Exploration of Mercury

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Mariner 10.jpg
The first probe to visit Mercury was Mariner 10 .
Mercury Mariner10.jpg
View of Mercury from Mariner 10 in March 1975.

The exploration of Mercury has a minor role in the space interests of the world. It is the least explored inner planet. [1] As of 2015, the Mariner 10 and MESSENGER missions have been the only missions that have made close observations of Mercury. MESSENGER made three flybys before entering orbit around Mercury. [2] A third mission to Mercury, BepiColombo , a joint mission between the Japan Aerospace Exploration Agency (JAXA) and the European Space Agency, is to include two probes. MESSENGER and BepiColombo are intended to gather complementary data to help scientists understand many of the mysteries discovered by Mariner 10's flybys.

Contents

Compared to other planets, Mercury is difficult to explore. The speed required to reach it is relatively high, and its proximity to the Sun makes it difficult to maneuver a spacecraft into a stable orbit around it. [3] MESSENGER was the first probe to orbit Mercury.

Interest in Mercury

Few missions have targeted Mercury because it is very difficult to obtain a satellite orbit around the planet. Mercury orbits the Sun very quickly (between 24.25 miles per second (39.03 km/s) and 30 miles per second (48 km/s)), so spacecraft must be travelling very fast to reach it. Mercury's close proximity to the Sun means that spacecraft are accelerated even further by the Sun's gravitational pull, requiring significant fuel expenditure in order to decelerate for orbit insertion. [4] Mercury's lack of any significant atmosphere [5] poses further challenges because it precludes aerobraking. Thus a landing mission would have even more demanding fuel requirements. [6]

Missions

Past missions

Mariner 10

Mariner 10 was a NASA probe whose primary objective was to observe the atmosphere, surface, and physical characteristics of Mercury and Venus. It was a low-cost mission completed for under $98 million. [7] Mariner 10 was launched at 12:45 am EST on November 3, 1973, from Cape Canaveral. [8] Since Mercury is so close to the Sun it was too difficult to incorporate an orbit around Mercury in the route so Mariner 10 orbited the Sun. In order to reach its destination, the satellite was accelerated with the gravity field of Venus. It then passed close to Mercury on March 29, 1974, as it flew towards the Sun. This was the first observation made of Mercury at close range. After the encounter Mariner 10 was in an orbit around the Sun such that for every one of its orbits Mercury made two, and the spacecraft and the planet would be able to meet again. This allowed the probe to pass by Mercury two additional times before completing the mission; these encounters were made on September 21, 1974, and March 16, 1975. However, since the same side of Mercury was illuminated during each of the flybys, at the conclusion of the mission Mariner 10 had only photographed approximately 45 percent of its surface. [9] The mission ended when the probe's attitude control gas ran out on March 24, 1975. As the spacecraft was no longer controllable without its nitrogen gas thrusters, a command was sent to the probe to shut down its transmitter. [10]

The close observations collected two important sets of data. The probe detected Mercury's magnetic field, which is very similar to Earth's. This was a surprise to scientists, because Mercury spins so slowly on its axis. Secondly, visual data was provided, which showed the high number of craters on the surface of the planet. [11] The visual data also allowed scientists to determine that Mercury had "not experienced significant crustal modification”. [12] This also added to the mystery of the magnetic field, as it was previously believed that the magnetic fields are caused by a molten dynamo effect, but since there was little crustal modification this undermined that idea. The visual data also allowed scientists to investigate the composition and age of the planet. [13]

MESSENGER

Animation of MESSENGER's trajectory around Mercury from March 15, 2011 to December 30, 2014 .mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{} MESSENGER * Mercury Animation of MESSENGER trajectory around Mercury.gif
Animation of MESSENGER 's trajectory around Mercury from March 15, 2011 to December 30, 2014
   MESSENGER  ·   Mercury
Photograph of Mercury from MESSENGER's first flyby of the planet, showing many previously unknown features MESSENGER first photo of unseen side of mercury.jpg
Photograph of Mercury from MESSENGER's first flyby of the planet, showing many previously unknown features

MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) was a NASA orbital probe of Mercury. It was launched from Cape Canaveral on August 3, 2004, after a one-day delay due to bad weather. [14] [15] It took the probe about six and a half years before it entered orbit around Mercury. In order to correct the speed of the satellite it undertook several gravitational slingshot flybys of Earth, Venus and Mercury. It passed by the Earth in February 2005 and then Venus in October 2006 [2] and in October 2007. Furthermore, the probe made three passes of Mercury, one in January 2008, one in October 2008 and one in September 2009, before entering orbit in 2011. During these flybys of Mercury, enough data was collected to produce images of over 95% of its surface.

MESSENGER used a chemical bi-propellant system both to reach Mercury and achieve orbit. [16] MESSENGER's scheduled orbital insertion took place successfully on March 18, 2011. In November 2012, NASA reported that MESSENGER had discovered a possibility of both water ice and organic compounds in permanently shadowed craters in Mercury's north pole. [17] The mission was scheduled to end sometime in 2012, when it was estimated that there would no longer be enough fuel to maintain the probe's orbit. [18] The primary mission was completed on March 17, 2012, having collected close to 100,000 images. [19] MESSENGER achieved 100% mapping of Mercury on March 6, 2013, and completed its first year-long extended mission on March 17, 2013. [20] In February 2013, NASA published the most detailed and accurate 3D map of Mercury to date, assembled from thousands of images taken by MESSENGER. [21] The probe continued collecting scientific data until April 30, 2015, when under a decaying orbit, the probe was allowed to crash onto the surface of Mercury. [22] [23]

Baranauskas crater (center) on Mercury. Bright patches within the crater are Hollows. Approximate color representation combining three images acquired by MESSENGER Baranauskas crater MESSENGER WAC IGF to RGB.jpg
Baranauskas crater (center) on Mercury. Bright patches within the crater are Hollows. Approximate color representation combining three images acquired by MESSENGER

The MESSENGER mission was designed to study the characteristics and environment of Mercury from orbit. Specifically, the scientific objectives of the mission were: [24] [25]

  • characterize the chemical composition of Mercury's surface.
  • study the geologic history.
  • elucidate the nature of Mercury's magnetic field (magnetosphere).
  • determine the size and state of the core.
  • determine the volatile inventory at the poles.
  • study the nature of Mercury's exosphere.

Ongoing missions

BepiColombo

Artist's depiction of the BepiColombo mission, with the Mercury Planetary Orbiter (left) and Mercury Magnetospheric Orbiter (right) BepiColombo spacecraft model.png
Artist's depiction of the BepiColombo mission, with the Mercury Planetary Orbiter (left) and Mercury Magnetospheric Orbiter (right)

BepiColombo consists of two spacecraft: the Mercury Planetary Orbiter (MPO) and Mio (Mercury Magnetospheric Orbiter, MMO). Each orbiter has a distinct purpose: the MPO is to acquire images in several wavelengths to map the surface and exosphere composition of Mercury, and Mio's is to study the magnetosphere. It is a joint mission of the European Space Agency and Japan Aerospace Exploration Agency; ESA provided the MPO, while JAXA provided Mio. [3] The BepiColombo mission will attempt to gather enough information to answer these questions:

  1. What can we learn from Mercury about the composition of the solar nebula and the formation of the planetary system?
  2. Why is Mercury's normalized density markedly higher than that of all other terrestrial planets, as well as the Moon?
  3. Is the core of Mercury liquid or solid?
  4. Is Mercury tectonically active today?
  5. Why does such a small planet possess an intrinsic magnetic field, while Venus, Mars, and the Moon do not have any?
  6. Why do spectroscopic observations not reveal the presence of any iron, while this element is supposedly the major constituent of Mercury?
  7. Do the permanently shadowed craters of the polar regions contain sulfur or water ice?
  8. What are the production mechanisms of the exosphere?
  9. In the absence of any ionosphere, how does the magnetic field interact with the solar wind?
  10. Is Mercury's magnetised environment characterized by features reminiscent of the aurorae, radiation belts and magnetospheric substorms observed on Earth?
  11. Since the advance of Mercury's perihelion was explained in terms of space-time curvature, can we take advantage of the proximity of the Sun to test general relativity with improved accuracy? [3]

Like Mariner 10 and MESSENGER, BepiColombo will use gravity slingshots from Venus and Earth. BepiColombo will use solar electric propulsion (ion engines) and then also use similar maneuvers at the Moon, Venus, and Mercury. These techniques will slow the orbiters as they approach Mercury. It is essential to avoid using fuel to slow the orbiters as they get closer to the Sun to minimize the gravitational influence of the Sun. [2]

The BepiColombo mission was approved in November 2009, [26] and successfully launched on October 20, 2018. It is scheduled to enter orbit around Mercury in December 2025. Its primary mission will last until May 2027, with a possible extension to May 2028. [27]

Proposed missions

Mercury-P (Меркурий-П) is a proposed lander mission to Mercury by the Russian Space Agency. The proposed launch date is 2031.[ citation needed ]

In August 2020, the Applied Physics Laboratory proposed the Mercury Lander for NASA's New Frontiers program. If selected, it would launch in March 2035 and land in April 2045. [28]

Canceled missions

Mercury Observer was a cancelled proposal in the Planetary Observer program.

Comparison of MESSENGER and BepiColombo

BepiColombo was designed to complement the findings of MESSENGER and is equipped with far more measuring equipment than MESSENGER to obtain a larger range of data. The orbit patterns of BepiColombo and MESSENGER are significantly different. [16]

The BepiColombo mission comprises two satellites launched together: the Mercury Planetary Orbiter (MPO) and Mio (Mercury Magnetospheric Orbiter, MMO). The MPO will have a circular orbit much closer to Mercury. The reason for this orbit is that the MPO will be measuring the composition of the surface and exosphere, and the close orbit will aid on data quality. On the other hand, Mio (MMO) and MESSENGER took largely elliptical orbits. This is because of the stability of the orbit and the lower amount of fuel required to obtain and maintain the orbit. [29] Another reason for the different orbits of Mio and MESSENGER was to provide complementary data. The data of the two combined satellites will provide more accurate measurements. [16]

See also

Related Research Articles

<span class="mw-page-title-main">Mercury (planet)</span> First planet from the Sun

Mercury is the first planet from the Sun and the smallest in the Solar System. In English, it is named after the ancient Roman god Mercurius (Mercury), god of commerce and communication, and the messenger of the gods. Mercury is classified as a terrestrial planet, with roughly the same surface gravity as Mars. The surface of Mercury is heavily cratered, as a result of countless impact events that have accumulated over billions of years. Its largest crater, Caloris Planitia, has a diameter of 1,550 km (960 mi), which is about one-third the diameter of the planet. Similarly to the Earth's Moon, Mercury's surface displays an expansive rupes system generated from thrust faults and bright ray systems formed by impact event remnants.

<span class="mw-page-title-main">Mariner program</span> NASA space program from 1962 to 1973

The Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the inner Solar System – visiting the planets Venus, Mars and Mercury for the first time, and returning to Venus and Mars for additional close observations.

<span class="mw-page-title-main">Space exploration</span> Exploration of space, planets, and moons

Space exploration is the use of astronomy and space technology to explore outer space. While the exploration of space is currently carried out mainly by astronomers with telescopes, its physical exploration is conducted both by uncrewed robotic space probes and human spaceflight. Space exploration, like its classical form astronomy, is one of the main sources for space science.

<i>Mariner 10</i> First spacecraft to visit Mercury (1973–1975)

Mariner 10 was an American robotic space probe launched by NASA on 3 November 1973, to fly by the planets Mercury and Venus. It was the first spacecraft to perform flybys of multiple planets.

<span class="mw-page-title-main">Gravity assist</span> Space navigation technique

A gravity assist, gravity assist maneuver, swing-by, or generally a gravitational slingshot in orbital mechanics, is a type of spaceflight flyby which makes use of the relative movement and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expense.

<i>MESSENGER</i> NASA mission to Mercury

MESSENGER was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for Mercury Surface, Space Environment, Geochemistry, and Ranging, and a reference to the messenger god Mercury from Roman mythology.

<span class="mw-page-title-main">Discovery Program</span> Ongoing solar system exploration program by NASA

The Discovery Program is a series of Solar System exploration missions funded by the U.S. National Aeronautics and Space Administration (NASA) through its Planetary Missions Program Office. The cost of each mission is capped at a lower level than missions from NASA's New Frontiers or Flagship Programs. As a result, Discovery missions tend to be more focused on a specific scientific goal rather than serving a general purpose.

<span class="mw-page-title-main">BepiColombo</span> ESA/JAXA mission to study Mercury in orbit (2018–present)

BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury. The mission comprises two satellites launched together: the Mercury Planetary Orbiter (MPO) and Mio. The mission will perform a comprehensive study of Mercury, including characterization of its magnetic field, magnetosphere, and both interior and surface structure. It was launched on an Ariane 5 rocket on 20 October 2018 at 01:45 UTC, with an arrival at Mercury planned for November 2026, after a flyby of Earth, two flybys of Venus, and six flybys of Mercury. The mission was approved in November 2009, after years in proposal and planning as part of the European Space Agency's Horizon 2000+ programme; it is the last mission of the programme to be launched.

<span class="mw-page-title-main">Solar Orbiter</span> European space-based solar observatory

The Solar Orbiter (SolO) is a Sun-observing probe developed by the European Space Agency (ESA) with a National Aeronautics and Space Administration (NASA) contribution. Solar Orbiter, designed to obtain detailed measurements of the inner heliosphere and the nascent solar wind, will also perform close observations of the polar regions of the Sun which is difficult to do from Earth. These observations are important in investigating how the Sun creates and controls its heliosphere.

<span class="mw-page-title-main">Geology of Mercury</span>

The geology of Mercury is the scientific study of the surface, crust, and interior of the planet Mercury. It emphasizes the composition, structure, history, and physical processes that shape the planet. It is analogous to the field of terrestrial geology. In planetary science, the term geology is used in its broadest sense to mean the study of the solid parts of planets and moons. The term incorporates aspects of geophysics, geochemistry, mineralogy, geodesy, and cartography.

<span class="mw-page-title-main">Observations and explorations of Venus</span>

Observations of the planet Venus include those in antiquity, telescopic observations, and from visiting spacecraft. Spacecraft have performed various flybys, orbits, and landings on Venus, including balloon probes that floated in the atmosphere of Venus. Study of the planet is aided by its relatively close proximity to the Earth, compared to other planets, but the surface of Venus is obscured by an atmosphere opaque to visible light.

<span class="mw-page-title-main">Manned Venus flyby</span> Proposed crewed Venus flyby

Manned Venus Flyby was a 1967–1968 NASA proposal to send three astronauts on a flyby mission to Venus in an Apollo-derived spacecraft in 1973–1974, using a gravity assist to shorten the return journey to Earth.

<span class="mw-page-title-main">Atmosphere of Mercury</span> Composition and properties of the atmosphere of the innermost planet of the Solar System

Mercury, being the closest to the Sun, with a weak magnetic field and the smallest mass of the recognized terrestrial planets, has a very tenuous and highly variable atmosphere containing hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor, with a combined pressure level of about 10−14 bar. The exospheric species originate either from the Solar wind or from the planetary crust. Solar light pushes the atmospheric gases away from the Sun, creating a comet-like tail behind the planet.

<span class="mw-page-title-main">Mercury's magnetic field</span> Mercurys small magnetic field

Mercury's magnetic field is approximately a magnetic dipole, apparently global, on the planet of Mercury. Data from Mariner 10 led to its discovery in 1974; the spacecraft measured the field's strength as 1.1% that of Earth's magnetic field. The origin of the magnetic field can be explained by dynamo theory. The magnetic field is strong enough near the bow shock to slow the solar wind, which induces a magnetosphere.

The following outline is provided as an overview of and topical guide to Mercury:

<span class="mw-page-title-main">Ariane flight VA245</span> Space launch

Ariane Flight VA245 is the Ariane 5 space launch of BepiColombo that took place on 20 October 2018 at 01:45:28 UTC from the Guiana Space Centre. It was the 101st launch of Ariane 5, and the 301st Arianespace mission.

References

  1. ↑ JHU/APL (2006). MESSENGER: MErcury Surface, Space ENvironment, GEochemistry, and Ranging Retrieved on 2007-01-27
  2. 1 2 3 Munsell Kirk-editor (November 6, 2006). NASA: Solar System Exploration: Missions to Mercury Archived September 29, 2006, at the Wayback Machine . Retrieved on 2007-01-27.
  3. 1 2 3 ESA (2007). BepiColombo. Retrieved 2007-02-01.
  4. ↑ Ley, Willy (July 1968). "Interplanetary Communications". For Your Information. Galaxy Science Fiction. pp. 116–124.
  5. ↑ Munsell Kirk-editor (November 6, 2006). NASA: Solar System Exploration: Planet Mercury Archived September 29, 2006, at the Wayback Machine . Retrieved on 2007-01-27.
  6. ↑ "Critical decisions on Cosmic Vision".
  7. ↑ Shirley, 2003
  8. ↑ Dunne, James A. (1978). The Voyage of Mariner 10: Mission to Venus and Mercury (NASA SP-424). U.S. Government Printing Office. p. 45. ASIN B000C19QHA.
  9. ↑ Mix, Lucas John (2009). Life in Space: Astrobiology for Everyone. Cambridge, Massachusetts London, England: Harvard University Press. ISBN   978-0-674-03321-4.
  10. ↑ Murray, Bruce; Burgess, Eric (1977). Flight to Mercury . New York: Columbia University Press. p.  138. ISBN   9780231039963.
  11. ↑ Dunne, 1978, p. 74
  12. ↑ Dunne, 1978, p. 101
  13. ↑ Dunne, 1978, p. 103
  14. ↑ Malik, T. (2004). Mercury MESSENGER Launch Postponed. Retrieved 2015-07-18.
  15. ↑ NBC News (2004). NASA launches spacecraft to Mercury. Retrieved 2015-07-18.
  16. 1 2 3 McNutt, Ralph L.; Solomon, Sean C.; Grard, Réjean; Novara, Mauro; Mukai, Toshifumi (2004). "An international program for Mercury exploration: Synergy of MESSENGER and Bepi Colombo". Advances in Space Research. 33 (12): 2126–2132. Bibcode:2004AdSpR..33.2126M. doi:10.1016/S0273-1177(03)00439-3.
  17. ↑ "The Moon and Mercury May Have Thick Ice Deposits - NASA". August 2, 2019. Retrieved November 19, 2024.
  18. ↑ Planetary Society(2007) Space Topics: MESSENGER Archived April 23, 2012, at the Wayback Machine . Retrieved September 11, 2010
  19. ↑ "MESSENGER Provides New Look at Mercury's Landscape, Metallic Core, and Polar Shadows" (Press release). Johns Hopkins University. March 21, 2012. Archived from the original on May 13, 2013. Retrieved March 22, 2012.
  20. ↑ "MESSENGER Completes Its First Extended Mission at Mercury". JHU–APL. March 17, 2013. Archived from the original on July 29, 2013. Retrieved July 8, 2013.
  21. ↑ Cho, Adrian (March 1, 2017). "Scientists unveil the most detailed map of dark matter to date". Science. doi:10.1126/science.aal0847. ISSN   0036-8075.
  22. ↑ Wu, Brian (April 3, 2014). "NASA Set to Extend Mercury Mission for Another Month". Johns Hopkins University APL. The Science Times. Retrieved April 4, 2015.
  23. ↑ "MESSENGER's Operations at Mercury Extended". Johns Hopkins University APL. Space Ref. April 3, 2014. Archived from the original on April 4, 2015. Retrieved April 4, 2015.
  24. ↑ "MESSENGER - Mission description". NASA. Retrieved July 8, 2013.
  25. ↑ "Discovery Program: MESSENGER". NASA. Archived from the original on June 3, 2013. Retrieved July 8, 2013.
  26. ↑ "BepiColombo Overview". European Space Agency. September 5, 2016. Retrieved March 13, 2017.
  27. ↑ "BepiColombo: Fact Sheet". European Space Agency. September 1, 2019. Retrieved March 9, 2020.
  28. ↑ "Mercury Lander". Space@APL. August 8, 2020. Retrieved April 20, 2024.
  29. ↑ Mukai, T.; Yamakawa, H.; Hayakawa, H.; Kasaba, Y.; Ogawa, H. (2006). "Present status of the Bepi Colombo/Mercury magnetospheric orbiter". Advances in Space Research. 38 (4): 578–582. Bibcode:2006AdSpR..38..578M. doi:10.1016/j.asr.2005.09.038.
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