A Near Record Ozone Hole in 2003

A Near Record Ozone Hole in 2003



As expected, the ozone hole near Earth's South Pole is back again this year.This year's hole, being slightly larger than North America, is larger than last year but short of the record set on 2000 September 10 Ozone is important because it shields us from damaging ultraviolet sunlight. Ozone is vulnerable, though, to CFCs and halons being released into the atmosphere. Inte national efforts to reduce the use of these damaging chemicals appear to be having a positive effect on their atmospheric abundance. The relatively large size of the ozone hole this year, however, is attributed partly to colder than normal air in the surrounding stratosphere. The above picture of the ozone hole was taken on September 11 by TOMS on board the orbiting Earth Probe satellite.

Apollo 12 Visits Surveyor 3

Apollo 12 Visits Surveyor 3



Apollo 12 was the second mission to land humans on the Moon.The landing site was picked to be near the location of Surveyor 3, a robot spacecraft that had landed on the Moon three years earlier.In the above photograph, taken by lunar module pilo Alan Bean,mission commander Pete Conrad jiggles the Surveyor spacecraft to see how firmly it is situated.The lunar module is visible in the distance. Apollo 12brought back many photographs and moon rocks. Among the milestones achieved byApollo 12 was the deployment of the Apollo Lunar Surface Experiments Package, which carried out many experiments including one that measured the solar wind.

X-Ray Moon

X-Ray Moon



This x-ray image of the Moonwas made by the orbitin ROSAT Röntgensatellit) Observatory in 1990.In this digital picture, pixel brightness corresponds to x-ray intensity.Consider the image in three parts:the bright hemisphere of the x-ray moon,the darker half of the moon,and the x-ray sky background.The bright lunar hemisphere shine in x-rays because it scattersx-rays emitted by the sun.The background sky has an x-rayglow in part due tothe myriad of distant, powerful active galaxies, unresolvedin the ROSAT picture but recently detected in Chandra Observator x-ray images.But why isn't the dark half of the moon completely dark NewChandra results also suggest that a few x-rays only seemto come from the shadowedlunar hemisphere.Instead, theyoriginate in Earth's geocorona o extendedatmosphere which surrounds the orbiting x-ray observatories.

Cold Comet Halley

Cold Comet Halley



While this may not be the most esthetic image o Comet Halleythat you have ever seen, it is likely the most unique.The tiny cluster of pixels circled is th famouscomet along its orbit over4 billion (4,000,000,000) kilometers or 2 AUfrom the Sun - a record distance for a comet observation.Its last passage throug our neck of the woods in 1986 Comet Halleypresently cruises through the dim reaches of the outer solarsystem, almost as far away as outermost gas giant Neptune, and shows nosign of activity.Captured in March, this negative image is a composite ofdigital exposures made with threeof ESO's Very Large Telescopes.The exposures are registered on th moving comet, so thepicture shows background stars and galaxies as elongated smudges.An earth-orbiting satellite appears as a dark streak at the top CometHalley is clearly extremely faint here, but large earthboundtelescopes will be able to followit as it grows fainter still, reachingthe most distant point in its orbit, more than 5 billion kilometers(35 AU) from the Sun, in 2023.