Lights Out!

Royal Astronomical Society; Aug. 13, 2001; Press Release: "First Global Atlas of Artificial Night Sky Brightness Shows How Humans are Enveloping World in 'Luminous Fog'"

U.S.A.: Hopeless in the East.

In a paper recently accepted for publication in the "Monthly Notices of the Royal Astronomical Society," researchers from Italy and the U.S. present quantitative data on the effects of light pollution for the first time. They believe light pollution has consequences not only for astronomy, but as "one of the most dramatic changes occurring in our natural environment," it will impact the whole biosphere.

E.U.: Awash in light.

University of Padua, researchers Pierantonio Cinzano and Fabio Falchi, with Boulder, CO, based Chris Elvidge of NOAA, have produced the "First World Atlas of Artificial Night Sky Brightness." This dramatic atlas displays global light pollution contours calculated at sea-level, to eliminate altitude effects and make it easier to discern more light-polluting regions of the world. The researchers started with nighttime satellite images from the US Air Force Defense Meteorological Satellite Program. Using calculations of artificial light propagation, they created a set of maps showing the global severity of the problem. Many areas that appeared dark on the raw satellite images were found to be affected by light pollution from neighboring locals.

These results were quantified to arrive at the following facts:

Japan: Looks like a glow-worm

Light pollution affects 99% of the population in the U.S. and European Union. Two-thirds of the world's population also suffers from light pollution. For 97% of the U.S. population the sky is always at least as bright as when lit by a half-Moon. For the E.U. this is 96% and the rest of the world 50%. Seeing the band of the Milky Way in the nighttime sky is not possible for more than two-thirds of the U.S. population. The numbers are 50% for the E.U. population and 20% for the rest of the worlds population. A stunning 40% of the U.S. population cannot become dark adapted under the "night" sky. This is also true for one-sixth of the E.U. population and one-tenth of the world's population.

Australia: Don't change!

The atlas images are available on the web at The Night Sky in the World Homepage.

"Large number of people in many countries have had their vision of the night sky severely degraded. And our atlas refers to the situation in 1996-97. It is undoubtedly worse today, " says Dr Cinzano.

Images here are from the "World Atlas of Artificial Sky Brightness".  Credit: P. Cinzano, F. Falchi (University of Padova), C. D. Elvidge (NOAA National Geophysical Data Center, Boulder). Copyright Royal Astronomical Society. Reproduced from the Monthly Notices of the RAS by permission of Blackwell Science.

Thar She Blows!

Cosmiverse.com; Aug. 14, 2001; Space News: "Mars Rovers May Blow in the Wind"

Houston, we are 'go' for penalty kick!  NASA/JPL

What climbs up steep slopes, tumbles over boulders, and is driven by the wind? Answer: a 2-story "tumbleweed ball" that may roll over the Martian surface, powered by the Martian breeze. JPL scientists are now conducting tests on such contraptions, in hopes they will be able to go where traditional ground rovers can't.

The great many boulders, apparent on images from Mars, make navigation difficult for all types of ground vehicles. Initial experiments with small beach ball sized "tumbleweed" rovers on Earth didn't get far. They would get lodged against knee and waist-high rocks typical of Mars.

A serendipitous accident in the Mojave Desert, with a multi-wheeled rover that carried man-sized spherical tires, was an inspiration to a rover-testing team. When one of the tires broke off the rover, the 20-mile an hour wind took the big ball fast and far across the boulder-strewn dessert and up steep sand cliffs. According to technician Tim Connors: "It went a quarter of a mile in nothing flat." He knew, because he tried to chase it down in an ATV.

This event inspired tests with a scaled down, 1.5 meter-tall "tumbleweed" this summer.  They confirmed that a 6-meter balls would be able to surmount meter tall rocks and scamper up 25-degree slopes -- all done with only the thin, breezy Martian air.

Science payload on a deployed "tumbleweed" could contain magnetometers, water-seeking radar, and cameras. In order to stop at a location the ball could be made to partially deflate -- like a flat tire. Once finished with a location, it would re-inflate and get back on the move.

As an added bonus, the ball might be made to withstand a bounce landing on the Red Planet, like the airbags used on the successful mini-rover deploying Mars Pathfinder mission of a few years back.

Orville & Wilbur -- The "Wright" Stuff

NASA/Ames; Aug. 13, 2001; Press Release: "Ames Completes Successful Test of Mars Airplane Prototype"

As a follow-up to test flights conducted last month by "Wilbur", "Orville" made a successful test flight this August. The flight director concluded that "it was a great flight and everything went really well. It appears that we realized all of our test objectives." Hey -- since when did the history of the Wright brothers include a "flight director" at Kitty Hawk, NC?

"Orville" -- NASA/Ames

It turns out that we aren't reminiscing about events from early last century but recent test flights of high-tech gliders dubbed "Wilbur" and "Orville." Like the Wright brother's aerial craft, these machines are part of a series of tests that will evolve into powered airplanes, but they won't be flying over the sands of Kitty Hawk: they'll be flying over the sands of Mars! Designed as robotic survey craft, they'll be no pilots onboard.

Test flights for this NASA/Ames project, named "Kitty Hawk 3", were conducted from a balloon 101,000-feet above the state of Oregon. The extreme altitude was needed to confirm the aerodynamic qualities of the remote-controlled "Orville" glider in a thin atmosphere similar to that of Mars. These tests confirmed the craft to be a stable platform for scientific payloads.

Actual payload on the Mars plane may include detectors for water and high-resolution cameras. "During a Mars airplane mission, we will be able to view the planet at very close proximity and this will convey to the public that there is a real planet there, not just an abstract," says project manager Larry Lemke.

"Orville" has a 4-foot fuselage with 8-foot wingspan. The mission aircraft will be too bulky for transport to the Red Planet. The next version will have folding wings and an engine powered propeller version will follow afterwards.

Asteroid Had Impact on Dino Evolution

Reuters; Aug 14, 2001; Newswire: "Did asteroid help dinosaurs rule Earth?"

End of an era -- NASA

Millions of years ago, on an Earth that did not yet know large mammals or modern seed-bearing plants, there was a brilliant flash in the sky followed by shock waves traveling through the air and ground. Dust, from a great crater gouged in the Earth, circled the planet and blotted out the sunlight. Mass global extinction followed for many species of plants and animals on land and sea. Ironically, this die-off of life ended the Triassic period -- a period that had been marked by evolutionary experimentation in life forms. But this life-extinguishing event, caused by a giant asteroid or comet, cleared the way for the dominance of a surviving species, one that we all know and love. For the deaths that closed the Triassic period paved the way for the dominance of the dinosaurs in the Jurassic periods.

Yes, you read that right. Various documentaries, live-action movies, and cartoons have instilled the notion in the popular culture that dinosaurs ruled Earth until they were wiped out by the sudden climatic changes, caused by a large impact on the Earth. As a result, the planet was safe for the evolution of mammals and eventually man. Now, a new theory claims the dinosaurs clawed their way to the top of the food chain with the help of an earlier impact that wiped out their competitors. "The Triassic-Jurassic boundary wiped out the competitors to the dinosaurs. It's only after the boundary that you get a dinosaur-dominated ecosystem," says dino expert Paul Olsen, a Columbia University paleontologist.

The fossil record tells us that dinosaurs evolved from reptiles about 230-million years ago. At that time there were many species competing with them. Among them were the dominant carnivorous reptiles as well as reptilian herbivores. The dinosaurs that lived in this late-Triassic era were much smaller than those from the latter Jurassic era.  The Jurassic beasts are more well-known to the public, having been immortalized in such popular films as "Jurassic Park".

The mass extinction that ushered in the dino dominance of the Jurassic period happened 200-million years ago, and the party ended 65-million years ago when the dinos were made part of the next mass extinction. In the popularly known latter case, at the boundary of the Cretaceous and Tertiary, evidence points to the location of the impact crater near the Yucatan peninsula. But the former Triassic-Jurassic impact lacks that sort of evidence. Samples of shocked quartz from that era, caused by a sudden increase in pressure over a short time, are being sought around the world in order to confirm the extinction event was caused by a sudden impact. One piece of evidence that supports an impact at the Triassic-Jurassic boundary is the sudden rise in the number of fern plants. This suggests the quickly reproducing ferns replaced forests that had been suddenly destroyed over a large area.