Neptune Dark Spot

 Neptune Dark Spot

Hubble Uncovers a Pair of Dark Vortices on Neptune

This Hubble Space Telescope snapshot of the dynamic blue-green planet Neptune reveals a monstrous dark storm [top center] and the emergence of a smaller dark spot nearby [top right].

The giant vortex, which is wider than the Atlantic Ocean, was traveling south toward certain doom by atmospheric forces at the equator when it suddenly made a U-turn and began drifting back northward.

Hubble's Wide Field Camera 3 captured this visible-light image on Jan. 7, 2020, the same time a slightly smaller dark spot mysteriously appeared nearby. That spot then vanished a few months later. The smaller feature may have been a piece of the giant storm that broke off as the larger vortex approached the equator.

Hubble uncovered the giant storm in September 2018 in Neptune's northern hemisphere. The feature is roughly 4,600 miles across. The estimated width of the smaller spot is 3,900 miles.

The large storm is the fourth transient dark spot Hubble has observed since 1993. NASA's Voyager 2 spacecraft first imaged two dark features in Neptune's southern hemisphere in 1989 as Voyager flew by the distant planet. Those storms had disappeared by the time Hubble looked at Neptune in 1994. However, Hubble detected two new dark spots in the planet's northern hemisphere in 1994 and 1996.

It's unclear how these storms form. Their clouds may be rising to higher altitudes, compared to surrounding regions in the gas giant's atmosphere.

Neptune's predominant blue color is due to the absorption of red light by the distant planet's methane-rich atmosphere.

Credits

NASA, ESA, STScI, M.H. Wong (University of California, Berkeley) and L.A. Sromovsky and P.M. Fry (University of Wisconsin-Madison)

About The Object
Object Name Neptune
Object Description Neptune with two dark spots
Distance Neptune was approximately 2.83 billion miles from Earth at the time of observations
About The Data
Data Description The HST observations include those from program (M.Wong)
Instrument WFC3/UVIS
Exposure Dates 07 January 2020, 08 January 2020
Filters F467M, F547M, F763M
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 medium 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: F467M
Green: F547M
Red: F763M

To enhance the contrast between dark features and their surroundings, many individual Hubble exposures were combined, and an average background map was subtracted to remove the geometrical effect of limb darkening.
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
  • Proposal: 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.
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.