Practical Astronomy Magazine - Free Download eZine

Practical Astronomy Magazine - Free Download eZine



For anyone with the slightest interest in the night sky and/or astronomy! Become a member and subscribe for free and get access to back issues and other cool stuff on this site! But it's a time-limited offer folks, so get there now or be square!

Also, if you have a mind to, and can actually write worth a whit, they you can also write and submit your own articles for consideration. Wouldn't it be cool to be published in this magazine? I'm going to have to try this out myself!

From Practical Astronomy's about page:

About Practical Astronomy Magazine

Practical Astronomy magazine was founded in 2009 and has always been distributed for free, using digital download from the internet.

Its primary driver is to encourage amateur astronomers worldwide, to share their observations and astronomical experience. So far, contributors from at least ten countries have been published in the magazine.

Contact (and send images/articles for publication) to Kevin Brown: editor@practicalastronomy.com

The magazine is published by Structure Ltd (a UK registered company) in pdf format, making it readable and printable by most computers in the World.

It’s been assigned the International Standard Serial Number ISSN 2042-2687, by the British Library.

Here’s a message from the editor..

The title “Practical Astronomy” just about sums-up my personal Astronomy ethos. So I thought, I really should help create this regular, downloadable magazine.

Magazine Editor, Kevin Brown

The objective (!) is to share practical astronomy techniques and news…

And also, encourage you to get outside and do some observing!

Thank You,

Kevin Brown FRAS

PlanetQuest - the number of Exoplanets Found is about to skyrocket!

PlanetQuest: Exoplanet Exploration

NASA's JPL/CalTech website reports the current exoplanet count at 453 as of June 19, 2010. The number of stars with planets is a bit lower and stands at 385, meaning that some stars have more than one planet orbiting them.

The image below is a screen shot (from this author's screen) of a widget for your desktop and can be downloaded from the PlanetQuest Planet Counter page. It will keep you current on the hunt for exoplanets, but you'll have to have Yahoo! Widgets installed to make it work.

As soon as the recent first data set from the Kepler mission, which is devoted to finding exoplanets (particularly, Earth-like planets), is fully analyzed, the count of exoplanets is sure to skyrocket. But right now, the data set, just released to the public, reports 306 exoplanet "candidates." That means those candidate explanets must still be confirmed before adding them to the official exoplanet count.

Look Up And See Into The Past

There's a curious thing about looking up, especially if you happen to be looking up at a clear, dark night sky - you can literally see into the past! Now, this applies to things in the sky other than clouds and bats - things like stars, planets, and galaxies.

But before we get to the crux of the matter, you have to realize that light travels at about 186,000 miles (300,000 km) per second - that would be about 7 times around the Earth in one second. Now, that's pretty fast, but not infinetly so. And since the distances we are considering are significantly greater than 186,000 miles, you can see that it is going to take time for light to travel those immense distances.

The Moon is about 240,000 miles (384,00 km) away. Divide that by 186,000 and you get the appromately 1.3 seconds that light takes to travel from the Moon to Earth. So that means whenever you look a the Moon, you are seeing it as it was 1.3 seconds ago. Well, that's not so bad, you say? Harumpn, Big deal!

But it gets better, really! When you look at the Sun, you are seeing it as it was about 8 minutes ago. Do the math: 93,000,000 miles (distance from Earth to the Sun) divided by 186,000 (speed of light per second) = 500 seconds = about 8.3 minutes. Keep in mind that the light you see Now actually left the Sun about 8.3 minutes ago and is just now getting to your eyes. So, when you see the Sun rise, it actually rose 8.3 minutes ago. And if the Sun were to suddenly go supernova, we wouldn't know it until 8.3 minutes later because the light from the supernova event would take over 8 minutes to get here.

But we're not going to stop here,... because it just keeps getting sooo much better.