Juno (minor-planet designation: 3 Juno) is an asteroid in the asteroid belt. Juno was the third asteroid discovered, in 1804, by German astronomer Karl Harding. It is the 11th-largest asteroid, and one of the two largest stony (S-type) asteroids, along with 15 Eunomia. It is estimated to contain 1% of the total mass of the asteroid belt.
The orbit of Juno is significantly elliptical with a small inclination, moving between Mars and Jupiter.
|Discovered by||Karl Ludwig Harding|
|Discovery date||September 1, 1804|
|MPC designation||(3) Juno|
|Juno (Latin: Iūno)|
|Main belt (Juno clump)|
|Epoch JD 2457000.5 (9 December 2014)|
Average orbital speed
|Proper orbital elements|
Proper semi-major axis
Proper mean motion
|82.528181 deg / yr|
Proper orbital period
Precession of perihelion
|43.635655 arcsec / yr|
Precession of the ascending node
|−61.222138 arcsec / yr|
|216 000 km2|
|Volume||8 950 000 km3|
|Mass||2.67 ×1019 kg|
Equatorial surface gravity
Equatorial escape velocity
|7.21 hr (0.3004 d)|
Equatorial rotation velocity
max: 301 K (+28°C)
|7.4 to 11.55|
|0.30" to 0.07"|
Juno was discovered on 1 September 1804, by Karl Ludwig Harding. It was the third asteroid found, but was initially considered to be a planet; it was reclassified as an asteroid and minor planet during the 1850s.
Juno is named after the mythological Juno, the highest Roman goddess. The adjectival form is Junonian (jūnōnius).
With two exceptions, 'Juno' is the international name, subject to local variation: Italian Giunone, French Junon, Russian Yunona, etc.[a] Its planetary symbol is ③. An older symbol, still occasionally seen, is ⚵ ().
Juno is one of the larger asteroids, perhaps tenth by size and containing approximately 1% the mass of the entire asteroid belt. It is the second-most-massive S-type asteroid after 15 Eunomia. Even so, Juno has only 3% the mass of Ceres.
The orbital period of Juno is 4.36578 years.
Amongst S-type asteroids, Juno is unusually reflective, which may be indicative of distinct surface properties. This high albedo explains its relatively high apparent magnitude for a small object not near the inner edge of the asteroid belt. Juno can reach +7.5 at a favourable opposition, which is brighter than Neptune or Titan, and is the reason for it being discovered before the larger asteroids Hygiea, Europa, Davida, and Interamnia. At most oppositions, however, Juno only reaches a magnitude of around +8.7—only just visible with binoculars—and at smaller elongations a 3-inch (76 mm) telescope will be required to resolve it. It is the main body in the Juno family.
Juno was originally considered a planet, along with 1 Ceres, 2 Pallas, and 4 Vesta. In 1811, Schröter estimated Juno to be as large as 2290 km in diameter. All four were reclassified as asteroids as additional asteroids were discovered. Juno's small size and irregular shape preclude it from being designated a dwarf planet.
Juno orbits at a slightly closer mean distance to the Sun than Ceres or Pallas. Its orbit is moderately inclined at around 12° to the ecliptic, but has an extreme eccentricity, greater than that of Pluto. This high eccentricity brings Juno closer to the Sun at perihelion than Vesta and further out at aphelion than Ceres. Juno had the most eccentric orbit of any known body until 33 Polyhymnia was discovered in 1854, and of asteroids over 200 km in diameter only 324 Bamberga has a more eccentric orbit.
Juno rotates in a prograde direction with an axial tilt of approximately 50°. The maximum temperature on the surface, directly facing the Sun, was measured at about 293 K on October 2, 2001. Taking into account the heliocentric distance at the time, this gives an estimated maximum temperature of 301 K (+28 °C) at perihelion.
Spectroscopic studies of the Junonian surface permit the conclusion that Juno could be the progenitor of chondrites, a common type of stony meteorite composed of iron-bearing silicates such as olivine and pyroxene. Infrared images reveal that Juno possesses an approximately 100 km-wide crater or ejecta feature, the result of a geologically young impact.
Juno was the first asteroid for which an occultation was observed. It passed in front of a dim star (SAO 112328) on February 19, 1958. Since then, several occultations by Juno have been observed, the most fruitful being the occultation of SAO 115946 on December 11, 1979, which was registered by 18 observers. Juno occulted the magnitude 11.3 star PPMX 9823370 on July 29, 2013, and 2UCAC 30446947 on July 30, 2013.
Radio signals from spacecraft in orbit around Mars and on its surface have been used to estimate the mass of Juno from the tiny perturbations induced by it onto the motion of Mars. Juno's orbit appears to have changed slightly around 1839, very likely due to perturbations from a passing asteroid, whose identity has not been determined.
In 1996, Juno was imaged by the Hooker Telescope at Mount Wilson Observatory at visible and near-IR wavelengths, using adaptive optics. The images spanned a whole rotation period and revealed an irregular shape and a dark albedo feature, interpreted as a fresh impact site.
Juno seen at four wavelengths with a large crater in the dark (Hooker telescope, 2003)
Juno moving across background stars
Juno during opposition in 2009
Video of Juno taken as part of ALMA's Long Baseline Campaign
Juno reaches opposition from the Sun every 15.5 months or so, with its minimum distance varying greatly depending on whether it is near perihelion or aphelion. Sequences of favorable oppositions occur every 10th opposition, i.e. just over every 13 years. The last favorable oppositions were on December 1, 2005 at a distance of 1.063 AU, magnitude 7.55, and on November 17, 2018 at a minimum distance of 1.036 AU, magnitude 7.45. The next opposition will be October 30, 2031, at a distance of 1.044 AU, magnitude 7.42.
17246 Christophedumas, provisional designation 2000 GL74, is a stony Koronian asteroid and binary system from the outer regions of the asteroid belt, approximately 4.6 kilometers in diameter.
It was discovered on 5 April 2000, by the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. It was named after planetary scientist Christophe Dumas. The asteroid's minor-planet moon was discovered in 2004.23rd Independent Spirit Awards
The 23rd Independent Spirit Awards, honoring the best in independent filmmaking for 2007, were announced on February 23, 2008. It was hosted by Rainn Wilson.Asteroid
Asteroids are minor planets, especially of the inner Solar System. Larger asteroids have also been called planetoids. These terms have historically been applied to any astronomical object orbiting the Sun that did not resemble a planet-like disc and was not observed to have characteristics of an active comet such as a tail. As minor planets in the outer Solar System were discovered they were typically found to have volatile-rich surfaces similar to comets. As a result, they were often distinguished from objects found in the main asteroid belt. In this article, the term "asteroid" refers to the minor planets of the inner Solar System including those co-orbital with Jupiter.
There exist millions of asteroids, many thought to be the shattered remnants of planetesimals, bodies within the young Sun's solar nebula that never grew large enough to become planets. The vast majority of known asteroids orbit within the main asteroid belt located between the orbits of Mars and Jupiter, or are co-orbital with Jupiter (the Jupiter trojans). However, other orbital families exist with significant populations, including the near-Earth objects. Individual asteroids are classified by their characteristic spectra, with the majority falling into three main groups: C-type, M-type, and S-type. These were named after and are generally identified with carbon-rich, metallic, and silicate (stony) compositions, respectively. The sizes of asteroids varies greatly; the largest, Ceres, is almost 1,000 km (625 mi) across.
Asteroids are differentiated from comets and meteoroids. In the case of comets, the difference is one of composition: while asteroids are mainly composed of mineral and rock, comets are primarily composed of dust and ice. Furthermore, asteroids formed closer to the sun, preventing the development of cometary ice. The difference between asteroids and meteoroids is mainly one of size: meteoroids have a diameter of one meter or less, whereas asteroids have a diameter of greater than one meter. Finally, meteoroids can be composed of either cometary or asteroidal materials.Only one asteroid, 4 Vesta, which has a relatively reflective surface, is normally visible to the naked eye, and this only in very dark skies when it is favorably positioned. Rarely, small asteroids passing close to Earth may be visible to the naked eye for a short time. As of October 2017, the Minor Planet Center had data on almost 745,000 objects in the inner and outer Solar System, of which almost 504,000 had enough information to be given numbered designations.The United Nations declared 30 June as International Asteroid Day to educate the public about asteroids. The date of International Asteroid Day commemorates the anniversary of the Tunguska asteroid impact over Siberia, Russian Federation, on 30 June 1908.In April 2018, the B612 Foundation reported "It's 100 percent certain we'll be hit [by a devastating asteroid], but we're not 100 percent sure when." Also in 2018, physicist Stephen Hawking,
in his final book Brief Answers to the Big Questions, considered an asteroid collision to be the biggest threat to the planet. In June 2018, the US National Science and Technology Council warned that America is unprepared for an asteroid impact event, and has developed and released the "National Near-Earth Object Preparedness Strategy Action Plan" to better prepare. According to expert testimony in the United States Congress in 2013, NASA would require at least five years of preparation before a mission to intercept an asteroid could be launched.Asteroid spectral types
An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated, the surface and internal compositions are presumably similar, while large bodies such as Ceres and Vesta are known to have internal structure. Over the years, there has been a number of surveys that resulted in a set of different taxonomic systems such as the Tholen, SMASS and Bus–DeMeo classification.GD 40
GD 40 is a white dwarf in the constellation Cetus. The star's spectrum has been found to show traces of external of metal contamination due to disruption of an extrasolar dwarf planet or an asteroid. The disrupted object should have had roughly the same mass of the Solar System asteroid 3 Juno.H chondrite
The H type ordinary chondrites are the most common type of meteorite, accounting for approximately 40% of all those catalogued, 46% of the ordinary chondrites, and 44% of the chondrites. The ordinary chondrites are thought to have originated from three parent asteroids, whose fragments make up the H chondrite, L chondrite and LL chondrite groups respectively.Iris subg. Scorpiris
Iris subg. Scorpiris, commonly called Juno is a subgenus of Iris, representing the smooth-bulbed bulbous irises. For a while it was an independent genus Juno Tratt. in some classifications.There are around 60 different species of Juno irises, making it the largest group of bulbous irises.
They generally have thick fleshy storage roots (between a few and to several) under a fleshy-like bulb. Most are native to the Middle East and Central Asia (excluding China). There is a single Mediterranean species, 'Iris planifolia'.All the species are dormant in summer and then grow leaves in mid-winter or early spring.Many of the bulbs produce scented flowers. Most bulbs are not frost hardy and are best grown in a bulb frame or alpine house.It consists of a single section, Scorpiris.Juno
Juno may refer to:
Juno (mythology), the Roman goddess of marriage and queen of the godsJuno clump
The Juno clump is a probable main-belt asteroid family in the vicinity of 3 Juno.
3 Juno is a large asteroid with a mean diameter of about 235 km, but the remaining bodies are all small. (32326) 2000 QO62, the brightest of those clearly in the visible clump would have a diameter of about 6 km, given the same albedo as 3 Juno. This indicates that it is probably a so-called cratering family composed of ejecta from impacts on 3 Juno.
The HCM analysis by (Zappalà 1995) determined several likely core members, whose proper elements lie in the approximate ranges
At the present epoch, the range of osculating orbital elements of these core members isKarl Ludwig Harding
Karl Ludwig Harding (September 29, 1765 – August 31, 1834) was a German astronomer, who discovered 3 Juno, the third asteroid of the main-belt in 1804. The lunar crater Harding and the asteroid 2003 Harding are named in his honor.Harding was born in Lauenburg. From 1786–89, he was educated at the University of Göttingen, where he studied theology, mathematics, and physics. In 1796 Johann Hieronymus Schröter hired Harding as a tutor for his son. Schröter was an enthusiastic astronomer, and Harding was soon appointed observer and inspector in his observatory.
In 1804, Harding discovered Juno at Schröter's observatory. In the same year he was appointed professor of astronomy in Göttingen and left Lilienthal, where his successor became Friedrich Wilhelm Bessel.
In addition to Juno, he discovered three comets and the variable stars R Virginis, R Aquarii, R Serpentis and S Serpentis.He also published:
Atlas novus coelestis (1808–1823; re-edited by Jahn, 1856) which catalogued 120,000 stars
Kleine astronomische Ephemeriden (edited with Wiessen, 1830–35)
the fifteenth in the series of Sternkarten of the Berlin Academy's publications (1830)List of 2008 box office number-one films in Mexico
This is a list of films that were number one at the weekend box office in Mexico during 2008.List of exceptional asteroids
The following is a collection of lists of exceptional asteroids in the Solar System. For the purposes of this article "asteroid" means minor planet up to the orbit of Jupiter, which includes the dwarf planet Ceres. For a complete list of minor planets in numerical order, see List of minor planets.
Asteroids are given minor planet numbers, but not all minor planets are asteroids. Minor planet numbers are also given to objects of the Kuiper belt, which is similar to the asteroid belt but farther out around 30–60 AU, whereas asteroids are mostly between 2–3 AU from the Sun. Also, comets are not typically included under minor planet numbers, and have their own naming methodology.
Asteroids are given a unique sequential identifying number once their orbit is precisely determined. Prior to this, they are known only by their systematic name or provisional designation, such as 1950 DA.MGWR Class 6
Midland Great Western Railway (MGWR) Classes 6,8,10,11,17 and 18 were 2-4-0 locomotives introduced in the period 1852-1870. The 22 locomotives were spread across 6 different manufacturers and all were withdrawn in the decade between 1880 and 1890 though some donated parts to other builds at Broadstone Works.MGWR Class D
The MGWR Class D were 2-4-0 steam locomotives built in batches from 1873 to 1887 for the Midland Great Western Railway (MGWR) of Ireland to a Martin Atock design. Numbering 39 at their peak they were the standard MGWR passenger locomotive of their era. Six of the class were rebuilt as 4-4-0.Minor planet
A minor planet is an astronomical object in direct orbit around the Sun (or more broadly, any star with a planetary system) that is neither a planet nor exclusively classified as a comet. Before 2006 the International Astronomical Union (IAU) officially used the term minor planet, but during that year's meeting it reclassified minor planets and comets into dwarf planets and small Solar System bodies (SSSBs).Minor planets can be dwarf planets, asteroids, trojans, centaurs, Kuiper belt objects, and other trans-Neptunian objects. As of 2018, the orbits of 789,069 minor planets were archived at the Minor Planet Center, 523,824 of which had received permanent numbers (for the complete list, see index).The first minor planet to be discovered was Ceres in 1801. The term minor planet has been used since the 19th century to describe these objects. The term planetoid has also been used, especially for larger (planetary) objects such as those the International Astronomical Union (IAU) has called dwarf planets since 2006. Historically, the terms asteroid, minor planet, and planetoid have been more or less synonymous. This terminology has become more complicated by the discovery of numerous minor planets beyond the orbit of Jupiter, especially trans-Neptunian objects that are generally not considered asteroids. A minor planet seen releasing gas may be dually classified as a comet.
Objects are called dwarf planets if their own gravity is sufficient to achieve hydrostatic equilibrium and form an ellipsoidal shape. All other minor planets and comets are called small Solar System bodies. The IAU stated that the term minor planet may still be used, but the term small Solar System body will be preferred. However, for purposes of numbering and naming, the traditional distinction between minor planet and comet is still used.Moka Only
Daniel Denton (born November 14, 1973), better known by his stage name Moka Only is a Canadian underground hip hop artist. He has won 3 JUNO Awards, 5 MuchMusic Video Awards, and has been nominated for 11 Western Canadian Music Awards.Originally from Langford, British Columbia, near Victoria, he is now based in Vancouver. He was previously part of the hip hop group Swollen Members, and briefly a part of Len. Moka has released albums through Feelin' Music, Legendary Entertainment, Battleaxe Records, Domination Recordings, Camobear Records, Wandering Worx and URBNET Records. Moka Only often works with different hip-hop artists and groups, and often works under his alias Ron Contour.In October 2018, Moka Only announced that he would be retiring from rapping via Instagram. However, soon returned claiming he would be focusing on more Jazz, Instrumentals and rapping.Orbital eccentricity
The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit, and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a Klemperer rosette orbit through the galaxy.S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. Approximately 17% of asteroids are of this type, making it the second most common after the carbonaceous C-type.Tenth planet (disambiguation)
Tenth planet is a term formerly applied to possible planets beyond Neptune, before the reclassification of Pluto. It may also refer to:
The Tenth Planet, the Doctor Who serial
The Tenth Planet, a novel by Leo Melamed
The Tenth Planet, a 1952 sci-fi radio play
3 Juno, an asteroid that was the tenth object to be identified as a planet before the asteroids were demoted
2060 Chiron, claimed by some to be the tenth planet upon discovery
Charon, regarded together with Pluto as a binary planet
Eris, which came very close to being considered the tenth planet, after Pluto; it is 27% more massive than Pluto and of similar size
Many other trans-Neptunian objects discovered at this time, such as Haumea, Makemake, Quaoar (the biggest object found since Pluto and Charon themselves) and Sedna
Large asteroids (over 200 km in diameter)
|Asteroids over 500 km|
|Asteroids between 300 and 500 km|
|Asteroids between 200 and 300 km|
The Solar System
Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → Observable universe → Universe