Discoveries

The Fluffy Stuff of Comets

Scientists used to call comets "dirty snowballs." Now they call them "snowy dirtballs." But comet Tempel 1, it seems, is
all fluff.

The Deep Impact team, which smashed a probe into Tempel on July 4, has finished its first homework assignment. Scientific surprise #1: the 9-mile-long Tempel comet is just a loose collection of very fine dust and ice, held together by gravity. Said one Deep Impact scientist, "You could probably dig from one side to the other with your hands--it's that weak."

Scientific surprise #2: infrared measurements taken by the Spitzer Space Telescope at the moment of Deep Impact's deep impact show that, inside, Tempel contains a relatively high concentration of organic compounds, including methyl cyanide. And biologists say methyl cyanide is key to the reactions that form DNA.

Many scientists have long thought that comets are made of the primordial stuff that existed when the solar system formed some 4.6 billion years ago. Many also think that frequent collisions with water-bearing comets in those early times brought Earth its oceans--and perhaps the organic chemicals necessary for life, too. The fluffy stuff inside Tempel may well have strengthened their case.

Pin the tail on the comet

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Spray-On Skin

Doctors may now have a way to spray new skin tissue onto people with severe burns. Hospitals in Australia have already used the technique on some patients. So has a team in England. Now they're looking to see whether the sprayed-on skin becomes a fully functional part of the human body.

Doctors say the technique works like this. First, they take some healthy skin from the patient, separate out the surface cells, and culture those cells in a lab. Then, they take more healthy skin from the patient, and cut it into tiny squares. The cultured cells are then put in a suspension and sprayed onto the tiny squares, where they combine, amazingly, to form new skin.

Of course, a healthy human body makes new skin for itself all the time. The top layer of your epidermis is pretty much a patchwork of dead skin cells. You shed millions and millions every day, and new cells grow all time to take their place. In fact, on average, you completely regenerate your epidermal skin once each month.

Beneath your regenerating epidermis, your dermis houses the thicket of blood vessels, nerves, and glands you need to stay sensitive (touchy-feely) and cool (perspiration before inspiration). The thickness of the two layers together varies a lot, from as little as half a millimeter on your eyelids to as much as 4 millimeters on your palms and soles. A layer of subcutaneous tissue, mostly fat, anchors your skin to everything else. It's crucial, too, for nutrients and insulation. But doctors aren't likely to make spray-on fat.

Get under your own skin

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Mysterious Matisse Reemerges

New York's Museum of Modern Art has acquired "The Plum Blossoms," a major painting by French master Henri Matisse. Worth at least $20 million, the painting's whereabouts have been unknown for 35 years.

Painted in 1948, "The Plum Blossoms" was last publicly displayed in Paris in 1970. After that, an unidentified private collector purchased it, and the rest of the world largely lost track of the work. Then, this summer, a Manhattan art dealer approached the Museum of Modern Art about buying the piece. The museum jumped at the chance to add "a monument of art" to its collection.

Many consider Matisse the most important French painter of the 20th century. Born into a middle-class family in 1869, he showed little interest in art until he was 20 years old. Yet by 40, he was a recognized leader of the Parisian avant-garde. At a time when many questioned "modernist" artistic sensibilities, that didn't always win him fans. One early critic accused him of "mistreating square meters of canvas." Those meters are now worth millions.

Matisse's later years were less Parisian avant-garde, more French Riviera--but he never stopped experimenting with new means of expression, including colorful paper cutouts that are now as famous as his paintings. Of those paintings, "The Plum Blossoms" is one of the last Matisse made before his death in 1954. It once hung in his studio in the south of France. Now it will hang in the Museum of Modern Art's collection of nearly 100 Matisse works.

Explore MoMA's Matisse collection online

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"Discovery consists in seeing what
everyone else has seen and thinking
what no one else has thought."
--Albert Szent-Györgyi,
winner of the Nobel Prize
for Medicine in 1937

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Sight of the Week:
Satellites See Katrina's Effects

Hurricane Katrina's horrible effects are sadly clearer than they were 10 days ago, when many believed that New Orleans had been spared a direct hit. It was not spared. Nor was Gulfport or Biloxi in Mississippi, or Mobile in Alabama, or many other areas along the Gulf Coast.

For an unfiltered overview of Katrina's effects, check out these satellite photos from the National Oceanic and Atmospheric Administration (NOAA). They are compiled into maps that you can click on to zoom in, with a remarkable amount of detail.

See satellite photos of Hurricane Katrina's effects

Zoom in on New Orleans's north side

Zoom in on New Orleans's south side

Michael Himick and Steve Sampson
September 9, 2005