These two huge L-shaped structures visible at a very low zoom level are the LIGO (Laser Interferometer Gravitational-Wave Observatory) facilities in Livingston, Louisiana and Hanford, Washington.

Each arm of the structures is 4km in length, making them longer than the Stanford Linear Accelerator Centre we visited some time ago here on Google Sightseeing, which is the longest building in the United States. However, the LIGO structures appear to be low concrete tunnels, so aren’t officially buildings.

The observatories are an attempt to detect cosmic gravitational waves, the existence of which was predicted by Einstein in 1916. Almost 100 years later, scientists are still searching for direct evidence of these waves which are thought to originate from supernovas and other astrophysical events.

The science involved is far beyond the comprehension of this writer (who failed high school physics) but here’s what I can figure out. Lasers housed in the main building at each complex (Livingston, Hanford) pass through ultra high vacuums housed in each of the tunnel arms and bounce back-and-forth on mirrors at the end of each arm a number of times.

Along the way they pass through interferometers before returning to the main building. If a gravitational wave happens to hit the Earth during this process, the laser beams will be out of step with each other, allowing the wave to be measured. The 3,002km distance between the observatories is equivalent to 10 milliseconds at the speed of light, which would allow triangulation of the source of any waves detected.

However, the measurements involved are so incredibly minuscule that the one of the main challenges faced by the scientists is learning how to distinguish actual wave measurements from random movements in the mirrors caused by minor earth tremors, vehicles on nearby roads, or (one assumes) something as simple as a mouse running over the concrete tube.

I’m totally out of my depth once I start reading about alteration of space-time, cosmic strings and other wonders, so if you want to learn more, Wikipedia is a good place to start, while the official LIGO site has options ‘for scientists’ and ‘for all’. There’s also an introductory video on Youtube.

Thanks to punk floyd, Joel Koerwer, Nicolas Ward and Rich Holmes.

Looking up at the moon, one of the most striking visible features has to be the sheer number of impact craters around its surface. These giant holes in the ground are made by asteroids and comets flying through space and then crashing into our little satellite.

Of course many of these are easy to see without any special equipment, so for many years scientists on Earth wondered if we can see them all so easy up there, why can’t we see them down here on our planet? Then along came aerial photography…

GSS visited some of the most recognizable impact craters on Earth already, including Barringer Meteor Crater in the United States and Manicouagan Impact Crater in Canada, but updated and enhanced imagery makes these sites worth a second visit.

We start our tour with the largest verified impact crater on Earth, Vredefort Crater in South Africa. Measuring a staggering 250 – 300 km (155 – 186 miles) across, this crater was formed over 2 billion years ago by an asteroid estimated 10 km (6 miles) in size.

Today, the most recognizable feature of the crater is the northwest rim that created the mountains near the town of Parys. Vredefort was also added to the list of UNESCO World Heritage Sites in 2005.

Our next stop is a crater in southern Northern Ontario, Canada near the city of Sudbury. The Sudbury Basin was formed by a meteorite impact 1.85 billion years ago, creating a round 250-km (155 miles) crater.

Subsequent geological processes like tectonic plate movement then stretched into its current oval shape, which is hard to see on the satellite image. However, the crater shape is strikingly obvious when using Google’s terrain mapping. It is the second largest verified impact site on the planet.

Perhaps the most famous meteorite impact of them all is the one that slammed the Earth in the Yucatán Peninsula of Mexico, and also is the one that scientists believed killed 75% of the species on Earth including the dinosaurs¹.

About 65 million years ago, a 10 km (6 mi) wide meteorite slammed into the Earth and created a 180 km (110 mi) wide crater centered just off the coast of present day Mexico in the Gulf of Mexico. Today, the south to southeast rim can still seen with Google’s satellite maps if you know where to look. The Chicxulub crater is the third largest verified impact crater on the planet.

Be sure to check out the other GSS articles on impact craters and other natural landmarks, including the Kebira Crater. Check Wikipedia for more information about the Vredefort Crater, Sudbury Basin, or the Chicxulub Crater. Since there are so many sites around the Earth, we’ll be sure to have more crater articles soon!

Roughly 1 out of every 5 countries in the world are completely surrounded by land, or landlocked. In a handful of cases a country can be completely surrounded by another single country. These landlocked enclaves are such a rare geographic occurrence that there are only three such countries in the world.

The Republic of San Marino

The unique thing about visiting an enclave is that no matter where you’re coming from, you must travel through another country first, in this case Italy. San Marino is one of the smallest countries in the world, only 60 sq km (23.5 sq mi) in total area, ranking it number 221 out of 233 countries (and outlying territories) in total size.

The Kingdom of Lesotho

An enclave within the country of South Africa, Lesotho’s other most interesting geographical feature is that its lowest point is the highest of any country in the world! Lesotho also produces one of the most striking visual borders we’ve seen on Google’s satellite images, due to the change in vegetation as you pass from Lesotho’s west side to South Africa.

Vatican City

The smallest sovereign state in the world, Vatican City is an enclave not just inside Italy, but also inside the city of Rome. This is also the world’s only walled enclave, since its small border is marked almost entirely with a city wall.

Of course it’s also home to the Pope and the governing body of the Roman Catholic Church, and although not commonly known as its own country, Vatican City offers clergy, guard members and other workers optional citizenship; they generate their own income from tourist sales; and they even issue their own Euro coins.

Be sure to check out other enclave/exclave GSS articles like Point Roberts, USA, Complicated borders featuring the split personality town of Baarle-Hertog/Baarle-Nassau, and Interesting Exclaves of the United States.

Also check out Wikipedia for more information about landlocked countries, San Marino, Lesotho, and Vatican City!

This week Google launched an absolutely massive update to Street View in Hong Kong, Macau, and in particular, the UK. With an incredible 96% of British roads now visible, there were always going to be scandals about what was discovered.

While some are making objections to the passing car in their own special way, others aren’t really understanding the nature of the technology.

This woman was inside when she spotted the Google car, and leapt up to expose her bra through a window at the passing car.

However she probably failed to realise that – while the existence an anonymised picture of you flashing your underwear isn’t a particularly risky thing in itself – having a picture of you posted on Google Maps while flashing your underwear at work is probably another matter.

Update: We’ve been contacted by the business owner, and it turns out this is indeed a farm nursery after all. In fact, they think it’s as funny as we do, and the woman involved will not be disciplined in any way.

For all the very latest funny and shocking Street View sightings, you should follow us on Twitter!

In an absolutely enormous update, Google have in the last few minutes launched brand new Street View images for the whole of the UK – bringing the total coverage to a reported 96% of all UK roads.

The images cover roads from Land’s End to John o’ Groats, and actually extend all the way beyond, right up into Shetland.

Google have recorded images of a further 210,000 miles of roads, bringing the total to approximately 246,985 miles of coverage.

We expect lots of new fascinating and probably scandalous sights to be discovered in the next couple of days, so be sure to leave a comment with a link to anything you find!

Update: This update also provided imagery for Hong Kong and Macau.

For all the very latest funny and shocking Street View sightings, you should follow us on Twitter!