The Solar System consists of the Sun and the other celestial objects gravitationally bound to it: the eight planets, their moons, five currently identified dwarf planets and their seven known moons, and billions of small bodies. This last category includes asteroids, Kuiper belt objects, comets, meteoroids and interplanetary dust. In broad terms, the charted regions of the Solar System consist of the Sun, four terrestrial inner planets, an asteroid belt composed of small rocky bodies, four gas giant outer planets, and a second belt, called the Kuiper belt, composed of icy objects. Beyond the Kuiper belt lies the scattered disc, the heliopause, and ultimately the hypothetical Oort cloud. In order of their distances from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Six of the eight planets are in turn orbited by natural satellites, usually termed "moons" after Earth's Moon, and each of the outer planets is encircled by planetary rings of dust and other particles. All the planets except Earth are named after gods and goddesses from Greco-Roman mythology. The five dwarf planets are Pluto, Makemake, and Haumea, the three largest known Kuiper belt objects; Ceres, the largest object in the asteroid belt; and Eris, the largest known object in the scattered disc.
), also designated 1 Ceres
(see minor planet names
), is the smallest dwarf planet
in the Solar System
and the only one located in the main asteroid belt
. Its name is derived from the Roman goddess Ceres
— the goddess of growing plants, the harvest, and of motherly love. It was discovered on January 1, 1801, by Giuseppe Piazzi
. With a diameter of about 950 km, Ceres is by far the largest
and most massive body in the asteroid belt, and contains approximately a third of the belt's total mass. Recent observations have revealed that it is spherical, unlike the irregular shapes of smaller bodies with less gravity.
- ...that although NASA originally thought that there was only one scalloped margin dome on the planet Venus (pictured), they have since discovered hundreds of them?
- ...that there is no widely accepted explanation for geographic features called Carolina bays, but that meteors may be the cause?
- ...that the Oort cloud, a postulated spherical cloud of comets around the Sun, is thought to be the origin of comets in the Solar System?