Mercury definition, a heavy, silver-white, highly toxic metallic element, the only one that is liquid at room temperature; quicksilver: used in barometers, thermometers, pesticides, pharmaceutical preparations, reflecting surfaces of mirrors, and dental fillings, in certain switches, lamps, and other electric apparatus, and as a laboratory catalyst. { bidder: 'ix', params: { siteId: '195455', size: [300, 250] }}, A plant of a genus which includes dog's mercury. Hydrogen and helium may come from the solar wind.

These observations were most likely made by an Assyrian astronomer around the 14th century BC. We've put together a guide with 2020 dates explaining the meaning of Mercury Retrograde and how will it affect your life. { bidder: 'ix', params: { siteId: '195465', size: [300, 250] }}, { bidder: 'ix', params: { siteId: '195464', size: [120, 600] }}, Radar observations in 1965 proved that the planet has a 3:2 spin-orbit resonance, rotating three times for every two revolutions around the Sun. Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_mpuslot1' }}]}, [152], The difficulties inherent in observing Mercury mean that it has been far less studied than the other planets. The second time was mainly used to take pictures of Mercury's surface. [84] Measurements from both the Mariner 10 and MESSENGER space probes have indicated that the strength and shape of the magnetic field are stable. { bidder: 'appnexus', params: { placementId: '11654157' }},

Its ‘day’ of 58.65 days is precisely two thirds the length of its ‘year’ of 87.97 days. It determines how you make sense of your world, formulate ideas and share them with others. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }},

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{ bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_leftslot_160x600' }}, [81], On November 29, 2012, NASA confirmed that images from MESSENGER had detected that craters at the north pole contained water ice.

[14] This exosphere is not stable—atoms are continuously lost and replenished from a variety of sources. 'buckets': [{ [125] In both of these cases, the angle at which the planet's orbit intersects the horizon is maximized, allowing it to rise several hours before sunrise in the former instance and not set until several hours after sundown in the latter from southern mid-latitudes, such as Argentina and South Africa.[125]. ). "sign-in": "https://dictionary.cambridge.org/auth/signin?rid=READER_ID", [71] The origin of the ice on Mercury is not yet known, but the two most likely sources are from outgassing of water from the planet's interior or deposition by impacts of comets. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, { bidder: 'ix', params: { siteId: '195455', size: [300, 250] }}, It cannot be easily seen as it is usually too close to the Sun. { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_rightslot2_flex' }}, [182] Most of the hemisphere not imaged by Mariner 10 was mapped during these fly-bys. ϵ [2][12] Mercury is bright when it is visible from Earth, ranging from −2.0 to 5.5 in apparent magnitude. name: "unifiedId", This contributes to the space weathering of the planet's surface. Mercury is made of about 70% metallic and 30% silicate material. The MESSENGER observations showed the reconnection rate is ten times higher at Mercury, but its proximity to the Sun only accounts for about a third of the reconnection rate observed by MESSENGER. googletag.pubads().setTargeting("cdo_tc", "resp"); pbjs.que.push(function() { It makes one trip around the Sun once every 87.969 days. }

Friedrich Bessel used Schröter's drawings to erroneously estimate the rotation period as 24 hours and an axial tilt of 70°.

[96] Its period of retrograde motion as seen from Earth can vary from 8 to 15 days on either side of inferior conjunction.

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{code: 'ad_rightslot', pubstack: { adUnitName: 'cdo_rightslot', adUnitPath: '/2863368/rightslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, Mercury is bright when it is visible from Earth, ranging from −2.0 to 5.5 in apparent magnitude.It cannot be easily seen as it is usually too close to the Sun. { bidder: 'sovrn', params: { tagid: '387233' }}, var pbTabletSlots = [

{ bidder: 'ix', params: { siteId: '195465', size: [300, 250] }}, This would indicate an interaction between the magnetosphere and the planet's surface. { bidder: 'openx', params: { unit: '539971067', delDomain: 'idm-d.openx.net' }}, { bidder: 'ix', params: { siteId: '195453', size: [300, 50] }}, { bidder: 'sovrn', params: { tagid: '346688' }},

It showed that the planet's magnetic field is much like Earth's. [13] Observation of Mercury is complicated by its proximity to the Sun, as it is lost in the Sun's glare for much of the time.

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