Himalia (moon)

Himalia

Himalia as seen by Cassini-Huygens
Discovery
Discovered by:C. D. Perrine
Discovery date:December 3, 1904
Orbital characteristics
Periapsis:9,782,900 km
Apoapsis:13,082,000 km
Mean radius of orbit:11,460,000 km[1]
Eccentricity:0.16[1]
Orbital period:250.56 d (0.704 a)[1]
Avg. orbital speed:3.312 km/s
Inclination:27.50° (to the ecliptic)
29.59° (to Jupiter's equator)[1]
Satellite of:Jupiter
Physical characteristics
Mean radius:85 km
Surface area:~90,800 km²
Volume:~2,570,000 km³
Mass:6.71018 kg
Mean density:2.6 g/cm³ (assumed)
Equatorial surface gravity:~0.062 m/s2 (0.006 g)
Escape velocity:~0.100 km/s
Sidereal rotation period:~0.4 d (10 h)
Albedo:0.04[2]
Temperature:~124 K
Himalia (hye-mey'-lee-ə, IPA: /haɪˈmeɪliə/, or hi-maal'-ee-ə /hɪˈmɑliə/) is the largest irregular satellite of Jupiter. It was discovered by Charles Dillon Perrine at the Lick Observatory on 1904 December 3[3] and is named after the nymph Himalia who bore three sons of Zeus (the Greek equivalent of Jupiter).

Name

Himalia did not receive its present name until 1975;[4] before then, it was simply known as Jupiter VI or Jupiter Satellite VI, although calls for a full name appeared shortly after its and Elara's discovery; A.C.D. Crommelin wrote in 1905,
"Unfortunately the numeration of Jupiter's satellites is now in precisely the same confusion as that of Saturn's system was before the numbers were abandoned and names substituted. A similar course would seem to be advisable here; the designation V for the inner satellite was tolerated for a time, as it was considered to be in a class by itself; but it has now got companions, so that this subterfuge disappears. The substitution of names for numerals is certainly more poetic."[5]


The moon was sometimes called Hestia[6], after the Greek goddess from 1955 to 1975.

Orbit

It is the largest member of the group that bears its name, the moons orbiting between 11.4 and 13 million kilometers from Jupiter at an inclination of about 27.5°.[7] The orbital elements are as of January 2000.[1] They are continuously changing due to Solar and planetary perturbations.

Physical characteristics

Himalia appears neutral (grey), like the other members of its group, with colour indices B-V=0.62, V-R= 0.4, similar to a C-type asteroid.[8] Measurements by Cassini confirm a featureless spectrum, with a slight absorption at 3 μm which could indicate the presence of water.[9]

Exploration

In November 2000, the Cassini spacecraft, enroute to Saturn, made a number of images of Himalia, including photos from a distance as close as 4.4 million km. The moon covers only a few pixels, but seems to be an elongated object with axes 150 ± 20 and 120 ± 20 km, close to the Earth-based estimations.[2]

In February and March 2007, the New Horizons spacecraft to Pluto made a series of images of Himalia, culminating in photos from a distance of eight million km. Again, Himalia appears only a few pixels across.

See also

References

1. ^ Jacobson, R. A. (2000). "The orbits of outer Jovian satellites". Astronomical Journal 120: 2679-2686. DOI:10.1086/316817. 
2. ^ Porco, Carolyn C.; et al. (March 2003). "Cassini Imaging of Jupiter's Atmosphere, Satellites, and Rings". Science 299: 1541-1547. DOI:10.1126/science.1079462. 
3. ^ (1905 January 9) "Discovery of a Sixth Satellite of Jupiter". Astronomical Journal 24 (18): 154B;. ; (1905 January 25) "Sixth Satellite of Jupiter Confirmed (Himalaia)". Harvard College Observatory Bulletin 175: 1. ; Perrine, C. D. (1905). "Discovery of a Sixth Satellite to Jupiter". Publications of the Astronomical Society of the Pacific 17: 22–23. ; Perrine, C. D. (1905). "Orbits of the sixth and seventh satellites of Jupiter". Astronomische Nachrichten 169: 43–44. 
4. ^ Marsden, B. G. (7 October 1974). "Satellites of Jupiter". IAUC Circular 2846. 
5. ^ Crommelin, A. C. D. (March 10 1905)). "Provisional Elements of Jupiter's Satellite VI". Monthly Notices of the Royal Astronomical Society 65 (5): 524–527. 
6. ^ Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-134-78107-4. 
7. ^ Sheppard, S. S., Jewitt, D. C., Porco, C.; Jupiter's Outer Satellites and Trojans, in Jupiter: The Planet, Satellites and Magnetosphere, edited by Fran Bagenal, Timothy E. Dowling, William B. McKinnon, Cambridge Planetary Science, Vol. 1, Cambridge, UK: Cambridge University Press, ISBN 0-521-81808-7, 2004, pp. 263-280
8. ^ Rettig, Terrence W. (2001). "Implied Evolutionary Differences of the Jovian Irregular Satellites from a BVR Color Survey". Icarus 154: 313-320. DOI:10.1006/icar.2001.6715. 
9. ^ Chamberlain, Matthew A.; Brown, Robert H. (2004). "Near-infrared spectroscopy of Himalia". Icarus 172: 163-169. DOI:10.1016/j.icarus.2003.12.016. 

External links


... | Leda | Himalia | Lysithea | ...


Charles Dillon Perrine (July 28 1867–June 21 1951) was an American-Argentine astronomer.

Born in Ohio, he worked at Lick Observatory from 1893 to 1909 and then was director of the Argentine National Observatory (today, Observatorio Astronómico de Córdoba) [1]
..... Click the link for more information.
December 3 is the 1st day of the year (2nd in leap years) in the Gregorian calendar. There are 0 days remaining.

Events

  • 1800 - Battle of Hohenlinden, which was an Austrian Defeat

..... Click the link for more information.
19th century - 20th century - 21st century
1870s  1880s  1890s  - 1900s -  1910s  1920s  1930s
1901 1902 1903 - 1904 - 1905 1906 1907

Year 1904 (MCMIV
..... Click the link for more information.
ORBit is a CORBA compliant Object Request Broker (ORB). The current version is called ORBit2 and is compliant with CORBA version 2.4. It is developed under the GPL license and is used as middleware for the GNOME project.
..... Click the link for more information.

..... Click the link for more information.
1 kilometre =
SI units
0 m 0106 mm
US customary / Imperial units
0 ft 0 mi
A kilometre (American spelling: kilometer, symbol km
..... Click the link for more information.

..... Click the link for more information.
1 kilometre =
SI units
0 m 0106 mm
US customary / Imperial units
0 ft 0 mi
A kilometre (American spelling: kilometer, symbol km
..... Click the link for more information.
In classical geometry, a radius (plural: radii) of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment. The radius is half the diameter.
..... Click the link for more information.
1 kilometre =
SI units
0 m 0106 mm
US customary / Imperial units
0 ft 0 mi
A kilometre (American spelling: kilometer, symbol km
..... Click the link for more information.
orbit's eccentricity, is an important parameter of the orbit that defines its absolute shape. Eccentricity may be interpreted as a measure of how much this shape deviates from a circle.
..... Click the link for more information.
The orbital period is the time taken for a planet (or another object) to make one complete orbit.

When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.
..... Click the link for more information.
A year (from Old English gēr) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. By extension, this can be applied to any planet: for example, a "Martian year" is the time in which Mars completes its own orbit.
..... Click the link for more information.
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.
..... Click the link for more information.


Inclination in general is the angle between a reference plane and another plane or axis of direction.
..... Click the link for more information.
ecliptic is the apparent path that the Sun traces out in the sky, as it appears to move in the sky in relation to the stars, this apparent path aligns with the planets throughout the course of the year.
..... Click the link for more information.
A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. Such objects are often called moons. Technically, the term could also refer to a planet orbiting a star, or even to a star orbiting a galactic center, but these
..... Click the link for more information.
Jupiter  

This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979. The colors have been enhanced to bring out detail.
..... Click the link for more information.
Square kilometre (U.S. spelling: square kilometer), symbol km², is a decimal multiple of the SI unit of surface area, the square metre, one of the SI derived units. 1 km² is equal to:
  • 1,000,000 m²
  • 100 ha (hectare)
Conversely:
  • 1 m² = 0.

..... Click the link for more information.
The volume of a solid object is the three-dimensional concept of how much space it occupies, often quantified numerically. One-dimensional figures (such as lines) and two-dimensional shapes (such as squares) are assigned zero volume in the three-dimensional space.
..... Click the link for more information.
cubic metre (symbol ) is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. In the United States it is spelled cubic meter. An alternate name, which allowed a different usage with SI prefixes, was the stère.
..... Click the link for more information.
Mass is a fundamental concept in physics, roughly corresponding to the intuitive idea of "how much matter there is in an object". Mass is a central concept of classical mechanics and related subjects, and there are several definitions of mass within the framework of relativistic
..... Click the link for more information.
kilogram or kilogramme (symbol: kg) is the SI base unit of mass. The kilogram is defined as being equal to the mass of the International Prototype Kilogram (IPK), which is almost exactly equal to the mass of one liter of water.
..... Click the link for more information.
In physics, density is mass m per unit volume V—how heavy something is compared to its size. A small, heavy object, such as a rock or a lump of lead, is denser than a lighter object of the same size or a larger object of the same weight, such as pieces of
..... Click the link for more information.
The surface gravity, g, of an astronomical or other object is the gravitational acceleration experienced at its surface. The surface gravity may be thought of as the acceleration due to gravity experienced by a hypothetical test particle which is very close to the object's
..... Click the link for more information.
acceleration is defined as the rate of change of velocity, or, equivalently, as the second derivative of position. It is thus a vector quantity with dimension length/time². In SI units, acceleration is measured in metres/second² (m·s-²).
..... Click the link for more information.
escape velocity is the speed where the kinetic energy of an object is equal in magnitude to its potential energy in a gravitational field.

It is commonly described as the speed needed to "break free" from a gravitational field; however, this is not true for objects under
..... Click the link for more information.
For the novel Sidereal Time see Christopher Meredith.


Sidereal time is a measure of the position of the Earth in its rotation around its axis.
..... Click the link for more information.
The albedo of an object is the extent to which it reflects light, defined as the ratio of reflected to incident electromagnetic radiation. It is a unitless measure indicative of a surface's or body's diffuse reflectivity.
..... Click the link for more information.
trillion fold).]]

Temperature is a physical property of a system that underlies the common notions of hot and cold; something that is hotter generally has the greater temperature. Temperature is one of the principal parameters of thermodynamics.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.