page_title: Ceres (dwarf planet)
section_title: Orbit
hierarchical_section_title: Ceres (dwarf planet) / Orbit
caption_attribution_description: English: Animation of Dawn's trajectory from 27 September 2007 to 5 October 2018&#160;&#160;&#160;&#160;&#160;&#160;Dawn&#160;· &#160;&#160;&#160;&#160;&#160;&#160;Earth&#160;· &#160;&#160;&#160;&#160;&#160;&#160;Mars&#160;· &#160;&#160;&#160;&#160;&#160;&#160;4 Vesta&#160;· &#160;&#160;&#160;&#160;&#160;&#160;1 Ceres
context_page_description: Ceres is the largest object in the main asteroid belt that lies between the orbits of Mars and Jupiter. With a diameter of 940 km, Ceres is both the largest of the asteroids and the only dwarf planet inside Neptune's orbit. It is the 25th-largest body in the Solar System within the orbit of Neptune.
  Ceres was the first asteroid to be discovered. It was originally considered a planet, but was reclassified as an asteroid in the 1850s after many other objects in similar orbits were discovered.
  Ceres is the only object in the asteroid belt rounded by its own gravity, although Vesta and perhaps other asteroids were so in the past. From Earth, the apparent magnitude of Ceres ranges from 6.7 to 9.3, peaking once at opposition every 15 to 16 months, which is its synodic period. Thus even at its brightest, it is too dim to be seen by the naked eye, except under extremely dark skies. Ceres has been classified as a C-type asteroid and, due to the presence of clay minerals, as a G-type asteroid.
  Ceres appears to be partially differentiated into a muddy mantle/core and a less-dense but stronger crust that is at most 30 percent ice.
context_section_description: Ceres follows an orbit between Mars and Jupiter, within the asteroid belt and closer to the orbit of Mars, with a period of 4.6 Earth years. The orbit is moderately inclined (i = 10.6° compared to 7° for Mercury and 17° for Pluto) and moderately eccentric (e = 0.08 compared to 0.09 for Mars).
  The diagram illustrates the orbits of Ceres (blue) and several planets (white and gray). The segments of orbits below the ecliptic are plotted in darker colors, and the orange plus sign is the Sun's location. The top left diagram is a polar view that shows the location of Ceres in the gap between Mars and Jupiter. The top right is a close-up demonstrating the locations of the perihelia (q) and aphelia (Q) of Ceres and Mars. In this diagram (but not in general), the perihelion of Mars is on the opposite side of the Sun from those of Ceres and several of the large main-belt asteroids, including 2 Pallas and 10 Hygiea. The bottom diagram is a side view showing the inclination of the orbit of Ceres compared to the orbits of Mars and Jupiter.
  Ceres was once thought to be a member of an asteroid family. The asteroids of this family share similar proper orbital elements, which may indicate a common origin through an asteroid collision some time in the past. Ceres was later found to have spectral properties different from other members of the family, which is now called the Gefion family after the next-lowest-numbered family member, 1272 Gefion. Ceres appears to be merely an interloper in the Gefion family, coincidentally having similar orbital elements but not a common origin.
caption: Animation of  Dawn's trajectory from 27 September 2007 to 5 October 2018
     Dawn  ·   Earth ·   Mars ·   4 Vesta  ·   1 Ceres