Pale Blue Dot

Pale Blue Dot is a photograph of planet Earth taken on February 14, 1990, by the Voyager 1 space probe from a record distance of about 6 billion kilometers (3.7 billion miles, 40.5 AU), as part of that day's Family Portrait series of images of the Solar System.

In the photograph, Earth's apparent size is less than a pixel; the planet appears as a tiny dot against the vastness of space, among bands of sunlight reflected by the camera.[1]

Voyager 1, which had completed its primary mission and was leaving the Solar System, was commanded by NASA to turn its camera around and take one last photograph of Earth across a great expanse of space, at the request of astronomer and author Carl Sagan.[2]

Pale Blue Dot
Seen from about 6 billion kilometers (3.7 billion miles), Earth appears as a tiny dot (the blueish-white speck approximately halfway down the brown band to the right) within the darkness of deep space.

Background

In September 1977, NASA launched Voyager 1, a 722-kilogram (1,592 lb) robotic spacecraft on a mission to study the outer Solar System and eventually interstellar space.[3][4] After the encounter with the Jovian system in 1979 and the Saturnian system in 1980, the primary mission was declared complete in November of the same year. Voyager 1 was the first space probe to provide detailed images of the two largest planets and their major moons.

Voyager
The Voyager 1 spacecraft

The spacecraft, still travelling at 64,000 km/h (40,000 mph), is the most distant man-made object from Earth and the first one to leave the Solar System.[5] Its mission has been extended and continues to this day, with the aim of investigating the boundaries of the Solar System, including the Kuiper belt, the heliosphere and interstellar space. Operating for 41 years, 6 months and 17 days as of today (22 March 2019), it receives routine commands and transmits data back to the Deep Space Network.[3][6][7]

Voyager 1 was expected to work only through the Saturn encounter. When the spacecraft passed the planet in 1980, Sagan proposed the idea of the space probe taking one last picture of Earth.[8] He acknowledged that such a picture would not have had much scientific value, as the Earth would appear too small for Voyager's cameras to make out any detail, but it would be meaningful as a perspective on our place in the universe.

Although many in NASA's Voyager program were supportive of the idea, there were concerns that taking a picture of Earth so close to the Sun risked damaging the spacecraft's imaging system irreparably. It was not until 1989 that Sagan's idea was put into practice, but then instrument calibrations delayed the operation further, and the personnel who devised and transmitted the radio commands to Voyager 1 were also being laid off or transferred to other projects. Finally, NASA Administrator Richard Truly interceded to ensure that the photograph was taken.[5][9][10]

Camera

Voyager 1's Imaging Science Subsystem (ISS) consisted of two cameras: a 200 mm focal length, low-resolution wide-angle camera (WA), used for spatially extended imaging, and a 1500 mm high-resolution narrow-angle camera (NA) – the one that took Pale Blue Dot – intended for detailed imaging of specific targets. Both cameras were of the slow-scan vidicon tube type and were fitted with eight colored filters, mounted on a filter wheel placed in front of the tube.[11][12]

The challenge was that, as the mission progressed, the objects to be photographed would increasingly be farther away and would appear fainter, requiring longer exposures and slewing (panning) of the cameras to achieve acceptable quality. The telecommunication capability also diminished with distance, limiting the number of data modes that could be used by the imaging system.[13] The series of commands were compiled and sent to Voyager 1, with the images executed on February 14, 1990.

After taking the Family Portrait series of images, which included Pale Blue Dot, NASA mission managers commanded Voyager 1 to power its cameras down, as the spacecraft was not going to fly near anything else of significance for the rest of its mission, while other instruments that were still collecting data needed power for the long journey to interstellar space.[14]

Photograph

The design of the command sequence to be relayed to the spacecraft and the calculations for each photograph's exposure time were developed by space scientists Candy Hansen of NASA's Jet Propulsion Laboratory (JPL) and Carolyn Porco of the University of Arizona.[9] After the planned imaging sequence was taken on February 14, 1990, the data from the camera were stored initially in an on-board tape recorder. Transmission to Earth was also delayed by the Magellan and Galileo missions being given priority over the use of the Deep Space Network. Then, between March and May 1990, Voyager 1 returned 60 frames back to Earth, with the radio signal travelling at the speed of light for nearly five and a half hours to cover the distance.[5]

Three of the frames received showed the Earth as a tiny point of light in empty space. Each frame had been taken using a different color filter: blue, green and violet, with exposure times of 0.72, 0.48 and 0.72 seconds respectively. The three frames were then recombined to produce the image that became Pale Blue Dot.[15][16]

View of the Sun, Earth and Venus from Voyager 1
The wide-angle photograph of the Sun and inner planets (not visible), with Pale Blue Dot superimposed on the left, Venus to its right

Of the 640,000 individual pixels that compose each frame, Earth takes up less than one (0.12 of a pixel, according to NASA). The light bands across the photograph are an artifact, the result of sunlight reflecting off parts of the camera and its sunshade, due to the relative proximity between the Sun and the Earth.[5][17] Voyager's point of view was approximately 32° above the ecliptic. Detailed analysis suggested that the camera also detected the Moon, although it is too faint to be visible without special processing.[16]

The pale blue color of the dot is the result of polarization and scattering of the light reflected from Earth. The polarization in turn depends on various factors such as cloud cover, exposed areas of oceans, forests, deserts, snow fields etc.[18][19]

Pale Blue Dot, which was taken with the narrow-angle camera, was also published as part of a composite picture created from a wide-angle camera photograph showing the Sun and the region of space containing the Earth and Venus. The wide-angle image was inset with two narrow-angle pictures: Pale Blue Dot and a similar photograph of Venus. The wide-angle photograph was taken with the darkest filter (a methane absorption band) and the shortest possible exposure (5 milliseconds), to avoid saturating the camera's vidicon tube with scattered sunlight. Even so, the result was a bright burned-out image with multiple reflections from the optics in the camera and the Sun that appears far larger than the actual dimension of the solar disk. The rays around the Sun are a diffraction pattern of the calibration lamp which is mounted in front of the wide-angle lens.[16]

Distance

Voyager 1 - 14 February 1990
Position of Voyager 1 on February 14, 1990. The vertical bars are spaced one year apart and indicate the probe's distance above the ecliptic.

According to NASA's Jet Propulsion Laboratory's HORIZONS tool, the distances between Voyager 1 and the Earth on February 14 and May 15, 1990, were as follows:[20]

Distance of Voyager 1 from Earth
Unit of measurement February 14, 1990 May 15, 1990
Astronomical units 40.472229 40.417506
Kilometers 6,054,587,000 6,046,400,000
Miles 3,762,146,000 3,757,059,000

Reflections

PaleBlueDot
Sagan pointed out that on that dot, "every human being who ever lived, lived out their lives".

During a public lecture at Cornell University in 1994, Carl Sagan presented the image to the audience and shared his reflections on the deeper meaning behind the idea of the Pale Blue Dot:[21]

We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.

Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity – in all this vastness – there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. It's been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known.

— Carl Sagan, speech at Cornell University, October 13, 1994

Sagan also titled his 1994 book Pale Blue Dot: A Vision of the Human Future in Space after the photograph.[22][23]

In 2015, NASA acknowledged the 25th anniversary of Pale Blue Dot.[24]

Twenty-five years ago, Voyager 1 looked back toward Earth and saw a 'pale blue dot,' " an image that continues to inspire wonderment about the spot we call home.

— Ed Stone, Voyager project scientist[24]

See also

References

  1. ^ "A Pale Blue Dot". The Planetary Society. Archived from the original on December 19, 2014. Retrieved December 21, 2014.
  2. ^ "From Earth to the Solar System, The Pale Blue Dot". NASA. Archived from the original on December 18, 2014. Retrieved December 24, 2014.
  3. ^ a b "Mission Overview". starbrite.jpl.nasa.gov. Archived from the original on July 21, 2011. Retrieved July 27, 2011.
  4. ^ "Voyager 1". nssdc.gsfc.nasa.gov. Archived from the original on October 17, 2011. Retrieved July 27, 2011.
  5. ^ a b c d Sagan, Carl (September 9, 1990). "The Earth from the frontiers of the Solar system – The Pale, Blue Dot". PARADE Magazine. Retrieved July 28, 2011.
  6. ^ Butrica, Andrew.J (1994). "Chapter 11". From Engineering Science To Big Science (1st ed.). New York: Random House. p. 251. ISBN 0-679-43841-6.
  7. ^ "An Earthly View of Mars". space.com. Archived from the original on August 14, 2012. Retrieved July 28, 2011.
  8. ^ "It's our dot: For Carl Sagan, planet Earth is just a launch pad for human explorations of the outer universe". pqasb.pqarchiver.com. Retrieved July 28, 2011.
  9. ^ a b Sagan, 1994, pp. 4–5
  10. ^ "An Alien View Of Earth". npr.org. Archived from the original on July 21, 2011. Retrieved July 12, 2011.
  11. ^ "Voyager – Imaging Science Subsystem". Jet Propulsion Laboratory. NASA. Archived from the original on February 13, 2018. Retrieved December 26, 2014.
  12. ^ "Cassini Solstice Mission – ISS". NASA. Archived from the original on January 14, 2015. Retrieved December 26, 2014.
  13. ^ "Voyager 1 Narrow Angle Camera Description". Planetary Rings Node. SETI Institute. Archived from the original on January 1, 2016. Retrieved December 26, 2014.
  14. ^ "Voyager Celebrates 20-Year-Old Valentine to Solar System". NASA. Archived from the original on April 19, 2016. Retrieved June 23, 2016.
  15. ^ "PIA00452: Solar System Portrait – Earth as 'Pale Blue Dot'". photojournal.jpl.nasa.gov. Archived from the original on July 18, 2011. Retrieved July 27, 2011.
  16. ^ a b c "PIA00450: Solar System Portrait – View of the Sun, Earth and Venus". photojournal.jpl.nasa.gov. Archived from the original on July 5, 2011. Retrieved July 28, 2011.
  17. ^ "Solar System Exploration-Pale Blue Dot". solarsystem.nasa.gov. Archived from the original on November 13, 2011. Retrieved July 27, 2011.
  18. ^ "Polarization of terrestrial planets and the ZIMPOL technique". planetquest1.jpl.nasa.gov. Archived from the original on December 8, 2014. Retrieved July 27, 2011.
  19. ^ Woolf, N.J.; Smith, P.S.; Traub, W.A.; Jucks, K.W. (March 28, 2002). "The Spectrum of Earthshine: A Pale Blue Dot Observed from the Ground" (PDF). The Astrophysical Journal. The American Astronomical Society. 574 (1): 430. arXiv:astro-ph/0203465. Bibcode:2002ApJ...574..430W. doi:10.1086/340929. Retrieved December 5, 2014.
  20. ^ "NASA's JPL Horizon System for calculating ephemerides for solar system bodies". ssd.jpl.nasa.gov. Archived from the original on October 7, 2012. Retrieved July 13, 2011.
  21. ^ "A Pale Blue Dot". The Big Sky Astronomy Club. Archived from the original on June 18, 2017. Retrieved August 29, 2017.
  22. ^ Sagan, Carl (1994). Pale Blue Dot: A Vision of the Human Future in Space (1st ed.). New York: Random House. ISBN 0-679-43841-6.
  23. ^ Garfinkel, Simson.L (February 5, 1995). "Sagan looks to space for future salvation". The Daily Gazette. Retrieved July 28, 2011.
  24. ^ a b "Archived copy". Archived from the original on April 2, 2017. Retrieved February 15, 2017.CS1 maint: Archived copy as title (link)

Further reading

External links

Benn Jordan

Benn Lee Jordan (born October 28, 1978) is an American modern jazz and electronic musician operating under many pseudonyms. Since 1999 his most widely distributed and electric music has been released under the name of The Flashbulb. Other names Benn has released as are Acidwolf, Human Action Network, and FlexE.

Bluedot Festival

Bluedot is a music, science and culture event held annually in July since 2016 at Jodrell Bank Observatory in Cheshire, England, combining music, live science experiments, expert talks and immersive artworks.

The festival is named after Pale Blue Dot, a famous 1990 photograph of planet Earth popularised by Carl Sagan.

Carl Sagan Award for Public Appreciation of Science

The Carl Sagan Award for Public Understanding of Science is an award presented by the Council of Scientific Society Presidents (CSSP) to individuals who have become “concurrently accomplished as researchers and/or educators, and as widely recognized magnifiers of the public's understanding of science.” The award was first presented in 1993 to astronomer, Carl Sagan (1934–1996), who is also the award's namesake.

Carl Sagan Institute

The Carl Sagan Institute: Pale Blue Dot and Beyond was founded in 2014 at Cornell University in Ithaca, New York to further the search for habitable planets and moons in and outside the Solar System. It is focused on the characterization of exoplanets and the instruments to search for signs of life in the universe. The founder and current director of the institute is astronomer Lisa Kaltenegger.

The Institute, inaugurated in 2014 and renamed on 9 May 2015, collaborates with international institutions on fields as astrophysics, engineering, earth and atmospheric science, geology and biology with the goal of taking an interdisciplinary approach to the search for life elsewhere in the universe and of the origin of life on Earth.Carl Sagan was a faculty member at Cornell University beginning in 1968. He was the David Duncan Professor of Astronomy and Space Sciences and director of the Laboratory for Planetary Studies there until his death in 1996.

Carl Sagan Medal

The Carl Sagan Medal for Excellence in Public Communication in Planetary Science is an award established by the Division for Planetary Sciences of the American Astronomical Society to recognize and honor outstanding communication by an active planetary scientist to the general public. It is awarded to scientists whose efforts have significantly contributed to a public understanding of, and enthusiasm for planetary science.

Carl Sagan Memorial Award

The Carl Sagan Memorial Award is an award presented jointly by the American Astronautical Society and The Planetary Society to an individual or group "who has demonstrated leadership in research or policies advancing exploration of the Cosmos." The annual award, first presented in 1997, was created in honor of American astronomer, astrobiologist and science popularizer, Carl Sagan (1934–1996).

Circus in the Sky

Circus In The Sky is the fifth studio album by the Australian hip hop trio Bliss n Eso, following 2010's Running On Air. It was released on 28 June 2013 through Illusive Sounds. Bliss N Eso began recording the album in late 2012. The album revolves around themes such as optimism, freedom, and peace. The album instantly reached No. 1 on the iTunes albums chart upon release, and debuted at No. 1 on the ARIA Albums Chart. The album was positively received and was accredited gold. Bliss N Eso toured in support for the album on the House Of Dreams Tour in 2013 and the Circus Under The Stars Tour in 2014. Circus In The Sky was nominated for an ARIA Music Award for Best Urban Album.

Cosmos (Carl Sagan book)

Cosmos is a 1980 popular science book by astronomer and Pulitzer Prize-winning author Carl Sagan. Its 13 illustrated chapters, corresponding to the 13 episodes of the Cosmos TV series, which the book was co-developed with and intended to complement, explore the mutual development of science and civilization. One of Sagan's main purposes for the book and television series was to explain complex scientific ideas to anyone interested in learning. Sagan also believed the television was one of the greatest teaching tools ever invented, so he wished to capitalize on his chance to educate the world. Spurred in part by the popularity of the TV series, Cosmos spent 50 weeks on the Publishers Weekly best-sellers list and 70 weeks on the New York Times Best Seller list to become the best-selling science book ever published at the time. In 1981, it received the Hugo Award for Best Non-Fiction Book. The book's unprecedented success ushered in a dramatic increase in visibility for science-themed literature. The success of the book also jumpstarted Sagan's literary career. The sequel to Cosmos is Pale Blue Dot: A Vision of the Human Future in Space (1994).In 2013, Cosmos was published in a new edition, with a foreword by Ann Druyan and an essay by Neil deGrasse Tyson.

Dimensionaut

Dimensionaut is the debut (and as of 2018 only) album by British-based band Sound of Contact, and was released worldwide May 2013. Production of the album was a collaborative effort between Simon Collins and Dave Kerzner, two of the band's founding members. As of March 2014, two singles off the album have been released.Dimensionaut was mixed by veteran sound engineer Nick Davis, known for working with Genesis.

Family Portrait (Voyager)

The Family Portrait, or sometimes Portrait of the Planets, is an image of the Solar System acquired by Voyager 1 on February 14, 1990 from a distance of approximately 6 billion kilometers from Earth. It features individual frames of six planets and a partial background indicating their relative positions. The picture is a mosaic of 60 individual frames.The frames used to compose the image were the last photographs taken by either Voyager spacecraft (which continued to relay other telemetry afterward).

These frames were also the source of the famous Pale Blue Dot image of the Earth. Astronomer Carl Sagan, who was part of the Voyager imaging team, campaigned for many years to have the pictures taken.

Kim Tae-yong

Kim Tae-yong (born December 9, 1969) is a South Korean film director and screenwriter. After his feature directorial debut Memento Mori (1999), he helmed the critically acclaimed Family Ties (2006), and the English-language remake Late Autumn (2010).

Lucy in the Sky (film)

Lucy in the Sky (originally titled Pale Blue Dot) is an upcoming drama film directed by Noah Hawley in his directorial feature film debut and starring Natalie Portman, Jon Hamm, Dan Stevens, Zazie Beetz and Ellen Burstyn.

Overview effect

The overview effect is a cognitive shift in awareness reported by some astronauts during spaceflight, often while viewing the Earth from outer space.It is the experience of seeing firsthand the reality of the Earth in space, which is immediately understood to be a tiny, fragile ball of life, "hanging in the void", shielded and nourished by a paper-thin atmosphere. From space, national boundaries vanish, the conflicts that divide people become less important, and the need to create a planetary society with the united will to protect this "pale blue dot" becomes both obvious and imperative.Astronauts Ron Garan, Rusty Schweikart, Edgar Mitchell, Tom Jones, Scott Kelly, James Irwin, Mike Massimino and Chris Hadfield are all reported to have experienced the effect. Third-party observers of these individuals may also report a noticeable difference in attitude.The term and concept were coined in 1987 by Frank White, who explored the theme in his book The Overview Effect — Space Exploration and Human Evolution (Houghton-Mifflin, 1987), (AIAA, 1998).

PBD

PBD may refer to:

Pacific black duck, a dabbling duck

Pale Blue Dot, a photograph of Earth made by Voyager 1, and

Pale Blue Dot (book), a book inspired by the said photograph, written by Carl Sagan

Pale Blue Dot (album), a 2008 album by Benn Jordan

Parti bourgeois démocratique, the French-language name for the Conservative Democratic Party of Switzerland

The IATA code for Porbandar Airport, India

Papa Bouba Diop, a Senegalese footballer

Pediatric bipolar disorder, that is, bipolar disorder in children

Peroxisome Biogenesis Disorders, a group of rare and severe congenital disorders

PBD, Post buy depression, Depression after buying things

Programming by demonstration, a technique to create automated tasks for computers and robots without using a programming language

.pbd, a computer file name extension for PowerBuilder, an integrated development environment owned by Sybase.

PBD, a modern world short form, full name as Print-Burn-and-Drink; Originator from Guanyimma.com where Chinese people can download the yellow paper with god written magical words, burn and mix with water, and then drink it to absorb the divine energy as part of the body

Pale Blue Dot (book)

Pale Blue Dot: A Vision of the Human Future in Space is a 1994 book by Carl Sagan. It is the sequel to Cosmos and was inspired by the famous Pale Blue Dot photograph, for which Sagan provides a poignant description. In this book, Sagan mixes philosophy about the human place in the universe with a description of the current knowledge about the Solar System. He also details a human vision for the future.

Pale Blue Dot (disambiguation)

Pale Blue Dot is a photograph of Earth taken by the Voyager 1 space probe.

Pale Blue Dot may also refer to:

Pale Blue Dot (book), a 1994 book by Carl Sagan

Pale Blue Dot (short film), a 1998 short film by Kim Tae-yong

Pale Blue Dot (film), an upcoming drama film directed by Noah Hawley

The Black Swan (Story of the Year album)

The Black Swan is the third studio album by American rock band Story of the Year.

The Prototypes

The Prototypes is a British drum and bass duo consisting of Chris Garvey and Nick White. Founded in Brighton, England in the late 2000s, by 2010 they had released their first singles on labels such as Formation Records and Viper Recordings, and from 2011 to 2013 were signed to Shogun Audio. They have released a number of EPs, and have received radio and live PA support from DJs such as Matrix & Futurebound. Signing exclusively to Viper Recordings in 2014, in the following months the duo released a number of promo singles for a debut album. Their resulting single, "Pale Blue Dot" ranked as Beatport's second top selling drum and bass track of the year. The track was also nominated for Best Track at the Drum & Bass Arena Awards, with The Prototypes also nominated for Best Producer, Best Music Video, and Best DJ.UKF Music called their 2015 promo single "Pop It Off" "one of the most unanimously unifying cuts in D&B of the year so far," and they officially released their debut album City of Gold on 17 May 2015. They supported the album with an international tour with performances at festivals such as Urban Art Forms and Tomorrowland, and they have also performed at Nocturnal Festival in 2012. Featuring vocals from artists such as Ayah Marar and Amy Pearson, the week of its release City of Gold reached No. 22 on the UK Dance Chart. Robin Murray of UKF Music called it "a relentless, incendiary journey through a range of genres and tempos." Beyond original production, as of 2015 the duo had released remixes for artists such as Avicii, Ed Sheeran, Bingo Players, Hadouken!, Modestep, AlunaGeorge, and others.

Unafraid of the Dark

"Unafraid of the Dark" is the thirteenth and final episode of the American documentary television series Cosmos: A Spacetime Odyssey and its series finale. It premiered on June 8, 2014, on Fox and aired on June 9, 2014, on the National Geographic Channel. The episode was written by Ann Druyan and Steven Soter, and directed by Ann Druyan, making this her series directorial debut. The episode explores the mysteries of dark energy and dark matter, as well as the contributions and theories of Swiss astronomer Fritz Zwicky, who furthered our understanding of "supernovae, neutron stars and 'standard candles.'" The finale reveals a recording of life on Earth - the final message on the golden record of the space probe, Voyager. The episode ends with Carl Sagan's (host of the original Cosmos) iconic speech on Earth as the "Pale Blue Dot."

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