the outer planets
DESCRIPTION
The Outer Planets. Uranus, Neptune and Pluto. Uranus. About 4 times diameter of Earth 3 billion km (1-3/4 billion miles) from Sun 84 Years to Circle Sun Rotates in 16 hours Five large satellites (500-1500 km), ten smaller ones Nine narrow rings. Uranus. Uranus from Voyager. - PowerPoint PPT PresentationTRANSCRIPT
The Outer Planets
Uranus, Neptune and Pluto
Uranus
• About 4 times diameter of Earth• 3 billion km (1-3/4 billion miles) from Sun• 84 Years to Circle Sun• Rotates in 16 hours• Five large satellites (500-1500 km), ten smaller
ones• Nine narrow rings
Uranus
Uranus from Voyager
The Rings of Uranus
Uranus Shows Little Detail
Oberon
Titania
Umbriel
Ariel
Miranda
Neptune• About 4 times diameter of Earth- a bit
smaller than Uranus• 4.5 billion km (2.8 billion miles) from Sun• 165 Years to Circle Sun• Rotates in 18 hours• One large satellite (2700 km), seven smaller
ones• Four narrow rings
Neptune: A Twin of Uranus?
No!
The Great Dark Spot
Neptune and Triton
Neptune’s Rings
Triton
Pluto• At 2300 km, Pluto is the smallest planet• Has most elliptical orbit: ranges from 4.4 to
7.4 billion km from Sun (2.8-4.5 billion miles)
• Actually crosses orbit of Neptune; closer to Sun than Neptune until 2009
• Orbits in 248 years, 1.5 times Neptune• Because of orbital tilt and resonance,
cannot collide with Neptune
Pluto and Charon• Pluto’s moon Charon is almost half as big as
Pluto (1100 km)• Orbits only 20,000 km away• Pluto and Charon always keep same face to
each other (rotation locked)• Pluto rotates, and Charon revolves, in 6.4
days
Pluto and Charon
Pluto Has Three Moons
Why We Have to Go There
Plutinos and the Kuiper Belt• The Kuiper Belt is an outer ice asteroid belt,
probably the source of most comets• Hundreds are now known orbiting beyond
Neptune, some beyond Pluto• Pluto is just the biggest of these objects
and not really a planet• Several dozen have periods similar to
Pluto’s - 250 years - and have been dubbed “plutinos.”