Stig Östlund

lördag, april 25, 2020

Unforgettable Hubble Space Telescope Photos













Photo

CreditNASA and European Space Agency

“This is a really new birthplace of stars,” Jennifer Wiseman, senior project scientist for the Hubble Space Telescope, said of the new image, which shows a cluster of 3,000 stars known as Westerlund 2 in the constellation Carina. “The cluster is only about two million years old, which in stellar terms is very young. And it contains some of the galaxy’s hottest, brightest and most massive stars that we know of.”
  1. Photo

    This was one of the first images taken by an upgraded camera installed in 2002. CreditNASA and European Space Agency
    Tadpole Galaxy, 2002
    John Grunsfeld, astronaut and associate administrator for science, NASA
    Mr. Grunsfeld is best known as the Hubble repairman for journeying to space to make repairs on Hubble three different times.
    This is a really interesting spiral galaxy that has only recently had an encounter with a dwarf galaxy. It perturbed the spiral structure, but you can see it's still an intact spiral and going out a hundred kilo parsecs is this huge tail. And in that tail are brand new star-forming regions, incredible activity caused by shocks traveling through this tadpole tail.
    Finally, with Hubble, we were able to see the universe with the same kind of resolution that we see with our eyeballs. In the background, virtually every pixel that is lit up, is another galaxy.
    You could pick any small region of the image — not the tadpole. You could pick any other small region and do great science.
    This is why I risked my life, to be able to allow the Hubble to provide this level of wonderful science. This is the image I have hanging up in my home.
  2. Photo

    The top series shows the spherical aberration model, which matched what Hubble was actually seeing, bottom series. A sort of contact lens was later installed to fix the problem. CreditSandra Faber
    Proof of Blurriness, 1990
    Sandra Faber, professor of astronomy and astrophysics, University of California, Santa Cruz
    Soon after the Hubble Space Telescope was deployed in 1990, astronomers and engineers discovered that images taken by Hubble's camera were not as clear as they should have been. The telescope's mirror had been ground to the wrong curvature, making it near-sighted.
    Here is the actual figure that Jon Holtzman, then at Lowell Observatory, and I produced for NASA that clinched the diagnosis of spherical aberration. We got the project to run the telescope through focus and take images as a test. The top series is our set of model through-focus images. The bottom series is the set of real through-focus images.
  3. Photo

    A 50-light-year-wide panorama of the center of the Carina Nebula shows a region of rapid star birth and death. CreditNASA and European Space Agency
    Carina Nebula, 2007
    Pam Jeffries, graphic designer at the Space Telescope Science Institute, which operates Hubble
    This large panoramic image of the Carina Nebula is my favorite Hubble image because of the sweeping visual movement combined with compelling and interesting tiny details. Hubble has taken many close-up shots, and each detail is its own masterpiece. I loved it when I first started working with Hubble images in 2010, and I still love its breathtaking iconic appeal. It is always humbling to think about the birth of other stars and how they mirror our own. The time, distance and forces involved always put your stress and self-importance in perspective.
  4. Photo

    The slice of the Orion Nebula, only 0.14 light-years wide, shows young stars enshrouded in disks of dust and gas. CreditNASA and European Space Agency
    Baby Planets? 1994
    Sara Seager, professor of planetary science and physics, Massachusetts Institute of Technology
    This striking 1994 Hubble Space Telescope image shows the rich tapestry of a small region of the Orion Nebula, a stellar nursery 1,500 light years away. Newborn stars are seen with surrounding disks of raw planetary materials – protoplanetary disks or"propylids" – that will likely evolve into planets. This image is my favorite because even more astonishing than the beauty is the implication – one that came well before exoplanets orbiting nearby stars was established – that protoplanetary disks around newborn stars are abundant and that planet-forming processes (and hence planets) should be common in the Milky Way Galaxy.

  5. Photo

    In December 1995, Hubble stared at one patch of the night sky. From 342 exposures over 10 days, the Hubble Deep Field image revealed a dazzling array of almost 3,000 galaxies. CreditNASA and European Space Agency
    The Hubble Deep Field, 1996
    Robert Williams, former director, Space Telescope Science Institute
    The prevailing opinion before Hubble telescope’s launch was that a very long exposure with the telescope was not likely to reveal distant new objects. Any would be too faint to be detected. One of the unique features of astronomy is that one can directly look back into the past because of the finite speed of light, and there is no better way to piece together the changing nature of the universe than to detect the most distant objects. They represent the ancestors of all that we see around us. A deep field with the Hubble simply had to be tried.
    When we announced to the science community that we would attempt to take a long series of exposures for a "deep field," a number of our colleagues were very troubled by our plans. Lyman Spitzer, who along with John Bahcall was one of the essential advocates to bring about Hubble, was serious, but muted in expressing his concerns.
    On several occasions he asked me at council meetings, “Are you sure you want to do this?” His colleague John Bahcall was much more vocal in working to prevent what he believed to be a much too risky venture, coming so soon after Hubble’s embarrassing spherical aberration had been fixed by the historic NASA Shuttle servicing mission. His concern, certainly understandable, was that if a large segment of time on the telescope produced little or no useful results, which would no doubt become public, the fallout could tarnish the mission of the telescope beyond repair.
    Scientific progress requires risk, so we executed the observations over a two-week period in December 1995. The resulting Hubble Deep Field image yielded a wondrous display of galaxies, many of them very small, faint, and distant. The image is really a core sample of the universe.
    The Hubble Deep Field has truly opened up the entire universe of galaxies to study and interpretation by simple imaging, turning the pretty faces of those galaxies into true talking heads that have helped us understand how structure formed and evolved over time in the universe.
    This image was created in 1995, but released in 1996.
  6. Photo

    The spiral shape is the result of two galaxies colliding and merging. This is a preview of what might happen when our Milky Way galaxy collides with the approaching Andromeda galaxy in a few billion years. CreditNASA and European Space Agency
    The Antennae, 2005
    Brad Whitmore, astronomer, Space Telescope Science Institute
    The Antennae are the most famous example of a colliding pair of galaxies, a phenomenon that results in some of the favorite Hubble images due to their great diversity and graceful appearance.

    For astronomers, they are also a wonderful laboratory for studying the formation of stars, since the collision ignites a starburst that lights up the galaxy like a display of fireworks. A surprise was that most of the star formation is in the form of star clusters — some of which survive to form the equivalent of the ancient globular clusters in our own galaxy — but most of which dissolve, their stars spreading out to form the stars that make up the galaxy as a whole. The contrast between the very bright blue stars formed in the starburst, the red light from hydrogen gas emission and the intricate dark dust structures result in spectacular images as the galaxies go through their gravitational dance and eventually merge to form an elliptical galaxy.
  7. Photo

    This image was part of a survey to detect infant galaxies, some of which existed when the universe was less than 2 billion years old. CreditNASA and European Space Agency
    A Black Hole in Every Galaxy, 2003
    Meg Urry, professor of astronomy, Yale University, and president of the American Astronomical Society
    My very favorite is the very deep image from the GOODS survey, which I designed while still at the Space Telescope Science Institute (along with Mark Dickinson and Mauro Giavalisco). It’s quiet and perhaps not as dramatic as many other Hubble Space Telescope images but it tells us about the history of the universe, including the growth of supermassive black holes — one in every galaxy, like a chicken in every pot — and the assembly of galaxies. So much information from such a little picture. (GOODS was an acronym we came up with: Great Observatories Origins Deep Survey. “Great Observatories because the full multiwavelength survey used Hubble, Spitzer and Chandra, i.e., what NASA referred to as the Great Observatories; “Deep Survey” because it was the deepest multiwavelength survey ever done at that time, about a quarter the size of the full moon; and “Origins” because without another letter the name was pure hubris.)
    Happy birthday, Hubble!
  8. Photo

    The Helix Nebula, located 690 light-years from Earth, is a ball of glowing gas expelled from a dying sun-like star. This image was a composite of a photograph taken by Hubble in 2002 and one by a telescope in Chile in 2003. CreditNASA and European Space Agency
    “The Eye of God,” 2003
    Barbara A. Mikulski, senator from Maryland and senior Democrat on the appropriations subcommittee that funds NASA
    I keep a huge print of “The Eye of God” hanging in my office. It’s the planetary nebulae nearest to Earth, extending 2.5 light-years across, making it larger than our entire solar system.
    The scientists and staff of the Space Telescope Science Institute in Baltimore autographed it and gave it to me after we saved the Hubble in 1993 during Servicing Mission 1. Every time I stand in front of it I’m reminded, not just of the insight and beauty that Hubble brought home, but also of the people – the engineers, scientists, technicians, support staff, cafeteria workers and custodians – who have all done so much to advance our understanding of the cosmos. So now not only do I have God looking down on me as I work, I have the angels of the Space Telescope Science Institute watching over me as well.
  9. Photo

    A decade after the Hubble Deep Field observations, an improved camera installed on Hubble enabled a look even further back in time. In 2012, further enhancements led to the Hubble Extreme Deep Field. CreditNASA and European Space Agency.
    The Hubble Ultra Deep Field, 2004
    Steven Beckwith, professor of astronomy at University of California, Berkeley and former director of the Space Telescope Science Institute
    When we first looked at the final Ultra Deep Field on the big computer screen at the institute, the entire image was filled with galaxies: blue, yellow and red, a menagerie of different shapes and sizes. We were looking back to the time when the universe was very young. These early galaxies were not at all like the ones we see today; they were little train wrecks, clumps of stars and clusters of stars beginning to assemble the structures that would eventually become the beautiful spiral and elliptical galaxies we see today. It was a magical moment for all of us, one of those times that you never forget.
    After the loss of the space shuttle Columbia in 2003, Sean O'Keefe, then NASA's administrator, canceled the last planned space shuttle mission for another round of repairs and upgrades for Hubble, calling it too risky. Dr. Beckwith, then director of the Space Telescope Science Institute, sparred publicly and loudly with Mr. O'Keefe. Mr. O'Keefe stepped down as NASA administrator in 2004; his successor, Michael Griffin, reinstated the repair mission.
  10. Photo

    The Tarantula Nebula, about 170,000 light-years away, is a turbulent star-forming region in the Large Magellanic Cloud. It is close enough that Hubble can make out individual stars. CreditNASA and European Space Agency
    Tarantula Nebula, 2012
    John Troeltzsch, senior program manager, Ball Aerospace
    Ball Aerospace built scientific instruments for the Hubble, including the "corrective lens" that fixed its vision in 1993.
    This image is my favorite because I used Hubble in 1990 to image this region for an engineering test shortly after launch. The image was severely degraded by Hubble’s focus problem. The modern version of Hubble took a spectacular image of the region in 2012, which shows both the beauty of a stellar nursery and the immense power of some of the most massive stars in our universe. Astronomy has come so far in the past 25 years thanks to Hubble and the people who built and operate it.
  11. Photo

    The biggest, brightest circle at the center is Pluto. Just to the right is Charon, the large moon of Pluto that was discovered in 1978. CreditNASA and European Space Agency
    Pluto and Its Moons, 2006
    Max Mutchler, research and instrument scientist, Space Telescope Science Institute
    My favorite, personally most exciting and meaningful, is a no-brainer: the discovery of Pluto’s small moons.
    Late at night on June 15, 2005, I was working in my office on Hubble observations of Pluto for Hal Weaver of the Johns Hopkins Applied Physics Laboratory, who intentionally over-exposed a series of images to try and detect faint moons. Hal is the project scientist for NASA's New Horizons mission to Pluto. I thought I was merely cleaning up the raw images, so I hadn’t really begun to search them yet, when a moment of pure scientific discovery snuck up on me: Pluto has two small moons (to go with the large moon Charon discovered in 1978)!
    The actual discovery images were nowhere near as clear and obvious as this later confirmation image (which has also been heavily processed), but it was still surprisingly easy for Hubble to clearly detect not just one but two moons which had been missed in previous searches. It actually seemed too easy, and we gave ourselves many months to confirm the discovery and convince ourselves they weren’t some camera artifact (but I was 90 percent sure they were real that night).
    By 2012, the New Horizons team used Hubble to discover two more small Pluto moons, Styx and Kerberos. To me, this image represents the symbiosis of two great NASA missions working in concert to discover and explore new worlds. Hubble set the stage, and now New Horizons will fly through the Pluto system on July 14, and turn these small dots into real places for the first time.
  12. Photo

    More Hubble photos: "Pillars of Creation," Jupiter, a pair of interacting galaxies called Arp 273 the star-forming region NGC 3603, Horsehead Nebula. CreditNASA and European Space Agency
    Just One Favorite?
    Neil deGrasse Tyson, director, Hayden Planetarium, American Museum of Natural History
    Can't do it. Like picking your favorite child. What’s certain, however, is that nobody ever required a caption to appreciate them. The images convey their own majesty and splendor without it.

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