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.

Will an astronaut explode if he takes off his helmet?

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We’ve all seen it happen in science fiction films. The expendable character is outside the space ship, or trapped in the air-lock.  The space suit is damaged, or the helmet is removed.  His friends frantically bang on the glass as we get a nice close-up of his face as it blows up like a balloon.  And then… well it depends on the film.  Sometimes he freezes solid and shatters like glass, other times he explodes in a messy shower of … Continue reading →

Is there life on Mars?

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Andrew Versfeld writes:   Dear Urban Astronomer The author of this URL (http://www.rdrop.com/users/tblackb/life_on_mars/life_on_mars.htm) claims to be in possession of actual photographic proof that there is life on mars. As you can imagine, I was, and still am very skeptical. But this got me thinking about other forms of life. I’ve heard rumours of bacteria and other unicellular organisms on mars. This leads me to my question.Have scientists actually found bacteria on mars?Could life actually survive on Mars?     Before … Continue reading →

How many people have walked on the Moon?

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Twelve.  There were six successful moon missions (Apollo 11, 12, 14, 15, 16 and 17), and each of these had a crew of three.  One crew member stayed in orbit in the command module, while the other two landed the lunar module, and walked on the Moon’s surface.  Everybody remembers the names of the two men who landed in the first mission (Neil Armstrong and Buzz Aldrin), but hardly anybody remembers that the third man was Michael Collins.     … Continue reading →

How can I learn about Astronomy?

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There are lots of ways to learn astronomy.  You can join an astronomy club and learn from the members, or you could enroll in a course at a local school, or community college, or university.  Or you could simply take the time to read up on it on the Internet or in your local library.  These are all good methods, but your choice will depend partly on what’s most easily available, whether you’re prepared to spend a lot of money, … Continue reading →

What does a star’s colour mean?

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Stars are hard to study because, apart from the Sun, they are so far away that they appear as nothing more than geometric points of light.  All that we can measure about this light (without getting complicated and breaking out the spectrometer) is its brightness and its colour, but fortunately this is enough for us to work out quite a lot about the star.  Its colour, for example, tell us how hot the star is at its surface. If you’ve … Continue reading →