Bay - a large semi-oval indentation in the edge of a belt. Common along the northern and southern edge of the NEB, as well as along the southern edge of the SEB. Small bays are known as Notches. The Red Spot Hollow (RSH) would be an example of a large bay.

Central Meridian (CM) - the central meridian is an imaginary line through the center of the disk from the south pole to the north pole, dividing the disk into equal halves, independent of phase. By noting the time a feature transits the CM, it is possible to determine the period of rotation of surface or atmospheric features. See Following and Preceding.

Condensation - a small round or somewhat elongated dark spot usually found in belts. If they are very elongated they are called Rods or Bars. Rods or bars (sometimes appearing red in color) are very common along the northern edge of, and embedded in, the NEB, and are occasionally seen in the north temperate latitudes of Jupiter. Bars or rods are sometimes called barges.

Festoons - a dark feature that extends across a zone and connects two belts, such as the NEB to EB. If festoon loops into zone and reconnects to the same belt it started from it is sometimes called a Loop Festoon or Garland. Color of festoons is blue or gray. If festoon does not connect to a belt it is called a Hook. Diffuse, broad vertical festoons are known as Columns. Festoons are often seen in EZ and along the southern edge of NEB.

Following and Preceding - when observing Jupiter with a telescope with an even number of reflections, such as a Newtonian reflector, or refractor used without a star diagonal, south is at the top. Features on the disk appear to rotate from the right hand side to the left hand side of the disk (when using a telescope of different configuration, note that north may be at the top, and the planet may appear to rotate from left to right). The right hand side of the disk (as defined by the Central Meridian or CM) is the following side of the disk; the left hand side is the preceding side. Using an accurate watch, pencil, and notepad it is possible to make CM timings. When a feature, such as the GRS, approaches the CM, note the time to the nearest minute the time its preceding edge transits the CM. Do the same for its center and following edge. In our example of the GRS, the notation would read GRSp, GRSc, GRSf, which translates to GRS preceding, GRS center, GRS following. As shorthand notation for other dark or light features, you can use the letter D to indicate a dark feature, W to indicate a white feature. These timings will give you an estimate of when the feature transited the CM. Since features in Jupiter's atmosphere tend to drift over time, these timings will give an estimate of its drift rate relative to other features.

Gap - a wide break in a belt that divides the belt into two or more sections.

Knots - darker, thicker sections of a belt.

Nodule - the opposite of a Condensation, these are small, round bright spots. Seen in NEB, SEB, and Polar Regions.

Ovals - light colored areas, round or oval in shape, that are medium to large in size. Can appear both in dark belts and light zones. Very common in the EZ. Small ovals are known as White Spots. The Great Red Spot (GRS) is an example of a very large oval.

Patch - a large, irregular shaped whitish colored area, seen in the EZ and the polar regions.

Projection - a dark prominence on the edge of a belt.

Rift - a long, thin bright streak that extends horizontally along the interior of a belt.

Streak - an elongated Nodule.

Veil or Shading - the opposite of Patch, these are large, uniform dusky areas sometimes seen in zones or polar areas. The EZ near opposition sometimes has a veil or shaded appearance to it.

Jupiter's atmosphere is thought to be composed mostly of hydrogen and helium, with traces of ammonia, phosphine, water vapor, and hydrocarbons. The light colored zones, and dark colored belts, seen in Jupiter's atmosphere are caused by differences in chemical composition and temperature. The colors of the zones and belts give an idea as to their altitude: reds are the highest, then whites and browns, followed by blue as the lowest.

Jupiter's alternating bright zones and dark belts are designated in order from the pole to the equator as: polar, temperate, tropical, and equatorial. Below is a list of each of the belts and zones, its abbreviation, and the system it resides in. Note that belts and zones can sometimes have a north, center, and south component to them, and not all belts and zones are visible during each opposition.

*Since Jupiter does not rotate on its axis at a uniform rate, two rotation periods have been assigned to it: System I is 9 hours 50 minutes and 30 seconds, encompassing the Equatorial Zone, which extends from the northern edge of the South Equatorial Belt to the southern edge of the North Equatorial Belt. All other Jovian latitudes, except for the polar regions, have been assigned a rotation period of 9 hours 55 minutes and 40 seconds, which is System II.

**System III is sometimes used to define the polar regions, or alternately is used by radio astronomers to study Jupiter's rotation. For amateur observations only System I and II are used.