My Dark Sky

The Wide Field and Planetary Camera 2 (WFPC2) was Hubble Space Telescope “workhorse” instrument. It was originally installed in the first Hubble servicing mission in 1993 with a special optics to solve the spherical aberration in the telescope primary mirror. And because of this it was nicknamed “the camera that saved Hubble”.

Although WFPC2 had became Hubble’s most requested instrument, time has come for it to make way for an improved version camera – the Wide Field Camera 3 (WFC3). During the first spacewalk of Hubble Servicing Mission 4 on 15 May 2009, astronaut Grunsfeld and Feustel removed the WFPC2 and installed the new WFC3. WFPC2 will return to Earth together with Atlantis and hopefully once of these days we will have the chance to see it sitting in a museum.

The Hubble community bids farewell to the soon-to-be decommissioned Wide Field Planetary Camera 2 (WFPC2) onboard the Hubble Space Telescope. In tribute to Hubble’s longest-running optical camera, planetary nebula K 4-55 has been imaged as WFPC2’s final “pretty picture”. Credit: NASA, ESA, Hubble Heritage Team.

During the camera’s amazing years in space, it provided outstanding science and spectacular images of our universe. Before we say bye bye to WFPC2, let us look at its top five breakthroughs:

(1) Deepest photograph of the universe. Hubble’s famous “Deep Field” picture left the world with its mouth agape when it was first revealed in 1996. In just a small patch of sky, more than 1,000 galaxies located billions of light-years away could be seen floating in space like sea creatures at the bottom of an endless ocean. Our world and our galaxy suddenly seemed very small.

(2) Observations of comet collision with Jupiter. WFPC2 gave the world a rare, stunning view of Comet Shoemaker-Levy 9 plunging into the gas giant Jupiter in 1994. The images revealed the event in great detail, including ripples expanding outward from the impact.

(3) The birth and death of stars. WFPC2 brought the cosmos down to Earth with its exquisite pictures of stars in all stages of development. Its famed picture of the “Pillars of Creation” and other images of colorful dying stars offered the first, glorious views of a star’s life. The camera also took the first pictures of the dusty disks around stars where planets are born, demonstrating that planet-forming environments are common in the universe.

Gas Pillars in the Eagle Nebula (M16): Pillars of Creation in a Star-Forming Region. Credit: NASA, ESA, STScI, J. Hester and P. Scowen (Arizona State University).

(4) The age and rate of expansion of our universe. Our universe formed from a colossal explosion known as the Big Bang, and has been stretching apart ever since. WFPC2 by observing stars that vary periodically in brightness, was able to calculate the pace of this expansion to an unprecedented degree of error of 10 percent. The camera also played a leading role in discovering that the expansion of the universe is accelerating, driven by a mysterious force called “dark energy.” Together, these findings led to the calculation that our universe is approximately 13.7 billion years old.

(5) Most galaxies harbor huge black holes. Before Hubble, astronomers suspected, but had no proof, that supermassive black holes lurk deep in the bellies of galaxies. WFPC2 together with spectroscopy data from Hubble, showed that most galaxies in the universe do indeed harbor monstrous black holes up to billions of times the mass of our sun.

<= Black Hole-Powered Jet of Electrons and Sub-Atomic Particles Streams From Center of Galaxy M87. Credit: NASA and The Hubble Heritage Team.

The scientific and inspirational legacy of the camera will be felt by astronomers and the public alike, for as long as the story of the Hubble Space Telescope is told.

Posted in Satellites & Spacecrafts
Tags: HST

Hubble Space Telescope “workhorse” instrument — the Wide Field and Planetary Camera 2 (WFPC2) which was built by JPL and added to the observatory in December 1993 — is behind most of Hubble’s famous pictures. WFPC2 is the telescope’s main camera. It observes just about everything, recording razor-sharp images of faraway objects in relatively broad views, covering wavelengths from ultraviolet to near-infrared.

You may not known WFPC2, but I believed you must have seen a lot of its images. If you ever wonder why some of Hubble’s images has a funny wacky shape (see right), then you are looking at a product of WFPC2.

The unique WFPC2 design results in the stair-step appearance of many of its images. The “heart” of WFPC2 consists of four cameras: one high-resolution “planetary” camera and three “wide-field” cameras. Although the planetary camera sees a smaller region of the sky, it delivered a finer-detailed image because it compact the same number of pixels into a smaller area. The difference between the wide-field cameras and the planetary camera is like the difference between a wide-angle lens and a telephoto lens.

Each of the 4 cameras records a separate image that represents one part of the overall view. After that, the magnified view from the planetary camera is reduced to the proportion of the other 3 wide-field cameras, resulting in one small image and three larger images. And when the four images are stitched together, the wacky shape emerges in the final image. Click here for illustration.

For 15 years, WFPC2 had non-stop producing breathtaking images of our universe. But just like everything else, someday, it has to come to an end. And that someday is now… During Hubble Servicing Mission 4, which is under way now, a new and improved version camera – the Wide Field Camera 3 (WFC3) – will replaced this old workhorse.

NASA’s Wide Field and Planetary Camera 2 is more than just a scientific instrument, it is a tool of artistic expression; it’s “painting” of the universe not only has scientific but also artistic values that can be admired by all of us.

The Hourglass Nebula, taken by the Wide Field and Planetary Camera 2, is pretty enough to frame. Read more: A Universal Art Form: NASA’s Wide Field and Planetary Camera 2.

Posted in Satellites & Spacecrafts
Tags: HST