![]() | |||
| |||
|
|||
Recent Articles
|
Topic: Gravitational Lensing
They have uncovered a discrepancy between the theoretical models of how dark matter should be distributed in galaxy clusters, and observations of dark matter’s grip on clusters. Dark matter does not emit, absorb, or reflect light. Its presence is only known through its gravitational pull on visible matter in space. Therefore, dark matter remains as elusive as Alice in Wonderland’s Cheshire Cat – where you only see its grin (in the form of gravity) but not the animal itself. ![]() This Hubble Space Telescope image shows the massive galaxy cluster MACS J1206. Embedded within the cluster are the distorted images of distant background galaxies, seen as arcs and smeared features. These distortions are caused by the amount of dark matter in the cluster, whose gravity bends and magnifies the light from faraway galaxies. This effect, called gravitational lensing, allows astronomers to study remote galaxies that would otherwise be too faint to see. (NASA, ESA, P. Natarajan (Yale University), G. Caminha (University of Groningen), M. Meneghetti (INAF-Observatory of Astrophysics and Space Science of Bologna), the CLASH-VLT/Zooming teams; acknowledgment: NASA, ESA, M. Postman (STScI), the CLASH team) «Read the rest of this article» Sections: News | No Comments
NASA’s Hubble Space Telescope discovers first Stars were formed earlier than thought
The exploration of the very first galaxies remains a significant challenge in modern astronomy. We do not know when or how the first stars and galaxies in the universe formed. ![]() New results from the Hubble Space Telescope suggest the formation of the first stars and galaxies in the early universe took place sooner than previously thought. A European team of astronomers have found no evidence of the first generation of stars, known as Population III stars, when the universe was less than 1 billion years old. This artist’s impression presents the early universe. (ESA/Hubble, M. Kornmesser and NASA) «Read the rest of this article» Sections: Technology | No Comments
NASA’s Hubble Space Telescope expands view of far off GalaxiesNASA Headquarters
This dilemma for cosmologists is called cosmic variance. By expanding the survey area, such uncertainties in the structure of the universe can be reduced. ![]() This image shows a massive galaxy cluster embedded in the middle of a field of nearly 8,000 galaxies scattered across space and time. This “galaxies galore” snapshot is from a new Hubble Space Telescope survey to boldly expand its view by significantly enlarging the area covered around huge galaxy clusters previously photographed by Hubble. (NASA, ESA, A. Koekemoer (STScI), M. Jauzac (Durham University), C. Steinhardt (Niels Bohr Institute), and the BUFFALO team) «Read the rest of this article» Sections: Technology | No Comments
NASA’s Hubble Space Telescope finds farthest Star on recordSpace Telescope Science Institute
But through a quirk of nature that tremendously amplifies the star’s feeble glow, astronomers using NASA’s Hubble Space Telescope were able to pinpoint this faraway star and set a new distance record. They also used Icarus to test one theory of dark matter, and to probe the make-up of a foreground galaxy cluster. ![]() Icarus, whose official name is MACS J1149+2223 Lensed Star 1, is the farthest individual star ever seen. It is only visible because it is being magnified by the gravity of a massive galaxy cluster, located about 5 billion light-years from Earth. Called MACS J1149+2223, this cluster, shown at left, sits between Earth and the galaxy that contains the distant star. The panels at the right show the view in 2011, without Icarus visible, compared with the star’s brightening in 2016. (NASA, ESA, and P. Kelly (University of Minnesota)) «Read the rest of this article» Sections: Technology | No Comments
NASA’s Hubble and Spitzer Space Telescopes discover farthest Galaxy seen to date using Gravitational LensingWritten by Laurie Cantillo / Dwayne Brown
The embryonic galaxy named SPT0615-JD existed when the universe was just 500 million years old. Though a few other primitive galaxies have been seen at this early epoch, they have essentially all looked like red dots, given their small size and tremendous distances. However, in this case, the gravitational field of a massive foreground galaxy cluster not only amplified the light from the background galaxy but also smeared the image of it into an arc (about 2 arcseconds long). ![]() This Hubble Space Telescope image shows the farthest galaxy yet seen in an image that has been stretched and amplified by a phenomenon called gravitational lensing. (NASA , ESA, and B. Salmon (STScI)) «Read the rest of this article» Sections: Technology | No Comments
NASA says Dark Energy Survey helps us understand structure of the UniverseWritten by Elizabeth Landau
Three scientists from NASA’s Jet Propulsion Laboratory in Pasadena, California, are part of this group that is helping to further our understanding of the structure of the universe. The advances in astrophysics from DES are crucial to preparations for two upcoming space missions that will probe similar questions about the nature of the universe: ESA’s Euclid mission (which has significant NASA participation) and NASA’s Wide-Field Infrared Survey Telescope mission, both expected to launch in the 2020s. ![]() Map of dark matter made from gravitational lensing measurements of 26 million galaxies in the Dark Energy Survey. The map covers about 1/30th of the entire sky and spans several billion light years in extent. Red regions have more dark matter than average, blue regions less dark matter. (Chihway Chang/Kavli Institute for Cosmological Physics at the University of Chicago/DES Collaboration) «Read the rest of this article» Sections: Technology | No Comments
NASA’s Hubble Space Telescope spots Clumps of New Stars in Distant GalaxyNASA Goddard Space Flight Center
By applying a new computational analysis to a galaxy magnified by a gravitational lens, astronomers have obtained images 10 times sharper than what Hubble could achieve on its own. The results show an edge-on disk galaxy studded with brilliant patches of newly formed stars. ![]() In this Hubble photograph of a distant galaxy cluster, a spotty blue arc stands out against a background of red galaxies. That arc is actually three separate images of the same background galaxy. The background galaxy has been gravitationally lensed, its light magnified and distorted by the intervening galaxy cluster. On the right: How the galaxy would look to Hubble without distortions. (NASA, ESA, and T. Johnson (University of Michigan) «Read the rest of this article» Sections: Technology | No Comments
NASA’s Space Exploration could discover planets similar to ones in “Star Wars: Rogue One”Written by Arielle Samuelson
Some of the planets discovered around stars in our own galaxy could be very similar to arid Tatooine, watery Scarif and even frozen Hoth, according to NASA scientists. ![]() Stormtroopers in the new Star Wars film “Rogue One” wade through the water of an alien ocean world. NASA scientists believe ocean worlds exist in our own galaxy, along with many other environments. (Disney/Lucasfilm Ltd. & TM.) «Read the rest of this article» Sections: Technology | No Comments
NASA’s Spitzer Space Telescope completes Frontier Fields project observationsWritten by Elizabeth Landau
Even with today’s best telescopes, it is difficult to gather enough light from the very first galaxies, located more than 13 billion light years away, to learn much about them beyond their approximate distance. ![]() This image of galaxy cluster Abell 2744, also called Pandora’s Cluster, was taken by the Spitzer Space Telescope. The cluster is also being studied by NASA’s Hubble Space Telescope and Chandra X-Ray Observatory in a collaboration called the Frontier Fields project. (NASA/JPL-Caltech) «Read the rest of this article» Sections: Technology | No Comments
|
Now playing at the Movies
Archives |
|
© 2006-2021 Clarksville, TN Online is owned and operated by residents of Clarksville Tennessee.
|