Sky

Using Google Earth to find a dark sky

May 7, 2014

The best stargazing occurs when you live in an area with very little artificial light, and the Bortle Dark Sky Scale is a great tool to measure it. Here is an example:

To get a rough idea of what the light is like in the areas around you, Ethan Siegel at Medium.com has put together a nice process for adding Bortle data to Google Earth. Once you follow their steps, you can zoom in anywhere in North America (or other areas with other maps) to see Bortle values for that region.

You can also try it in a browser by loading this map from Jonathan Tomshine.

If you can’t find a dark area near you, you can always use Google Earth to do your star gazing for you. The incredible night sky feature will take you to the stars, and the “starry sky” released last year gives you a beautiful view around the planet.

When you have a chance, make sure to read Ethan’s full post at Medium, as it does an excellent job of digging into the Bortle Scale and exactly how to use Google Earth to determine the Bortle value for your area.

The next generation of satellites for Google Earth

February 17, 2014

To understand how images make it from satellites in orbit to Google Earth, you should take a look at Frank’s excellent about Google Earth imagery post from a few years ago. In short, Google doesn’t own any satellites that capture imagery; they buy the imagery from providers such as DigitalGlobe.

With that in mind, Richard Hollingham of the BBC took a trip to Ball Aerospace in Boulder, Colorado, where the WorldView-3 satellite is currently being assembled for DigitalGlobe.

WorldView-3 will be able to capture imagery at a remarkable resolution of just 25cm, though only the US government can purchase imagery that detailed. For Google Earth (and similar mapping projects, such as Bing Maps), the imagery will be released at a resolution of 50cm. As the article points out, from more than 600km away, travelling at around eight kilometres per second, capturing an image half-a-metre across is an impressive technical achievement, and is less likely to raise concerns about privacy.

It’s an excellent article that shows a bit more about how things work in regards to satellite imagery, and I recommend you check out the full story for yourself.

All of the views from the “Gravity” movie in Google Earth

January 27, 2014

Over the years we’ve shown you many great articles from Stefan Geens at OgleEarth. He’s shared geotagged hiking trips, the destruction of the city of Kashgar, the path of the Chelyabinsk meteor, imagery of Osama bin Laden’s compound, and much more.

Now he’s back with an amazing post that maps out all of the views from the motion picture “Gravity” onto Google Earth.

He’s taken 62 screenshots from the movie and compiled them all into this 8.8MB KMZ file for you to use in Google Earth. Here are a few of his thoughts on it:

Gravity‘s daytime Earth is a highly accurate rendering. I was in almost all cases able to get a perfect match, not just for coastlines, but also for geographic features such as lakes, mountain ranges and forests. … The rendering of Earth at night is geographically just as accurate, but city lights and lit roads are impressionistic rather than realistic.

…

Here’s how I made that KMZ file: The biggest clue to getting an accurate placement for the screenshots in Google Earth is the film’s opening line of text: “At 600km above Planet Earth…” This was a great help, for fixing the viewpoint above Earth at this height proved to be accurate and removed a major variable from the process. Another big clue was the Earth’s curved horizon in a screenshot. Matching the horizon removed two more degrees of freedom (tilt and field of view), leaving only a horizontal plane across which to match the angles of the landscape.

Stefan put an amazing amount of work into tracking down all of these views, and the result is stunning. His post goes into much greater detail about the process and shows off many more the photos, and we highly recommend you go check it out for yourself.

Great work Stefan!

What is that mystery object on Google Moon?

January 21, 2014

A recent story on the Daily Mail claims to have found a “craft” on Google Moon. While you certainly should take anything from that site with a grain of salt, it’s indeed an interesting image:

So what could the image be? The “object” is likely to be a visual anomaly possibly caused by light from the sun cast on rocks that happen to appear regular at certain angles, and also a function of the resolution of the imagery. There have been similar sightings in the past, such as the famous “face on Mars” from years ago, which also turned out to be a trick due to resolution of imagery, processing, and lighting.

You can check it out for yourself by loading this KML file. Be sure to enable the “featured satellite images” layer in Google Moon in order to see this particular image.

What do you think it might be?

(via Daily Mail)

Exploring the moon in Google Earth

August 23, 2013

While hundreds millions of people have used Google Earth over the years, many aren’t aware of some of the great things it can do. One of those is the ability to explore our moon, which is an excellent feature to have. Google first introduced this feature back in 2009, and it’s still amazing to see.

Just look for the little planet icon in the upper middle of Google Earth and you’ll see an option titled “Moon“. The moon in Google Earth changes the virtual globe into a 3D rendition of the moon. The terrain of the moon is in 3D and there are layers telling you more about the moon.

Here’s a screenshot that Frank took a few years ago showing the Apollo 11 landing site:

The first thing you should check out in the Google Earth moon mode is the awesome Apollo 11 tour found in the layers under: Moon Gallery->Guided Tours->Apollo 11. This tour is narrated by Andrew Chaiken and Astronaut Buzz Aldrin and is one of the best illustrations of the Apollo 11 mission I’ve seen to date!

Here is a YouTube video introduction of Moon in Google Earth by Google:

When this feature first came out, Frank was fortunate enough to be on hand for the official announcement, and he mentioned quite a few thoughts and features about this new piece of Google Earth. After you finish reading that, head into Google Earth and try it out for yourself if you never have before.