5 Astraea (as-tree'-a; written Astræa in the early scientific litterature) is a large main belt asteroid. Its surface is highly reflective (bright) and its composition is probably a mixture of nickel-iron with magnesium- and iron-silicates. Karl Ludwig Hencke (April 8, 1793 – September 25, 1866) was a German astronomer. ... December 8 is the 342nd day (343rd in leap years) of the year in the Gregorian calendar. ... 1845 was a common year starting on Wednesday (see link for calendar). ... The provisional designation of comets and asteroids are similar to each other: they both follow a pattern set in 1925 by the Minor Planet Center of the IAU. Historical designations At first, astronomers strove to assign symbols to the minor planets: 1 Ceres a stylized sickle 2 Pallas a lozenge... Minor planets, or planetoids are minor bodies of the solar system orbiting the sun that are larger than meteoroids (the largest of which might be taken to be around 10 meters or so across) but smaller than major planets (Mercury having a diameter of about 4880 km). ... The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... July 14 is the 195th day (196th in leap years) of the year in the Gregorian Calendar, with 170 days remaining. ... 2004 is a leap year starting on Thursday of the Gregorian calendar. ... The Julian day or Julian day number (JDN) is the number of SI days that have elapsed since 12 noon Greenwich Mean Time (UT or TT) on Monday, January 1, 4713 BC in the proleptic Julian calendar 1. ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... Giga (symbol: G) is a prefix in the SI system of units denoting 109, or 1 000 000 000. ... The metre, or meter, is the basic unit of length in the International System of Units (SI: Système International dUnités). ... The astronomical unit (AU or au or a. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... A day is any of several different units of time. ... A Julian year is the length of an average year in the Julian calendar, 365. ... The orbital speed of a body, generally a planet, a natural satellite, an artificial satellite, or a multiple star, is the speed at which it orbits around the barycenter of a system, usually around a more massive body. ... The second (symbol s) is a unit for time, and one of seven SI base units. ... Inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit and is the angular distance of the orbital plane from the plane of the reference (usually planets equator or the ecliptic), stated in degrees. ... A degree (or in full a degree of arc), usually symbolized °, is a measurement of plane angle, representing 1/360 of a full rotation. ... The Longitude of the ascending node () is one of the orbital elements used to specify the orbit of an object in space. ... The argument of the perihelion is one of the orbital elements describing the orbit of a planet. ... In the study of orbital dynamics the mean anomaly is a measure of time, specific to the orbiting body p, which is a multiple of 2π radians at and only at periapsis. ... Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... A cubic centimetre (cm3) is an SI derived unit of volume, equal to the volume of a cube with side length of 1 centi metre. ... It has been suggested that Law of universal gravitation be merged into this article or section. ... In physics, for a given gravitational field and a given position, the escape velocity is the minimum speed an object without propulsion, at that position, needs to have to move away indefinitely from the source of the field, as opposed to falling back or staying in an orbit within a... In astronomy, a rotation period is the time an astronomical object takes to complete one revolution around its rotation axis. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... Approximately 17% of all known asteroids are of an S-type (for stony) composition. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... The albedo is a measure of reflectivity of a surface or body. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... In chemistry, a silicate is a compound consisting of silicon and oxygen (SixOy), one or more metals, and possibly hydrogen. ...

Size comparison: the first 10 asteroids profiled against Earth's Moon. Astrea is the fifth from the left.

Astraea was the fifth asteroid discovered, on December 8, 1845 by K. L. Hencke. It was his first of two asteroid discoveries. The second was 6 Hebe. An amateur astronomer and post office employee, Hencke was looking for 4 Vesta when he stumbled on Astraea. The King of Prussia awarded him with an annual pension of 300 $ (1968 dollars) for the discovery. Image File history File links The first 10 asteroids profiled against the Earths Moon. ... Image File history File links The first 10 asteroids profiled against the Earths Moon. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... December 8 is the 342nd day (343rd in leap years) of the year in the Gregorian calendar. ... 1845 was a common year starting on Wednesday (see link for calendar). ... Karl Ludwig Hencke (April 8, 1793 – September 25, 1866) was a German astronomer. ... 6 Hebe (hee-bee, Greek ‘Ήβη) is a very large Main belt asteroid. ... 4 Vesta (ves-ta) is the third-largest asteroid in the Main belt, between 530 and 468 km in diameter. ... The coat of arms of the Kingdom of Prussia, 1701-1918 The word Prussia (German: Preußen or Preussen, Polish: Prusy, Lithuanian: PrÅ«sai, Latin: Borussia) has had various (often contradictory) meanings: The land of the Baltic Prussians (in what is now parts of southern Lithuania, the Kaliningrad exclave of... 1968 was a leap year starting on Monday (the link is to a full 1968 calendar). ...

Astrea is notable mainly because for 38 years (since the discovery of Vesta in 1807) it had been thought that there were only four asteroids. After the discovery of Astraea, thousands of other asteroids would follow. 4 Vesta (ves-ta) is the third-largest asteroid in the Main belt, between 530 and 468 km in diameter. ... 1807 was a common year starting on Thursday (see link for calendar). ...

There has been only one observed stellar occultation by Astraea (February 2, 1991). The Pleiades star cluster A star is any massive gaseous body in outer space. ... In this July, 1997 still frame captured from video, the bright star Aldebaran has just reappeared on the dark limb of the waning crescent moon in this predawn occultation. ... February 2 is the 33rd day of the year in the Gregorian Calendar. ... 1991 is a common year starting on Tuesday of the Gregorian calendar. ...

Aspects

June 8 is the 159th day of the year in the Gregorian Calendar (160th in leap years), with 206 days remaining. ... 2005 is a common year starting on Saturday of the Gregorian calendar and is the current year. ... August 2 is the 214th day of the year in the Gregorian Calendar (215th in leap years), with 151 days remaining. ... 2005 is a common year starting on Saturday of the Gregorian calendar and is the current year. ... September 24 is the 267th day of the year (268th in leap years). ... 2005 is a common year starting on Saturday of the Gregorian calendar and is the current year. ... March 6 is the 65th day of the year in the Gregorian Calendar (66th in Leap years). ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... September 8 is the 251st day of the year (252nd in leap years). ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... October 24 is the 297th day of the year (298th in leap years) in the Gregorian Calendar, with 68 days remaining. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... December 14 is the 348th day of the year (349th in leap years) in the Gregorian Calendar. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... July 2 is the 183rd day of the year (184th in leap years) in the Gregorian Calendar, with 182 days remaining. ... 2007 is a common year starting on Monday of the Gregorian calendar. ... February 26 is the 57th day of the year in the Gregorian Calendar. ... Leap year starting on Tuesday // Predicted events January-June January 15 - NASAs MESSENGER spacecraft makes the first of three flybys of Mercury. ... April 5 is the 95th day of the year in the Gregorian calendar (96th in leap years). ... Leap year starting on Tuesday // Predicted events January-June January 15 - NASAs MESSENGER spacecraft makes the first of three flybys of Mercury. ... May 19 is the 139th day of the year in the Gregorian Calendar (140th in leap years). ... Leap year starting on Tuesday // Predicted events January-June January 15 - NASAs MESSENGER spacecraft makes the first of three flybys of Mercury. ... December 11 is the 345th day (346th in leap years) of the year in the Gregorian calendar. ... Leap year starting on Tuesday // Predicted events January-June January 15 - NASAs MESSENGER spacecraft makes the first of three flybys of Mercury. ... May 29 is the 149th day of the year in the Gregorian calendar (150th in leap years). ... 2009 is a common year starting on Thursday of the Gregorian calendar. ... July 23 is the 204th day (205th in leap years) of the year in the Gregorian Calendar, with 161 days remaining. ... 2009 is a common year starting on Thursday of the Gregorian calendar. ... September 14 is the 257th day of the year (258th in leap years). ... 2009 is a common year starting on Thursday of the Gregorian calendar. ... February 25 is the 56th day of the year in the Gregorian Calendar. ... 2010 is a common year starting on Friday of the Gregorian calendar. ... August 24 is the 236th day of the year in the Gregorian Calendar (237th in leap years), with 129 days remaining. ... 2010 is a common year starting on Friday of the Gregorian calendar. ... October 11 is the 284th day of the year (285th in Leap years). ... 2010 is a common year starting on Friday of the Gregorian calendar. ... December 2 is the 336th day (337th in leap years) of the year in the Gregorian calendar. ... 2010 is a common year starting on Friday of the Gregorian calendar. ... June 9 is the 160th day of the year in the Gregorian calendar (161st in leap years), with 205 days remaining. ... 2011 is a common year starting on Saturday of the Gregorian calendar. ... February 5 is the 36th day of the year in the Gregorian Calendar. ... 2012 is a leap year starting on Sunday of the Gregorian calendar. ... March 13 is the 72nd day of the year in the Gregorian calendar (73rd in leap years). ... 2012 is a leap year starting on Sunday of the Gregorian calendar. ... April 23 is the 113th day of the year in the Gregorian Calendar (114th in leap years). ... 2012 is a leap year starting on Sunday of the Gregorian calendar. ... November 28 is the 332nd day (333rd on leap years) of the year in the Gregorian calendar. ... 2012 is a leap year starting on Sunday of the Gregorian calendar. ... May 19 is the 139th day of the year in the Gregorian Calendar (140th in leap years). ... 2013 is a common year starting on Tuesday of the Gregorian calendar. ... July 13th is the 194th day (195th in leap years) of the year in the Gregorian Calendar, with 171 days remaining. ... 2013 is a common year starting on Tuesday of the Gregorian calendar. ... September 4 is the 247th day of the year (248th in leap years). ... 2013 is a common year starting on Tuesday of the Gregorian calendar. ... February 16 is the 47th day of the year in the Gregorian Calendar. ... 2014 is a common year starting on Wednesday of the Gregorian calendar. ... August 11 is the 223rd day of the year (224th in leap years) in the Gregorian Calendar. ... 2014 is a common year starting on Wednesday of the Gregorian calendar. ... September 29 is the 272nd day of the year (273rd in leap years). ... 2014 is a common year starting on Wednesday of the Gregorian calendar. ... November 21 is the 325th day of the year (326th in leap years) in the Gregorian Calendar. ... 2014 is a common year starting on Wednesday of the Gregorian calendar. ... May 20 is the 140th day of the year in the Gregorian Calendar (141st in leap years). ... 2015 is a common year starting on Thursday of the Gregorian calendar. ... January 11 is the 11th day of the year in the Gregorian Calendar. ... 2016 is a Leap year starting on Friday. ... February 17 is the 48th day of the year in the Gregorian calendar. ... 2016 is a Leap year starting on Friday. ... March 26 is the 85th day of the year in the Gregorian Calendar (86th in leap years). ... 2016 is a Leap year starting on Friday. ... November 13 is the 317th day of the year (318th in leap years) in the Gregorian Calendar, with 48 days remaining. ... 2016 is a Leap year starting on Friday. ... May 9 is the 129th day of the year in the Gregorian Calendar (130th in leap years). ... 2017 is a Common year starting on Sunday. ... July 2 is the 183rd day of the year (184th in leap years) in the Gregorian Calendar, with 182 days remaining. ... 2017 is a Common year starting on Sunday. ... August 23 is the 235th day of the year in the Gregorian Calendar (236th in leap years), with 130 days remaining. ... 2017 is a Common year starting on Sunday. ... February 6 is the 37th day of the year in the Gregorian Calendar. ... 2018 is a Common year starting on Monday. ... July 30 is the 211th day (212th in leap years) of the year in the Gregorian Calendar, with 154 days remaining. ... 2018 is a Common year starting on Monday. ... September 18 is the 261st day of the year (262nd in leap years). ... 2018 is a Common year starting on Monday. ... November 11 is the 315th day of the year (316th in leap years) in the Gregorian Calendar, with 50 days remaining. ... 2018 is a Common year starting on Monday. ... May 3 is the 123rd day of the year in the Gregorian calendar (124th in leap years). ... 2019 is a Common year starting on Tuesday. ... December 15 is the 349th day of the year (350th in leap years) in the Gregorian calendar. ... 2019 is a Common year starting on Tuesday. ... January 22 is the 22nd day of the year in the Gregorian Calendar. ... 2020 is a leap year starting on Wednesday. ... March 1 is the 60th day of the year in the Gregorian calendar (61st in leap years). ... 2020 is a leap year starting on Wednesday. ... October 28 is the 301st day of the year (302nd in leap years) in the Gregorian Calendar, with 64 days remaining. ... 2020 is a leap year starting on Wednesday. ...

External links

• AN 23 (1846) 393 (in German)
• MNRAS 7 (1846) 27

… | Previous asteroid | 5 Astraea | Next asteroid | … 4 Vesta (ves-ta) is the third-largest asteroid in the Main belt, between 530 and 468 km in diameter. ... 6 Hebe (hee-bee, Greek ‘Ήβη) is a very large Main belt asteroid. ...