Hello Dr Kate Rubins, why conduct your researches in space? What is there in space that you need for your research? Best regards.
We’re always making amazing discoveries about the farthest reaches of our universe, but there’s also plenty of unexplored territory much closer to home.
Our “Backyard Worlds: Planet 9” is a citizen science project that asks curious people like you — yes, you there! — to help us spot objects in the area around our own solar system like brown dwarfs. You could even help us figure out if our solar system hosts a mysterious Planet 9!
In 2009, we launched the Wide-field Infrared Survey Explorer (WISE). Infrared radiation is a form of light that humans can’t see, but WISE could. It scans the sky for infrared light, looking for galaxies, stars and asteroids. Later on, scientists started using it to search for near-Earth objects (NEOWISE) like comets and asteroids.
These searches have already turned up so much data that researchers have trouble hunting through all of it. They can’t do it on their own. That’s why we asked everyone to chip in. If you join Backyard Worlds: Planet 9, you’ll learn how to look at noisy images of space and spot previously unidentified objects.
You’ll figure out how to tell the difference between real objects, like planets and stars, and artifacts. Artifacts are blurry blobs of light that got scattered around in WISE’s instruments while it was looking at the sky. These “optical ghosts” sometimes look like real objects.
Why can’t we use computers to do this, you ask? Well, computers are good at lots of things, like crunching numbers. But when it comes to recognizing when something’s a ghostly artifact and when it’s a real object, humans beat software all the time. After some practice, you’ll be able to recognize which objects are real and which aren’t just by watching them move!
One of the things our citizen scientists look for are brown dwarfs, which are balls of gas too big to be planets and too small to be stars. These objects are some of our nearest neighbors, and scientists think there’s probably a bunch of them floating around nearby, we just haven’t been able to find all of them yet.
But since Backyard Worlds launched on February 15, 2016, our volunteers have spotted 432 candidate brown dwarfs. We’ve been able to follow up 20 of these with ground-based telescopes so far, and 17 have turned out to be real!
Image Credit: Ryan Trainor, Franklin and Marshall College
How do we know for sure that we’ve spotted actual, bona fide, authentic brown dwarfs? Well, like with any discovery in science, we followed up with more observation. Our team gets time on ground-based observatories like the InfraRed Telescope Facility in Hawaii, the Magellan Telescope in Chile (pictured above) and the Apache Point Observatory in New Mexico and takes a closer look at our candidates. And sure enough, our participants found 17 brown dwarfs!
But we’re not done! There’s still lots of data to go through. In particular, we want your help looking for a potential addition to our solar system’s census: Planet 9. Some scientists think it’s circling somewhere out there past Pluto. No one has seen anything yet, but it could be you! Or drop by and contribute to our other citizen science projects like Disk Detective.
Congratulations to the citizen scientists who spotted these 17 brown dwarfs: Dan Caselden, Rosa Castro, Guillaume Colin, Sam Deen, Bob Fletcher, Sam Goodman, Les Hamlet, Khasan Mokaev, Jörg Schümann and Tamara Stajic.
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A human journey to Mars, at first glance, offers an inexhaustible amount of complexities. To bring a mission to the Red Planet from fiction to fact, NASA’s Human Research Program has organized some of the hazards astronauts will encounter on a continual basis into five classifications.
A spacecraft is not only a home, it’s also a machine. NASA understands that the ecosystem inside a vehicle plays a big role in everyday astronaut life.
Important habitability factors include temperature, pressure, lighting, noise, and quantity of space. It’s essential that astronauts are getting the requisite food, sleep and exercise needed to stay healthy and happy. The space environment introduces challenges not faced on Earth.
Technology, as often is the case with out-of-this-world exploration, comes to the rescue! Technology plays a big role in creating a habitable home in a harsh environment and monitoring some of the environmental conditions.
Astronauts are also asked to provide feedback about their living environment, including physical impressions and sensations so that the evolution of spacecraft can continue addressing the needs of humans in space.
Exploration to the Moon and Mars will expose astronauts to five known hazards of spaceflight, including hostile and closed environments, like the closed environment of the vehicle itself. To learn more, and find out what NASA’s Human Research Program is doing to protect humans in space, check out the "Hazards of Human Spaceflight" website. Or, check out this week’s episode of “Houston We Have a Podcast,” in which host Gary Jordan further dives into the threat of hostile and closed environments with Brian Crucian, NASA immunologist at the Johnson Space Center.
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Is there such thing as a ‘gentle black hole’ (as in Interstellar) that would one day be a candidate for sending probes? Or is it a lost cause?
Is earth doing fine, I'm afraid of all the bad stuff that's happening. I just wanna know if it's doing okay (◍•﹏•)
In Hollywood blockbusters, explosions and eruptions are often among the stars of the show. In space, explosions, eruptions and twinkling of actual stars are a focus for scientists who hope to better understand their births, lives, deaths and how they interact with their surroundings. Spend some of your Fourth of July taking a look at these celestial phenomenon:
Credit: NASA/Chandra X-ray Observatory
This object became a sensation in the astronomical community when a team of researchers pointed at it with our Chandra X-ray Observatory telescope in 1901, noting that it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness. Today, astronomers cite it as an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star.
Credit: NASA/Hubble Space Telescope
The brilliant tapestry of young stars flaring to life resemble a glittering fireworks display. The sparkling centerpiece is a giant cluster of about 3,000 stars called Westerlund 2, named for Swedish astronomer Bengt Westerlund who discovered the grouping in the 1960s. The cluster resides in a raucous stellar breeding ground located 20,000 light-years away from Earth in the constellation Carina.
Credit: NASA/THEMIS/Sebastian Saarloos
Sometimes during solar magnetic events, solar explosions hurl clouds of magnetized particles into space. Traveling more than a million miles per hour, these coronal mass ejections, or CMEs, made up of hot material called plasma take up to three days to reach Earth. Spacecraft and satellites in the path of CMEs can experience glitches as these plasma clouds pass by. In near-Earth space, magnetic reconnection incites explosions of energy driving charged solar particles to collide with atoms in Earth’s upper atmosphere. We see these collisions near Earth’s polar regions as the aurora. Three spacecraft from our Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, observed these outbursts known as substorms.
Credit: NASA/Hubble Space Telescope//ESA/STScI
Every galaxy has a black hole at its center. Usually they are quiet, without gas accretions, like the one in our Milky Way. But if a star creeps too close to the black hole, the gravitational tides can rip away the star’s gaseous matter. Like water spinning around a drain, the gas swirls into a disk around the black hole at such speeds that it heats to millions of degrees. As an inner ring of gas spins into the black hole, gas particles shoot outward from the black hole’s polar regions. Like bullets shot from a rifle, they zoom through the jets at velocities close to the speed of light. Astronomers using our Hubble Space Telescope observed correlations between supermassive black holes and an event similar to tidal disruption, pictured above in the Centaurus A galaxy.
Credit: NASA/Hubble Space Telescope/ESA
Supernovae can occur one of two ways. The first occurs when a white dwarf—the remains of a dead star—passes so close to a living star that its matter leaks into the white dwarf. This causes a catastrophic explosion. However most people understand supernovae as the death of a massive star. When the star runs out of fuel toward the end of its life, the gravity at its heart sucks the surrounding mass into its center. At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. Our Hubble Telescope captured this image of Eta Carinae, binary star system. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star.
Credit: NASA/GSFC/SDO
Extremely energetic objects permeate the universe. But close to home, the Sun produces its own dazzling lightshow, producing the largest explosions in our solar system and driving powerful solar storms.. When solar activity contorts and realigns the Sun’s magnetic fields, vast amounts of energy can be driven into space. This phenomenon can create a sudden flash of light—a solar flare.The above picture features a filament eruption on the Sun, accompanied by solar flares captured by our Solar Dynamics Observatory.
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What's a SPOC? Isn't that a star trek character?
From Mars to the asteroid belt to Saturn, our hardworking space robots are exploring the solar system. These mechanical emissaries orbit distant worlds or rove across alien landscapes, going places that are too remote or too dangerous for people (for now).
We often show off the pictures that these spacecraft send home, but this week we’re turning that around: here are some of the best pictures of the space robots, taken by other robots (or themselves), in deep space.
1. So Selfless with the Selfies
The Mars Curiosity rover makes breathtaking panoramas of the Martian landscape — and looks good doing it. This mission is famous for the remarkable self portraits of its robotic geologist in action. See more Martian selfies HERE. You can also try this draggable 360 panorama HERE. Find out how the rover team makes these images HERE.
2. Two Spaceships Passing in the Moonlight
In a feat of timing on Jan. 14, 2014, our Lunar Reconnaissance Orbiter caught a snapshot of LADEE, another robotic spacecraft that was orbiting the moon at the time. LADEE zoomed past at a distance of only about five miles below.
3. Bon Voyage, Galileo
The history-making Galileo mission to Jupiter set sail from the cargo bay of another spacecraft, Space Shuttle Atlantis, on Oct. 18, 1989. Get ready for Juno, which is the next spacecraft to arrive at Jupiter in July.
4. Cometary Close-Up
Using a camera on the Philae lander, the Rosetta spacecraft snapped an extraordinary self portrait at comet 67P/Churyumov-Gerasimenko from a distance of about 10 miles. The image captures the side of Rosetta and one of its 14-meter-long solar wings, with the comet in the background. Learn more about Rosetta HERE.
5. Man and Machine
This snapshot captures a remarkable moment in the history of exploration: the one and only time a human met up in space with a robotic forerunner on location. The Surveyor 3 lander helped pave the way for the astronaut footsteps that came a few years later. See the story of Apollo 12 and this unique encounter HERE.
Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.
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A human journey to Mars, at first glance, offers an inexhaustible amount of complexities. To bring a mission to the Red Planet from fiction to fact, NASA’s Human Research Program has organized some of the hazards astronauts will encounter on a continual basis into five classifications.
The variance of gravity fields that astronauts will encounter on a mission to Mars is the fourth hazard.
On Mars, astronauts would need to live and work in three-eighths of Earth’s gravitational pull for up to two years. Additionally, on the six-month trek between the planets, explorers will experience total weightlessness.
Besides Mars and deep space there is a third gravity field that must be considered. When astronauts finally return home they will need to readapt many of the systems in their bodies to Earth’s gravity.
To further complicate the problem, when astronauts transition from one gravity field to another, it’s usually quite an intense experience. Blasting off from the surface of a planet or a hurdling descent through an atmosphere is many times the force of gravity.
Research is being conducted to ensure that astronauts stay healthy before, during and after their mission. Specifically researchers study astronauts’ vision, fine motor skills, fluid distribution, exercise protocols and response to pharmaceuticals.
Exploration to the Moon and Mars will expose astronauts to five known hazards of spaceflight, including gravity. To learn more, and find out what NASA’s Human Research Program is doing to protect humans in space, check out the "Hazards of Human Spaceflight" website. Or, check out this week’s episode of “Houston We Have a Podcast,” in which host Gary Jordan further dives into the threat of gravity with Peter Norsk, Senior Research Director/ Element Scientist at the Johnson Space Center.
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On Aug. 21, 2017, a solar eclipse will be visible in North America. Throughout the continent, the Moon will cover part – or all – of the Sun’s super-bright face for part of the day.
Since it’s never safe to look at the partially eclipsed or uneclipsed Sun, everyone who plans to watch the eclipse needs a plan to watch it safely. One of the easiest ways to watch an eclipse is solar viewing glasses – but there are a few things to check to make sure your glasses are safe:
Glasses should have an ISO 12312-2 certification
They should also have the manufacturer’s name and address, and you can check if the manufacturer has been verified by the American Astronomical Society
Make sure they have no scratches or damage
To use solar viewing glasses, make sure you put them on before looking up at the Sun, and look away before you remove them. Proper solar viewing glasses are extremely dark, and the landscape around you will be totally black when you put them on – all you should see is the Sun (and maybe some types of extremely bright lights if you have them nearby).
Never use solar viewing glasses while looking through a telescope, binoculars, camera viewfinder, or any other optical device. The concentrated solar rays will damage the filter and enter your eyes, causing serious injury. But you can use solar viewing glasses on top of your regular eyeglasses, if you use them!
If you don’t have solar viewing glasses, there are still ways to watch, like making your own pinhole projector. You can make a handheld box projector with just a few simple supplies – or simply hold any object with a small hole (like a piece of cardstock with a pinhole, or even a colander) above a piece of paper on the ground to project tiny images of the Sun.
Of course, you can also watch the entire eclipse online with us. Tune into nasa.gov/eclipselive starting at noon ET on Aug. 21!
For people in the path of totality, there will be a few brief moments when it is safe to look directly at the eclipse. Only once the Moon has completely covered the Sun and there is no light shining through is it safe to look at the eclipse. Make sure you put your eclipse glasses back on or return to indirect viewing before the first flash of sunlight appears around the Moon’s edge.
You can look up the length of the total eclipse in your area to help you set a time for the appropriate length of time. Remember – this only applies to people within the path of totality.
Everyone else will need to use eclipse glasses or indirect viewing throughout the entire eclipse!
Whether you’re an amateur photographer or a selfie master, try out these tips for photographing the eclipse.
#1 — Safety first: Make sure you have the required solar filter to protect your camera.
#2 — Any camera is a good camera, whether it’s a high-end DSLR or a camera phone – a good eye and vision for the image you want to create is most important.
#3 — Look up, down, and all around. As the Moon slips in front of the Sun, the landscape will be bathed in long shadows, creating eerie lighting across the landscape. Light filtering through the overlapping leaves of trees, which creates natural pinholes, will also project mini eclipse replicas on the ground. Everywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.
#4 — Practice: Be sure you know the capabilities of your camera before Eclipse Day. Most cameras, and even many camera phones, have adjustable exposures, which can help you darken or lighten your image during the tricky eclipse lighting. Make sure you know how to manually focus the camera for crisp shots.
#5 —Upload your eclipse images to NASA’s Eclipse Flickr Gallery and relive the eclipse through other peoples’ images.
Learn all about the Aug. 21 eclipse at eclipse2017.nasa.gov, and follow @NASASun on Twitter and NASA Sun Science on Facebook for more. Watch the eclipse through the eyes of NASA at nasa.gov/eclipselive starting at 12 PM ET on Aug. 21.
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One hundred years ago, on May 29, 1919, astronomers observed a total solar eclipse in an ambitious effort to test Albert Einstein’s general theory of relativity by seeing it in action. Essentially, Einstein thought space and time were intertwined in an infinite “fabric,” like an outstretched blanket. A massive object such as the Sun bends the spacetime blanket with its gravity, such that light no longer travels in a straight line as it passes by the Sun.
This means the apparent positions of background stars seen close to the Sun in the sky – including during a solar eclipse – should seem slightly shifted in the absence of the Sun, because the Sun’s gravity bends light. But until the eclipse experiment, no one was able to test Einstein’s theory of general relativity, as no one could see stars near the Sun in the daytime otherwise.
The world celebrated the results of this eclipse experiment— a victory for Einstein, and the dawning of a new era of our understanding of the universe.
General relativity has many important consequences for what we see in the cosmos and how we make discoveries in deep space today. The same is true for Einstein's slightly older theory, special relativity, with its widely celebrated equation E=mc². Here are 10 things that result from Einstein’s theories of relativity:
Einstein's famous equation E=mc² contains "c," the speed of light in a vacuum. Although light comes in many flavors – from the rainbow of colors humans can see to the radio waves that transmit spacecraft data – Einstein said all light must obey the speed limit of 186,000 miles (300,000 kilometers) per second. So, even if two particles of light carry very different amounts of energy, they will travel at the same speed.
This has been shown experimentally in space. In 2009, our Fermi Gamma-ray Space Telescope detected two photons at virtually the same moment, with one carrying a million times more energy than the other. They both came from a high-energy region near the collision of two neutron stars about 7 billion years ago. A neutron star is the highly dense remnant of a star that has exploded. While other theories posited that space-time itself has a "foamy" texture that might slow down more energetic particles, Fermi's observations found in favor of Einstein.
Just like the Sun bends the light from distant stars that pass close to it, a massive object like a galaxy distorts the light from another object that is much farther away. In some cases, this phenomenon can actually help us unveil new galaxies. We say that the closer object acts like a “lens,” acting like a telescope that reveals the more distant object. Entire clusters of galaxies can be lensed and act as lenses, too.
When the lensing object appears close enough to the more distant object in the sky, we actually see multiple images of that faraway object. In 1979, scientists first observed a double image of a quasar, a very bright object at the center of a galaxy that involves a supermassive black hole feeding off a disk of inflowing gas. These apparent copies of the distant object change in brightness if the original object is changing, but not all at once, because of how space itself is bent by the foreground object’s gravity.
Sometimes, when a distant celestial object is precisely aligned with another object, we see light bent into an “Einstein ring” or arc. In this image from our Hubble Space Telescope, the sweeping arc of light represents a distant galaxy that has been lensed, forming a “smiley face” with other galaxies.
When a massive object acts as a lens for a farther object, but the objects are not specially aligned with respect to our view, only one image of the distant object is projected. This happens much more often. The closer object’s gravity makes the background object look larger and more stretched than it really is. This is called “weak lensing.”
Weak lensing is very important for studying some of the biggest mysteries of the universe: dark matter and dark energy. Dark matter is an invisible material that only interacts with regular matter through gravity, and holds together entire galaxies and groups of galaxies like a cosmic glue. Dark energy behaves like the opposite of gravity, making objects recede from each other. Three upcoming observatories -- Our Wide Field Infrared Survey Telescope, WFIRST, mission, the European-led Euclid space mission with NASA participation, and the ground-based Large Synoptic Survey Telescope --- will be key players in this effort. By surveying distortions of weakly lensed galaxies across the universe, scientists can characterize the effects of these persistently puzzling phenomena.
Gravitational lensing in general will also enable NASA’s James Webb Space telescope to look for some of the very first stars and galaxies of the universe.
So far, we’ve been talking about giant objects acting like magnifying lenses for other giant objects. But stars can also “lens” other stars, including stars that have planets around them. When light from a background star gets “lensed” by a closer star in the foreground, there is an increase in the background star’s brightness. If that foreground star also has a planet orbiting it, then telescopes can detect an extra bump in the background star’s light, caused by the orbiting planet. This technique for finding exoplanets, which are planets around stars other than our own, is called “microlensing.”
Our Spitzer Space Telescope, in collaboration with ground-based observatories, found an “iceball” planet through microlensing. While microlensing has so far found less than 100 confirmed planets, WFIRST could find more than 1,000 new exoplanets using this technique.
The very existence of black holes, extremely dense objects from which no light can escape, is a prediction of general relativity. They represent the most extreme distortions of the fabric of space-time, and are especially famous for how their immense gravity affects light in weird ways that only Einstein’s theory could explain.
In 2019 the Event Horizon Telescope international collaboration, supported by the National Science Foundation and other partners, unveiled the first image of a black hole’s event horizon, the border that defines a black hole’s “point of no return” for nearby material. NASA's Chandra X-ray Observatory, Nuclear Spectroscopic Telescope Array (NuSTAR), Neil Gehrels Swift Observatory, and Fermi Gamma-ray Space Telescope all looked at the same black hole in a coordinated effort, and researchers are still analyzing the results.
This Spitzer image shows the galaxy Messier 87 (M87) in infrared light, which has a supermassive black hole at its center. Around the black hole is a disk of extremely hot gas, as well as two jets of material shooting out in opposite directions. One of the jets, visible on the right of the image, is pointing almost exactly toward Earth. Its enhanced brightness is due to the emission of light from particles traveling toward the observer at near the speed of light, an effect called “relativistic beaming.” By contrast, the other jet is invisible at all wavelengths because it is traveling away from the observer near the speed of light. The details of how such jets work are still mysterious, and scientists will continue studying black holes for more clues.
Speaking of black holes, their gravity is so intense that they make infalling material “wobble” around them. Like a spoon stirring honey, where honey is the space around a black hole, the black hole’s distortion of space has a wobbling effect on material orbiting the black hole. Until recently, this was only theoretical. But in 2016, an international team of scientists using European Space Agency's XMM-Newton and our Nuclear Spectroscopic Telescope Array (NUSTAR) announced they had observed the signature of wobbling matter for the first time. Scientists will continue studying these odd effects of black holes to further probe Einstein’s ideas firsthand.
Incidentally, this wobbling of material around a black hole is similar to how Einstein explained Mercury’s odd orbit. As the closest planet to the Sun, Mercury feels the most gravitational tug from the Sun, and so its orbit’s orientation is slowly rotating around the Sun, creating a wobble.
Ripples through space-time called gravitational waves were hypothesized by Einstein about 100 years ago, but not actually observed until recently. In 2016, an international collaboration of astronomers working with the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors announced a landmark discovery: This enormous experiment detected the subtle signal of gravitational waves that had been traveling for 1.3 billion years after two black holes merged in a cataclysmic event. This opened a brand new door in an area of science called multi-messenger astronomy, in which both gravitational waves and light can be studied.
For example, our telescopes collaborated to measure light from two neutron stars merging after LIGO detected gravitational wave signals from the event, as announced in 2017. Given that gravitational waves from this event were detected mere 1.7 seconds before gamma rays from the merger, after both traveled 140 million light-years, scientists concluded Einstein was right about something else: gravitational waves and light waves travel at the same speed.
Planetary exploration spacecraft have also shown Einstein to be right about general relativity. Because spacecraft communicate with Earth using light, in the form of radio waves, they present great opportunities to see whether the gravity of a massive object like the Sun changes light’s path.
In 1970, our Jet Propulsion Laboratory announced that Mariner VI and VII, which completed flybys of Mars in 1969, had conducted experiments using radio signals — and also agreed with Einstein. Using NASA’s Deep Space Network (DSN), the two Mariners took several hundred radio measurements for this purpose. Researchers measured the time it took for radio signals to travel from the DSN dish in Goldstone, California, to the spacecraft and back. As Einstein would have predicted, there was a delay in the total roundtrip time because of the Sun’s gravity. For Mariner VI, the maximum delay was 204 microseconds, which, while far less than a single second, aligned almost exactly with what Einstein’s theory would anticipate.
In 1979, the Viking landers performed an even more accurate experiment along these lines. Then, in 2003 a group of scientists used NASA’s Cassini Spacecraft to repeat these kinds of radio science experiments with 50 times greater precision than Viking. It’s clear that Einstein’s theory has held up!
In 2004, we launched a spacecraft called Gravity Probe B specifically designed to watch Einstein’s theory play out in the orbit of Earth. The theory goes that Earth, a rotating body, should be pulling the fabric of space-time around it as it spins, in addition to distorting light with its gravity.
The spacecraft had four gyroscopes and pointed at the star IM Pegasi while orbiting Earth over the poles. In this experiment, if Einstein had been wrong, these gyroscopes would have always pointed in the same direction. But in 2011, scientists announced they had observed tiny changes in the gyroscopes’ directions as a consequence of Earth, because of its gravity, dragging space-time around it.
BONUS: Your GPS! Speaking of time delays, the GPS (global positioning system) on your phone or in your car relies on Einstein’s theories for accuracy. In order to know where you are, you need a receiver – like your phone, a ground station and a network of satellites orbiting Earth to send and receive signals. But according to general relativity, because of Earth’s gravity curving spacetime, satellites experience time moving slightly faster than on Earth. At the same time, special relativity would say time moves slower for objects that move much faster than others.
When scientists worked out the net effect of these forces, they found that the satellites’ clocks would always be a tiny bit ahead of clocks on Earth. While the difference per day is a matter of millionths of a second, that change really adds up. If GPS didn’t have relativity built into its technology, your phone would guide you miles out of your way!
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