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

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

New Moon


Neptune'sNewMoonThis composite Hubble Space Telescope picture shows a newly discovered moon, designated S/2004 N 1, orbiting Neptune. The black and white image and the color inset of Neptune were taken in 2009. The moon is the 14th known to be circling the giant planet.

S/2004 N 1 is believed to be about 20 km across, making it the smallest known moon of Neptune. It wasn’t noticed during the Voyager 2 flyby, which isn’t surprising since it very small and dim.

Mark Showalter of the SETI Institute in Mountain View, California, found the moon on 1 July while studying the ring system around Neptune. His method involved tracking the movement of a white dot that appears archival Neptune photographs taken by Hubble between 2004 and 2009.

Image Credit: NASA

Giant Spotted Planets


jupiter_red_spotOne of the most recognizable features in the Solar System is Jupiter’s Red Spot. However, Jupiter is not the only spotted planet. Neptune has long-term storm systems known as the dark spots. Voyager 2 made a close up picture of a Great Dark Spot when it flew by Neptune in 1989.

Based on observations taken by Voyager and with the Hubble Space Telescope, Neptune appears to have a Great Dark Spot more often than not. The Great Dark Spot is thought to be a hole in the methane cloud deck of Neptune. nepture_dark spot.

Neptune’s Great Dark Spot generates large white clouds at or just below the tropopause layer of the planet’s atmosphere similar to high-altitude cirrus clouds found on Earth. However, Neptune’s cirrus clouds are made up of crystals of frozen methane instead of water ice.

Image Credits: NASA

Approaching Neptune and Triton


This montage of images taken by Voyager 2 shows Neptune as it would appear from a spacecraft approaching Triton, Neptune’s largest moon. (Click on the picture to embiggen.) The eroded south polar cap of Triton is shown at the bottom of Triton’s image. Cryovolcanic terrain is at the upper right, and the as-yet unexplained “cantaloupe terrain” is at the upper left. Voyager 2 flew by Triton and Neptune in 1989.

Image Credit: NASA

Double Crescent


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/Voyager 2