Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2003 August 22 
Posted on 08/21/2003 9:50:29 PM PDT by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2003 August 22
Explanation: As the Sun sets, the Earth's shadow rises up from the east. The subtle beauty of this daily apparition is often overlooked in favor of the brighter, more colorful western horizon. But while gazing toward a nearly full rising Moon on August 9, astronomer Steve Mandel admired the shadow rise from his driveway near Soquel, California, USA. His view looks east from the northern tip of Monterey Bay toward Fremont Peak, the highest point in the small mountain range on the horizon. The Earth's rising shadow is cast through the dense atmosphere and is seen in his picture as the dark blue band along the horizon, bounded above by a pinkish purple glow or antitwilight arch. Also known as the Belt of Venus, the arch's lovely color is due to backscattering of reddened light from the setting Sun.
NASA seeks public suggestions for Mars photos
NASA NEWS RELEASE
Posted: August 20, 2003
Earth comes closer to Mars this month than it has in nearly 60,000 years, but one new opportunity for seeing details on the red planet comes from a vantage point much closer.
The public has an unprecedented opportunity to suggest places on Mars that should be photographed from a spacecraft orbiting that planet. Camera operators for NASA's Mars Global Surveyor spacecraft are ready to take suggestions online for new places for images from the Mars Orbiter Camera.
The spacecraft, managed by NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., has been orbiting Mars since 1997, with more than 20,000 orbits so far. The Mars Orbiter Camera has already taken more than 120,000 pictures of Mars. Many of the camera's images have sharp enough resolution to show features as small as a school bus. The images have revealed relatively recent gully erosion, ancient sedimentary rocks and many other spectacular scientific surprises.
"We've only covered about three percent of the surface area of Mars with the high-resolution camera. We want to be sure we're not missing some place that could be important, so we're casting a wide net for new suggestions," said Dr. Ken Edgett, staff scientist at Malin Space Science Systems, the San Diego firm that supplied and operates the camera for NASA. "We're looking for excellent suggestions of areas on Mars that we have not already imaged," Edgett said. "We'll look at every request that comes in."
"NASA's Mars Global Surveyor spacecraft team will examine each request to ensure the safety of this priceless 'eye in the sky' above Mars," said Dr. Jim Garvin, NASA's Lead Scientist for Mars Exploration at NASA Headquarters, Washington.
Information about how to submit requests is online at the new Mars Orbiter Camera Target Request Site, at: http://www.msss.com/plan/intro
Requesters should describe the purpose for the suggested image. Suggestions for target sites already imaged by the camera will be disqualified unless there is a convincing reason for repeating the target. An online gallery of pictures taken by the camera is at: http://www.msss.com/moc_gallery/
"Some of the best requests may be places nowhere near any site the Mars Orbiter Camera has imaged before," Edgett said. As with pictures desired by Mars scientists working with the camera every day, new suggestions will need to wait until the Mars Global Surveyor flies directly over the selected target, which could be several months or longer. The first images from this public suggestion program will probably be released this fall.
JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Office of Space Science in Washington. JPL's industrial partner is Lockheed Martin Space Systems, Denver, which developed and operates the spacecraft. Malin Space Science Systems and the California Institute of Technology built the Mars Orbiter Camera. Malin Space Science Systems operates the camera from facilities in San Diego.
Hubble has viewing plans for 'close encounter' with Mars
SPACE TELESCOPE SCIENCE INSTITUTE NEWS RELEASE
Posted: August 20, 2003
NASA's Hubble Space Telescope (HST) will make observations of the planet Mars on Aug. 26-27, when Earth and Mars will be closer together than they have been in the last 60,000 years. As soon as Hubble's high-resolution images of the Red Planet are received at the Space Telescope Science Institute (STScI) and are digitally processed by the Mars observing team, they will be released to the public and news media via the Internet.
High-resolution files for downloading will available on HubbleSite News Center at http://hubblesite.org/newscenter/2003/22, beginning at 6 a.m. EDT Aug. 27.
The Hubble images will be the sharpest views of Mars ever taken from Earth. They will reveal surface details as small as 17 miles (24 km) across. Though NASA's Mars-orbiting spacecraft can photograph the Red Planet in much finer detail, Hubble routinely serves as a "weather satellite" for tracking atmospheric changes on Mars and for probing its geology on a global scale.
Unlike "real-time" viewing through ground-based telescopes, Hubble observations are carried out automatically by the orbiting observatory. Free of clouds and atmospheric distortion, Hubble is guaranteed a front- row seat to the celestial close encounter. To study the planet's geology and weather, Hubble's Wide Field and Planetary Camera 2 will take separate images of Mars through as many as 10 different color filters. Hubble's unique ultraviolet- light sensitivity will allow it to trace ozone and water vapor in the Martian atmosphere.
The images will be stored in an onboard computer, transmitted to the Goddard Space Flight Center in Greenbelt, Md., and then to the Space Telescope Science Institute. Once received at STScI, the images will be calibrated and combined to make a natural, full-color view of Mars. A key image-processing step will be to combine and register images taken through different filters. Because Mars rotates a little between each Hubble exposure, each separate picture must be precisely aligned to make a color image. This means several hours will elapse from the time of a Hubble observation to the assembly of a full-color image.
Two close-approach images will be posted on the Internet on Aug. 27.
The first view, taken the evening of Aug. 26, when Mars is 34,648,840 miles (55,760,220 km) from Earth, will be posted as a full-resolution color image for downloading after approximately 6 a.m. EDT.
In the second image, taken within an hour of "closest approach," Mars will be merely 1,400 miles closer than the previous exposure. It will be at its closest distance of 34,647,420 miles (55,757,930 km). The resolution will effectively be the same as in the earlier image.
The image-processed color pictures will be posted on the Internet after 4 p.m. EDT Aug. 27. Mars researchers Jim Bell of Cornell University in Ithaca, N.Y., and Michael Wolff of the Space Science Institute in Boulder, Colo., will be at STScI and available for media interviews beginning at 5 a.m. EDT Aug. 27.
The Space Telescope Science Institute (STScI) is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for NASA, under contract with the Goddard Space Flight Center, Greenbelt, MD. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA).
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