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Harmony's big move

The station's new Harmony module is detached from the Unity hub and moved to its permanent location on the Destiny lab.


Delta 4-Heavy launch

The first operational Delta 4-Heavy rocket launches the final Defense Support Program missile warning satellite for the Air Force.

 Full coverage

Columbus readied

The European Space Agency's Columbus laboratory module moves to pad 39A and placed aboard shuttle Atlantis for launch.

 To pad | Installed

Station port moved

The station crew uses the robot arm to detach the main shuttle docking port and mount it to the new Harmony module Nov. 12.


Atlantis rolls out

Space shuttle Atlantis rolls from the Vehicle Assembly Building to pad 39A for its December launch with the Columbus module.


Atlantis goes vertical

Atlantis is hoisted upright and maneuvered into position for attachment to the external tank and boosters.


STS-120 SRB cameras

Spectacular footage from six cameras mounted on shuttle Discovery's solid rocket boosters.

 Full coverage

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A last look at Comet Holmes
Posted: November 26, 2007

Credit: M. Ashby & N. Caldwell (CfA)
CAMBRIDGE, MA - Comet 17P/Holmes, which dazzled sky watchers with a dramatic outburst that made it visible to the unaided eye, now is fading from sight. However, before it returns to the obscurity from which it came, astronomers at the MMT Observatory took a final look.

In late October, Holmes brightened by a factor of about one million times when it ejected a vast cloud of dust and gas. That cloud expanded over time and now spans more than 870,000 miles, making it larger than the Sun (which is 865,000 miles in diameter).

On November 4, Smithsonian scientists snapped this photo of Comet Holmes using an instrument called Megacam, which is one of the largest CCD cameras in existence. Megacam holds 36 9-megapixel CCD chips, for a total of more than 300 megapixels.

Separate exposures through three color filters were combined to make this final, full-color image. Individual stars appear as a line of colored dots because the photos were centered on the comet, which moved slightly across the sky.

Currently, Comet Holmes has a total brightness of 3rd magnitude, however its large size on the sky (and resulting low surface brightness) makes it difficult to see without binoculars or a telescope. However, when it was discovered in 1892 it underwent a second bright outburst five months after the first. If Holmes repeats its historical performance, then this comet may offer viewers one more chance to see the show before it bows from the stage.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.