Endeavour (crater)

Endeavour Crater
Planet Mars
Region Meridiani Planum
Coordinates 2°17′S 5°14′W / 2.28°S 5.23°W / -2.28; -5.23Coordinates: 2°17′S 5°14′W / 2.28°S 5.23°W / -2.28; -5.23
Diameter 22 kilometers (13.7 miles)[1]
Depth 300 meters (1,000 feet)[2]
Eponym

Endeavour, Saskatchewan, Canada (official name)[3]
HM Bark Endeavour (for early informal nickname)[4]

Space Shuttle Endeavour
Endeavour crater as viewed from Mars orbit
The tip of the bottom right of the star is the approximate location of Endeavour crater on Mars

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.[5] 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.[6]

When compared to the surrounding plains, the crater floor shows an enhanced spectral signature of basalt and hematite.[7] 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.[6] The plains surrounding the rim show evidence of polyhydrated sulfate.[7]

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,[8] and arriving at the edge on August 9, 2011.[9]

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.[10]

Nomenclature

The International Astronomical Union named the crater after a town in Canada.[3] The name was approved on 20 October 2008.[11] Due to rules for naming craters, it is officially named after the Canadian town, but the reason this name was proposed was because rover team was using informal nicknames based on a voyage of the HMS Endeavour.[4]

An informal working nickname by the Mars mission for the crater was Endeavour, and features of it, are based on the voyage of HM Bark Endeavour,[12] 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.[13] 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.

Elevation map of surroundings

Endeavour crater averages about 200 to 300 meters deep, with an area in its southeast that goes down to 500 meters deep, according to publication called Degradation of Endeavour Crater, Mars by the Smithsonian Institute.[14] The south-west depression goes down to an elevation of minus minus 1980 meters, the horse-shoe shaped depression sits in the south-east quadrant and is around minus 1800 to 1900 meters elevation, which is about 400 meters below the surrounding plains.[14] It is noted that the crater has under-gone various erosion processes, with wind being one cause.[14]

The proposed landing ellipse in Miyamoto when it was one of seven finalists under consideration as a landing site for MSL.[15] Endeavour crater can bee see on the right side of the map, the top of three medium-sized craters in a north-south line. This map is color-code based on elevation

Geology

The crater is understood by the 2010s to have two main rock types, the Shoemaker Formation and the Matijevic Formation.[16] It has been classified as a complex crater and it is thought to be so old many of its features have been worn away.[16] Some questions were raised about the tilt of the rim, however understanding is hampered by a lack of knowledge about Martian impact craters: Endeavour was the largest Martian impact crater up to that time to be studied that closely.[16] An example of the difficulty of studying Mars features is also apparent with Orcus Patera, which has various volcanic, tectonic, or cratering events explanations for its formation.[17] One famous Mars realization was that what was then called Nix Olympica was a volcano, and then renamed Olympus Mons thanks to Mariner 9 orbiter observations in the early 1970s.[18] Endeavour crater was identified as having clay minerals, as detected from orbit by Mars Reconnaissance Orbiter, which according to theories at that time indicated rock from an older, wetter, time period on Mars.[19] This type of rock is different from what prevails in other areas of surrounding plains.[19]

What is expected to be a fluid-carved gully was identified at Endeavour crater, probably water.[20] This gully is targeted for exploration by the MER-B rover mission as of October 2016.[20]

Mineral map of surrounding

Colored for minerals. Opportunity traverse is dated to 2010 while it was still on its way to Endeavour. The coloring is based on geological information as observed by the Mars Reconnaissance Orbiter CRISM instrument

Western rim

Western rim of the crater as seen from Cape York looking south, with the first ridge being Solander Point

The next rim section proceeding counter-clockwise around the crater is Batavia, on the southern end of the whole crater but East of Torres Straight

Arrival at Spirit Point at Endeavour crater, in the distance is the crater floor and on the other side the eastern rim segments

Western rim mineral map

This is a geological map based on MRO's CRISM observations[23]

Western rim elevation

Elevation map from MRO, a digital terrain model

Western rim sections from Solander to Marathon

3492 (November 2013)

Traverse as of November 2013, to Sol 3492

3500 to 3689 (June 2014)

Traverse as of June 2014 from roughly sol 3500 to 3689

3728 to 3757 (August 2014)

Traverse as of August 2014 from roughly sol 3728 to 3757

3750 to 3869 (December 2014)

Traverse as of December 2014 from roughly sol 3750 to 3868

3870 to 4209 (December 2015)

Traverse as of December 2015 from roughly sol 3870 to 4227
Traverse map to October 2016 (annotated version)

Opportunity

Opportunity's traverse up to March 2015 from its landing site to Endeavour crater. It has traversed south along the Western rim and orbiting spacecraft have help collect data on the rim, which in turn allows the rover to more closely investigate
Self-portrait of Opportunity near Endeavour Crater on the surface of Mars (January 6, 2014).

The journey to Endeavour crater

Annotated image showing the May 2009 position of Opportunity and names for the craters Iazu, Endeavour, and Victoria

In August 2008, Mars Exploration Rover-B Opportunity set to reach Endeavour crater and began a journey towards it.[1][24] Some craters that were previously 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.[25][26][27]

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.[8][28] Opportunity also saw Iazu crater, which is about 38 kilometers (24 mi) away and about 7 kilometers (4.3 mi) in diameter.[28] 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.[8] 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).[8] 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.[29]

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.[30] By June 28, 2011, Opportunity was just under 2 kilometres (1.2 mi) from landfall at the rim of Endeavour crater.[31]

On August 4, 2011, Opportunity was only 120 metres (390 ft) from the rim of Endeavour,[32] and on August 9, 2011 Opportunity arrived at the west rim near Spirit Point to study outcrops never seen before.[9]

When it arrive it explored the northwest outcrops at Cape York (Mars) of the crater before heading south to Solander Point and the Eastern rim.[33]

MER-B on Sol 2239 imaged the then distant crater rim. On this map several locations of Endeavor are identified including: Cape Tribulation, Cape Bryon, Cape Dromedary, Point Hicks, Torres Strait, and Batavia. Further south the nearby crater Iazu is also marked.
Here is the view from the rover's perspective from that location noted in the above top-down view. The white lines indicate the rover's field of view
MER-B eventually reached Cape Tribulation, and took a panorama from its top: Opportunity's view from Cape Tribulation on the rim of Endeavour Crater, January 22, 2015.

Solander point

Main article: Solander Point
Solander Point

Proximity to Schiaparelli landing ellipse

In October 2016 the synergy between different missions reached new heights as the ESA's Schiaparelli lander, itself a test of entry, landing, and descent technology will attempt to re-use the proven Meridiani Planum landing site, with a landing ellipse that kisses the Endeavour crater location where Opportunity is still functioning.[34] This allows the opportunity for opportunity to attempt to image the lander during its descent from the surface of Mars.[35]

Proximity to MSL landing site candidates

Two of the seven final landing candidates for MSL were relatively near to Endeavour, one was in Miyamoto (crater) and another was south of Endeavour in southerner Meridiani.[15] Gale (crater) won the selection

Endeavour crater can be see on the right side of this map about halfway down;in the bottom left is the proposed landing ellipse for MSL in Miyamoto crater.

Crater floor exploration

MER-B from 2011 to 2016 explored the Eastern rim of Endeavour, starting at Cape York (Mars) then moving down through Botany Bay to Solander Point, then Murray Ridge and down to Marathon Valley; in late 2016 it began moving inward to the crater floor:

A detailed-class rover traverse map by the mission, released on September 28, 2016 showing the track of the rover up to Sol 4500 as it heads deeper in Endeavor crater
An annotated view of the traverse to Spirit mound, October 2016

Spirit of Saint Louis Crater

This crater sits at the Western mouth of Marathon Valley, south Cape Tribulation on the western rim of Endeavor crater. It was visited by the MER-B Opportunity rover in May 2015.[36]

In May 2015 the rover visited what was dubbed Spirit of St. Louis Crater, a shallow crater about 110 feet (34 meters) long and 80 feet (24 meters) across. In its center is Lindbergh Mound, about 2-3 meters (yards) high. This version of the panorma is annotated and in false color[36]

Sacagawea Panorama by Opportunity (Marathon Valley)

In 2016, the United States' space mission MER, operating the MER-B Opportunity rover took a special panoramic image called the Sacagawea Panorama in honor of the Lemhi Shoshone woman that helped the Lois and Clark expedition on their journey of exploration across America in 1804 to 1806.[37] The image was taken of Marathon Valley at Endeavour Crater on the planet Mars.[37]

Sacagawea Panorama by Opportunity, 2016

Comparison

Enedeavour is about the same size as Valles Caldera in the U.S. State of New Mexico;a volcanic Caldera of the Valles Caldera National Preserve.[22] Endeavour has been compared to the Mars craters' Santa Fe (crater), which is about 20.2 km in diameter, and also to Tooting (crater), which is 27.5 km in diameter.[14]

See also

References

  1. 1 2 3 4 "NASA'S Mars Rover to Head Toward Bigger Crater". NASA/JPL. 2008-09-22. Retrieved 2009-03-20.
  2. ↑ "Road Trip Gets Under Way". NASA/JPL. 2008-09-24. Retrieved 2009-04-27.
  3. 1 2 "Planetary Names: Crater, craters: Endeavour on Mars". Gazetteer of Planetary Nomenclature. Retrieved 2016-02-14.
  4. 1 2 http://www.planetary.org/explore/space-topics/space-missions/mer-updates/2008/09-30-mer-update.html
  5. ↑ 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
  6. 1 2 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
  7. 1 2 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
  8. 1 2 3 4 "One Mars Rover Sees A Distant Goal; The Other Takes A New Route". NASA/JPL. 2009-03-18. Retrieved 2009-03-20.
  9. 1 2 "NASA Mars Rover Arrives at New Site on Martian Surface" (Press release). NASA/JPL. 2011-08-10. Retrieved 2016-02-14.
  10. ↑ http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-403_Mars_Rover_Gypsum.html
  11. ↑ "Martian Crater Named Endeavour". USGS Astrogeology Science Center. 2008-10-20. Retrieved 2016-02-14.
  12. ↑
  13. ↑ NASA Mars Rover Seeing Destination in More Detail, NASA media release, 29 June 2010, accessed 25 July 2011
  14. 1 2 3 4 5 6
  15. 1 2
  16. 1 2 3
  17. ↑ "HRSC Press Release #471 - Orcus Patera (orbit 2216 & 2238)". 2010-08-27. Archived from the original on 2014-08-07.
  18. ↑
  19. 1 2
  20. 1 2
  21. 1 2 3 4
  22. 1 2
  23. ↑
  24. ↑ Rahl, A.J.S (2008-10-31). "Spirit "Bumps" a Move, Opportunity Puts the Pedal to the Metal". Planetary Society. Retrieved 2009-03-20.
  25. ↑ "NASA Rover Nears Martian Bowl Goal". NASA/JPL. 2006-09-06. Retrieved 2009-03-20.
  26. ↑ "Press Release Images: Opportunity". NASA/JPL. 2004-05-03. Retrieved 2009-03-20.
  27. ↑ "NASA Facts: Mars Exploration Rover" (PDF). NASA/JPL. 2004-10-24. Retrieved 2009-03-26.
  28. 1 2 "One Mars Rover Sees A Distant Goal; The Other Takes A New Route". NASA/JPL. 2009-03-18. Retrieved 2009-03-20.
  29. ↑ "Opportunity's Long and Winding Road to Endeavour Crater". Universe Today. 2010-05-05. Retrieved 2010-08-04.
  30. ↑ "Opportunity Rover Reaches Halfway Point of Long Trek". NASA/JPL. 2010-09-08. Retrieved 2010-09-11.
  31. ↑ "Opportunity Is Just Over a Mile From Crater Rim". NASA/JPL. 2011-07-08. Retrieved 2011-07-08.
  32. ↑ "Nearing First Landfall of Large Crater". NASA/JPL. 2011-08-04. Retrieved 2011-08-08.
  33. ↑ NASA - Sol 3351
  34. ↑
  35. ↑
  36. 1 2 Martian Reminder of a Pioneering Flight
  37. 1 2
Wikimedia Commons has media related to Endeavour crater.
This article is issued from Wikipedia - version of the 11/9/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.