Composite Image of Saturn with Six Moons
This composite image, taken by NASA’s Hubble Space Telescope on June 6, 2018, shows the ringed planet Saturn with six of its 62 known moons. From left to right, the moons visible in this image are Dione, Enceladus, Tethys, Janus, Epimetheus, and Mimas. With a diameter of 698 miles, Dione is the fourth-largest moon of Saturn and the largest of the siblings in this family portrait. The smallest satellite in this picture is the irregularly shaped Epimetheus, with a size of 89 miles by 67 miles by 61 miles.
The moons seen here are icy and cratered. Enceladus is considered a candidate for primitive life because it is outgassing water vapor from a subsurface ocean. Based on data from the NASA Cassini mission to Saturn, scientists hypothesize that a small, wayward moon like one of these disintegrated 200 million years ago to form Saturn’s ring system. The image is a composite because the moons move during the Saturn exposures, and individual frames must be realigned to make a color portrait.
Credits
NASA, ESA, A. Simon (GSFC) and the OPAL Team, and J. DePasquale (STScI)| About The Object | |
|---|---|
| Object Name | Saturn |
| Object Description | Saturn and moons near opposition |
| Distance | The semi-major axis of Saturn's orbit about the sun is 9.5 astronomical units (A.U.) or roughly 1.4 billion km. |
| Dimensions | The planet (without rings) has a diameter of roughly 75,000 miles (120,000 km) at the equator. |
| About The Data | |
| Data Description | The HST observations include those from the Outer Planet Atmospheres Legacy (OPAL) Program (A. Simon) |
| Instrument | WFC3/UVIS |
| Exposure Dates | June 6, 2018 |
| Filters | F395N, F502N, F631N |
| About The Image | |
| Color Info | These images are a composite of separate exposures acquired by the WFC3 instrument on the Hubble Space Telescope. Several filters were used to sample narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue: F395N Green: F502N Red: F631N |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
