Portal:Astronomy

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Astronomy portal

Astronomy (Greek: αστρονομία = άστρον + νόμος, astronomia = astron + nomos, literally "law of the stars") is the study of the evolution and physical and chemical properties of celestial objects. Astronomical observations are not only relevant for astronomy as such, but provide essential information for the verification of fundamental theories in physics, such as the general relativity theory. Complementary to observational astronomy, theoretical astrophysics seeks to explain astronomical phenomena.

More about Astronomy...

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Selected article

Triton is the largest moon of the planet Neptune, discovered on October 10, 1846 by William Lassell. It is the only large moon in the Solar System with a retrograde orbit, which is an orbit in the opposite direction to its planet's rotation. At 2700 km in diameter, it is the seventh-largest moon in the Solar System. Because of its retrograde orbit and composition similar to Pluto's, Triton is thought to have been captured from the Kuiper belt. Triton consists of a crust of frozen nitrogen over an icy mantle believed to cover a substantial core of rock and metal. The core makes up two-thirds of its total mass. Triton has a mean density of 2.061 g/cm³ and is composed of approximately 15–35% water ice.

Triton is one of the few moons in the Solar System known to be geologically active. As a consequence, its surface is relatively young, with a complex geological history revealed in intricate and mysterious cryovolcanic and tectonic terrains. Part of its crust is dotted with geysers believed to erupt nitrogen.

The moon was discovered by British astronomer William Lassell just 17 days after Neptune itself was discovered by German astronomers Johann Gottfried Galle and Heinrich Louis d'Arrest, who were following co-ordinates given them by French astronomer and mathematician Urbain Le Verrier.

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Did you know

... that William Herschel's 40-foot telescope (pictured) was the largest telescope in the world for 50 years?

...that Zeeman-Doppler imaging is a technique used to map the surface magnetic field of stars?

...that Astronomische Nachrichten, founded by H. C. Schumacher in 1821, is the world's oldest existant astronomical journal?

...that the Stingray Nebula, thought to have formed around 1987, is the youngest known planetary nebula?

...that the Mark II radio telescope built in 1964 at Jodrell Bank Observatory, UK was the first ever telescope to be controlled by a digital computer?

...that Comet Shoemaker-Levy 9 passed within Jupiter's Roche limit in 1992, causing it to break up into smaller pieces two years before it collided with the planet?

...that the Kaidun meteorite fell on March 12, 1980 on a Soviet military base in Yemen and may be from Phobos?

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Categories

Astronomy : Archaeoastronomy - Astrophysics - Calendars - Catalogues - Celestial coordinate system - Celestial mechanics - Cosmology - Images - Large-scale structure of the cosmos - Observatories - Planetary science - Telescopes

Biographies : Astronomers - Other people

Astronomical objects : Lists - Galaxies - Nebulae - Planets - Stars

Spaceflight : Human spaceflight - Satellites - SETI - Spacecraft

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Projects

WikiProject Astronomy	WikiProject Solar System
WikiProject Astronomical objects	WikiProject Spaceflight

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Space-related Portals

Star	Spaceflight	Moon
Space	Solar System	Mars
X-ray astronomy	Science	Jupiter

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Selected picture

NGC 7129 is an open cluster star-forming region in a reflection nebula which a circa 2004 survey shows has over 130 very young stars each less than 1 million years old. This image of the open cluster was taken by Spitzer Space Telescope.

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Astronomy News

Wikinews Space portal

• June 17: Study says young stars 'shoot water bullets'
• January 11: Moon water possibly originated from comets, data shows
• October 15: Brazilian astronomers propose new model of our galaxy
• October 1: New planet found in 'Habitable Zone'
• September 19: Jupiter at its brightest in 47 years
• August 25: Astronomers discover large exo-solar system
• August 22: Scientists say the moon is slowly shrinking
• August 20: Scientists conclude that the universe may expand forever

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January anniversaries

• 1 January 1925 - The American astronomer Edwin Hubble announces the discovery of galaxies outside the Milky Way.
• 2 January 1860 - The discovery of the planet Vulcan is announced at a meeting of the Académie des Sciences in Paris.
• 2 January 2004 - Stardust successfully flies past Comet Wild 2, collecting samples that it will return to Earth two years later.
• 3 January 1888 - The 91 cm refracting telescope at Lick Observatory is used for the first time. It was the largest telescope in the world at the time.

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Things you can do

Here are some Open Tasks : Copyedit: Roque de los Muchachos Observatory, Europa (moon) More... Wikify: More... Merge: More... Requests: Antigalaxy, Sunspot index, undefined names in the List of astronomers, More... Stubs: D Ring, Diffraction spike More... Discuss deletion: No deletion requests Astronomy featured article candidates: No current candidates Astronomy articles for which peer review has been requested: Epsilon Eridani (entry) Jupiter Trojan (entry)

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Wikibooks

These books may be in various stages of development. See also the related Science and Mathematics bookshelves.

• Astronomy
• GAT: A Glossary of Astronomical Terms
• Introduction to Astrophysics
• General relativity
• Observing the Sky from 30°S
• Observing the Sky from 40°N

Wikijunior

• Solar System

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Astronomical events

All times UT unless otherwise specified.

January 2012
Date	Time	Celestial Object	Category	Event	Mathematical Values	Notes
01 January	06:15	Moon	Lunar Phases	First quarter moon	Diameter = 29.7 '	Twice in the same month
02 January	20:20	Moon	Apsis	Moon at apogee	Diameter = 29.5 ' Moon-Earth Distance = 404 589 kms	Twice in the same month
	23:54	Moon	Conjunction of Planets with the Moon	Jupiter 4.8º south of Moon
04 January		Meteoroid	Meteor shower	Quadrantids peak
	22:00	Earth	Apsis	Earth at perihelion		Its closest to the Sun for the year (just 1 part in 30 closer than at aphelion in July)
		Mercury	Constellation	Mercury enters into the constellation Sagittarius
06 January	21:00	Moon	Lunar node	Moon at descending node	Diameter = 30.1 ' Furthest North (22.5)
09 January	07:32	Moon	Lunar Phases	Full moon	Diameter = 30.9 '
		Venus	Constellation	Venus enters into the constellation Aquarius
13 January	08:46	Mercury	Conjunction of Planets	Mercury 4.6º south of Pluto
	07:07	Venus	Conjunction of Planets	Venus 1.1º south of Neptune
14 January	00:47	Moon	Conjunction of Planets with the Moon	Mars 8.4º north of Moon
		Sun	Constellation	Sun enters into the constellation Capricorn
16 January	09:08	Moon	Lunar Phases	Last Quarter Moon	Diameter = 32.3 '
17 January	21:00	Meteoroid	Meteor shower	Delta Cancrids peak
	21:29	Moon	Apsis	Moon at perigee	Diameter = 32.3 ' Moon-Earth Distance = 369 899 kms
	15:41	Moon	Conjunction of Planets with the Moon	Saturn 6.0º north of Moon
18 January		Mercury	Apsis	Mercury at aphelion	Diameter = 4.9 "
20 January	02:00	Moon	Lunar node	Moon at ascending node	Diameter = 32.2 ' Furthest South (- 22.4)
		Saturn	Quadrature	Saturn at western quadrature	Diameter = 17.1 "
21 January	12:00	Moon	Conjunction of Planets with the Moon	Pluto 1.7º north of Moon
22 January	11:15	Moon	Conjunction of Planets with the Moon	Mercury 4.6º south of Moon
		Jupiter	Quadrature	Jupiter at eastern quadrature	Diameter = 40.4 "
23 January	07:39	Moon	Lunar Phases	New moon	Diameter = 31.4 '
24 January		Mercury	Constellation	Mercury enters into the constellation Capricorn
	23:00	Mars	Stationary	Mars at western stationary point	Diameter = 11.0 "
25 January	08:22	Moon	Conjunction of Planets with the Moon	Neptune 5.5º south of Moon
26 January	13:19	Moon	Conjunction of Planets with the Moon	Venus 6.2º south of Moon
27 January	21:59	Moon	Conjunction of Planets with the Moon	Uranus 5.5º south of Moon
30 January	12:07	Moon	Conjunction of Planets with the Moon	Jupiter 4.3º south of Moon
	17:43	Moon	Apsis	Moon at apogee	Diameter = 29.6 ' Moon-Earth Distance = 404 326 kms	Twice in the same month
31 January	04:00	Moon	Lunar Phases	First quarter moon	Diameter = 29.6 '	Twice in the same month
		433 Eros		433 Eros will pass the Earth	Visual Magnitude = + 8.1 Eros-Earth Distance = 0.17867 AU (26,729,000 km; 16,608,000 mi)	About 70 times the distance to the Moon

Celestial Events by month

 

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