How do we know that aliens aren't watching us right now? We don't. There could be cloaked vessels right on our doorstep. Luckily, some intrepid souls have been creating some illustrations for our new friends. Here are some of the wackiest pictures that are visible on Google Earth.
Top image: Stop Frames of the Planet.
A portrait of Genghis Khan in Ulaanbaatar, made for the traditional Mongol festival named Naadam in 2006
From The Vitruvian Man to Asterix and Obelix, 2001-2009
In this area near Utting am Ammersee, Germany there was a copy of Leonardo da Vinci's Vitruvian Man in 2001. Eight years later, the next available satellite picture shows us Asterix and Obelix. What a waste!
The naked Cerne Abbas Giant in Cerne Abbas, Dorset, England
Its age is unclear. There aren't any written references before 1694, and an 1617 land survey doesn't tell anything about, but it could have been created in Roman or Celtic times.
A gigantic chess board measuring 400 x 400 metres (1312 x 1312 ft) , near the Kyffhäuser Monument, near Bad Frankenhausen, Germany, 2009
In 2009, Germany's number one female player, Elisabeth Pähtz played a game on this board against a virtual chess community.
The Fovant Badges near Fovant, southwest Wiltshire, England
Created by soldiers waiting to go to France, during the First World War in 1916 and 1917. 19 of the badges are lost.
Mysterious petroglyphs (rock engravings) near Llipata, Peru, made by the Paracas culture between 500 BCE and 400 BCE.
A Star of David? No, it's just a SAM (surface-to-air missile) Site at Nellis Air Force Range, Nevada
U-2 photograph of a similar place like the under construction during the Cuban Missile Crisis near La Coloma, Cuba, August 29, 1962
The 2/3 mile long (1 km) Guitar-shaped forest of Argentina's Pampas, made up from over 7,000 eucalyptus and cypress trees by Pedro Martin Ureta to memorialize his wife who passed away in 1977, when she was only 25.
"An Island in Time", near the airport in Munich, Germany, created by William Holderid in 1995.
A heart-shaped meadow near Wickwar, South Gloucestershire, UK
A farmer, Winston Howes created this tribute after the death of his wife 18 years ago, using 6000 oak saplings.
The Long Man of Wilmington apparently comes from the Iron Age, but it may have been cut in the 16th or 17th century.
A white hawk in Whitehawk, a suburb of Brighton, carved in 2001 by local artists.
Naked Woman Crop Circle, Sicilia, Italy, 2005
The world's largest (124 ft or 38 m long) fingerprint in Hove Park, Brighton, UK
A man-shaped lake in Sao Paulo State, Brazil
The world's largest portrait: Mustafa Kemal Atatürk, the first President of Turkey, near Erzincan, Turkey
This picture (it has a massive 7.5 sq km or 2.9 sq mi. size) was made by 3000 soldiers for a month only.
The Alton Barnes White Horse, 1812
(via Brian Robert Marshall)
An eagle near Camp San Luis Obispo, an old California National Guard Camp in San Luis Obispo, California
This famous sight is on the side of Guard Mountain and created by some young cadets back in the mid-1960s.
"Ni pena ni miedo" ("Neither Shame Nor Fear), written in the sands of the Atacama Desert in Chile
These four words are the world's largest poem, written by Raúl Zurita, a Chilean poet who suffered for almost two decades under Agusto Pinochet's dictatorship. The poem is 1.96 mi (3.15 km) long.
A "golden spiral" installation in Morocco, designed by the German land artist Hannsjörg Voth and architect Peter Richter, 1992-1997
(via RFHT Architecturbüro)
A World Map in Lake Klejtrup in Denmark, built by Søren Poulsen between 1944 and 1969
(via Frank Vincentz)
The 374 feet (110 m) long prehistoric hill figure, the Uffington White Horse in Oxfordshire, England
Rudolph, the Red Nosed Reindeer near Vashon, Washington
Nazca Lines, in the Nazca Desert, southern Peru, created between 400 and 650 AD.