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By NASA
4 min read
May’s Night Sky Notes: How Do We Find Exoplanets?
Astronomers have been trying to discover evidence that worlds exist around stars other than our Sun since the 19th century. By the mid-1990s, technology finally caught up with the desire for discovery and led to the first discovery of a planet orbiting another sun-like star, Pegasi 51b. Why did it take so long to discover these distant worlds, and what techniques do astronomers use to find them?
The Transit Method
A planet passing in front of its parent star creates a drop in the star’s apparent brightness, called a transit. Exoplanet Watch participants can look for transits in data from ground-based telescopes, helping scientists refine measurements of the length of a planet’s orbit around its star. Credit: NASA’s Ames Research Center One of the most famous exoplanet detection methods is the transit method, used by Kepler and other observatories. When a planet crosses in front of its host star, the light from the star dips slightly in brightness. Scientists can confirm a planet orbits its host star by repeatedly detecting these incredibly tiny dips in brightness using sensitive instruments. If you can imagine trying to detect the dip in light from a massive searchlight when an ant crosses in front of it, at a distance of tens of miles away, you can begin to see how difficult it can be to spot a planet from light-years away! Another drawback to the transit method is that the distant solar system must be at a favorable angle to our point of view here on Earth – if the distant system’s angle is just slightly askew, there will be no transits. Even in our solar system, a transit is very rare. For example, there were two transits of Venus visible across our Sun from Earth in this century. But the next time Venus transits the Sun as seen from Earth will be in the year 2117 – more than a century from the 2012 transit, even though Venus will have completed nearly 150 orbits around the Sun by then!
The Wobble Method
As a planet orbits a star, the star wobbles. This causes a change in the appearance of the star’s spectrum called Doppler shift. Because the change in wavelength is directly related to relative speed, astronomers can use Doppler shift to calculate exactly how fast an object is moving toward or away from us. Astronomers can also track the Doppler shift of a star over time to estimate the mass of the planet orbiting it. NASA, ESA, CSA, Leah Hustak (STScI) Spotting the Doppler shift of a star’s spectra was used to find Pegasi 51b, the first planet detected around a Sun-like star. This technique is called the radial velocity or “wobble” method. Astronomers split up the visible light emitted by a star into a rainbow. These spectra, and gaps between the normally smooth bands of light, help determine the elements that make up the star. However, if there is a planet orbiting the star, it causes the star to wobble ever so slightly back and forth. This will, in turn, cause the lines within the spectra to shift ever so slightly towards the blue and red ends of the spectrum as the star wobbles slightly away and towards us. This is caused by the blue and red shifts of the star’s light. By carefully measuring the amount of shift in the star’s spectra, astronomers can determine the size of the object pulling on the host star and if the companion is indeed a planet. By tracking the variation in this periodic shift of the spectra, they can also determine the time it takes the planet to orbit its parent star.
Direct Imaging
Finally, exoplanets can be revealed by directly imaging them, such as this image of four planets found orbiting the star HR 8799! Space telescopes use instruments called coronagraphs to block the bright light from the host star and capture the dim light from planets. The Hubble Space Telescope has captured images of giant planets orbiting a few nearby systems, and the James Webb Space Telescope has only improved on these observations by uncovering more details, such as the colors and spectra of exoplanet atmospheres, temperatures, detecting potential exomoons, and even scanning atmospheres for potential biosignatures!
NASA’s James Webb Space Telescope has provided the clearest look in the infrared yet at the iconic multi-planet system HR 8799. The closest planet to the star, HR 8799 e, orbits 1.5 billion miles from its star, which in our solar system would be located between the orbit of Saturn and Neptune. The furthest, HR 8799 b, orbits around 6.3 billion miles from the star, more than twice Neptune’s orbital distance. Colors are applied to filters from Webb’s NIRCam (Near-Infrared Camera), revealing their intrinsic differences. A star symbol marks the location of the host star HR 8799, whose light has been blocked by the coronagraph. In this image, the color blue is assigned to 4.1 micron light, green to 4.3 micron light, and red to the 4.6 micron light. NASA, ESA, CSA, STScI, W. Balmer (JHU), L. Pueyo (STScI), M. Perrin (STScI) You can find more information and activities on NASA’s Exoplanets page, such as the Eyes on Exoplanets browser-based program, The Exoplaneteers, and some of the latest exoplanet news. Lastly, you can find more resources in our News & Resources section, including a clever demo on how astronomers use the wobble method to detect planets!
The future of exoplanet discovery is only just beginning, promising rich rewards in humanity’s understanding of our place in the Universe, where we are from, and if there is life elsewhere in our cosmos.
Originally posted by Dave Prosper: July 2015
Last Updated by Kat Troche: April 2025
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By NASA
3 min read
Help Classify Galaxies Seen by NASA’s James Webb Space Telescope!
The Galaxy Zoo classification interface shows you an image from NASA’s Webb telescope and asks you questions about it. Image credit: Galaxy Zoo, Zooniverse. Inset galaxy: NASA/STScI/CEERS/TACC/S. Finkelstein/M. Bagley/Z. Levay/A. Pagan NASA needs your help identifying the shapes of thousands of galaxies in images taken by our James Webb Space Telescope with the Galaxy Zoo project. These classifications will help scientists answer questions about how the shapes of galaxies have changed over time, what caused these changes, and why. Thanks to the light collecting power of Webb, there are now over 500,000 images of galaxies on website of the Galaxy Zoo citizen science project—more images than scientists can classify by themselves.
“This is a great opportunity to see images from the newest space telescope,” said volunteer Christine Macmillan from Aberdeen, Scotland. “Galaxies at the edge of our universe are being seen for the first time, just as they are starting to form. Just sign up and answer simple questions about the shape of the galaxy that you are seeing. Anyone can do it, ages 10 and up!”
As we look at more distant objects in the universe, we see them as they were billions of years ago because light takes time to travel to us. With Webb, we can spot galaxies at greater distances than ever before. We’re seeing what some of the earliest galaxies ever detected look like, for the first time. The shapes of these galaxies tell us about how they were born, how and when they formed stars, and how they interacted with their neighbors. By looking at how more distant galaxies have different shapes than close galaxies, we can work out which processes were more common at different times in the universe’s history.
At Galaxy Zoo, you’ll first examine an image from the Webb telescope. Then you will be asked several questions, such as ‘Is the galaxy round?’, or ‘Are there signs of spiral arms?’. If you’re quick, you may even be the first person to see the galaxies you’re asked to classify.
“I’m amazed and honored to be one of the first people to actually see these images! What a privilege!” said volunteer Elisabeth Baeten from Leuven, Belgium.
Galaxy Zoo is a citizen science project with a long history of scientific impact. Galaxy Zoo volunteers have been exploring deep space since July 2007, starting with a million galaxies from a telescope in New Mexico called the Sloan Digital Sky Survey and then, moving on to images from space telescopes like NASA’s Hubble Space Telescope and ESA (European Space Agency)’s Euclid telescope. The project has revealed spectacular mergers, taught us about how the black holes at the center of galaxies affect their hosts, and provided insight into how features like spiral arms form and grow.
Now, in addition to adding new data from Webb, the science team has incorporated an AI algorithm called ZooBot, which will sift through the images first and label the ‘easier ones’ where there are many examples that already exist in previous images from the Hubble Space Telescope. When ZooBot is not confident on the classification of a galaxy, perhaps due to complex or faint structures, it will show it to users on Galaxy Zoo to get their human classifications, which will then help ZooBot learn more. Working together, humans and AI can accurately classify limitless numbers of galaxies. The Galaxy Zoo science team acknowledges support from the International Space Sciences Institute (ISSI), who provided funding for the team to get together and work on Galaxy Zoo. Join the project now.
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Last Updated Apr 29, 2025 Related Terms
Astrophysics Division Citizen Science Get Involved James Webb Space Telescope (JWST) Explore More
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By USH
Shape-Shifting Materials are advanced, adaptive materials capable of changing their physical form, embedding sensors and circuits directly into their structure, and even storing energy, all without traditional wiring. Lockheed Martin is at the forefront of developing these futuristic materials, raising questions about the possible extraterrestrial origin of this technology.
In a previous article, we discussed why suppressed exotic technologies are suddenly being disclosed. One company that frequently comes up in this conversation is Lockheed Martin, the American defense and aerospace giant known for pushing the boundaries of aviation and space innovation.
Imagine an aircraft that can grow its own skin, embed sensors into its body, store energy without wires, and even shift its shape mid-flight to adapt to changing conditions. This isn’t science fiction anymore, Lockheed Martin’s cutting-edge research is turning these futuristic concepts into reality.
But where is all this coming from?
The rapid development and creativity behind Lockheed Martin’s projects raise intriguing questions. Whistleblowers like David Grusch have recently alleged that Lockheed Martin has had access to recovered UFO materials for decades. Supporting this, Don Phillips, a former Lockheed engineer, confirmed years ago that exotic materials have been held and studied by the company since at least the 1950s.
This suggests that for over half a century, Lockheed has secretly been engaged in researching and reverse-engineering off-world technologies. It's possible that the breakthroughs we’re seeing today are the result of this hidden legacy. Ben Rich, former head of Lockheed’s Skunk Works division, famously hinted at this when he said, "We now have the technology to take ET home."
One particularly stunning development involves "smart" materials that behave almost like muscles, allowing aircraft structures to morph in real-time. These materials enable a craft to fine-tune its aerodynamics on the fly, adjusting instantly to turbulence, speed shifts, or mission-specific demands.
Lockheed’s innovations go even further. By embedding carbon nanotubes, extremely strong and highly conductive microscopic structure, directly into the material, they have created surfaces that can transfer information and power without traditional wiring. In these next-generation aircraft, the "skin" itself acts as the nervous system, the energy grid, and the sensor network all at once.
You can only imagine the kinds of technologies that have been developed over the years through the reverse engineering of exotic materials and recovered extraterrestrial craft. Yet, governments and space agencies remain tight-lipped about the existence of advanced alien civilizations, who likely introduced these techniques to Earth unintentionally.
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By European Space Agency
Each year, cutting-edge technologies developed by the European Space Agency (ESA) for its complex missions and scientific discoveries find new life in applications used to benefit Earth and improve our daily lives.
From 9–13 April, ESA was guest of honour at the 50th International Exhibition of Inventions Geneva in Switzerland with more than 1000 inventions, which attracted 30 000 visitors from the public. ESA showcased its new technologies and applications that have been invented for space missions and patented for use in and outside the space arena.
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By European Space Agency
For decades, satellites have played a crucial role in our understanding of the remote polar regions. The ongoing loss of Antarctic ice, owing to the climate crisis, is, sadly, no longer surprising. However, satellites do more than just track the accelerating flow of glaciers towards the ocean and measure ice thickness.
New research highlights how ESA’s CryoSat mission has been used to uncover the hidden impact of subglacial lakes – vast reservoirs of water buried deep under the ice – that can suddenly drain into the ocean in dramatic outbursts and affect ice loss.
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