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September 28, 2015

First space probes to visit bodies of the Solar System

Filed under: science — ckrao @ 11:11 am

The table below shows the first space probes to visit various bodies of the Solar System (and the year) by mission type (flyby, orbit, impact or soft landing). Notably 2015 had three events: MESSENGER ended its four year orbit of Mercury with the first impact on the planet, Dawn became the first spacecraft to orbit a dwarf planet (Ceres, in the asteroid belt), and New Horizons flew by Pluto.


flyby orbit impact soft landing
Sun Helios 2 1976 (within 43m km) Luna 1 1959
Mercury Mariner 10 1974 MESSENGER 2011 MESSENGER 2015
Venus Venera 1 1961 Venera 9 1975 Venera 3 1966 Venera 9 1975
Mars Mariner 4 1965 Mariner 9 1971 Mars 2 1971 Mars 3 1971
Jupiter Pioneer 10 1973 Galileo 1995 Galileo 1995
Saturn Pioneer 11 1979 Cassini 2004
Uranus Voyager 2 1986
Neptune Voyager 2 1989
Pluto New Horizons 2015
Ceres Dawn 2015
Moon Luna 1 1959 Luna 10 1966 Luna 2 1959 Luna 9 1966
Titan Huygens 2005
asteroid Galileo asteroid 951 Gaspra – 1991 NEAR Shoemaker asteroid 433 Eros – 2000 NEAR Shoemaker asteroid 433 Eros – 2000
comet ICE comet Giacobini-Zinner – 1985 Rosetta comet Churyumov-Gerasimenko – 2014 Deep Impact – Impactor comet Tempel -2005 Philae comet Churyumov-Gersimenko – 2014




July 30, 2015

Nineteenth century non-avian dinosaur discoveries

Filed under: nature,science — ckrao @ 11:05 am

Below is an attempted chronological list of non-avian dinosaur discoveries of the 19th century that today are considered valid genera. There may still be some where there are only scant remains of the fossil (e.g. a tooth or single bone remain). The list came from [1] with some help from [2] and Wikipedia to filter out doubtful names. Many of the best known dinosaurs are listed here and it looks like most of the major groups are covered. Good histories of dinosaur paleontology are in [3] and [4].


Genus Discoverer Year Dinosaur type
Megalosaurus Buckland 1824 tetanuran (stiff-tailed) theropod
Iguanodon Mantell 1825 beaked ornithopod
Streptospondylus von Meyer 1830 megalosaurid
Hylaeosaurus Mantell 1833 armoured
Thecodontosaurus Riley & Stutchbury 1836 prosauropod
Plateosaurus von Meyer 1837 prosauropod
Poekilopleuron Eudes-Deslongchamps 1838 megalosaurid
Cardiodon Owen 1841 sauropod
Cetiosaurus Owen 1841 sauropod
Pelorosaurus Mantell 1850 brachiosaur
Aepisaurus Gervais 1852 sauropod
Oplosaurus Gervais 1852 sauropod
Massospondylus Owen 1854 prosauropod
Nuthetes Owen 1854 maniraptoran
Troodon Leidy 1856 raptor
Stenopelix von Meyer 1857 pachycephalosaur
Astrodon Johnston 1858 sauropod
Hadrosaurus Leidy 1858 duckbilled ornithopod
Compsognathus J. A. Wagner 1859 coelurosaur (fuzzy theropod)
Scelidosaurus Owen 1859 armoured
Echinodon Owen 1861 heterodontosaurid (early bird-hipped dinosaur)
Polacanthus Owen vide [Anonymous] 1865 armoured
Calamospondylus Fox 1866 oviraptorosaur
Euskelosaurus Huxley 1866 prosauropod
Acanthopholis Huxley 1867 armoured
Hypselosaurus Matheron 1869 sauropod
Hypsilophodon Huxley 1869 beaked ornithopod
Rhabdodon Matheron 1869 beaked ornithopod
Ornithopsis Seeley 1870 sauropod
Struthiosaurus Bunzel 1870 armoured
Craterosaurus Seeley 1874 stegosaurian
Chondrosteosaurus Owen 1876 sauropod
Macrurosaurus Seeley 1876 sauropod
Allosaurus Marsh 1877 carnosaur
Apatosaurus Marsh 1877 sauropod
Camarasaurus Cope 1877 sauropod
Dryptosaurus Marsh 1877 tyrannosaur
Dystrophaeus Cope 1877 sauropod
Nanosaurus Marsh 1877 early bird-hipped dinosaur
Stegosaurus Marsh 1877 plated dinosaur
Diplodocus Marsh 1878 sauropod
Brontosaurus Marsh 1879 sauropod
Anoplosaurus Seeley 1879 armoured
Coelurus Marsh 1879 coelurosaur (fuzzy theropod)
Mochlodon Seeley 1881 beaked ornithopod
Craspedodon Dollo 1883 horned dinosaur
Ceratosaurus Marsh 1884 theropod
Anchisaurus Marsh 1885 prosauropod
Camptosaurus Marsh 1885 beaked ornithopod
Aristosuchus Seeley 1887 coelurosaur (fuzzy theropod)
Ornithodesmus Seeley 1887 raptor
Cumnoria Seeley 1888 beaked ornithopod
Priconodon Marsh 1888 armoured
Coelophysis Cope 1889 early theropod
Nodosaurus Marsh 1889 armoured
Triceratops Marsh 1889 horned dinosaur
Barosaurus Marsh 1890 sauropod
Claosaurus Marsh 1890 duckbilled ornithopod
Ornithomimus Marsh 1890 ostrich dinosaur
Ammosaurus Marsh 1891 prosauropod
Torosaurus Marsh 1891 horned dinosaur
Argyrosaurus Lydekker 1893 sauropod
Sarcolestes Lydekker 1893 armoured
Dryosaurus Marsh 1894 beaked ornithopod


[1] Dinosaur Genera List –

[2] Genus List for Holtz (2007) Dinosaurs

[3] Benton, M. J. 2000. A brief history of dinosaur paleontology. Pp. 10-44, in Paul, G. S. (ed.), The Scientific American book of dinosaurs. St Martin’s Press, New York. –

[4] Equatorial Minnesota The generic history of dinosaur paleontology 1699 to 1869 –

September 18, 2013

Spacecraft missions to outer planets, minor planets or comets

Filed under: science — ckrao @ 11:50 am

After recently hearing news about Voyager 1 being the first human-made object to leave our solar system, I looked up other spacecraft that have visited the outer planets, minor planets (e.g. asteroids) and comets.

Outer Planets

 Spacecraft  Launch Date  Agency  Remarks
Pioneer 10 3-Mar-72 NASA / ARC flyby of Jupiter in Dec 1973, lost contact in Jan 2003 when 12b km from earth
Pioneer 11 6-Apr-73  NASA /ARC  flyby of Jupiter in Dec 1974, Saturn in May 1979, lost contact in 1995
Voyager 2 20-Aug-77  NASA / JPL flyby of all outer planets, the only one to fly by Uranus and Neptune
Voyager 1 5-Sep-77  NASA / JPL flyby of Jupiter in Sep 1977, Saturn in Mar 1979, now 19b km from earth
Galileo 18-Oct-89 NASA flyby of Venus, Earth, asteroids Gasra and Ida (both incidental) before detailed study of Jupiter and its moons, probe dropped into its atmosphere
Ulysses 6-Oct-90 NASA / ESA flyby of Jupiter (Feb 1992), orbiting sun, measuring solar wind and gamma ray bursts
Cassini–Huygens 15-Oct-97 NASA/ESA flyby of Jupiter & Saturn, Huygens deployed from Cassini, landed on Saturn’s moon Titan in Jan 2005
New Horizons 19-Jan-06  NASA expected to fly by Pluto in July 2015
Juno 5-Aug-11  NASA expected to reach Jupiter in Aug 2016

Minor Planets and comets (other than Halley)

 Spacecraft  Launch Date  Agency  Remarks
Dawn 27-Sep-07 NASA orbited Vesta July ’11-Sep ’12, expected to reach Ceres in Feb ’15
Hayabusa 9-May-03 JAXA visited asteroid Itokawa bringing back to earth tiny grains of asteroidal material in June 2010
NEAR Shoemaker 17-Feb-96 NASA studied near-earth asteroid Eros, touched down in Feb 2001
Deep Space 1 24-Oct-98 NASA/JPL flybys of asteroid Braille and Comet Borelly
Stardust 7-Feb-99 NASA/JPL returned dust samples from Comet Wild 2, also intercepted comet Tempel 1 in Feb 2011
Deep Impact 12-Jan-05 NASA/JPL impactor collided with nucleus of comet Tempel in July 2005, extended mission EPOXI flew by Comet 103P/Hartley, now on its way to asteroid 2002 GT
Rosetta 2-Mar-04 ESA flybys of asteroids Steins and Lutetia in 2008, 2010; expected to reach comet 67P/Churyumov-Gerasimenko in mid 2014 deploying the lander Philae
Chang’e-2 1-Oct-10 CNSA flew by asteroid 4179 Toutatis in Dec 2012 after orbiting moon
International Cometary Explorer (ICE) 12-Aug-78 NASA/ESA first spacecraft to pass through comet tail (Comet Giacobini-Zinner)

Halley’s Comet (during its most recent near-earth encounter in 1985-6)

 Spacecraft  Launch date  Agency  Remarks
Giotto 2-Jul-85 ESA passed within 600km of Halley’s comet, then flew by Comet Grigg-Skjellerup in Jul 1992
Vega 1 15-Dec-84 USSR flyby of Venus (descent craft surfaced on Venus) and Halley’s Comet (within 9,000km Mar ’86)
Vega 2 21-Dec-84 USSR flyby of Venus (descent craft surfaced on Venus) and Halley’s Comet (Mar ’86)
Suisei 18-Aug-85 ISAS (now part of JAXA) within 151,000km of Comet Halley in Mar ’86
Sakigake 7-Jan-85 ISAS (now part of JAXA) within 7m km of Comet Halley

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