NASA probes may find remnants of moon's lost sibling

[Vartok]

Two identical NASA space probes are due to arrive at the moon this weekend to learn what is inside Earth's companion and how it formed.  Among the most interesting questions scientists will attempt to answer is if our moon holds the wrecked body of a lost sibling body.  According to a recently published paper, scientists suspect a second moon once circled Earth in the same orbit and at roughly the same speed as our moon. It eventually bumped into its companion, but instead of causing an impact crater, the second moon stuck and made a mountain. That feature today would be the lunar highlands located on the side of the moon that permanently faces away from Earth.

And I thought only sci-fi shows had double moons!

V

you can read the entire article and look at interesting historcal moon photos here


http://www.msnbc.msn.com/id/45820164/ns/technology_and_science-space/?ocid=twitter#.Tv03uVa5Ikg

[turtlesrock]

fascinating! if this is true then there's probably many many moon siblings, this would only be one of the bigger ones.

[Vartok]

Think NASA planned it to arrive on New Years Eve having launched the twin satellites 112 days ago?  somebody working OT at the center.  More on the missions below.


December 31, 2011

NASA is counting down the seconds until its twin spacecraft bound for the moon make back-to-back arrivals over the New Year's weekend.  The washing machine-size probes have been cruising independently toward their destination since launching in September aboard the same rocket on a mission to measure lunar gravity.

Approaching the moon from the south pole, the Grail spacecraft — short for Gravity Recovery and Interior Laboratory — won't land on the surface, but will survey from orbit.  On New Year's Eve, Grail-A was poised to fire its engine for more than a half hour to slow itself and get captured into orbit. Grail-B will follow suit on New Year's Day.

Deep space antennas in the California desert and Madrid will track the tricky maneuvers and feed real-time updates to ground controllers.  "The anxiety level is heightened," project manager David Lehman of the NASA Jet Propulsion Laboratory said earlier this week.

Grail is the 110th mission to target the moon since the dawn of the Space Age including the six Apollo moon landings that put 12 astronauts on the surface. Despite the attention the moon has received, scientists don't know everything about Earth's nearest neighbor.  Why the moon is ever so slightly lopsided with the far side more mountainous than the side that always faces Earth remains a mystery. A theory put forth earlier this year suggested that Earth once had two moons that collided early in the solar system's history, producing the hummocky region.

http://www.nasa.gov/mission_pages/grail/main/index.html