This sequence of Hubble Space Telescope images chronicles the waxing and waning of the amount of cloud cover on Neptune. This long set of observations shows that the number of clouds grows increasingly following a peak in the solar cycle – where the Sun's level of activity rhythmically rises and falls over an 11-year period.
The chemical changes are caused by photochemistry, which happens high in Neptune's upper atmosphere and takes time to form clouds.
In 1989, NASA's Voyager 2 spacecraft provided the first close-up images of linear, bright clouds, reminiscent of cirrus clouds on Earth, seen high in Neptune's atmosphere. They form above most of the methane in Neptune's atmosphere and reflect all colors of sunlight, which makes them white. Hubble picks up where the brief Voyager flyby left off by continually keeping an eye on the planet yearly.
Credits
Science
NASA, ESA, Erandi Chavez (UC Berkeley), Imke de Pater (UC Berkeley)
| About The Object | |
|---|---|
| Object Name | Neptune |
| Object Description | Planet |
| Distance | The semi-major axis of Neptune's orbit about the Sun is 30.06 astronomical units (roughly 2.8 billion miles or 4.5 billion kilometers). |
| Dimensions | Neptune has a diameter of roughly 30,800 miles (49,600 kilometers) at the equator. |
| About The Data | |
| Data Description | The HST observations include those from several programs throughout three decades of observations including: , , , , , , , , , , , , , , , , , , , , , |
| Instrument | WFPC2 and WFC3 |
| Exposure Dates | Several observations spanning a time frame from 1994 to 2022 |
| Filters | F845M, F850LP, F953N, CH4p15 |
| About The Image | |
| Color Info | These images were acquired by the WFPC2 and WFC3 instruments on the Hubble Space Telescope. The color results from assigning a blue hue to a monochromatic (grayscale) image. |
| 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. |
