1 min read

Pluto and Its Moons: Charon, Nix, and Hydra

A pair of small moons that NASA's Hubble Space Telescope discovered orbiting Pluto now have official names: Nix and Hydra. Photographed by Hubble in 2005, Nix and Hydra are roughly 5,000 times fainter than Pluto and are about two to three times farther from Pluto than its large moon, Charon, which was discovered in 1978.

About the Object

Distance
DistanceThe 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.
Although its orbit is highly eccentric, Pluto's average distance from the Sun is 39.44 astronomical units (roughly 3.6 billion miles or 5.9 billion kilometers).
Dimensions
DimensionsThe physical size of the object or the apparent angle it subtends on the sky.
Pluto has a diameter of roughly 1,416 miles (2,280 kilometers) at the equator.

About the Data

Data Description
Data DescriptionProposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.
These HST data are from proposal 10774: H.A. Weaver (JHU/APL), S.A. Stern and J.R. Spencer (SwRI), M.W. Buie (Lowell Obs.), E. Young, L.A. Young, and A.J. Steffl (SwRI), M. Mutchler (STScI) and W.J. Merline (SwRI).
Instrument
InstrumentThe science instrument used to produce the data.
HST>ACS/HRC
Exposure Dates
Exposure DatesThe date(s) that the telescope made its observations and the total exposure time.
February 15, 2006
Filters
FiltersThe camera filters that were used in the science observations.
F606W (V)

Object Name
Object NameA name or catalog number that astronomers use to identify an astronomical object.
Pluto, Charon, Nix, Hydra
Object Description
Object DescriptionThe type of astronomical object.
Dwarf Planet with Satellites
Release Date
June 22, 2006
Science Release
Pluto’s Two Small Moons Officially Named Nix and Hydra
Read the release
Credits
NASA, ESA, H. Weaver (JHU/APL), A. Stern (SwRI), and the HST Pluto Companion Search Team

Downloads

PDF
(338.98 KB)
2017 × 1513
(253.29 KB)
200 × 200
(7.33 KB)
350 × 350
(18.36 KB)
800 × 600
(58.05 KB)

This image was originally black and white and recorded only overall brightness. These brightness values were translated into a range of bluish hues. Such color "maps" can be useful in helping to distinguish subtly-varying brightness in an image. The colors in this image are not what human eyes would see looking at Pluto.

Related Images & Videos