Category Archives: Astronomy 101

One of my main goals is to try and share a bit of knowledge and understanding about the incredible universe. I have been steadily writing and posting various articles to explain and educate the masses (that’s you, dear reader!) a bit more about some of the science behind the hobby. An urban astronomer might never see most of the things we talk about here, but it’s still good to know about them.

Do all planets spin in the same direction?

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Dear Urban Astronomer Do all planets spin the same way, or are there some planets where the sun rises in their equivalent of West? Does it depend on the particular solar system? What about the stars in a galaxy — do they all spin in the same direction? Do all galaxies spin the same way, or do they even spin at all? Regards Amanda Dominy (extracted from Facebook conversation) Dear Amanda First, the short answer: All rotations and revolutions in … Continue reading →

What is a Blood Moon?

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A few days ago, I was asked on facebook to explain what a Blood Moon was.  I’d heard the term before, but never as an astronomical term so I went online and googled it.  It seems that they are supposed to be incredibly rare events, but that according to the “Blood Moon Prophecy”, there will be a tetrad of them of them in 2014.  This is considered to be a hugely significant thing, and is being used to sell a … Continue reading →

What is the temperature of Space?

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Dear Urban Astronomer So, my good friend and I were talking about the temperature in space. He thinks it must be hot in space, since there is no atmosphere to absorb sunlight. I disagreed. I think that the fact that there is no air in space, means there is nothing to heat up. That’s how temperature on earth works. So, surely it must be cold in space. Can you shed light (excuse the pun) on this debate? Can you answer … Continue reading →

How long is a year on Jupiter?

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The planet Jupiter takes 4331.6 earth days to orbit around the Sun. This means than one Jupiter year equals almost 11.9 Earth years. Because Jupiter rotates so rapidly around its axis, its year lasts 10,501 of its own days. Jupiter has such a long year because it is quite far from the Sun. Not only does this mean it has a longer path to travel on its orbit, but the Sun’s gravity is much weaker at that distance, requiring it … Continue reading →

How long is a year on Mars?

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The planet Mars takes 687 Earth days to orbit the Sun. This means that a martian year lasts 22.9 months, or almost two full Earth years. A martian day is only very slightly longer than an Earth day, so that Mars’ year is 670 martian days long. Mars’s year is longer than Earth’s because it is further from the Sun than Earth is, so that it feels the Sun’s gravity more weakly than the Earth does. This means that it … Continue reading →