Happy 25th Anniversary, Hubble!

Hubble Space Telescope, taken on 2nd servicing mission. Photo credit: NASA
Hubble Space Telescope, taken on 2nd servicing mission. Photo credit: NASA

On April 24, 1990 the Hubble Space Telescope (HST) was launched from  the Space Shuttle Discovery. Previously, telescopes had been positioned on remote mountaintops and away from city lights in order to prevent distortion from Earth’s atmosphere. Now Hubble was being propelled into Earth’s orbit to prevent atmospheric distortion literally by rising above it.

That atmosphere is what causes start to look as if they are twinkling (sorry romantics, they don’t really twinkle….)1 But, once outside Earth’s atmosphere, “… [Hubble] can see astronomical objects with an angular size of 0.05 arc seconds, which is like seeing a pair of fireflies in Tokyo from your home in Maryland.” 2

As telescopes go, Hubble is not large, the mirror measures 7’10” across (2.4 meters), the length of a large school bus3 (the largest telescope in the southern hemisphere is 30 feet).4 Hubble weighs 24,500 pounds – as much as 2 full-grown elephants5 –  and  was named after Edwin Hubble, the man who is credited with discovering the cosmos.

Jeff Hoffman (with red stripes on the legs of his suit) and Story Musgrave work on the Hubble Space Telescope. Photo Credit: NASA
Jeff Hoffman (with red stripes on the legs of his suit) and Story Musgrave work on the Hubble Space Telescope. Photo Credit: NASA

Within a couple of weeks after it was launched, it became obvious that Hubble’s mirror had a flaw.  The curvature was off by off by 1/50 of a human hair – 2.2 microns – enough to cause fuzzy images to be sent back to earth. Hubble was circling Earth at 17, 500 miles per hour and 343 miles above it, and scientists needed to figure out a way to correct Hubble’s flawed mirror. In 1993 the first servicing mission was launched and Hubble’s flaw was successfully corrected. The mission was the first chance to fix the flaw, install new instruments and conduct routine maintenance.6

Hubble was designed to work with the Space Shuttles, the plan being that once it was no longer serviceable, it would be brought back to Earth and displayed in a museum. The retirement of the space shuttles means, however, that Hubble will not be able to be brought back to Earth. Now, a robotic mission is expected to help guide Hubble out of orbit, through Earth’s atmosphere and into the ocean.7

 

Hubble "Deep Field." Photo released in 1996
Hubble “Deep Field.” Photo released in 1996. Photo Credit

 

The Hubble Telescope doesn’t travel to distance stars, planets or galaxies, it photographs them and in January of 1996 the “Hubble Deep Field” was released. At that time it was humanity’s most distant view of the Universe. For ten days scientists aimed Hubble at a single spot in Ursa Major (the Big Dipper), taking several hundred photos with exposure times of 15 to 40 minutes.  “The result was a stunning still life of more than two thousand galaxies, a flurry of budding, tumultuous light whipped up in the shadowy primordial vacuum.” (Kanipe. pg 6)8

The brightest galaxies visible in the Deep Field are between 7 and 8 billion light-years away, some from 12 billion years ago. Some of the Milky Way’s oldest stars which congregate in globular clusters, are about 13 billion years old. 9 In fact, “Hubble has peered back into the very distant past, to locations more than 13.4 billion light years from Earth.”10

Mystic Mountain. Photo released for Hubble's 20th Anniversary.
Mystic Mountain. Photo released for Hubble’s 20th Anniversary.

 

The photo of  “Mystic Mountain Nebula” was released for Hubble’s 20th Anniversary. Mystic Mountain is a pillar of gas and dust, three light-years tall. The brilliant light from nearby stars is eating away at it, while infant stars within the Mystic Mountain fire jets of gas.11

 

 

The Sombrero Galaxy.
The Sombrero Galaxy.

 

The Sombrero Galaxy is just beyond the visibility of the naked eye, but can be seen with small telescopes. There are nearly 2,000 globular clusters which range in age from 10-13 billion years old. This is 10 times as many globular clusters as the Milky Way.12

 

Pandora's Cluster. Photo published 2013.
Pandora’s Cluster. Photo published 2013.

Pandora’s Cluster appears to have a complex and violent history. It seems to be the “… result of a simultaneous pile-up of at least four separate, smaller galaxy clusters. The crash took place over a span of 350 million years.”13

 

 

 

The Rose of Galaxies
The Rose of Galaxies

To celebrate Hubble’s 21st anniversary, scientists pointed it a group of interacting galaxies called Arp 273.  The larger of the spiral galaxies is distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy. The blue jewels across the top are combined light from intensely bright and hot young blue stars. They glow intensely in the ultraviolet light.  The series of unusual spiral patterns are signs of interaction.14

In the 25 years since Hubble was launched it has made more than 1 million observations. Astronomers using that data have published more than 12,700 articles, making it one of the most productive scientific instruments ever built.  It has circled Earth and traveled more than 3 billion miles and produces about 10 terabytes of new data each year.15 The policies governing Hubble have helped make it so rich in data and productivity. Any astronomer in the world can submit a proposal and request time on the telescope. When a proposal is chosen by a team of experts, that astronomer has a year to pursue their work. Once the year is up  the data is released to the scientific community, which has given rise to numerous findings – many not predicted in the original proposal.16

Happy 25th Anniversary!!

 

RESOURCES:

  1. Zimmerman, Robert. 2008. The universe in a mirror: the saga of the Hubble Telescope and the visionaries who built it. Princeton,
    The Universe in a Mirror Engineering Library QB500.268 .Z56 2008
    The Universe in a Mirror
    Engineering Library QB500.268 .Z56 2008

    N.J. : Princeton University Press. Engineering Library QB5.268 .Z56 2008

  2. Hubble Space Telescope. Feb. 20, 2015. NASA.
  3. Ibid.
  4. Southern Africa Large Telescope (SALT). Dec. 29, 2011. Space.com
  5. Hubble Space Telescope. Feb. 20, 2015. NASA.
  6. The Hubble Space Telescope. National Aeronautics and Space Administration, Goddard Space Flight Center. This website is kept for archival purposes only and is no longer updated. Accessed: April 2015.
  7. The Telescope Hubble Essentials. HubbleSite. Date Accessed: April 2015.
  8. Kanipe, Jeff. Chasing Hubble’s shadows: the search for galaxies at the edge of time. 2006. New York : Hill and Wang. Engineering Library QB500.262 .K36 2006.
  9. Ibid.
  10. Hubble Space Telescope. Feb. 20, 2015. NASA.
  11. Newscenter. April 22, 2010. HubbleSite.
  12. Gallery. HubbleSite. Date Accessed, April 2015.
  13. Newscenter. June 22, 2011. HubbleSite.
  14. Newscenter. “Rose” of Galaxies. April 20, 2011. HubbleSite.
  15. Hubble Space Telescope. Feb. 20, 2015. NASA
  16. The Telescope Hubble Essentials. HubbleSite. Date Accessed: April 2015.

FOR MORE INFORMATION:

  1. Chaline, Eric. 2012. Fifty machines that changed the course of history. Buffalo, N.Y. : Firefly Books. Engineering Library TJ15 .C44 2012
  2. Weintraub, David A. 2011. How old is the universe? Princeton, J.J. : Princeton University Press. Engineering Library QB501 .W45 2011
  3. O’Dell, C. Robert. 2003. The Orion Nebula : where stars are born. Cambridge, Mass. : Belknap press of Harvard University Press. Engineering Library QB855.9.O75 O34 2003
  4. Zimmerman, Robert. 2008. The universe in a mirror : the saga of the Hubble Telescope and the visionaries who built it. Princeton, N.J. : Princeton University Press. Engineering Library QB500.268 .Z56 2008.
  5. You and the rest’: twenty years since NASA’s dramatic Hubble repair mission (part 1)AmericaSpace. Date Accessed: April 2015
  6. Expect the unexpected in a Hubble 25th anniversary video. April 10, 2015. NASA.
  7. The Hubble Space Telescope turns 25 – here are its best 25 imagesApril 20, 2015. Extreme Tech.
  8. Highlights of HubbleApril 15, 2015. Nature: International weekly journal of science.
  9. Biography of a space telescope: Voices of Hubble. April 15, 2015. Nature: International weekly journal of science.