Popular Posts

Popular Posts

Pages

Total Pageviews

Sunday, December 11, 2011

Pluto Discovered..1930


Pluto  Astronomical symbol of Pluto
Pluto animiert.gif
Computer-generated map of Pluto fromHubble images, synthesised true colour[a]and among the highest resolutions possible with current technology
Discovery
Discovered byClyde W. Tombaugh
Discovery dateFebruary 18, 1930

File:ClydeTombaugh2.gifThe Pluto Telescope
Clyde W. Tombaugh alongside is the telescope used.


File:Pluto discovery plates.pngPlutoformal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System (after Eris) and the tenth-most-massive body observed directly orbiting the Sun. Originally classified as the ninth planet from the Sun, Pluto was recategorized as a dwarf planet and plutoid due to the discovery that it is one of several large bodies within the newly charted Kuiper belt.
Head-and-shoulders photograph of a young girl. She wears a light-coloured blouse and faces right, looking out of the picture, with a slight smile. Her short hair is pulled back from her face and pinned up.The name Pluto was proposed by Venetia Burney (1918–2009), an eleven-year-old schoolgirl in Oxford, England. Venetia was interested in classical mythology as well as astronomy, and considered the name, a name for the god of the underworld, appropriate for such a presumably dark and cold world. She suggested it in a conversation with her grandfatherFalconer Madan, a former librarian at the University of Oxford's Bodleian Library. Madan passed the name to ProfessorHerbert Hall Turner, who then cabled it to colleagues in the United States.



Space Topics: Compare the Planets

Worlds of the Solar System

Our solar system contains roughly a hundred round worlds in a wide range of sizes from gas giants like Jupiter to small rocky worlds like Mars to iceballs like Enceladus. Take a tour of the sizes of bodies in the solar system.

We begin at a very large scale, taking a distant view of the solar system. This largest scale, of 1,000 kilometers (623 miles) pixel, is the only one at which a tiny piece of the Sun can be fit onto the page. The Sun is vastly more enormous than everything else in the solar system put together. The gas giants Jupiterand Saturn and ice giants Uranus and Neptunedominate the rest of the worlds of the solar system. The rest of the planets are just visible at this scale.Earth, Venus, and Mars come in at 13, 12, and 7 pixels across, respectively. But a few of the giant moons are visible: Jupiter's Ganymede and Saturn'sTitan are larger than the planet Mercury, and Jupiter's Callisto is just about as big.The Solar System at a Scale of 1,000 Kilometers Per Pixel

The Sun at a scale of 1,000 km/pixel
The Sun - 1,391,000 km diameter
Jupiter at a scale of 1,000 km/pixelSaturn at a scale of 1,000 km/pixel
Uranus at a scale of 1,000 km/pixel
Uranus
51,118 km

Neptune at a scale of 1,000 km/pixel
Neptune
49,528 km
Jupiter
142,984 km
Saturn
120,536 km (main rings 273,550 km)
  
Earth at a scale of 1,000 km/pixelVenus at a scale of 1,000 km/pixelMars at a scale of 1,000 km/pixelGanymede at a scale of 1,000 km/pixelTitan at a scale of 1,000 km/pixelMercury at a scale of 1,000 km/pixelCallisto at a scale of 1,000 km/pixel
Earth
12,756 km
Venus
12,104 km
Mars
6,794 km
Ganymede
5,262 km
Titan
5,150 km
Mercury
4,879 km
Callisto
4,821 km
Image credits: the Hubble Space Telescope (Mars), NASA GSFC (Earth, from Terra), the Cassini imaging team(Jupiter, Saturn), Mark Robinson (Mercury, from Mariner 10), Mattias Malmer (Venus, from Mariner 10), Calvin Hamilton (Titan, from Voyager), and Bill Arnett (the Moon, from his own telescope). The rest are from thePlanetary Photojournal at NASA/JPL (Voyager, Galileo, and SOHO images).Now let's zoom in by a factor of 10...

The Solar System at a Scale of 100 Kilometers Per Pixel

Zooming in by a factor of 10 gets us to the scale of the terrestrial planets and the solar system's large moons. The gas and ice giants would be too large to fit on the page at this scale. Earth and Venus are now the standouts, both significantly larger than anything else visible at this scale. Then the smallest planets mix in size with the largest moons: Mars is followed closely in size by Jupiter's Ganymede and Saturn's Titan, both of which are larger than Mercury. Next in size come Jupiter's Callisto and Io, Earth's Moon, Jupiter's Europa, and Neptune's Triton, all of which are larger than Pluto. A jump down in size takes you to the icy moons of the outer solar system: Uranus' Titania, Saturn's Rhea, Uranus' Oberon, Saturn's Iapetus, Pluto's Charon, Uranus' Umbriel and Ariel, and Saturn's Dione andTethys. Finally, just a bit smaller than these, comes the largest of all the asteroids, Ceres. Several trans-Neptunian objects would appear at this scale but are not included because their sizes are uncertain and no images are available.
Earth at a scale of 100 km/pixelVenus at a scale of 100 km/pixel
Mars at a scale of 100 km/pixel
Mars
6,794 km

Ganymede at a scale of 100 km/pixel
Ganymede
5,262 km

Titan at a scale of 100 km/pixel
Titan
5,150 km
Earth
12,756 km
Venus
12,104 km
Mercury at a scale of 100 km/pixelCallisto at a scale of 100 km/pixelIo at a scale of 100 km/pixelThe Moon at a scale of 100 km/pixelEuropa at a scale of 100 km/pixel
Europa
3,122 km
Triton at a scale of 100 km/pixel
Triton
2,707 km
Pluto at a scale of 100 km/pixel
Pluto
2,390 km
Mercury
4,879 km
Callisto
4,821 km
Io
3,643 km
The Moon
3,476 km
Titania at a scale of 100 km/pixelRhea at a scale of 100 km/pixelOberon at a scale of 100 km/pixelIapetus at a scale of 100 km/pixelCharon at a scale of 100 km/pixelUmbriel at a scale of 100 km/pixelAriel at a scale of 100 km/pixelDione at a scale of 100 km/pixelTethys at a scale of 100 km/pixelCeres at a scale of 100 km/pixel
Titania
1,578 km
Rhea
1,528 km
Oberon
1,523 km
Iapetus
1,436 km
Charon
1,186 km
Umbriel
1,169 km
Ariel
1,162 km
Dione
1,162 km
Tethys
1,162 km
Ceres
960 km
Image credits: the Hubble Space Telescope (Mars), NASA GSFC (Earth, from Terra), the Cassini imaging team(Jupiter, Saturn and its moons), Marc Buie, Lowell Observatory (Pluto and Charon, from Earth-based photometry), Mark Robinson (Mercury, from Mariner 10), Ted Stryk (Uranian and Neptunian moons, from Voyager images), Mattias Malmer (Venus, from Mariner 10), A. Tayfun Öner (Triton, from Voyager), Calvin Hamilton (Titan, from Voyager) and Bill Arnett (the Moon, from his own telescope). The rest are from thePlanetary Photojournal at NASA/JPL (Voyager and Galileo images).Zooming by another factor of 10...

The Solar System at a Scale of 10 Kilometers Per Pixel

Zooming in by a factor of 100 from the orginal view takes us to a scale where the worlds of the solar system begin to deviate from spherical shapes, where mountains and ridges clearly spike above their visible disks. At this size, gravity (which tends to flatten mountains over time) is quite weak, and often is not strong enough to overcome the inherent strength of the rock and ice. At this scale, a spherical shape implies that something happened in the little world's geologic history to heat its interior enough to weaken or even melt the rock or ice and allow gravity to have its way.
We begin with the tribe of sub-2,000-kilometer outer planet moons mentioned above:TitaniaRheaOberonIapetusCharonUmbrielArielDione, and Tethys. Next up is the largest asteroid, Ceres. Following Ceres there is a jump in size down to the next largest asteroids, Pallas and Vesta. Pallas is also the first world in this lineup that has not yet been visited by a spacecraft or observed with a powerful enough telescope to produce an image that resolves features on its disk. Lumpy Vesta is followed by the surprisingly spherical moons Enceladus (Saturn) and Miranda (Uranus). Neptune's Proteus and Saturn's Mimasare the last of the bodies to achieve a basically spherical shape. The rest of the moonlets and asteroids for which there are images are definitely lumpy. Unfortunately, no disk-resolved images are available for many of the rest of these bodies, so their shapes are not well known.
Titania at a scale of 10 km/pixelRhea at a scale of 10 km/pixelOberon at a scale of 10 km/pixel
Titania
1,578 km
Rhea
1,528 km
Oberon
1,523 km
Iapetus at a scale of 10 km/pixel Charon at a scale of 10 km/pixel Umbriel at a scale of 10 km/pixel Ariel at a scale of 10 km/pixel
Iapetus
1,436 km
Charon
1,186 km
Umbriel
1,169 km
Ariel
1,162 km
Dione at a scale of 10 km/pixelTethys at a scale of 10 km/pixelCeres at a scale of 10 km/pixel
--


Pallas
570 km
Vesta at a scale of 10 km/pixel
Vesta
525 km
Enceladus at a scale of 10 km/pixel
Enceladus
512 km
Dione
1,162 km
Tethys
1,066 km
Ceres
960 km
Miranda at a scale of 10 km/pixelProteus at a scale of 10 km/pixelMimas at a scale of 10 km/pixelHyperion at a scale of 10 km/pixel
--

Nereid
340 km
Amalthea at a scale of 10 km/pixel
Amalthea
262x146 km
--
Juno
240 km
Miranda
480 km
Proteus
440 km
Mimas
418 km
Hyperion
370x280 km
Phoebe at a scale of 10 km/pixel----Larissa at a scale of 10 km/pixel--Janus at a scale of 10 km/pixel------
Phoebe
230x220
Eugenia
226
Kleopatra
217
Larissa
216x168
Galatea
204x184
Janus
194x190
Sycorax
190
Despina
180x148
Puck
162
Prometheus at a scale of 10 km/pixelEpimetheus at a scale of 10 km/pixel--Pandora at a scale of 10 km/pixel----------
Prometheus
148x100
Epimetheus
138x110
Portia
136
Pandora
110x88
Thalassa
108x100
Siwa
103
Caliban
96
Naiad
96x60
Juliet
94
Image credits: the Hubble Space Telescope (Ceres, Vesta), the Cassini imaging team (Saturn's moons), Marc Buie, Lowell Observatory (Charon, from Earth-based photometry), Ted Stryk (Uranian and Neptunian moons, from Voyager images), The rest are from the Planetary Photojournal at NASA/JPL (Voyager images).Juno, Eugenia, Kleopatra, and Siwa are asteroids. Amalthea is a moon of Jupiter. Mimas, Hyperion, Phoebe, Janus, Prometheus, Epimetheus, and Pandora are moons of Saturn. Miranda, Sycorax, Puck, Portia, and Caliban are moons of Uranus. Proteus, Nereid, Karissa, Galatea, Despina, Thalassa, and Naiad are moons of Neptune.

Images on this page come from a wide variety of sources, including the Hubble Space Telescope (Mars, Ceres, Vesta), NASA GSFC (Earth, from Terra), the Cassini imaging team (Jupiter, Saturn and its moons), Marc Buie, Lowell Observatory (Pluto and Charon, from Earth-based photometry), Mark Robinson (Mercury, from Mariner 10), Ted Stryk(Uranian and Neptunian moons, from Voyager images), Mattias Malmer (Venus, from Mariner 10), A. Tayfun Öner (Triton, from Voyager), Calvin Hamilton (Titan, from Voyager) and Bill Arnett (the Moon, from his own telescope). The rest are from thePlanetary Photojournal at NASA/JPL (Voyager, Galileo, and SOHO images).
   

No comments:

Post a Comment