Neptune’s Rings

While Saturn has the best known set rings, all four of the gas giant planets have rings. Jupiter’s are quite simple and almost unnoticeable. The rings of Uranus are more extensive, but not as complex as Saturn’s. Neptune’s rings are simple, but more complex than Jupiter’s. This 591-second exposure of the rings of Neptune was taken by Voyager 2’s wide-angle camera.

Image Credit: NASA

Climate Change on Neptune

These thermal images taken from Neptune were taken with the VISIR instrument on ESO’s Very Large Telescope. Taken between 2006 and 2021, they show Neptune gradually cooling down, followed by a dramatic heating of its south pole in the last few years. From 2003 to 2018 Neptune’s average temperature dropped about 8 °C, and over the next three years it spiked 11 °C hotter.

Video Credit: ESO

You Can’t See This From Here

The Voyager 2 spacecraft camera captured Neptune and Triton together in crescent phase as it passed by in 1989. This picture of the gas giant and its cloudy moon was taken from behind the planet just after closest approach. It could not have been taken from Earth because Neptune never shows a crescent phase to sunward Earth; the sun always fully illuminates Neptune from our point of view. The unusual vantage point robs Neptune of its familiar blue color because the sunlight seen from behind the planet is scattered forward and is reddened like the setting Sun.

Image Credit: NASA

The Rotation of Neptune

This video is a full-globe map of Neptune created from Hubble Space Telescope data taken in January, 2020. The planet completes a rotation every 16 hours.

Neptune has dynamic weather. White clouds of methane ice crystals swirl around the planet, and two giant dark spots, giant storms, circle around the northern hemisphere. Around the southern pole, banding is concentrated where the winds are blowing west to east, in the same direction as the planet’s rotation. but near the equator, the winds blow east to west, in the opposite direction as the planet’s rotation.

The giant vortex near the equator is 4,600 miles across, wider than the Atlantic Ocean. Its slightly smaller companion is 3,900 miles across.

Video Credit: STScI

Looking at Neptune

Neptune-This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera. The images were taken on 31 years ago at a range of about 7 million km, 4 days and 20 hours before closest approach on 25 August, 1989. The picture shows the Great Dark Spot and its companion bright smudge. The fast moving bright feature called “Scooter” and the little dark spot are visible near the western limb. These clouds were seen to persist for as long as Voyager‘s cameras could resolve them. A bright cloud band similar to the south polar streak may be seen to the north.

Six years ago, the New Horizons spacecraft crossed the orbit of Neptune today on its way to Pluto, but Neptune was not nearby. In July,2014, New Horizons took this picture of Neptune from almost 4 billion km away.neptune-triton-7-10-14-new_hoizonsImage Credit: NASA

Neptune, Triton, Rings, and Stars

Neptune-South-Pole-Voyager-2_950x682Voyager 2 took the images used to produce this picture of the Neptunian system as it was outbound from the planet on 25 August, 1989. Cruising through the outer solar system, the Voyager 2 spacecraft made its closest approach to Neptune on August 25, 1989, the only spacecraft to visit the most distant gas giant. The image captures the planet and Triton as thin sunlit crescents. A close look shows cirrus clouds and a dark band circle Neptune’s south polar region, with a cloudy vortex above the pole itself. (Pole is just past 6:30 on the planet in this orientation.) Parts of the very faint ring system that was discovered during the Voyager 2 flyby are also visible. The background starfield is composed from sky survey data centered on the constellation Camelopardalis, corresponding to the outbound Voyager‘s point of view.

Image Credit: NASA

30 Years Ago

It’s been 30 years since Voyager 2 did it’s last planetary flyby at Neptune. It took his picture  less than five days before the spacecraft’s closest approach 25 August, 1989. The picture shows Neptune’s “Great Dark Spot”—a giant storm—and the bright clouds that follow the storm.

Image Credit: NASA

Neptune’s New Moon

Hippocamp is a small moon of Neptune about 35 km in diameter. It orbits the planet in just under one Earth day. Its discovery in July, 2013, brought the number of Neptune’s known satellites to 14. Hippocampus is so dim that it was not notices when Voyager 2 flew by Neptune in 1989. It was detected by analyzing archived Neptune photographs taken by the Hubble Space Telescope.

This animation shows how Hippocamp might look close up.

Video Credit: ESA

Weather on Neptune

Neptune has seasons which drive some of the features in its atmosphere, but those seasons are much longer than on Earth, lasting for decades rather than months.

This new Hubble view of Neptune shows a dark storm near the top center of the planet’s disc in the region currently experiencing “summer.” The feature is the fourth and latest  dark vortex captured by Hubble since 1993. Two other dark storms were discovered by the Voyager 2 spacecraft in 1989 as it flew by the remote planet. Since the Voyager flyby, Hubble has been out only telescope with sufficient sensitivity in blue light to track such elusive features which have appeared and faded quickly.

Image Credit: NASA / STScI

A Dark Spot on Neptune

dark spot image2This new Hubble Space Telescope image reveals a new dark vortex in the atmosphere of Neptune. Neptune’s dark vortices are high-pressure systems and are usually accompanied by bright “companion clouds,” and the visible-light image on the left shows the dark feature near a patch of bright clouds in the planet’s southern hemisphere. The bright clouds form when the flow of the atmosphere is perturbed and diverted upward over the dark vortex, probably causing methane to freeze into ice crystals. The image at top right is a full-color close-up of the complex feature. The image at bottom right shows that the vortex as seen in blue wavelengths.

Image Credit: NASA

Neptune and Its Moons

This movie was put together using 70 days worth of solar system observations from the Kepler spacecraft taken during its reinvented “K2” mission. The planet Neptune appears from the left on Day 15, followed by its moon Triton, which looks small and faint. Sharp-eyed observers may also spot Neptune’s tiny moon Nereid at Day 24.

Neptune doesn’t actually move backward in its orbit, but it appears to do so because of the changing position of the Kepler spacecraft as it orbits around the sun. The same sort of retrograde motion is seen in the movement of the outer planets over the course of a year as viewed from Earth.

[youtube https://www.youtube.com/watch?v=Tw-q3uM_5_0]

Video Credit: NASA

Neptune

Neptune-This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera. The images were taken on 25 years ago at a range of about 7 million km, 4 days and 20 hours before closest approach on 25 August, 1989. The picture shows the Great Dark Spot and its companion bright smudge. The fast moving bright feature called “Scooter” and the little dark spot are visible near the western limb. These clouds were seen to persist for as long as Voyager‘s cameras could resolve them. A bright cloud band similar to the south polar streak may be seen to the north.

Image Credit: NASA

UPDATE—The New Horizons spacecraft crossed the orbit of Neptune today on its way to Pluto. Neptune was not nearby. In July, New Horizons took this picture of Neptune from almost 4 billion km away.neptune-triton-7-10-14-new_hoizonsImage Credit: NASA