworks orange into the cosmos.

When stars collide

White dwarfs aren’t the only “dead” stars that can shower their surroundings with new elements. Stars that are too massive to leave behind white dwarfs but not massive enough to create black holes end up as neutron stars.

If two of these extremely dense stellar skeletons collide, they can produce all kinds of elements, including the barium that makes fireworks bright green and the antimony that creates a glitter effect. Reading this on a phone or computer? You can thank crashing dead stars for some of the metals that make up your device, too!

As for most of the remaining elements we know of, we've only seen them in labs on Earth so far.

Sounds like we’ve got it all figured out, right? But there are still lots of open questions. Our Roman Space Telescope will help us learn more about how elements were created and distributed throughout galaxies. That’s important because the right materials had to come together to form the air we breathe, our bodies, the planet we live on, and yes – even fireworks!

So when you’re watching fireworks, think about their cosmic origins!

Learn more about the Roman Space Telescope at: https://roman.gsfc.nasa.gov/

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The stunning Veil Nebula was created after a star about 20 times the mass of the Sun lived fast and died young – exploding in a cataclysmic release of energy known as a supernova.

In a violent stellar explosion roughly 10,000 years ago, shockwaves and debris created this staggeringly beautiful trail through space. The picture above shows a mosaic of six Hubble Space Telescope pictures, a small area roughly two light-years across, and only a tiny fraction of the nebula's vast 110 light-year structure.

To learn more about Hubble’s celebration of Nebula November and see new nebula images, visit our space telescope's nebula page.

You can also keep up with Hubble on Twitter, Instagram, Facebook, and Flickr!

Image credits: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

What did you major in? What was your college experience?

Solar System: 10 Ways Interns Are Exploring Space With Us

Simulating alien worlds, designing spacecraft with origami and using tiny fossils to understand the lives of ancient organisms are all in a day’s work for interns at NASA.

Here’s how interns are taking our missions and science farther.

1. Connecting Satellites in Space

Becca Foust looks as if she’s literally in space – or, at least, on a sci-fi movie set. She’s surrounded by black, except for the brilliant white comet model suspended behind her. Beneath the socks she donned just for this purpose, the black floor reflects the scene like perfectly still water across a lake as she describes what happens here: “We have five spacecraft simulators that ‘fly’ in a specially designed flat-floor facility,” she says. “The spacecraft simulators use air bearings to lift the robots off the floor, kind of like a reverse air hockey table. The top part of the spacecraft simulators can move up and down and rotate all around in a similar way to real satellites.” It’s here, in this test bed on the Caltech campus, that Foust is testing an algorithm she’s developing to autonomously assemble and disassemble satellites in space. “I like to call it space K’nex, like the toys. We're using a bunch of component satellites and trying to figure out how to bring all of the pieces together and make them fit together in orbit,” she says. A NASA Space Technology Research Fellow, who splits her time between Caltech and NASA’s Jet Propulsion Laboratory (JPL), working with Soon-Jo Chung and Fred Hadaegh, respectively, Foust is currently earning her Ph.D. at the University of Illinois at Urbana-Champaign. She says of her fellowship, “I hope my research leads to smarter, more efficient satellite systems for in-space construction and assembly.”

2. Diving Deep on the Science of Alien Oceans

Three years ago, math and science were just subjects Kathy Vega taught her students as part of Teach for America. Vega, whose family emigrated from El Salvador, was the first in her family to go to college. She had always been interested in space and even dreamed about being an astronaut one day, but earned a degree in political science so she could get involved in issues affecting her community. But between teaching and encouraging her family to go into science, It was only a matter of time before she realized just how much she wanted to be in the STEM world herself. Now an intern at NASA JPL and in the middle of earning a second degree, this time in engineering physics, Vega is working on an experiment that will help scientists search for life beyond Earth. 

“My project is setting up an experiment to simulate possible ocean compositions that would exist on other worlds,” says Vega. Jupiter’s moon Europa and Saturn’s moon Enceladus, for example, are key targets in the search for life beyond Earth because they show evidence of global oceans and geologic activity. Those factors could allow life to thrive. JPL is already building a spacecraft designed to orbit Europa and planning for another to land on the icy moon’s surface. “Eventually, [this experiment] will help us prepare for the development of landers to go to Europa, Enceladus and another one of Saturn’s moons, Titan, to collect seismic measurements that we can compare to our simulated ones,” says Vega. “I feel as though I'm laying the foundation for these missions.”

3. Unfolding Views on Planets Beyond Our Solar System

“Origami is going to space now? This is amazing!” Chris Esquer-Rosas had been folding – and unfolding – origami since the fourth grade, carefully measuring the intricate patterns and angles produced by the folds and then creating new forms from what he’d learned. “Origami involves a lot of math. A lot of people don't realize that. But what actually goes into it is lots of geometric shapes and angles that you have to account for,” says Esquer-Rosas. Until three years ago, the computer engineering student at San Bernardino College had no idea that his origami hobby would turn into an internship opportunity at NASA JPL. That is, until his long-time friend, fellow origami artist and JPL intern Robert Salazar connected him with the Starshade project. Starshade has been proposed as a way to suppress starlight that would otherwise drown out the light from planets outside our solar system so we can characterize them and even find out if they’re likely to support life. Making that happen requires some heavy origami – unfurling a precisely-designed, sunflower-shaped structure the size of a baseball diamond from a package about half the size of a pitcher’s mound. It’s Esquer-Rosas’ project this summer to make sure Starshade’s “petals” unfurl without a hitch. Says Esquer-Rosas, “[The interns] are on the front lines of testing out the hardware and making sure everything works. I feel as though we're contributing a lot to how this thing is eventually going to deploy in space.”

4. Making Leaps in Extreme Robotics

Wheeled rovers may be the norm on Mars, but Sawyer Elliott thinks a different kind of rolling robot could be the Red Planet explorer of the future. This is Elliott’s second year as a fellow at NASA JPL, researching the use of a cube-shaped robot for maneuvering around extreme environments, like rocky slopes on Mars or places with very little gravity, like asteroids. A graduate student in aerospace engineering at Cornell University, Elliott spent his last stint at JPL developing and testing the feasibility of such a rover. “I started off working solely on the rover and looking at can we make this work in a real-world environment with actual gravity,” says Elliott. “It turns out we could.” So this summer, he’s been improving the controls that get it rolling or even hopping on command. In the future, Elliott hopes to keep his research rolling along as a fellow at JPL or another NASA center. “I'm only getting more and more interested as I go, so I guess that's a good sign,” he says.

5. Starting from the Ground Up

Before the countdown to launch or the assembling of parts or the gathering of mission scientists and engineers, there are people like Joshua Gaston who are helping turn what’s little more than an idea into something more. As an intern with NASA JPL’s project formulation team, Gaston is helping pave the way for a mission concept that aims to send dozens of tiny satellites, called CubeSats, beyond Earth’s gravity to other bodies in the solar system. “This is sort of like step one,” says Gaston. “We have this idea and we need to figure out how to make it happen.” Gaston’s role is to analyze whether various CubeSat models can be outfitted with the needed science instruments and still make weight. Mass is an important consideration in mission planning because it affects everything from the cost to the launch vehicle to the ability to launch at all. Gaston, an aerospace engineering student at Tuskegee University, says of his project, “It seems like a small role, but at the same time, it's kind of big. If you don't know where things are going to go on your spacecraft or you don't know how the spacecraft is going to look, it's hard to even get the proposal selected.”

6. Finding Life on the Rocks

By putting tiny samples of fossils barely visible to the human eye through a chemical process, a team of NASA JPL scientists is revealing details about organisms that left their mark on Earth billions of years ago. Now, they have set their sights on studying the first samples returned from Mars in the future. But searching for signatures of life in such a rare and limited resource means the team will have to get the most science they can out of the smallest sample possible. That’s where Amanda Allen, an intern working with the team in JPL’s Astrobiogeochemistry, or abcLab, comes in. “Using the current, state-of-the-art method, you need a sample that’s 10 times larger than we’re aiming for,” says Allen, an Earth science undergraduate at the University of California, San Diego, who is doing her fifth internship at JPL. “I’m trying to get a different method to work.” Allen, who was involved in theater and costume design before deciding to pursue Earth science, says her “superpower” has always been her ability to find things. “If there’s something cool to find on Mars related to astrobiology, I think I can help with that,” she says.

7. Taking Space Flight Farther

If everything goes as planned and a thruster like the one Camille V. Yoke is working on eventually helps send astronauts to Mars, she’ll probably be first in line to play the Mark Watney role. “I'm a fan of the Mark Watney style of life [in “The Martian”], where you're stranded on a planet somewhere and the only thing between you and death is your own ability to work through problems and engineer things on a shoestring,” says Yoke. A physics major at the University of South Carolina, Yoke is interning with a team that’s developing a next-generation electric thruster designed to accelerate spacecraft more efficiently through the solar system. “Today there was a brief period in which I knew something that nobody else on the planet knew – for 20 minutes before I went and told my boss,” says Yoke. “You feel like you're contributing when you know that you have discovered something new.”

8. Searching for Life Beyond Our Solar System

Without the option to travel thousands or even tens of light-years from Earth in a single lifetime, scientists hoping to discover signs of life on planets outside our solar system, called exoplanets, are instead creating their own right here on Earth. This is Tre’Shunda James’ second summer simulating alien worlds as an intern at NASA JPL. Using an algorithm developed by her mentor, Renyu Hu, James makes small changes to the atmospheric makeup of theoretical worlds and analyzes whether the combination creates a habitable environment. “This model is a theoretical basis that we can apply to many exoplanets that are discovered,” says James, a chemistry and physics major at Occidental College in Los Angeles. “In that way, it's really pushing the field forward in terms of finding out if life could exist on these planets.” James, who recently became a first-time co-author on a scientific paper about the team’s findings, says she feels as though she’s contributing to furthering the search for life beyond Earth while also bringing diversity to her field. “I feel like just being here, exploring this field, is pushing the boundaries, and I'm excited about that.”

9. Spinning Up a Mars Helicopter

Chloeleen Mena’s role on the Mars Helicopter project may be small, but so is the helicopter designed to make the first flight on the Red Planet. Mena, an electrical engineering student at Embry-Riddle Aeronautical University, started her NASA JPL internship just days after NASA announced that the helicopter, which had been in development at JPL for nearly five years, would be going to the Red Planet aboard the Mars 2020 rover. This summer, Mena is helping test a part needed to deploy the helicopter from the rover once it lands on Mars, as well as writing procedures for future tests. “Even though my tasks are relatively small, it's part of a bigger whole,” she says.

10. Preparing to See the Unseen on Jupiter's Moon Europa

In the 2020s, we’re planning to send a spacecraft to the next frontier in the search for life beyond Earth: Jupiter’s moon Europa. Swathed in ice that’s intersected by deep reddish gashes, Europa has unveiled intriguing clues about what might lie beneath its surface – including a global ocean that could be hospitable to life. Knowing for sure hinges on a radar instrument that will fly aboard the Europa Clipper orbiter to peer below the ice with a sort of X-ray vision and scout locations to set down a potential future lander. To make sure everything works as planned, NASA JPL intern Zachary Luppen is creating software to test key components of the radar instrument. “Whatever we need to do to make sure it operates perfectly during the mission,” says Luppen. In addition to helping things run smoothly, the astronomy and physics major says he hopes to play a role in answering one of humanity’s biggest questions. “Contributing to the mission is great in itself,” says Luppen. “But also just trying to make as many people aware as possible that this science is going on, that it's worth doing and worth finding out, especially if we were to eventually find life on Europa. That changes humanity forever!”

Read the full web version of this week’s ‘Solar System: 10 Things to Know” article HERE. 

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GPS: Coming to a Moon Near You!

The next generation of lunar explorers – the Artemis generation – will establish a sustained presence on the Moon, making revolutionary discoveries, prospecting for resources and proving technologies key to future deep space exploration. To support these ambitions, our navigation engineers are developing an architecture that will provide accurate, robust location services all the way out to lunar orbit.

How? We’re teaming up with the U.S. Air Force to extend the use of GPS in space by developing advanced space receivers capable of tracking weak GPS signals far out in space.

Spacecraft near Earth have long relied on GPS signals for navigation data, just as users on the ground might use their phones to maneuver through a highway system. Below approximately 1,860 miles, spacecraft in low-Earth orbit can rely on GPS for near-instantaneous location data. This is an enormous benefit to these missions, allowing many satellites the autonomy to react and respond to unforeseen events without much hands-on oversight.

Beyond this altitude, navigation becomes more challenging. To reliably calculate their position, spacecraft must use signals from the global navigation satellite system (GNSS), the collection of international GPS-like satellite constellations. The region of space that can be serviced by these satellites is called the Space Service Volume, which extends from 1,860 miles to about 22,000 miles, or geosynchronous orbit.

In this area of service, missions don’t rely on GNSS signals in the same way one would on Earth or in low-Earth orbit. They orbit too high to “see” enough signals from GNSS satellites on their side of the globe, so they must rely on signals from GNSS satellite signals spilling over to the opposite side of the globe.  This is because the Earth blocks the main signals of these satellites, so the spacecraft must “listen” for the fainter signals that extend out from the sides of their antennas, known as “side-lobes.”

Though 22,000 miles is considered the end of the Space Service Volume, that hasn’t stopped our engineers from reaching higher. In fact, our simulations prove that GNSS signals could even be used for reliable navigation in lunar orbit, far outside the Space Service Volume, over 200,000 miles from Earth. We’re even planning to use GNSS signals in the navigation architecture for the Gateway, an outpost in orbit around the Moon that will enable sustained lunar surface exploration.

It’s amazing that the same systems you might use to navigate the highways are putting us on the path forward to the Moon!

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Does the eclipse affect airplanes at all? Would pilots have to wear special glasses, and would people inside the airplane be told not to look out of the windows?

I don’t believe it should directly impact airplanes. We are looking at how the eclipse will affect radio communications which airplanes use, but that’s something we’ll learn with the data we collect during this eclipse. Pilots will need to be careful as always to not look directly at the Sun. If you are a lucky passenger on one of the flights that will cross the eclipse, make sure to bring your eclipse viewing glasses as you will need them to look at the Sun safely https://eclipse2017.nasa.gov/safety That would be an amazing opportunity to view the eclipse from a plane as you wouldn’t have to worry about cloud cover. You may also get a longer viewing experience if you are following the path of totality! In fact, some NASA scientist are going to be flying experiments on a couple of NASA planes! https://youtu.be/R0GNqlGNZkI?list=PL_8hVmWnP_O2oVpjXjd_5De4EalioxAUi

Cosmic Couples and Devastating Breakups

Relationships can be complicated — especially if you’re a pair of stars. Sometimes you start a downward spiral you just can’t get out of, eventually crash together and set off an explosion that can be seen 130 million light-years away.

For Valentine’s Day, we’re exploring the bonds between some of the universe’s peculiar pairs … as well as a few of their cataclysmic endings.

Stellar Couples

When you look at a star in the night sky, you may really be viewing two or more stars dancing around each other. Scientists estimate three or four out of every five Sun-like stars in the Milky Way have at least one partner. Take our old north star Thuban, for example. It’s a binary, or two-star, system in the constellation Draco.

Alpha Centauri, our nearest stellar neighbor, is actually a stellar triangle. Two Sun-like stars, Rigil Kentaurus and Toliman, form a pair (called Alpha Centauri AB) that orbit each other about every 80 years. Proxima Centauri is a remote red dwarf star caught in their gravitational pull even though it sits way far away from them (like over 300 times the distance between the Sun and Neptune).

Credit: ESO/Digitized Sky Survey 2/Davide De Martin/Mahdi Zamani

Sometimes, though, a stellar couple ends its relationship in a way that’s really disastrous for one of them. A black widow binary, for example, contains a low-mass star, called a brown dwarf, and a rapidly spinning, superdense stellar corpse called a pulsar. The pulsar generates intense radiation and particle winds that blow away the material of the other star over millions to billions of years.

Black Hole Beaus

In romance novels, an air of mystery is essential for any love interest, and black holes are some of the most mysterious phenomena in the universe. They also have very dramatic relationships with other objects around them!

Scientists have observed two types of black holes. Supermassive black holes are hundreds of thousands to billions of times our Sun’s mass. One of these monsters, called Sagittarius A* (the “*” is pronounced “star”), sits at the center of our own Milky Way. In a sense, our galaxy and its black hole are childhood sweethearts — they’ve been together for over 13 billion years! All the Milky-Way-size galaxies we’ve seen so far, including our neighbor Andromeda (pictured below), have supermassive black holes at their center!

These black-hole-galaxy power couples sometimes collide with other, similar pairs — kind of like a disastrous double date! We’ve never seen one of these events happen before, but scientists are starting to model them to get an idea of what the resulting fireworks might look like.

One of the most dramatic and fleeting relationships a supermassive black hole can have is with a star that strays too close. The black hole’s gravitational pull on the unfortunate star causes it to bulge on one side and break apart into a stream of gas, which is called a tidal disruption event.

The other type of black hole you often hear about is stellar-mass black holes, which are five to tens of times the Sun’s mass. Scientists think these are formed when a massive star goes supernova. If there are two massive stars in a binary, they can leave behind a pair of black holes that are tied together by their gravity. These new black holes spiral closer and closer until they crash together and create a larger black hole. The National Science Foundation’s LIGO project has detected many of these collisions through ripples in space-time called gravitational waves.

Credit: LIGO/T. Pyle

Here’s hoping your Valentine’s Day is more like a peacefully spiraling stellar binary and less like a tidal disruption! Learn how to have a safe relationship of your own with black holes here.

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Watch Mercury Transit the Sun on Nov. 11

On Nov. 11, Earthlings will be treated to a rare cosmic event — a Mercury transit.

For about five and a half hours on Monday, Nov. 11 — from about 7:35 a.m. EST to 1:04 p.m. EST — Mercury will be visible from Earth as a tiny black dot crawling across the face of the Sun. This is a transit and it happens when Mercury lines up just right between the Sun and Earth.

Mercury transits happen about 13 times a century. Though it takes Mercury only about 88 days to zip around the Sun, its orbit is tilted, so it's relatively rare for the Sun, Mercury and Earth to line up perfectly. The next Mercury transit isn't until 2032 — and in the U.S., the next opportunity to catch a Mercury transit is in 2049!

How to watch

Our Solar Dynamics Observatory satellite, or SDO, will provide near-real time views of the transit. SDO keeps a constant eye on the Sun from its position in orbit around Earth to monitor and study the Sun's changes, putting it in the front row for many eclipses and transits.

Visit mercurytransit.gsfc.nasa.gov to tune in!

Our Solar Dynamics Observatory also saw Mercury transit the Sun in 2016.

If you're thinking of watching the transit from the ground, keep in mind that it is never safe to look directly at the Sun. Even with solar viewing glasses, Mercury is too small to be easily seen with the unaided eye. Your local astronomy club may have an opportunity to see the transit using specialized, properly-filtered solar telescopes — but remember that you cannot use a regular telescope or binoculars in conjunction with solar viewing glasses.

Transits in other star systems

Transiting planets outside our solar system are a key part of how we look for exoplanets.

Our Transiting Exoplanet Survey Satellite, or TESS, is NASA’s latest planet-hunter, observing the sky for new worlds in our cosmic neighborhood. TESS searches for these exoplanets, planets orbiting other stars, by using its four cameras to scan nearly the whole sky one section at a time. It monitors the brightness of stars for periodic dips caused by planets transiting those stars.

This is similar to Mercury’s transit across the Sun, but light-years away in other solar systems! So far, TESS has discovered 29 confirmed exoplanets using transits — with over 1,000 more candidates being studied by scientists!

Discover more transit and eclipse science at nasa.gov/transit, and tune in on Monday, Nov. 11, at mercurytransit.gsfc.nasa.gov.

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