Pallas

Pallas has been observed occulting a star several times, including the best observed of all asteroid occultation events onMay 29, 1983, when careful occultation timing measurements were taken by 140 observers.

Pallas has an ellipsoidal shape with radial dimensions of 285 × 262 × 250 km, equivalent to a sphere with a diameter of 530 km—i.e., about 15 percent of the diameter of the Moon.

Pallas Related Category: Astronomy: General (pl´s), in astronomy, 2d asteroid to be discovered. It was found in 1802 by H. Olbers. The second largest asteroid, it has a diameter of c.300 mi (480 km). Its orbit has a semimajor axis of 2.

Pallas Home ... Science and Technology Astronomy and Space Exploration Astronomy: General ... Essential reading Compare side-by-side A Dictionary of Earth Sciences The Oxford Dictionary of ... The Columbia Encyclopedia, ...

2 Pallas '2 Pallas' is one of the largest asteroids and is located in the main asteroid belt. It was the second asteroid to be discovered, by astronomy Heinrich Wilhelm Matth?us Olbers on March 28, 1802.... , and Hygiea 10 Hygiea ...

PALLAS Pallas is the second-biggest asteroid and one of the four brightest asteroids. Its dimensions are: 570 x 525 x 482 km and its mass is 3.18 x 1020 kg. Pallas is about 4.145 x 108 km from the Sun and takes 4.

Pallasites Mesosiderites Iron meteorites (5.7%) Meteorites have proven difficult to classify, but the three broadest groupings are stony, stony iron, and iron. The most common meteorites are chondrites, which are stony meteorites.

Pallas The second asteroid to be discovered (by Olbers in 1802). Diameter about 560 km; a = 2.77 AU, e = 0.235, i = 34°.8. Orbital period 1,686 days; rotation period 9-12 hours. Albedo ~ 0.05; mass (1972 est.) 2.6 × 1023 g.

Pallas 14 Paradas: Paradas system Parvenium: Parvenium system Pegos Minor: Pegos Minor system Pelosa: Pelosa system Pendari: Pendari system Pentath: Pentath system Pernaia: Pernaia system Phylos: Phylos system Portas: Portas system ...

Pallasite a stony-iron meteorite in which nodules of olivine (a silicate mineral) are surrounded by a network of iron-nickel metal. Parallax the apparent change in position of two objects viewed from different locations.

2 Pallas has an unusually high orbital inclination. 4 Vesta is the brightest of the asteroids. It is the only one that can reach the limit of naked-eye visibility, sixth magnitude. After a gap of 38 years, 5 Astraea was discovered.

(2) Pallas Close approaches by Asteroids In 2008, up to the end of August, some 14 asteroids are known to have passed the Earth at a distance less than that of the Moon, 384 000 km, about .0025 astronomical units.

Ceres,[e] Pallas, Juno, and Vesta The first known asteroids, from their discoveries between 1801 and 1807 until their reclassification as asteroids during the 1850s.[41] Ceres has subsequently been classified as a dwarf planet.

Although none is visible to the naked eye, many can be seen at times with binoculars or small telescopes, including the four largest: (1) Ceres, (2) Pallas, (4) Vesta, and (10) Hygiea.

The three largest asteroids in the main belt (individually named 4 Vesta, 2 Pallas and 10 Hygiea) have mean diameters of more than 400 km, while the main belt's only dwarf planet, Ceres, is about 950 km in diameter.

The densities of Ceres, Pallas, and Vesta are 2.3, 3.4, and 4.0 grams per cubic centimetre, respectively. These compare with 5.4, 5.2, and 5.5 g/cm for Mercury, Venus, and the Earth, respectively; 3.9 g/cm for Mars; and 3.3 g / cm for the Moon.

The largest representatives are Ceres, with a diameter of about 930 km (about 578 mi); Pallas, with a diameter of about 552 km (about 343 mi); and Vesta, with a diameter of about 521 km (about 324 mi).

The most beautiful meteorites are those stony-irons called pallasites, a fusion of metal and mineral.

It is interesting to note that, historically, the first four asteroids (1 Ceres, 2 Pallas, 3 Juno and 4 Vesta) were considered planets for several decades (their size was not accurately known at the time).

Heinrich Wilhelm Olbers found another, Pallas, on March 28, 1802. Karl L. Harding found a third, Juno, on Septemer 1, 1804. Olbers found the fourth, Vesta, on March 29, 1807.

It is 1003 km in diameter. Pallas and Vesta have diameters of about 500 km and 30 more asteroids have diameters greater than 200 km. Most asteroids, however, are small objects only a few kilometres across.

Pallas and Vesta have diameters of about 500 kilometers and about 15 others have diameters larger than 250 kilometers. The number of asteroids shoots up with decreasing size. The combined mass of all of the asteroids is less than the Moon's mass.

It is 974 km in diameter and contains about 25% of the mass of all the asteroids combined. The next largest are 2 Pallas, 4 Vesta and 10 Hygiea which are between 400 and 525 km in diameter. All other known asteroids are less than 340 km across.

The surprise came when three more bodies (Pallas, Juno, and Vesta) were discovered in the same area. A few others were visually observed thereafter.

It is the only minor planet known to have an albedo less than 5 percent, and some astronomers think it may be larger than Pallas. Mean opposition magnitude +11.41, absolute magnitude +8.14. Rotation period 8h(?).

Ceres, the largest Main-Belt asteroid, has been acknowledged by many astronomers as a dwarf planet. In addition, the next three largest asteroids in the Main Belt (Vesta, Pallas, and Hygeia) may also be "round enough" to be eventually classified as ...

a German astronomer and physician who published Olbers' paradox (Why is the sky dark at night? or Why doesn't starlight make the night sky bright?) (1823), determined that is a planet, not a comet (1781), discovered Olbers's (1815), the #2 Pallas ...

and physician who published Olbers' paradox (Why is the sky dark at night? or Why doesn't starlight make the night sky bright?) (1823), determined that Uranus is a planet, not a comet (1781), discovered Olbers's comet (1815), the asteroids #2 Pallas ...

1802 - Heinrich Wilhelm Olbers discovers the asteroid Pallas 1821 - Alexis Bouvard detects irregularities in the orbit of Uranus ...

The largest are Ceres (900-km diameter), Pallas and Vesta (500-km diameter). asteroid belt A ring of asteroids containing perhaps thousands of big rocks several kilometers in diameter, and millions of smaller chunks. Asteroids orbit between 2 and 3.

See also: Planet, Asteroid, Earth, Sun, Orbit