Neptune’s Great Dark Spot

Definition

Neptune's Great Dark Spot is a massive storm system located in the planet's southern hemisphere. It was first observed by the Voyager 2 spacecraft in 1989 and has similar characteristics to Jupiter's Great Red Spot.

5 Must Know Facts For Your Next Test

1. The Great Dark Spot is an anticyclonic storm, meaning it rotates counterclockwise in Neptune's atmosphere.
2. Unlike Jupiter’s more stable Great Red Spot, Neptune’s Great Dark Spot appears and disappears over shorter periods of time.
3. The storm spans roughly 13,000 km (8,000 miles) in diameter, comparable to Earth's size.
4. The Great Dark Spot was not visible during Hubble Space Telescope observations in 1994, suggesting it had dissipated or evolved.
5. In addition to the primary spot, smaller storms and bright cirrus-like clouds often accompany the Great Dark Spot.

Review Questions

• What type of atmospheric phenomenon is Neptune’s Great Dark Spot?
• How does the stability of Neptune’s Great Dark Spot compare to Jupiter’s Great Red Spot?
• What happened to the Great Dark Spot when observed by the Hubble Space Telescope in 1994?

Related terms

Great Red Spot: A persistent high-pressure region on Jupiter producing an anticyclonic storm, visible as a large red spot.

Voyager 2: A NASA space probe that conducted flybys of Jupiter, Saturn, Uranus, and Neptune providing detailed images and data about these planets' atmospheres.

Anticyclonic Storm: A weather system with winds spiraling outward from a center of high pressure, rotating clockwise in the Southern Hemisphere and counterclockwise in the Northern Hemisphere on Earth.