BEYOND IOWA: TWIN INSTRUMENTS ORBITING THE MOON

Nasa's 'gravity twins' are now circling the moon.
A BBC science reporter, Jonathan Amos, writes::  "This will help scientists refine our theories for how the Moon formed.
It will also enable them to test new ideas, such as the provocative suggestion made earlier this year that there were probably two moons in the sky above Earth billions of years ago". The twins have been named the Grail Twins.

"Grail is a journey to the centre of the Moon and it will use exceedingly precise measurements of gravity to reveal what the inside of the Moon is like," the Massachusetts Institute of Technology (MIT) researcher said.
"This information will be combined with the plethora of remarkable observations of the Moon that have been taken by other satellites before, and together they will enable us to reconstruct the Moon's early evolution.""...gravity differences are the result of an uneven distribution of mass. Obvious examples at the Moon's surface include big mountain ranges or deep impact basins, but even inside the lunar body the rock will be arranged in an irregular fashion, with some regions being denser than others.
All this will have a subtle influence on the pull of gravity sensed by the over-flying spacecraft.
The Grail twins will make their measurements by carrying out a carefully calibrated pursuit of each other."  For the entire article, click here

There are many who believe we should put all funds into holding onto what we have now and see no reason for space research.  However, they are very short sighted.  To understand why space exploration is so important, I suggest you read this article by NASA. This from the text:  "For its part, the United States has much at stake. Pulitzer Prize winning historian William Goetzmann saw the history of the United States as inextricably linked with exploration. "America has indeed been 'exploration's nation,'" he wrote, "a culture of endless possibilities that, in the spirit of both science and its component, exploration, continually looks forward in the direction of the new." The space exploration vision must be seen in that context."