Wispy remains of a supernova explosion hide a possible 'survivor.' Of all the varieties of exploding stars, the ones called Type Ia are perhaps the most intriguing. Their predictable brightness lets astronomers measure the expansion of the universe, which led to the discovery of dark energy. Yet the cause of these supernovae remains a mystery. Do they happen when two white dwarf stars collide? Or does a single white dwarf gorge on gases stolen from a companion star until bursting? If the second theory is true, the normal star should survive. Astronomers used the Hubble Space Telescope to search the gauzy remains of a Type Ia supernova in a neighboring galaxy called the Large Magellanic Cloud. They found a sun-like star that showed signs of being associated with the supernova. Further investigations will be needed to learn if this star is truly the culprit behind a white dwarf's fiery demise.
This supernova remnant is located 160,000 light-years from Earth. The actual supernova remnant is the irregular shaped dust cloud, at the upper center of the image. The gas in the lower half of the image and the dense concentration of stars in the lower left are the outskirts of a star cluster.
Image credit: NASA, ESA and H.-Y. Chu (Academia Sinica, Taipei)
Putting your life’s work on top of a rocket may seem like a daunting task, but that’s exactly what scientists have been doing for decades as they launch their research to the International Space Station.
This season on #NASAExplorers, we’re exploring why we send science to space, and what it takes to get it there!
Watch this week’s episode to meet a team of researchers who are launching an experiment to space for the first time.
Follow NASA Explorers on Facebook to catch new episodes of season 4 every Wednesday!
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Crazyspacesuit: Were you aware of the Overview Effect before experiencing it?
One hundred years ago this month, Albert Einstein published his theory of general relativity (GR), one of the most important scientific achievements in the last century.
A key result of Einstein’s theory is that matter warps space-time, and thus a massive object can cause an observable bending of light from a background object. The first success of the theory was the observation, during a solar eclipse, that light from a distant background star was deflected by the predicted amount as it passed near the sun.
When Einstein developed the general theory of relativity, he was trying to improve our understanding of how the universe works. At the time, Newtonian gravity was more than sufficient for any practical gravity calculations. However, as often happens in physics, general relativity has applications that would not have been foreseen by Einstein or his contemporaries.
How many of us have used a smartphone to get directions? Or to tag our location on social media? Or to find a recommendation for a nearby restaurant? These activities depend on GPS. GPS uses radio signals from a network of satellites orbiting Earth at an altitude of 20,000 km to pinpoint the location of a GPS receiver. The accuracy of GPS positioning depends on precision in time measurements of billionths of a second. To achieve such timing precision, however, relativity must be taken into account.
Our Gravity Probe B (GP-B) mission has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test. The experiment, launched in 2004, and measured the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates.
Scientists continue to look for cracks in the theory, testing general relativity predictions using laboratory experiments and astronomical observations. For the past century, Einstein’s theory of gravity has passed every hurdle.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Freaky fast and really awesome! NASA astronaut Jack Fischer posted this GIF to his social media Tuesday saying, “I was checking the view out the back window & decided to take a pic so you can see proof of our ludicrous speed! #SpaceIsAwesome”.
In case you didn’t know, the International Space Station travels 17,500 miles per hour as it orbits 250 miles above the Earth.
Currently, three humans are living and working there, conducting important science and research. The orbiting laboratory is home to more than 250 experiments, including some that are helping us determine the effects of microgravity on the human body. Research on the station will not only help us send humans deeper into space than ever before, including to Mars, but also benefits life here on Earth.
Follow NASA astronaut Jack Fischer on Instagram and Twitter.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
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
Our Sun has an entourage of planets, moons, and smaller objects to keep it company as it traverses the galaxy. But it’s still lonely compared to many of the other stars out there, which often come in pairs. These cosmic couples, called binary stars, are very important in astronomy because they can easily reveal things that are much harder to learn from stars that are on their own. And some of them could even host habitable planets!
New stars emerge from swirling clouds of gas and dust that are peppered throughout the galaxy. Scientists still aren’t sure about all the details, but turbulence deep within these clouds may give rise to knots that are denser than their surroundings. The knots have stronger gravity, so they can pull in more material and the cloud may begin to collapse.
The material at the center heats up. Known as a protostar, it is this hot core that will one day become a star. Sometimes these spinning clouds of collapsing gas and dust may break up into two, three, or even more blobs that eventually become stars. That would explain why the majority of the stars in the Milky Way are born with at least one sibling.
We can’t always tell if we’re looking at binary stars using just our eyes. They’re often so close together in the sky that we see them as a single star. For example, Sirius, the brightest star we can see at night, is actually a binary system (see if you can spot both stars in the photo above). But no one knew that until the 1800s.
Precise observations showed that Sirius was swaying back and forth like it was at a middle school dance. In 1862, astronomer Alvan Graham Clark used a telescope to see that Sirius is actually two stars that orbit each other.
But even through our most powerful telescopes, some binary systems still masquerade as a single star. Fortunately there are a couple of tricks we can use to spot these pairs too.
Since binary stars orbit each other, there’s a chance that we’ll see some stars moving toward and away from us as they go around each other. We just need to have an edge-on view of their orbits. Astronomers can detect this movement because it changes the color of the star’s light – a phenomenon known as the Doppler effect.
Stars we can find this way are called spectroscopic binaries because we have to look at their spectra, which are basically charts or graphs that show the intensity of light being emitted over a range of energies. We can spot these star pairs because light travels in waves. When a star moves toward us, the waves of its light arrive closer together, which makes its light bluer. When a star moves away, the waves are lengthened, reddening its light.
Sometimes we can see binary stars when one of the stars moves in front of the other. Astronomers find these systems, called eclipsing binaries, by measuring the amount of light coming from stars over time. We receive less light than usual when the stars pass in front of each other, because the one in front will block some of the farther star’s light.
Twin stars don’t always get along with each other – their relationship may be explosive! Type Ia supernovae happen in some binary systems in which a white dwarf – the small, hot core left over when a Sun-like star runs out of fuel and ejects its outer layers – is stealing material away from its companion star. This results in a runaway reaction that ultimately detonates the thieving star. The same type of explosion may also happen when two white dwarfs spiral toward each other and collide. Yikes!
Scientists know how to determine how bright these explosions should truly be at their peak, making Type Ia supernovae so-called standard candles. That means astronomers can determine how far away they are by seeing how bright they look from Earth. The farther they are, the dimmer they appear. Astronomers can also look at the wavelengths of light coming from the supernovae to find out how fast the dying stars are moving away from us.
Studying these supernovae led to the discovery that the expansion of the universe is speeding up. Our Nancy Grace Roman Space Telescope will scan the skies for these exploding stars when it launches in the mid-2020s to help us figure out what’s causing the expansion to accelerate – a mystery known as dark energy.
Astronomers like finding binary systems because it’s a lot easier to learn more about stars that are in pairs than ones that are on their own. That’s because the stars affect each other in ways we can measure. For example, by paying attention to how the stars orbit each other, we can determine how massive they are. Since heavier stars burn hotter and use up their fuel more quickly than lighter ones, knowing a star’s mass reveals other interesting things too.
By studying how the light changes in eclipsing binaries when the stars cross in front of each other, we can learn even more! We can figure out their sizes, masses, how fast they’re each spinning, how hot they are, and even how far away they are. All of that helps us understand more about the universe.
Thanks to observatories such as our Kepler Space Telescope, we know that worlds like Luke Skywalker’s home planet Tatooine in “Star Wars” exist in real life. And if a planet orbits at the right distance from the two stars, it could even be habitable (and stay that way for a long time).
In 2019, our Transiting Exoplanet Survey Satellite (TESS) found a planet, known as TOI-1338 b, orbiting a pair of stars. These worlds are tricker to find than planets with only one host star, but TESS is expected to find several more!
Want to learn more about the relationships between stellar couples? Check out this Tumblr post: https://nasa.tumblr.com/post/190824389279/cosmic-couples-and-devastating-breakups
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
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, our Human Research Program has organized hazards astronauts will encounter on a continual basis into five classifications.
The first hazard of a human mission to Mars is also the most difficult to visualize because, well, space radiation is invisible to the human eye. Radiation is not only stealthy, but considered one of the most menacing of the five hazards.
Above Earth’s natural protection, radiation exposure increases cancer risk, damages the central nervous system, can alter cognitive function, reduce motor function and prompt behavioral changes. To learn what can happen above low-Earth orbit, we study how radiation affects biological samples using a ground-based research laboratory.
Exploration to the Moon and Mars will expose astronauts to five known hazards of spaceflight, including radiation. To learn more, and find out what our 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 our host Gary Jordan further dives into the threat of radiation with Zarana Patel, a radiation lead scientist at the Johnson Space Center.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
How can citizens become more involved and informed about Earth sciences and developments? Are there mailing lists or accounts you suggest following?
Website: https://science.nasa.gov/citizenscience
Hii! I'm unsure if you've been asked this before, but I'd like to give it a shot anyway. What's the greatest legacy you hope to leave to the future generations? Whether it's one of the things you've accomplished already or are hoping to accomplish yet. Thank you very much!
Explore the universe and discover our home planet with the official NASA Tumblr account
1K posts