Earth's companion is so large and fascinating that geologists count the Moon as one of the solar system's "terrestrial planets." In fact, it was probably born from Earth, after a Mars-sized body collided with the proto-Earth, in a collision so violent that the Moon that coalesced from the leftover fragments was entirely (or almost entirely) molten. We can tell this story of Earth and the Moon's creation thanks to our analysis of the rocks returned to Earth by the Apollo astronauts, Luna landers, and chance discoveries of lunar meteorites. New laboratory techniques yield new discoveries every year even though no samples have been collected from the surface of the Moon since 1972.
In the years since the end of the space race between the United States and Russia, many other nations have sent robotic spacecraft to orbit the Moon as a first step in their planetary exploration: Japan, the European Space Agency, India, and China. Likewise, many people see a staging station on the Moon as a necessary first stepping stone toward sending humans on missions to asteroids or Mars. Thanks to the combined data from lunar orbiters from all nations we know that there is water stored in lunar soil and that there are permanently sunlit peaks at the lunar poles, providing for two basic needs of human settlements: water and power. We can go back to the Moon; but who will make the effort?
Recent Blog Articles About the Moon
A few days ago, I wrote a post about the basins of the Moon -- a result of a trip down a rabbit hole of book research. Here's the next step in that journey: the Geologic Time Scales of Earth and the Moon.
A baby Moon and aging Venus crescents are positioned close in the sky today, and lots of people are taking beautiful photos.
Here it is: the view from Saturn of our Earthly home, one and a half billion kilometers away. We see Earth and the Moon through a thin veil of faintly blue ice crystals, the outskirts of Saturn's E ring. Earth is just a bright dot -- a bit brighter than the other stars in the image, but no brighter than any planet (like Saturn!) in our own sky.
Posted by Emily Lakdawalla on 2010/04/02 02:41 CDT
Here's the first cool pic I've managed to produce from the recently-released Lunar Reconnaissance Orbiter Camera data set.
Deepak Dhingra reports on a planetary analog field trip exploring a very young volcanic terrain in Idaho at Craters of the Moon National Monument and Preserve.
An asteroid or comet headed for Earth is the only large-scale natural disaster we can prevent. Working together to fund our Shoemaker NEO Grants for astronomers, we can help save the world.