MARS: A SIGHT TO BEHOLD!
INTERNATIONAL BREAKING NEWS, August 28, 2003 (GLOBE & MAIL) - Mars attracts! Sight to behold!!
[Photo: AP/NASA) - NASA's Hubble Space Telescope took this snapshot of Mars 11 hours before the planet made its closest approach to Earth. The two planets are 55.7 million kilometres apart]
Astronauts reacted with jubilation Wednesday at new pictures of Mars taken by the Hubble Space Telescope, saying the planet's close pass to Earth enabled the Hubble to capture "quite spectacular" images.
"We've never seen this kind of resolution in Hubble images, that kind of detail," said Cornell University astronomer Jim Bell said, pointing to a canyon wall on the Valles Marineris, a giant canyon that runs 4,480 kilometres across the red planet.
The Baltimore-based Space Telescope Science Institute, which operates the telescope, released the first Hubble images of Mars early Wednesday. The pictures were taken late Tuesday and early Wednesday as the as the planet made its closest pass by Earth in 60,000 years.
"They are quite spectacular. You knew they were going to be good; seeing them is something else," said Michael Wolff, an astronomer with the Space Science Institute in Boulder, Colo., who was also on hand for the release.
The images, taken when Mars was about 55.4 million kilometres from Earth, show surface details as small as 27 kilometres across.
"These are the best that have ever been, and will ever be taken with the Hubble Space Telescope," Mr. Wolff said.
Scientists will now study the pictures in detail, and there's hope that the images will lead to new discoveries, Mr. Wolff said.
"Before we were looking at broad areas and things tend to get averaged out," Mr. Wolff said. "There's the possibility something we missed before will be there."
While spacecraft orbiting Mars can show objects in greater detail, they often cannot make an image of the entire planet at once, or at all times of the Martian day, Mr. Wolff said.
Earth-bound telescopes, meanwhile, have to deal with the distorting effects of the Earth's atmosphere. The Hubble also has instruments that allow it to capture wavelengths the spacecraft orbiting Mars cannot see.
Surf was never up on Mars
Washington — Researchers said there is virtually no evidence of limestone formation on Mars, a finding that suggests the Red Planet never had oceans or seas.
That conclusion, however, does not alter the possibility of life on Mars, experts said.
Philip Christensen of Arizona State University said an instrument on NASA's Mars Global Surveyor that searched the entire planet for evidence of carbonate found only trace amounts of the limestone-like mineral.
The finding means it is unlikely Mars ever had oceans of water as some scientists have suggested, he said.
"Maybe instead of calling them oceans, we should call them glaciers," said Mr. Christensen.
"A frozen ocean will not form carbonate. I believe Mars has a lot of water but it is cold and frozen most of the time."
"That is consistent with what we have seen."
Other Mars experts said the finding makes a significant contribution to the continuing debate among scientists about how much water there was on Mars, where did it go and how did the planet's intricate patterns of river beds, carved canyons and delta fans form without huge volumes of flowing water.
"This is dramatically important," Matt Golombek, a geologist with the Jet Propulsion Laboratory, the lead agency in NASA's program of Mars exploration, said of the new study.
He said there is clear evidence water flowed on Mars in the past but yet, the thin atmosphere and frigid temperatures of the planet now make liquid surface water impossible. This suggests Mars was once warmer and wetter and with a denser carbon-dioxide atmosphere. The new finding by the Arizona State researchers shows that may not have been the case, said Mr. Golombek.
"If you had a warmer, wetter, thicker atmosphere, you would expect to find carbonate somewhere and so far we haven't found it," he said.
"This geochemical information is in direct contradiction to an early warmer, wetter Mars."
In the study, Mr. Christensen and his co-authors, Joshua Bandfield and T.D. Glotch, used a Global Surveyor spacecraft instrument called the thermal-emission spectrometer, or TES, that was designed to search for evidence of carbonate minerals on Mars.
Carbonate is formed in the presence of water and carbon dioxide. On Earth, the mineral is found in the immense deposits of limestone that are present on every continent, in soils and layers of stone formed beneath some lakes, seas and oceans.
Mars's atmosphere is mostly carbon dioxide, so it has long been believed if the planet at one time had large bodies of water, then there would have been large deposits of carbonate. But the TES found only trace amounts of the chemical.
Mr. Christensen said even though there may not have been large bodies of liquid water on Mars, some lifeforms could still have evolved.
"When people say there are no oceans or lakes, does that mean there was no life? Not at all," he said.
"There's the possibility that ice and snow on Mars melted from time to time, forming those gullies and then refreezing again."
Areas where this happened on Mars, he said, "are excellent potential abodes for life and certainly worth looking at."
Mr. Golombek agreed, noting around the edges of large deposits of ice there are small areas of liquid water that could host life.
"On Earth, there are growing communities of microbes that live at the edge of glaciers where you get flashes of water, even though the dominant feature is ice," he said.
Ross Irwin, a geologist with the Smithsonian Institution, said the new finding does not eliminate the possibility conditions on Mars once allowed for large bodies of standing water on the Red Planet.
He said geological features on Mars, such as basins and river beds, were clearly carved by running water and it is possible any carbonate formed was carried beneath the surface of the planet, beyond the detection range of the TES.
"Lots of basins have been resurfaced on Mars," said Mr. Irwin.
"Carbonate could be in the subsurface or buried beneath sediment. There could be extensive carbonate deposits that are difficult to locate."
Reported by: Sol Jose Vanzi
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