Endeavour (crater)
| Endeavour Crater | |
|---|---|
 | |
| Planet | Mars |
| Region | Meridiani Planum |
| Coordinates | 2°17′S 5°14′W / 2.28°S 5.23°WCoordinates: 2°17′S 5°14′W / 2.28°S 5.23°W |
| Diameter | 22 kilometers (13.7 miles)[1] |
| Depth | 300 meters (1,000 feet)[2] |
| Eponym | HM Bark Endeavour and Space Shuttle Endeavour |
Endeavour is an impact crater located in the Meridiani Planum extraterrestrial plain within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. Endeavour is about 22 kilometers (14 mi) in diameter.[1] Using Mars Reconnaissance Orbiter data, phyllosilicate-bearing outcrops have been detected along the rim of this crater. These minerals may have formed under wet conditions in a low-acidic environment during the early history of Mars.[3] There are raised rim segments to the north, east, and southwest. The rim has become worn, rounded and degraded, with infilling of plains material in a manner similar to the Victoria crater.[4]
When compared to the surrounding plains, the crater floor shows an enhanced spectral signature of basalt and hematite.[5] The interior contains two groups of dune fields. Images taken since 2008 show evidence of changes in some of the associated formations, which may be evidence of active erosion by the martian wind over a period of two to three years.[4] The plains surrounding the rim show evidence of polyhydrated sulfate.[5]
The Mars Exploration Rover-B Opportunity began travelling toward this crater in August 2008,[1] with the rim coming into sight on March 7, 2009,[6] and arriving at the edge on August 9, 2011.[7]
In December 2011, Opportunity Rover discovered a vein of gypsum sticking out of the soil along the rim of Endeavour crater. Tests confirmed that it contained calcium, sulfur, and water. The mineral gypsum is the best match for the data. It likely formed from mineral-rich water moving through a crack in the rock. The vein, called "Homestake," is in Mars' Meridiani plain. It could have been produced in conditions more neutral than the harshly acidic conditions indicated by the other sulfate deposits; hence this environment may have been more hospitable for a large variety of living organisms. Homestake is in a zone where the sulfate-rich sedimentary bedrock of the plains meets older, volcanic bedrock exposed at the rim of Endeavour crater.[8]
Nomenclature
The name of the crater, and features of it, are based on the voyage of HM Bark Endeavour, a British Royal Navy research vessel commanded by Lieutenant James Cook on his first voyage of discovery, to Fiji, New Zealand and Australia from 1769 to 1771, using Australian places named by James Cook. Examples include: Cape Dromedary, Point Hicks, Byron Bay, Cape Tribulation, Cape Byron, and Cape York.[9] The purpose of the voyage was to observe the transit of Venus, to accurately measure the distance to the Sun, then to explore lands found on the return journey.
Opportunity
Since August 2008, Mars Exploration Rover-B Opportunity has been travelling toward this crater.[1][10] Craters that have been explored by Opportunity include Victoria crater which is 750 meters (0.47 miles) in diameter, Endurance crater which is 130 meters (0.08 miles) in diameter, and Eagle crater which is 22 meters (0.01 miles) in diameter.[11][12][13]
On March 7, 2009 (sol 1,820), Opportunity first saw the rim of Endeavour after driving about 3.2 kilometers (2.0 mi) since it left Victoria in August 2008.[6][14] Opportunity also saw Iazu crater, which is about 38 kilometers (24 mi) away and about 7 kilometers (4.3 mi) in diameter.[14] At that time, Opportunity was 12 kilometers (7.5 mi) from Endeavour as the Martian crow flies, but to avoid hazards, it was estimated that it would take about 30% more driving distance than that to reach Endeavour.[6] Based on the amount of time it had taken to drive from Victoria, it was estimated that this journey would take over one Martian year (23 months).[6] On May 5, 2010, to avoid hazardous dune fields along the direct path between Victoria and Endeavour, the charted route between the two craters was extended to an estimated 19 kilometers.[15]
On September 8, 2010, it was announced that Opportunity had reached the halfway point of the 19-kilometer journey between Victoria crater and Endeavour crater.[16] By June 28, 2011, Opportunity was just under 2 kilometres (1.2 mi) from landfall at the rim of Endeavour crater.[17]
On August 4, 2011, Opportunity was only 120 metres (390 ft) from the rim of Endeavour,[18] and on August 9, 2011 Opportunity arrived at the west rim near Spirit Point to study outcrops never seen before.[7] It explored the northwest outcrops of the crater for about 2 Earth years, before heading south Solander Point.[19]
Craters visited by Opportunity
See also
References
- ↑ 1.0 1.1 1.2 1.3 "NASA'S Mars Rover to Head Toward Bigger Crater". NASA/JPL. 2008-09-22. Retrieved 2009-03-20.
- ↑ "Road Trip Gets Under Way". NASA/JPL. 2008-09-24. Retrieved 2009-04-27.
- ↑ Wray, J. J. et al. (November 2009), "Phyllosilicates and sulfates at Endeavour Crater, Meridiani Planum, Mars", Geophysical Research Letters 36 (21), Bibcode:2009GeoRL..3621201W, doi:10.1029/2009GL040734
- ↑ 4.0 4.1 Chojnacki, M.; Burr, D. M.; Moersch, J. (March 2010), "Recent Dune Changes at Endeavour Crater, Meridiani Planum, Mars, from Orbital Observations", 41st Lunar and Planetary Science Conference, held March 1–5, 2010, The Woodlands, Texas, p. 2326, Bibcode:2010LPI....41.2326C
- ↑ 5.0 5.1 Chojnacki, M.; Moersch, J.; Wray, J. J.; Burr, D. M. (March 2010), "The Stratigraphy, Composition and Thermophysical Properties of Endeavour Crater, Meridiani Planum, Mars, from Orbital Remote Sensing", 41st Lunar and Planetary Science Conference, held March 1–5, 2010, The Woodlands, Texas, p. 2175, Bibcode:2010LPI....41.2175C
- ↑ 6.0 6.1 6.2 6.3 "One Mars Rover Sees A Distant Goal; The Other Takes A New Route". NASA/JPL. 2009-03-18. Retrieved 2009-03-20.
- ↑ 7.0 7.1 "NASA Mars Rover Arrives at New Site on Martian Surface". NASA/JPL. 2011-08-10. Retrieved 2011-08-10.
- ↑ http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-403_Mars_Rover_Gypsum.html
- ↑ NASA Mars Rover Seeing Destination in More Detail, NASA media release, 29 June 2010, accessed 25 July 2011
- ↑ Rahl, A.J.S (2008-10-31). "Spirit "Bumps" a Move, Opportunity Puts the Pedal to the Metal". Planetary Society. Retrieved 2009-03-20.
- ↑ "NASA Rover Nears Martian Bowl Goal". NASA/JPL. 2006-09-06. Retrieved 2009-03-20.
- ↑ "Press Release Images: Opportunity". NASA/JPL. 2004-05-03. Retrieved 2009-03-20.
- ↑ "NASA Facts: Mars Exploration Rover". NASA/JPL. 2004-10-24. Retrieved 2009-03-26.
- ↑ 14.0 14.1 "One Mars Rover Sees A Distant Goal; The Other Takes A New Route". NASA/JPL. 2009-03-18. Retrieved 2009-03-20.
- ↑ "Opportunity's Long and Winding Road to Endeavour Crater". Universe Today. 2010-05-05. Retrieved 2010-08-04.
- ↑ "Opportunity Rover Reaches Halfway Point of Long Trek". NASA/JPL. 2010-09-08. Retrieved 2010-09-11.
- ↑ "Opportunity Is Just Over a Mile From Crater Rim". NASA/JPL. 2011-07-08. Retrieved 2011-07-08.
- ↑ "Nearing First Landfall of Large Crater". NASA/JPL. 2011-08-04. Retrieved 2011-08-08.
- ↑ NASA - Sol 3351
External links
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