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Fobos/Grunt is falling!

January 14th, 2012

You think living on Mars would be dangerous and difficult? Try just getting there!

Of the 38 Mars mission launched from Earth so far, exactly half of them arrived at Mars in operating condition.

A case in point is the Russian “Fobos/Grunt” (in English we would call it “Phobos/Soil”) mission launched last November that was intended to land on one of Mars’ moons, Phobos, scoop up some surface material, and then rocket the sample back to Earth. Total round-trip time: three years.

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“Gateway to the Stars” on January 7

January 3rd, 2012

We may have passed the Winter Solstice (Dec. 21, when the sun takes its lowest path across the sky) and the “Birthday of the Unconquered Sun” (Dec. 25, when the ancient Romans first noticed the sun’s path climbing higher again), but the nights are still long as winter marches on.

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2012 Perihelion

January 3rd, 2012

Happy Perihelion 2012!

Okay, so it’s not a commonly-celebrated event. Nevertheless, January 4th, 2012 is a significant date for the year, at least astronomically. Perihelion occurs on Wednesday, January 4th, 2012. This marks the time when the Earth is closest to the Sun for the year. Yes, I said closest. ‘Peri’ comes from the French for ‘near to,’ and ‘helion’ comes from the Greek for ‘Sun.’

Many people believe, mistakenly, that the Earth is farthest from the Sun in winter. However, we need to realize that when it is winter in the northern hemisphere it is summer in the southern hemisphere, and vice versa.

Earth (and every other planet) orbits the Sun in an elliptical orbit, not in a circular one. So, there will be one moment of the year when the Earth is closest to the Sun and another moment in the year when the Earth is farthest from the Sun. Those moments are known as perihelion and aphelion, respectively; and always occur around January 4th and July 4th, respectively.

Perihelion 2012

The difference in distance from the Sun between these two dates is rather small, around 5 million km, and has little noticeable effect on temperatures.