Jun 24, 2025 02:13 AM
(This post was last modified: Jun 24, 2025 06:51 PM by C C.)
How the Rubin Observatory will reinvent astronomy
https://spectrum.ieee.org/vera-rubin-obs...rst-images
EXCERPTS: Rubin is unlike any telescope ever built. Its exceptionally wide field of view, extreme speed, and massive digital camera will soon begin the 10-year Legacy Survey of Space and Time (LSST) across the entire southern sky. The result will be a high-resolution movie of how our solar system, galaxy, and universe change over time, along with hundreds of petabytes of data representing billions of celestial objects that have never been seen before.
[...] Originally, Rubin was intended to be a dark-matter survey telescope, to search for the 85 percent of the mass of the universe that we know exists but can’t identify. ... But once astronomers considered what else might be possible with a survey telescope that combined enormous light-collecting ability with a wide field of view, Rubin’s science mission rapidly expanded beyond dark matter.
Trading the ability to focus on individual objects for a wide field of view that can see tens of thousands of objects at once provides a critical perspective for understanding our universe, says Ivezić.
[...] Every night, the telescope will take a thousand images, one every 34 seconds. After three or four nights, it’ll have the entire southern sky covered, and then it’ll start all over again. After a decade, Rubin will have taken more than 2 million images, generated 500 petabytes of data, and visited every object it can see at least 825 times. In addition to identifying an estimated 6 million bodies in our solar system, 17 billion stars in our galaxy, and 20 billion galaxies in our universe, Rubin’s rapid cadence means that it will be able to delve into the time domain, tracking how the entire southern sky changes on an almost daily basis.
[...] Rubin is also unique in that it utilizes the largest digital camera ever built. ... After the data leaves Rubin’s camera, most of the processing will take place at the SLAC National Accelerator Laboratory in Menlo Park, Calif., over 9,000 kilometers from Cerro Pachón. It takes less than 10 seconds for an image to travel from the focal plane of the camera to SLAC, thanks to a 600-gigabit fiber connection from the summit to La Serena, and from there, a dedicated 100-gigabit line and a backup 40-gigabit line that connect to the Department of Energy’s science network in the United States. The 20 terabytes of data that Rubin will produce nightly makes this bandwidth necessary. “There’s a new image every 34 seconds,” O’Mullane tells me. “If I can’t deal with it fast enough, I start to get behind. So everything has to happen on the cadence of half a minute if I want to keep up with the data flow.”
At SLAC, each image will be calibrated and cleaned up, including the removal of satellite trails. Rubin will see a lot of satellites, but since the satellites are unlikely to appear in the same place in every image, the impact on the data is expected to be minimal when the images are coadded. The processed image is compared with a baseline image and any alerts are sent out, by which time processing of the next image has already begun.
[...] As Rubin’s catalog of objects grows, astronomers will be able to query it in all kinds of useful ways. Want every image of a particular patch of sky? No problem. All the galaxies of a certain shape? A little trickier, but sure. Looking for 10,000 objects that are similar in some dimension to 10,000 other objects? That might take a while, but it’s still possible. Astronomers can even run their own code on the raw data.
“Pretty much everyone in the astronomy community wants something from Rubin,” O’Mullane explains, “and so they want to make sure that we’re treating the data the right way..." (MORE - missing details)
Is the cosmic microwave background a huge mistake?
https://youtu.be/KFgwQICae8c
INTRO: In the Big Bang Theory, the cosmic microwave background — microwave-range radiation that floats through the entire universe at a steady 2.7 Kelvin — is evidence that a hot explosion of plasma kicked off the creation of the universe. But according to a new paper, the microwave radiation came from early galaxies instead. Does this mean that the big bang theory is wrong? Let’s take a look...
Is the Cosmic Microwave Background a Huge Mistake? ... https://youtu.be/KFgwQICae8c
https://www.youtube-nocookie.com/embed/KFgwQICae8c
https://spectrum.ieee.org/vera-rubin-obs...rst-images
EXCERPTS: Rubin is unlike any telescope ever built. Its exceptionally wide field of view, extreme speed, and massive digital camera will soon begin the 10-year Legacy Survey of Space and Time (LSST) across the entire southern sky. The result will be a high-resolution movie of how our solar system, galaxy, and universe change over time, along with hundreds of petabytes of data representing billions of celestial objects that have never been seen before.
[...] Originally, Rubin was intended to be a dark-matter survey telescope, to search for the 85 percent of the mass of the universe that we know exists but can’t identify. ... But once astronomers considered what else might be possible with a survey telescope that combined enormous light-collecting ability with a wide field of view, Rubin’s science mission rapidly expanded beyond dark matter.
Trading the ability to focus on individual objects for a wide field of view that can see tens of thousands of objects at once provides a critical perspective for understanding our universe, says Ivezić.
[...] Every night, the telescope will take a thousand images, one every 34 seconds. After three or four nights, it’ll have the entire southern sky covered, and then it’ll start all over again. After a decade, Rubin will have taken more than 2 million images, generated 500 petabytes of data, and visited every object it can see at least 825 times. In addition to identifying an estimated 6 million bodies in our solar system, 17 billion stars in our galaxy, and 20 billion galaxies in our universe, Rubin’s rapid cadence means that it will be able to delve into the time domain, tracking how the entire southern sky changes on an almost daily basis.
[...] Rubin is also unique in that it utilizes the largest digital camera ever built. ... After the data leaves Rubin’s camera, most of the processing will take place at the SLAC National Accelerator Laboratory in Menlo Park, Calif., over 9,000 kilometers from Cerro Pachón. It takes less than 10 seconds for an image to travel from the focal plane of the camera to SLAC, thanks to a 600-gigabit fiber connection from the summit to La Serena, and from there, a dedicated 100-gigabit line and a backup 40-gigabit line that connect to the Department of Energy’s science network in the United States. The 20 terabytes of data that Rubin will produce nightly makes this bandwidth necessary. “There’s a new image every 34 seconds,” O’Mullane tells me. “If I can’t deal with it fast enough, I start to get behind. So everything has to happen on the cadence of half a minute if I want to keep up with the data flow.”
At SLAC, each image will be calibrated and cleaned up, including the removal of satellite trails. Rubin will see a lot of satellites, but since the satellites are unlikely to appear in the same place in every image, the impact on the data is expected to be minimal when the images are coadded. The processed image is compared with a baseline image and any alerts are sent out, by which time processing of the next image has already begun.
[...] As Rubin’s catalog of objects grows, astronomers will be able to query it in all kinds of useful ways. Want every image of a particular patch of sky? No problem. All the galaxies of a certain shape? A little trickier, but sure. Looking for 10,000 objects that are similar in some dimension to 10,000 other objects? That might take a while, but it’s still possible. Astronomers can even run their own code on the raw data.
“Pretty much everyone in the astronomy community wants something from Rubin,” O’Mullane explains, “and so they want to make sure that we’re treating the data the right way..." (MORE - missing details)
Is the cosmic microwave background a huge mistake?
https://youtu.be/KFgwQICae8c
INTRO: In the Big Bang Theory, the cosmic microwave background — microwave-range radiation that floats through the entire universe at a steady 2.7 Kelvin — is evidence that a hot explosion of plasma kicked off the creation of the universe. But according to a new paper, the microwave radiation came from early galaxies instead. Does this mean that the big bang theory is wrong? Let’s take a look...
Is the Cosmic Microwave Background a Huge Mistake? ... https://youtu.be/KFgwQICae8c