The Earth and Moon are slowly moving apart. The moon’s distance from the Earth is not constant, because the Moon’s orbit is not perfectly circular. Over the course of a month the moon comes as close as 363,000 km and as far as 405,000 km due to the eccentricity of its orbit. However its average distance is slowly increasing.
Blood Moon
This week those of us in the western hemisphere will have the chance to observe a lunar eclipse. It will happen in the evening/morning of April 14/15, reaching peak darkness at about 3 a.m. EDT (0600 GMT). Depending on the darkness of your sky, the Moon may be invisible to the naked eye, or it may appear as a dark, blood moon.
Broken World
The view of Earth from space often evokes thoughts of an Eden. That pale blue dot that cradles humanity. But our planet’s fragile beauty was born from violent collisions large and small.
Rocking the Moon
Back in September of 2013 a bright flash was observed on the surface of the Moon. It was soon found that this was due to a meteor impact on the lunar surface. Now an analysis of this impact has been published in the Monthly Notices of the Royal Astronomical Society.
That’s No Moon
Cruithne is a small, rocky body about 5 kilometers across. It was discovered in 1986, and it is sometimes referred to as Earth’s second moon. The argument for calling it a moon of Earth is because it is gravitationally bound by the Earth, just like the Moon. But Cruithne doesn’t orbit the Earth, so what exactly is going on? The answer has to do with some interesting complexities of orbital dynamics.