Europa (moon)
Europa is a large moon of the planet Jupiter. It is a little smaller than Earth's Moon and it is the sixth-largest moon in the Solar System.
 Europa has a white surface | |||||||||
| Discovery | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Discovered by | Galileo Galilei Simon Marius | ||||||||
| Discovery date | 8 January 1610 | ||||||||
| Designations | |||||||||
| Jupiter II | |||||||||
| Adjectives | Europan | ||||||||
| Orbital characteristics[2] | |||||||||
| Epoch 8 January 2004 | |||||||||
| Periapsis | 664862 km[a] | ||||||||
| Apoapsis | 676938 km[b] | ||||||||
Mean orbit radius | 670900 km[1] | ||||||||
| Eccentricity | 0.009[1] | ||||||||
| 3.551181 d[1] | |||||||||
Average orbital speed | 13.740 km/s[1] | ||||||||
| Inclination | 0.470° (to Jupiter's equator) 1.791° (to the ecliptic)[1] | ||||||||
| Satellite of | Jupiter | ||||||||
| Physical characteristics | |||||||||
Mean radius | 1560.8±0.5 km (0.245 Earths)[3] | ||||||||
| 3.09×107 km2 (0.061 Earths)[c] | |||||||||
| Volume | 1.593×1010 km3 (0.015 Earths)[d] | ||||||||
| Mass | (4.799844±0.000013)×1022 kg (0.008 Earths)[3] | ||||||||
Mean density | 3.013±0.005 g/cm3[3] | ||||||||
| 1.314 m/s2 (0.134 g)[e] | |||||||||
| 0.346±0.005[4] (estimate) | |||||||||
| 2.025 km/s[f] | |||||||||
| Synchronous | |||||||||
| 0.1°[5] | |||||||||
| Albedo | 0.67 ± 0.03[3] | ||||||||
| |||||||||
| 5.29 (opposition)[3] | |||||||||
| Atmosphere | |||||||||
Surface pressure | 0.1 µPa (10−12 bar)[6] | ||||||||
Europa's diameter is about 3000 kilometers. It probably has an iron core, and a thin atmosphere of mostly oxygen. The surface is icy and very smooth. There are not a lot of craters, but there are some cracks and lines.
Scientists believe that there is a liquid ocean under the surface, and that it is kept warm by tidal heating.[7] In other words, heat from tidal flexing (Jupiter's strong gravitational pull on Europa) makes it warm. Europa certainly has a lot of water.[8]
The moon Europa was found by Simon Marius in December 1609. Galileo Galilei first saw the moon in January 1610 (he did not know Marius had found it). Simon Marius was the one who had the idea of the name 'Europa'.
Europa is named after a princess from Greek mythology who became the first queen of Crete.
Europa (moon) Media
Animation of the Laplace resonance of Io, Europa and Ganymede (conjunctions are highlighted by color changes)
Size comparison of Europa (lower left) with the Moon (top left) and Earth (right)
Map of Europa, by the United States Geological Survey
True color mosaic of Europa's numerous lineae
Two possible models of Europa
Closeup views of Europa obtained on 26 September 1998; images clockwise from upper left show locations from north to south as indicated at lower left.
Europa closeup(9 September 2022)
Water vapor plumes on Jupiter's moon Europa (artist's impression)
Photo composite of suspected water plumes on Europa
Magnetic field around Europa. The red line shows a trajectory of the Galileo spacecraft during a typical flyby (E4 or E14).
.jpg)
References
- ↑ 1.0 1.1 1.2 1.3 1.4 "Overview of Europa Facts". NASA. Archived from the original on 26 March 2014. Retrieved 27 December 2007.
- ↑ "JPL HORIZONS solar system data and ephemeris computation service". Solar System Dynamics. NASA, Jet Propulsion Laboratory. Retrieved 10 August 2007.
- ↑ 3.0 3.1 3.2 3.3 3.4 Yeomans, Donald K. (13 July 2006). "Planetary Satellite Physical Parameters". JPL Solar System Dynamics. Retrieved 5 November 2007.
- ↑ Showman, A. P.; Malhotra, R. (1 October 1999). "The Galilean Satellites". Science. 286 (5437): 77–84. doi:10.1126/science.286.5437.77. PMID 10506564.
- ↑ Bills, Bruce G. (2005). "Free and forced obliquities of the Galilean satellites of Jupiter". Icarus. 175 (1): 233–247. Bibcode:2005Icar..175..233B. doi:10.1016/j.icarus.2004.10.028.
- ↑ McGrath (2009). "Atmosphere of Europa". In Pappalardo, Robert T.; McKinnon, William B.; Khurana, Krishan K. (eds.). Europa. University of Arizona Press. ISBN 978-0-8165-2844-8.
- ↑ Greenberg, Richard; Europa: the ocean moon: search for an alien biosphere, Springer Praxis Books, 2005
- ↑ Chang, Kenneth (12 March 2015). "Suddenly, it seems, water is everywhere in Solar System". The New York Times. Archived from the original on 9 May 2020. Retrieved 13 March 2015. [1]
Notes
- ↑ Periapsis is derived from the semimajor axis (a) and eccentricity (e): a(1−e).
- ↑ Apoapsis is derived from the semimajor axis (a) and eccentricity (e): a(1+e).
- ↑ Surface area derived from the radius (r): 4πr 2
- ↑ Volume derived from the radius (r): 4/3πr 3
- ↑ Surface gravity derived from the mass (m), the gravitational constant (G) and the radius (r): Gm/r 2
- ↑ Escape velocity derived from the mass (m), the gravitational constant (G) and the radius (r): [math]\displaystyle{ \textstyle\sqrt{\frac{2Gm}{r}} }[/math]
Other websites
- Europa Archived 2011-05-20 at the Wayback Machine