Europa ( minor planet designation: 52 Europa) is the 6th-largest asteroid in the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, c ...

, having a diameter of over 300 km, though it is not correspondingly massive. It is not round but is shaped like an ellipsoid of approximately 380×330×250 km. It was discovered on 4 February 1858, by

Hermann Goldschmidt Hermann Mayer Salomon Goldschmidt (June 17, 1802 – August 30 or September 10 1866) was a German-French astronomer and painter who spent much of his life in France. He started out as a painter, but after attending a lecture by the famous Fren ...

from his balcony in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), ma ...

. It is named after Europa, one of

Zeus Zeus or , , ; grc, Δῐός, ''Diós'', label= genitive Boeotian Aeolic and Laconian grc-dor, Δεύς, Deús ; grc, Δέος, ''Déos'', label= genitive el, Δίας, ''Días'' () is the sky and thunder god in ancient Greek reli ...

's conquests in

Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities ...

, a name it shares with

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

's moon Europa.

Physical characteristics

left, 3D model of ''Europa'' based on lightcurve modeling Europa is approximately the sixth largest asteroid by volume. Most likely it has a density of around 1.5 g/cm³, typical of C-type asteroids. In 2007, James Baer and Steven R. Chesley estimated Europa to have a mass of kg. A more recent estimate by Baer suggests it has a mass of 3.27 kg. Europa is a very dark carbonaceous C-type, and is the second largest of this group. Spectroscopic studies have found evidence of

olivine The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...

s and pyroxenes on the surface, and there is some indication that there may be compositional differences between different regions It orbits close to the Hygiea asteroid family, but is not a member.

Lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular freq ...

data for Europa have been particularly tricky to interpret, so much so that for a long time its period of rotation was in dispute (ranging from hours to 11 hours), despite numerous observations. It has now been determined that Europa is a prograde rotator, but the exact direction in which its pole points remains ambiguous. The most detailed analysis indicates that it points either towards about

ecliptic coordinates The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small Solar System bodi ...

(β, λ) = (70°, 55°) or (40°, 255°) with a 10° uncertainty. This gives an

axial tilt In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orb ...

of about 14° or 54°, respectively. In 1988 a search for satellites or dust orbiting this asteroid was performed using the

UH88 The University of Hawai'i 88-inch (2.24-meter) telescope—called UH88, UH2.2, or simply 88 by members of the local astronomical community—is situated at the Mauna Kea Observatories and operated by the University's Institute for Astronomy. It ...

telescope at the

Mauna Kea Observatories The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on the Big Island of Hawaiʻi, United States. The facilities are located ...

, but the effort came up empty.

Observations

It has been found that the reputed

cataclysmic variable In astronomy, cataclysmic variable stars (CVs) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state. They were initially called novae (), since ones with an outburst brightness visible t ...

star CV Aquarii, discovered in 1934, was actually a misidentification of 52 Europa. Animation of 52 Europa orbit 2000-2020

Notes

References

Bibliography

PDS lightcurve data
* * Schmeer, P., and M. L. Hazen,
CV Aquarii identified with (52) Europa
', Journal of the American Association of Variable Star Observers, Vol. 28, p. 103 (2000).

External links

*
shape model deduced from lightcurve
* * {{DEFAULTSORT:000052 Hygiea asteroids Europa Europa CF-type asteroids (Tholen) C-type asteroids (SMASS) 18580204