New "planets" rhyme

[Dr Mordrid]

Courtesy of 4th-grader Maryn Smith, the winner of the National Geographic planetary mnemonic contest, it covers the 11 worlds defined as "planets" - 8 major and 3 minors;

Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto and Eris

My Very Exciting Magic Carpet Just Sailed Under Nine Palace Elephants

[High_Jumbllama]

This is the first I have heard of Ceres.

[cjolley]

I was surprised too.
But Ceres is round.
Possibly because of a thick water layer, but still it qualifies.

[Dr Mordrid]

Possibly because of a thick water layer, but still it qualifies.

Not water, ice. Enough ice that when melted it could fill the Atlantic Ocean. Mean temp = -108C, max temp = -34C.

This makes it a major target for deep space missions. All that ice plus a reactor could allow us to build a fuel depot providing enough water, hydrogen and oxygen to motor us around the solar system almost forever.

This is the first I have heard of Ceres.

Ceres is very likely a residual proto-planet that never collected enough mass to grow larger than it is, about 974.6 km. This is mainly due to the gravitational pull on the surrounding asteroid belt by Jupiter.

NASA recently launched DAWN, a probe to both Ceres and the large asteroid Vesta. DAWN is powered by 3 ion-drives similar to those used on Deep Space 1. This will give it the ability to change orbit, maneuver around both bodies and change the mission on the fly in an extended mission.

DAWN is in ion cruse for the next 8 years on a 3 BILLION mile trip. This is necessary because the required trajectory is an increasingly wide spiral around the sun from Earth space to the asteroid belt.

Link to the DAWN homepage here

[cjolley]

Not water, ice.

More correctly "water ice" since "ice" does not necessarily denote H2O.
The point is that I didn't know whether the origin of it's shape was because it's gravity is strong enough to form a rocky body into a sphere or just because Ceres had a liquid water surface while it was forming.
It's pretty small (center body):