Edward Gibson Sketched Comet Kohoutek’s Changes During Close Approach

Summary: Skylab 4 mission’s Edward Gibson sketched Comet Kohoutek’s changes during its close approach, December 1973 to January 1974.

sketch of Comet Kohoutek’s appearance Sunday, Jan. 6, 1974, by Skylab 4 mission’s scientist pilot Edward Gibson, based on the three-astronaut crew’s collective impressions; in-flight, black-and-white sketch (above) and post-flight, color version (below); G. Gary, Comet Kohoutek (1974), Figure 10, page 12: Public Domain, via Internet Archive

Skylab 4 mission’s Edward Gibson sketched Comet Kohoutek’s changes during its close approach, December 1973 to January 1974, and then, after the mission’s end, paired the in-flight black-and-white sketches with post-flight color versions.

Comet Kohoutek’s December 1973 through January 1974 perihelion passage prioritized the National Aeronautics and Space Administration’s (NASA) scheduling of the agency’s third and last manned mission to Skylab, the first United States space station. Skylab’s position in low Earth orbit eased observations that were troubled on the ground by Earth’s sunlight-scattering atmosphere. The Skylab 4 mission docked Friday, Nov. 16, 1973, at the space station and undocked Friday, Feb. 8, 1974.

Commander Gerald Paul Carr (born Aug. 22, 1932), scientist pilot Edward George Gibson (born Nov. 8, 1936) and pilot William Reid Pogue (Jan. 23, 1930-March 3, 2014) were tasked with 13 experiments for observing the recently discovered comet. Czech astronomer Luboš Kohoutek (born Jan. 29, 1935) had discovered the long-period comet Wednesday, March 7, 1973, at northern Germany’s Hamburg Observatory (Hamburger Sternwarte).

In his free time at the space station, Edward Gibson sketched Comet Kohoutek’s progressive changes during its close approach. The comet’s perihelion (Ancient Greek: περί, perí, “near” + ἥλιος, hḗlios, “sun”) passage centered on its reach of perihelion Friday, Dec. 28.

Gibson aimed to present collective impressions of Comet Kohoutek’s changes during its close approach. Each sketch was vetted by Commander Carr and Pilot Pogue.

Gibson was able to make 10 black-and-white sketches. The first sketch, dated Tuesday, Dec. 18, was his only pre-perihelion drawing. In a paper presented at the Comet Kohoutek Workshop of June 13-14, 1974, at Marshall Space Flight Center (MSFC) in Huntsville, Alabama, Gibson explained that, after Dec. 18, the comet “. . . was occulted by space station structure until perihelion” (page 3).

Nine of the 10 sketches depicted the comet’s post-perihelion appearances. At the Comet Kohoutek Workshop, Gibson noted that the last nine sketches were based observations “. . . made on the 9 days following perihelion. During this time period, the comet could be observed from Skylab unobstructed by space station structure, but it could not be properly observed from the ground.”

Gibson made three post-perihelion sketches in December. Sunday, Dec. 29, was one day after perihelion; Sunday, Dec. 30, was perihelion plus two days; Monday, Dec. 31, was three days after perihelion.

Six sketches were drawn in January. The month’s first sketch was made Tuesday, Jan. 1, 1974, four days after perihelion. Sketches successively dated Thursday, Jan. 3, through Sunday, Jan. 6, presented progressive changes on post-perihelion days five through nine.

Visual observations of the comet were mostly made with 10-power binoculars. Gibson’s first sketch did not specify the viewpoint for the observation. Only his second sketch culled observations from inside and outside the space station. The comet’s appearance in his Sunday, Dec. 29, sketch reflected observations made outside, during the mission’s third EVA (extravehicular activity), and inside at number three window in the Structural Transition Section (STS) linking the station’s Multiple Docking Adaptor (MDA) and Airlock Module (AM).

Gibson noted at the Marshall Space Flight Center’s June 1974 Comet Kohoutek Workshop that his first view of the comet Dec. 29 happened during the EVA. He observed the comet through a sun visor. He described the comet as “extremely bright and its most unusual feature was a sunward spike . . . This spike was faint in relation to the coma and tail immediately behind the coma. A very faint diffuse feature could be seen in the acute angle between the spike and tail.”

Sketches three through 10 were based upon observations at the number three window in the Structural Transition Section and at the number one window in the Apollo Command and Service Module (CSM). CSM-118 delivered the crew to the station and, during the mission, docked at the Multiple Docking Adaptor.

Gibson’s in-flight sketches included notes about the color changes as the comet progressed through its perihelion passage. After completing the Skylab 4 mission, Gibson paired the black-and-white sketches with post-flight, color drawings.

The takeaways for Edward Gibson’s sketches of Comet Kohoutek’s changes during its close approach December 1973 through January 1974 are that the Skylab 4 mission’s scientist pilot made 10 black-and-white sketches between Tuesday, Dec. 18, 1973, and Sunday, Jan. 6, 1974; that the sketches were based upon collective impressions of the mission’s three-astronaut crew; and that, after completing Skylab 4, Gibson rendered post-flight, color versions of each of his 10 in-flight, black-and-white sketches.

progressive appearances of Comet Kohoutek between Dec. 18, 1973, and Jan. 6, 1974; post-flight drawings, based upon in-flight, black-and-white sketches, by Skylab 4 scientist pilot Edward Gibson; G. Gary, Comet Kohoutek (1974), Figure 11, page 13: Public Domain, via Internet Archive

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

sketch of Comet Kohoutek’s appearance Sunday, Jan. 6, 1974, by Skylab 4 mission’s scientist pilot Edward Gibson, based on the three-astronaut crew’s collective impressions; in-flight, black-and-white sketch (above) and post-flight, color version (below); G. Gary, Comet Kohoutek (1974), Figure 10, page 12: Public Domain, via Internet Archive @ https://archive.org/details/CometKohoutek/page/n22

progressive appearances of Comet Kohoutek between Dec. 18, 1973, and Jan. 6, 1974; post-flight drawings, based upon in-flight, black-and-white sketches, by Skylab 4 scientist pilot Edward Gibson; G. Gary, Comet Kohoutek (1974), Figure 11, page 13: Public Domain, via Internet Archive @ https://archive.org/details/CometKohoutek/page/n23

For further information:

Carney, Emily. “Ed Gibson’s Dances With the Sun: Skylab 4, 1973-1974.” National Space Society. Dec. 24, 2017.
Available @ https://space.nss.org/ed-gibsons-dances-with-the-sun-skylab-4-1973-1974/

Carney, Emily. “You All Need to Know: Skylab Had a Superbad Solar Telescope.” National Space Society. June 5, 2016.
Available @ https://space.nss.org/you-all-need-to-know-skylab-had-a-superbad-solar-telescope/

Gary, Gilmer Allen, ed. Comet Kohoutek: A Workshop Held at Marshall Space Flight Center Huntsville, Alabama June 13-14, 1974. Washington DC: National Aeronautics and Space Administration, 1975.
Available via Internet Archive @ https://archive.org/details/CometKohoutek

George C. Marshall Space Flight Center. MSFC Skylab Kohoutek Project Report. NASA Technical Memorandum TM X-64880. Huntsville AL: October 1974.
Available via Internet Archive @ https://archive.org/details/NASA_NTRS_Archive_19740027130
Available via NASA Technical Reports Server (NASA NTRS) @ https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740027130.pdf

Gibson, Edward G. “Skylab Visual Observation of Comet Kohoutek.” Pages 3-14. In: Gilmer Allen Gary, ed. Comet Kohoutek: A Workshop Held at Marshall Space Flight Center Huntsville, Alabama June 13-14, 1974. Washington DC: National Aeronautics and Space Administration, 1975.
Available @ https://archive.org/details/CometKohoutek/page/n13

Hitt, David; Owen Garriott; and Joe Kerwin. Homesteading Space: The Skylab Story. Featuring the In-Flight Diary of Alan Bean. Lincoln NE: University of Nebraska Press, 2008.
Available via Google Books @ https://books.google.com/books/about/Homesteading_Space.html?id=sR5Cm_zeIekC

Lundquist, Charles A., ed. “Chapter 4: Observations of Comet Kohoutek.” Skylab’s Astronomy and Space Sciences: 42-63. NASA SP-404. Washington DC: National Aeronautics and Space Administration Scientific and Technical Information Office, 1979.
Available @ https://history.nasa.gov/SP-404/ch4.htm

Marriner, Derdriu. "Arabella and Anita Spun First Space Webs in August 1973 at Skylab.” Earth and Space News. Wednesday, July 31, 2013.
Available @ https://earth-and-space-news.blogspot.com/2013/07/arabella-and-anita-spun-first-space.html

Shayler, David J.; and Colin Burgess. NASA’s Scientist-Astronauts. Springer-Praxis Books in Space Exploration. Chichester UK: Praxis Publishing Limited, 2007.