Astronomy Archives

July 20, 2005

We welcome our galactic google overlords.

Google has mapped the moon. Just don't get too close. I think it might be limberger.

November 5, 2005

A different pair of eyes

As you are probably aware from the potential of microwaves to cause your cup of coffee to boil over, the universe is filled with electromagnetic waves which are largely invisible to us. Sometimes they reveal quite interesting things. The "Cool Cosmos" site shows a number of photos of the sun and moon using different wavelengths in the electromagnetic spectrum. The xray photo's of the sun look like it has spent a few too many minutes in the microwave and is starting to explode.

Oh, and by the way, on a clear night Mars is shining brightly right now. Apparently it is as close to the Earth as it is going to be for many years.

February 28, 2006

How to buy a telescope

After looking at the high resolution versions of the 200 megapixel view of the Pinwheel Galaxy taken by the Hubble Space Telescope


and seeing the effects of light pollution on urban skies - as an example compare these two images taken during and after the 2003 Eastern North America Blackout:

I have concluded that for looking at the stars the best view can be obtained not with any telescope which you can buy in a store, but simply by buying a computer and getting a fast internet connection.

Trying to see the details of constellations and other cosmic wonders through a backyard telescope is rather like producing an international news broadcast by walking around with your video camera. Doing so might be fun, but the results are not comparable to what you can find simply by googling for a few minutes.

Thanks to the "Bad Astronomer", Phil Plait for pointing me to the image of the Pinwheel Galaxy.

August 16, 2006

Massive Planetary Inflation - plutons held responsible

You know you are getting old when candy you bought for a nickel when you were a kid is 65 cents. In comparison moving from 9 planets to "maybe 12" with potential for millions (imagine the wheelbarrow you would need to carry that many planets!) is bound to happen over a few billion years, but is not something you expect in a single lifetime - but it has.

The International Astronomical Union is working out a defintion of "planet" in order to cope with some recently discovered objects which are larger than Pluto and are orbiting the sun. Apparently, until now there has been no scientific defintion of planet. But the discovery in 2005 of 2003 UB313 (nicknamed Xena) which orbits the Sun every 557 years or so has pretty much forced the issue.

Now at their annual conference, the IAU has issued some guidelines for the definition of planet:

  1. A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet.
  2. We distinguish between the eight classical planets discovered before 1900, which move in nearly circular orbits close to the ecliptic plane, and other planetary objects in orbit around the Sun. All of these other objects are smaller than Mercury. We recognize that Ceres is a planet by the above scientific definition. For historical reasons, one may choose to distinguish Ceres from the classical planets by referring to it as a “dwarf planet.”
  3. We recognize Pluto to be a planet by the above scientific definition, as are one or more recently discovered large Trans-Neptunian Objects. In contrast to the classical planets, these objects typically have highly inclined orbits with large eccentricities and orbital periods in excess of 200 years. We designate this category of planetary objects, of which Pluto is the prototype, as a new class that we call “plutons”.
  4. All non-planet objects orbiting the Sun shall be referred to collectively as “Small Solar System Bodies”.

For a more scholarly take on the rules and the potential loopholes in them I encourage you to visit Phil Plait's "Bad Astronomy".

UPDATE: Things change. Pluto is no longer a planet

March 1, 2007

Time for Pi

It is probably not important, but...

There are roughly pi*10e7 seconds in a year.
Combine this with the fact that light travels 300,000Km/second and it makes it easier to remember that a light year is around 9 trillion kilometers.

June 22, 2008

Longest and Shortest Day of the Year


Summer is finally here in the Northern Hemisphere - Friday being the longest day of the year and one of the hottest so far. However, we should not forget that it is the beginning of Winter in the Southern Hemisphere.

About Astronomy

This page contains an archive of all entries posted to Project in the Astronomy category. They are listed from oldest to newest.

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