Novas imagens de alta resolução da superfície de Mercúrio

À medida que vão sendo processadas as imagens da primeira aproximação da MESSENGER a Mercúrio, vão sendo divulgadas novas imagens de alta definição da superfície. São de esperar mais imagens nos próximos dias.

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Fonte: MESSENGER

As MESSENGER approached Mercury on January 14, 2008, the spacecraft’s Narrow-Angle Camera on the Mercury Dual Imaging System (MDIS) instrument captured this view of the planet’s rugged, cratered landscape illuminated obliquely by the Sun. The large, shadow-filled, double ringed crater to the upper right was glimpsed by Mariner 10 more than three decades ago and named Vivaldi, after the Italian composer. Its outer ring has a diameter of about 200 kilometers (about 125 miles). MESSENGER’s modern camera has revealed detail that was not well seen by Mariner 10, including the broad ancient depression overlapped by the lower-left part of the Vivaldi crater. The MESSENGER science team is in the process of evaluating later images snapped from even closer range showing features on the side of Mercury never seen by Mariner 10. It is already clear that MESSENGER’s superior camera will tell us much that could not be resolved even on the side of Mercury viewed by Mariner’s vidicon camera in the mid-1970s.

This MESSENGER image was taken from a distance of about18,000 kilometers (11,000 miles), about 56 minutes before the spacecraft's closest encounter with Mercury. It shows a region roughly 500 kilometers (300 miles) across, and craters as small as 1 kilometer (0.6 mile) can be seen in this image.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington


Just 21 minutes after MESSENGER’s closest approach to Mercury, the Narrow Angle Camera (NAC) took this picture showing a variety of intriguing surface features, including craters as small as about 300 meters (about 300 yards) across. This is one of a set of 68 NAC images showing landscapes near Mercury’s equator on the side of the planet never before imaged by spacecraft. From such highly detailed close-ups, planetary geologists can study the processes that have shaped Mercury’s surface over the past 4 billion years. One of the highest and longest scarps (cliffs) yet seen on Mercury curves from the top center down across the right side of this image. (The Sun is shining low from the left, so the scarp casts a wide shadow.) Great forces in Mercury’s crust have thrust the terrain occupying the left two-thirds of the picture up and over the terrain to the right. An impact crater has subsequently destroyed a small part of the scarp near the top of the image.

This image was taken from a distance of only 5,800 kilometers (3,600 miles) from surface of the planet and shows a region about 170 kilometers (about 100 miles) across.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

During its flyby of Mercury, the MESSENGER spacecraft acquired high-resolution images of the planet's surface. This image, taken by the Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS), was obtained on January 14, 2008, about 37 minutes after MESSENGER's closest approach to the planet. The image reveals the surface of Mercury at a resolution of about 360 meters/pixel (about 1180 feet/pixel), and the width of the image is about 370 kilometers (about 230 miles). This image is the 98th in a set of 99 images that were taken in a pattern of 9 rows and 11 columns to enable the creation of a large, high-resolution mosaic of the northeast quarter of the region not seen by Mariner 10. During the encounter with Mercury, the MDIS instrument acquired image sets for seven large mosaics with the NAC.

This image shows a previously unseen crater with distinctive bright rays of ejected material extending radially outward from the crater's center. A chain of craters nearby is also visible. Studying impact craters provides insight into the history and composition of Mercury as well as dynamical processes that occurred throughout our Solar System. The MESSENGER Science Team has begun analyzing these high-resolution images to unravel these fundamental questions.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

MESSENGER mostra pela primeira vez a face desconhecida de Mercúrio

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Quando a sonda Mariner 10 passou por Mercúrio, em 1974 e 1975, fotografou sempre a mesma metade do planeta. Agora, 33 anos depois a MESSENGER fotografou cerca de metade da face de Mercúrio que não foi observada então.

A MESSENGER ainda passará duas vezes por Mercúrio, antes de finalmente entrar em órbita do planeta, em Março de 2011.


Fonte: MESSENGER

MESSENGER’s First Look at Mercury’s Previously Unseen Side

When Mariner 10 flew past Mercury three times in 1974 and 1975, the same hemisphere was in sunlight during each encounter. As a consequence, Mariner 10 was able to image less than half the planet. Planetary scientists have wondered for more than 30 years about what spacecraft images might reveal about the hemisphere of Mercury that Mariner 10 never viewed.

On January 14, 2008, the MESSENGER spacecraft observed about half of the hemisphere missed by Mariner 10. This image was snapped by the Wide Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, about 80 minutes after MESSENGER's closest approach to Mercury (2:04 pm EST), when the spacecraft was at a distance of about 27,000 kilometers (about 17,000 miles). The image shows features as small as 10 kilometers (6 miles) in size. This image was taken through a filter sensitive to light near the red end of the visible spectrum (750 nm), one of a sequence of images taken through each of MDIS’s 11 filters.

Like the previously mapped portion of Mercury, this hemisphere appears heavily cratered. It also reveals some unique and distinctive features. On the upper right is the giant Caloris basin, including its western portions never before seen by spacecraft. Formed by the impact of a large asteroid or comet, Caloris is one of the largest, and perhaps one of the youngest, basins in the Solar System. The new image shows the complete basin interior and reveals that it is brighter than the surrounding regions and may therefore have a different composition. Darker smooth plains completely surround Caloris, and many unusual dark-rimmed craters are observed inside the basin. Several other multi-ringed basins are seen in this image for the first time. Prominent fault scarps (large ridges) lace the newly viewed region.

Other images obtained during the flyby will reveal surface features in color and in much more detail. Collectively, these images and measurements made by other MESSENGER instruments will soon provide a detailed global view of the surface of Mercury, yielding key information for understanding the formation and geologic history of the innermost planet.

MESSENGER fará a maior aproximação a Mercúrio dentro de poucas horas

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Durante esta aproximação serão tiradas cerca de 1200 fotografias. Na foto acima já são visíveis crateras, e serão de esperar detalhes muito melhores nas próximas horas.

Fonte: MESSENGER

Today, January 14, 2008, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will experience its closest approach to Mercury, passing just 200 kilometers (124 miles) above the planet's surface. As the MESSENGER spacecraft continues to speed toward Mercury, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired this crescent view of Mercury. The image was taken on January 13, 2008, when the spacecraft was at a distance of about 760,000 kilometers (470,000 miles) from Mercury. Mercury is about 4880 kilometers (about 3030 miles) in diameter, and the smallest feature visible in this image is about 20 kilometers (12 miles) across.

During the historic flyby encounter today, extensive scientific data will be gathered. The MDIS instrument will acquire over 1200 images of Mercury, including images of portions of the surface never before viewed by a spacecraft. The MDIS instrument is just one member of a whole suite of instruments that will be used to study Mercury during the flyby. The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) will observe Mercury's surface as well as its tenuous atmosphere. The MESSENGER Magnetometer (MAG) will accurately measure Mercury's magnetic field, and the Energetic Particle and Plasma Spectrometer (EPPS) will characterize Mercury's space environment and interactions with the solar wind. The Mercury Laser Altimeter (MLA) will sense surface topography along a narrow profile. The Gamma-Ray and Neutron Spectrometer (GRNS) and X-Ray Spectrometer (XRS) will make the first measurements of Mercury’s surface elemental composition.

MESSENGER will begin to transmit the new data to Earth once all of the scientific measurements are completed, about 22 hours after the spacecraft's closest approach to Mercury. These flyby data will shed light on fundamental scientific questions related to the formation and evolution of the planet Mercury. As scientists analyze the data, the MESSENGER spacecraft will continue on its planned journey, which includes two more encounters of Mercury in October 2008 and September 2009, before entering an orbit around Mercury in March 2011.

Image acquired on January 13, 2008, 06:34 UTC.