Science
First-known interstellar Solar System visitor ‘Oumuamua a comet in disguise
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The cigar-shaped ‘Oumuamua, the first interstellar object in recorded human history to whizz through the Solar System, is a comet after all, a pair of astronomers declared in research published in Nature on Wednesday.
In 2017, ‘Oumuamua captured the imagination of scientists and space fans with its peculiar characteristics. It had a nobbly, rocky surface, and was elongated and flat unlike anything they had seen before. The object looked like it might be an asteroid, but behaved more like a comet.
As it travelled through the Solar System, astronomers were puzzled over how it was accelerating using non-gravitational forces. Some people even suggested the first-known foreign visitor, whose name is a Hawaiian word meaning “a messenger from afar” might be an alien spaceship. But new evidence suggests ‘Oumuamua was just an icy comet after all.
Jennifer Bergner, assistant professor of astrochemistry at the University of Berkeley, and Darryl Seligman, an postdoctoral fellow studying theoretical and computational planetary science at Cornell University, and co-authors of the Nature study, believe they have cracked the mystery by figuring out ‘Oumuamua was powered by the outgassing of hydrogen gas as it was heated by the Sun.
“A comet traveling through the interstellar medium basically is getting cooked by cosmic radiation, forming hydrogen as a result,” Bergner said in a statement. “Our thought was: If this was happening, could you actually trap it in the body, so that when it entered the solar system and it was warmed up, it would outgas that hydrogen? Could that quantitatively produce the force that you need to explain the non-gravitational acceleration?”.
They found old research papers which showed that cosmic rays bombarding ice could produce molecular hydrogen (H2) that was trapped within the ice. In Oumuamua’s case, as it absorbed solar radiation, its ice produced hydrogen to propel it along its path, but the gas remained trapped underneath its surface so it didn’t have a dust coma like typical comets do.
“Even if there was dust in the ice matrix, you’re not sublimating the ice, you’re just rearranging the ice and then letting H2 get released. So, the dust isn’t even going to come out,” Seligman said.
“For a comet several kilometers across, the outgassing would be from a really thin shell relative to the bulk of the object, so both compositionally and in terms of any acceleration, you wouldn’t necessarily expect that to be a detectable effect,” Bergner added. “But because ‘Oumuamua was so small, we think that it actually produced sufficient force to power this acceleration.”
Planetary systems like the Solar System also contain comets and asteroids. These space rocks can be expelled due to gravitational interactions with other objects, and end up travelling through our Solar System. Rogue objects like ‘Oumuamua provide rare opportunities to study planet formation in distant worlds if astronomers could study them in more detail.
“The comets and asteroids in the solar system have arguably taught us more about planet formation than what we’ve learned from the actual planets in the solar system,” Seligman said. “I think that the interstellar comets could arguably tell us more about extrasolar planets than the extrasolar planets we are trying to get measurements of today.”
A second interstellar visitor, 2I/Borisov, was spotted passing by in 2019. Astronomers immediately realized it was a comet due to its visible coma created by water vaporized from its surface as it was warmed by the Sun. ®
Science
New image from the James Webb Space Telescope shows thousands upon thousands of stars in a galaxy 17 million light years away – Yahoo Canada
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The James Webb Space Telescope snapped a new image of a galaxy 17 million light-years away.
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Thousands upon thousands of stars are visible, many of which are concentrated in the galaxy’s heart.
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JWST is peering into the hearts of many galaxies to help scientists better understand star formation.
With the power of the James Webb Space Telescope, we can peer into the mysterious hearts of galaxies. And that’s exactly what you’re seeing here, in this new image from Webb of the galaxy NGC 5068.
NGC 5068 is located about 17 million light-years from Earth. For perspective, the Milky Way’s neighborhood of galaxies called the Local Group, is 5 million light-years away. So, this galaxy is beyond what we might consider close.
Each individual dot of white light you can see is a star, per Mashable. NASA said there are thousands upon thousands of stars in this image. And many of them are hanging out at the galaxy’s center, which you can see in the upper left as a bright bar of white light.
This region appears so bright because that’s where most of the stars are concentrated. That’s also where all the action is.
James Webb peers into the hearts of many galaxies to uncover their secrets
Most galaxies have an ultra-bright center due to warm dust that’s heated by massive bursts of star formation, according to the Harvard Smithsonian. And it’s this star formation that astronomers are interested in studying more with the help of JWST.
In fact, NGC 5068 is just one in a series of other galaxies Webb is observing for a project to help us better understand star formation. Webb has also taken images of the spiral galaxy IC 5332:
And the heart of galaxy M74, aka the “Phantom Galaxy”:
The James Webb Space Telescope has the advantage of seeing in the infrared.
Infrared wavelengths are too long for the human eye to detect. But they’re especially important for studying in space because they allow JWST to peer past obstructive visual light that would otherwise block our ability to see into the hearts of galaxies and their bustling environments of star formation.
“By observing the formation of stars in nearby galaxies, astronomers hope to kick-start major scientific advances with some of the first available data from Webb,” NASA said.
Watch a video of NGC 5068 below:
Read the original article on Business Insider
Science
ESA – Nicolas Bobrinsky on innovation and risk management | ESA Masterclass – European Space Agency
Innovation is triggered by many drivers. One of these is the constant need for ESA to develop innovative solutions, such as unique spacecraft technologies.
In this first video, Nicolas recalls how he and his team had to think outside the box to find a solution for ESA to communicate with Ulysses. The spacecraft was flying around the north pole of the Sun, which is much farther in deep space than satellites had been launched up to that point.
The success of this solution motivated the decision to build ESA’s first deep-space communications antennas in New Norcia, in Australia, thus enabling many ESA scientific firsts in deep-space exploration.
The antennas would, some decades after, be critically important receivers for the messages sent by the very distant Rosetta probe, on its quest to find and land on the comet 67P/Churyumov–Gerasimenko, and other ESA science and exploration missions such as Mars Express, Venus Express and Cassini-Huygens.
With 35 years of experience at ESA, Nicolas Bobrinsky is the former Head of Ground Systems Engineering & Innovation Department. He initiated and further managed the Space Situational Awareness and later the ESA Space Safety Programme.
In four episodes of this new series of ESA Masterclass, Nicolas takes us through major events in his career at ESA, covering cornerstone missions, first attempts, overcoming technical challenges, leading diverse teams and solving the unexpected problems that are part of any space endeavour.
Access all episodes of ESA Masterclass with Nicolas Brobinsky.
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This image of the barred spiral galaxy NGC 5068 is a composite from two of the James Webb Space Telescope’s instruments, MIRI and NIRCam. Credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST Team
<span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>NASA’s <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>James Webb Space Telescope has captured a detailed image of the barred spiral galaxy NGC 5068. Part of a project to record star formation in nearby galaxies, this initiative provides significant insights into various astronomical fields. The telescope’s ability to see through gas and dust, typically hiding star formation processes, offers unique views into this crucial aspect of galactic evolution.
A delicate tracery of dust and bright star clusters threads across this image from the James Webb Space Telescope. The bright tendrils of gas and stars belong to the barred spiral galaxy NGC 5068, whose bright central bar is visible in the upper left of this image – a composite from two of Webb’s instruments. NASA Administrator Bill Nelson revealed the image on June 2 during an event with students at the Copernicus Science Centre in Warsaw, Poland.
In this image of the barred spiral galaxy NGC 5068, from the James Webb Space Telescope’s MIRI instrument, the dusty structure of the spiral galaxy and glowing bubbles of gas containing newly-formed star clusters are particularly prominent. Three asteroid trails intrude into this image, represented as tiny blue-green-red dots. Asteroids appear in astronomical images such as these because they are much closer to the telescope than the distant target. As Webb captures several images of the astronomical object, the asteroid moves, so it shows up in a slightly different place in each frame. They are a little more noticeable in images such as this one from MIRI, because many stars are not as bright in mid-infrared wavelengths as they are in near-infrared or visible light, so asteroids are easier to see next to the stars. One trail lies just below the galaxy’s bar, and two more in the bottom-left corner. Credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST Team
NGC 5068 lies around 20 million light-years from Earth in the constellation Virgo. This image of the central, bright star-forming regions of the galaxy is part of a campaign to create an astronomical treasure trove, a repository of observations of star formation in nearby galaxies. Previous gems from this collection can be seen here (IC 5332) and here (M74). These observations are particularly valuable to astronomers for two reasons. The first is because star formation underpins so many fields in astronomy, from the physics of the tenuous <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>plasma that lies between stars to the evolution of entire galaxies. By observing the formation of stars in nearby galaxies, astronomers hope to kick-start major scientific advances with some of the first available data from Webb.
This view of the barred spiral galaxy NGC 5068, from the James Webb Space Telescope’s NIRCam instrument, is studded by the galaxy’s massive population of stars, most dense along its bright central bar, along with burning red clouds of gas illuminated by young stars within. This near-infrared image of the galaxy is filled by the enormous gathering of older stars which make up the core of NGC 5068. The keen vision of NIRCam allows astronomers to peer through the galaxy’s gas and dust to closely examine its stars. Dense and bright clouds of dust lie along the path of the spiral arms: These are H II regions, collections of hydrogen gas where new stars are forming. The young, energetic stars ionize the hydrogen around them, creating this glow represented in red. Credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST Team
The second reason is that Webb’s observations build on other studies using telescopes including the Hubble Space Telescope and ground-based observatories. Webb collected images of 19 nearby star-forming galaxies which astronomers could then combine with Hubble images of 10,000 star clusters, spectroscopic mapping of 20,000 star-forming emission nebulae from the <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>Very Large Telescope (VLT), and observations of 12,000 dark, dense molecular clouds identified by the Atacama Large Millimeter/submillimeter Array (ALMA). These observations span the electromagnetic spectrum and give astronomers an unprecedented opportunity to piece together the minutiae of star formation.
With its ability to peer through the gas and dust enshrouding newborn stars, Webb is particularly well-suited to explore the processes governing star formation. Stars and planetary systems are born amongst swirling clouds of gas and dust that are opaque to visible-light observatories like Hubble or the VLT. The keen vision at infrared wavelengths of two of Webb’s instruments — MIRI (Mid-Infrared Instrument) and NIRCam (Near-Infrared Camera) — allowed astronomers to see right through the gargantuan clouds of dust in NGC 5068 and capture the processes of star formation as they happened. This image combines the capabilities of these two instruments, providing a truly unique look at the composition of NGC 5068.
The James Webb Space Telescope stands as the apex of space science observatories worldwide. Tasked with demystifying enigmas within our own solar system, Webb will also extend its gaze beyond, seeking to observe distant worlds orbiting other stars. In addition to this, it aims to delve into the cryptic structures and the origins of our universe, thereby facilitating a deeper understanding of our position within the cosmic expanse. The Webb project is an international endeavor spearheaded by NASA, conducted in close partnership with the <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>European Space Agency (ESA) and the Canadian Space Agency.
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