National Geographic Museum Blog

Today we’ll share more mysteries of the Mona Lisa as revealed by the work of the French scientific engineer Pascal Cotte with his multispectral camera.

1. Her glance is a very different look from that which is seen today.
2. The reduction of the cracks on the lips and the eyes suggests a probable restoration or the varnish lightening in color with age.
3. Her face, slightly wider than today shows us how Leonardo constructed the painting and the first expression of Mona Lisa.
4. Her smile is more expressive and more marked, showing perhaps the first intention of Leonardo da Vinci.
5. The drawing of the veil; never seen before with such definition. This most likely indicates Leonardo’s painting method to underline the border of the veil.

Bog Turtle – approximately 18,100
Glyptemys muhlenbergii
Zoo Atlanta, Atlanta, Georgia

America’s tiniest turtle, the palm-size bog turtle, now survives mostly on private lands from Massachusetts to Georgia. Adapted to soggy soils, the species suffers where wetlands are filled or groundwater is diverted, and significant numbers end up as roadkill.

Puerto Rican Crested Toad – less than or equal to 2,400
Peltophryne lemur
Sedgwick County Zoo, Wichita, Kansas

Puerto Rico’s only native toad species is disappearing in the wake of development, primarily for tourism. Cats, dogs, pigs, nonnative toads, and fire ants also prey on or compete with the crested toad. A captive breeding program of about 400 offers a chance to rebuild.

Check out this little guy and other threatened species in Rare: Photographs by Joel Sartore on display through October 12, 2010.

Whooping Crane – 539
Grus americana
Audubon Nature Institute, New Orleans, Louisiana

Once overhunted, these magnificent national treasures are now carefully monitored to prevent their total annihilation. Captive breeding and migration training have saved the whooping crane, but collisions with power lines along migration routes and reduced genetic diversity still trouble the species.

Pascal Cotte; French scientific engineer and inventor of the multispectral camera, was granted the privilege to photograph the famous Mona Lisa in the Louvre Museum, Paris. Taking her out of her frame, she was photographed with incredible definition of 240 million pixels. The specially created giant infrared print on display is a result of his photographic scientific examination. It is a masterpiece in its own right.

An infrared ray has the optical properties to penetrate inside the picture layer and show us what is behind each apparent layer. Analysis of the pictorial findings educates us immensely in many interesting areas such as retouching, restorations, under drawings, pigments etc.

1. The Mona Lisa was painted on poplar board and it can be seen in its entirety. We can see the pictorial layer limits as well as the preparation (Gesso). This now proves that the board was never cut.
2. The restoration made to the top of the sky and the numerous small alterations.
3. The split of 4.3 inches in the board and the 2 superimposed restorations.
4. The fine double thickness of the head veil, sometimes attributed by error to a cap.
5. The blotch or blot or mark on the corner of the eye is a varnish accident – we also find one on the chin. This contradicts the hypothesis that Mona Lisa was sick!

Texas Blind Salamander – less than or equal to 1,150
Eurycea rathbuni
Detroit Zoo, Detroit, Michigan

Conserve water, don’t dump toxins, and monitor development. Those are ways to save this vulnerable species, says the International Union for Conservation of Nature. Harmful fertilizers can make their way into the bodies of these sightless salamanders, which occur only in the Edwards aquifer of San Marcos, Texas.

In his notebooks, Leonardo da Vinci often used “mirror writing.” He wrote from right to left in a backwards script that is readable if held up to a mirror. Some speculate that Leonardo was trying to be secretive about his notes. However, he may also have been avoiding smearing wet ink, as he was left-handed. Try writing “Leonardo da Vinci was a genius” in mirror writing, and share your efforts on our Facebook page.

You can see more examples of his writing at the Da Vinci – The Genius exhibition.

Red Wolf – less than or equal to 330
Canis rufus
Great Plains Zoo, Sioux Falls, South Dakota

The U.S. Fish and Wildlife Service captured the remaining 14 wild red wolves in the 1970s to start a captive breeding program. The species was kept alive and now over 100 of these animals roam free in North Carolina. Unfortunately, their numbers are again dwindling. They interbreed with coyotes and are also frequently shot as they roam outside of the few protected areas that remain.

“The trouble is, where do you put a far-roaming predator these days without it getting shot? Many that have been released have died of acute lead poisoning when they came into contact with guns and intolerance. Among endangered species fanatics, the story of the red wolf is high drama. For this book, my encounter came in the dead of winter at a zoo in Sioux Falls, South Dakota. And though they’ve spent all their lives in captivity, the wild is still in their eyes. You get the feeling that their kind could make it again in the wild, if only we would let them.” – Joel Sartore, photographer

Leading up to our Solar Oven Workshop on July 11 at 1pm we are doing periodic features about solar technology.

This week’s post is all about solar street lights! Many versions have been designed and produced – some for the developing world and some for the developed world.

Check out some examples below.

1. For a little bit of whimsy, check out designer Ross Lovegrove’s solar trees, which debuted in Vienna a few years ago.

2. Featured in the Design for the Other 90% exhibition is the StarSight, which goes beyond street lighting to include Internet access in a wireless configuration. Designed by Kolam Partnership Ltd in 2007, it is currently in use in Cote d’Ivoire, Republic of Congo, and Cameroon.

Clay’s Hibiscus – less than or equal to 75
Hibiscus clayi
U.S. Botanical Garden Production Facility, Washington, D.C.

Found only on the island of Kauai, Hawaii, this striking member of the mallow family can grow up to 26 feet tall. Cattle destroyed much of the original habitat. Now protected, the few remaining wild trees are still threatened by competing plants, a nearby hiking trail, and rats, which eat the seed.