Scientists reveal knowledge of Mercury

This photo of Mercury revealed subtle color differences.

QUICK FACTS:

MESSENGER traveled 2 billion miles.

1,200 images collected.

Last information from Mercury came in 1975 from Mariner 10.

Mercury is only 5 percent of the Earth's mass.

Mission cost $446 million, including the launch.

Spacecraft holds seven science instruments.

In October, Messenger will flyby again and eventually orbit Mercury by 2011.

Some 85 percent of the planet's surface has now been seen.

MERCURY BECOMING KNOWN TO SCIENTISTS.

Scientific knowledge of Mercury has grown tremendously since the Jan. 14 flyby of the planet by NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging
(Messenger) spacecraft.

A revelation included knowledge that one side of the planet is more heavily cratered than the other.

"That shows pretty much that there has been a lot of volcanic activity on Mercury," said Robert Strom, Messenger science team member.

"This cratering record is going to give us a lot clues about the geologic evolution of Mercury."

Strom worked on the Mariner 10 project in 1975 and is excited about the depth of knowledge coming from Messenger.

"Wait until we go into orbit (in 2011)," he added. "The best is yet to come."

One instrument revealed details about Mercury's magnetic field.

"Among the inner planets, only Mercury has a magnetic field like the Earth's," said Sean Solomon, Messenger principal investigator.

Instruments also revealed Mercury has a very thin atmosphere. "The molecules don't even collide with one another," he said.














This feature, called "the Spider," shows the variation of features on Mercury, which has features five kilometers high. The planet seems to have had volcanic activity, and its atmosphere is so thin that the molecules do not bump together.

View NASA's images of Mercury.