After visits with Vesta and Ceres asteroidexploring Dawn spacecraft goes dark

first_img Sign up for our daily newsletter Get more great content like this delivered right to you! Country Related Email After visits with Vesta and Ceres, asteroid-exploring Dawn spacecraft goes dark *Update, 1 November, 1:55 p.m.: After several missed attempts to communicate with Dawn over the past 2 days, NASA declared that the spacecraft had run out of hydrazine and reached the end of its mission. Here is our original coverage from 17 October.After an 11-year journey to Vesta and Ceres, the asteroid belt’s two largest members, NASA’s Dawn spacecraft is expected to run out of thruster fuel in the next few weeks, ending its mission. The robotic explorer, which gave a close-up view of how the presence or absence of water can shape asteroids, will remain tumbling in orbit around Ceres for decades before ultimately crashing into it.Launched in 2007, Dawn is the only NASA mission to orbit two planetary bodies, a feat made possible by its efficient ion thrusters. In 2011, it arrived at the egg-shaped, 600-kilometer-long Vesta, orbiting for a year before departing for Ceres, where it arrived in 2015. By Paul VoosenNov. 1, 2018 , 2:05 PM Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe Ceres’s Occator crater contains an ice-spewing cryovolcano. Kepler, NASA’s planet-hunting space telescope, is dead Click to view the privacy policy. Required fields are indicated by an asterisk (*) The two asteroids, which together account for 45% of the belt’s mass, turned out to be a tale of contrasts. Parched Vesta has a composition like the terrestrial planets, with an iron core and a dry, rocky surface carved up into canyons, craters, and mountains, remnants of past impacts and volcanism. Dawn was able to verify that a class of meteorites found on Earth are chips off of Vesta, making it a sort of “reverse sample return mission,” says Carol Raymond, the mission’s principal investigator and a planetary scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.Telescopes had already found water-rich minerals on Ceres, a 900-kilometer-wide body classified as a dwarf planet because of its large size and spherical shape. Dawn revealed the remnants of a frozen ocean topped by a heavily cratered crust of clays and salts. “We could not have imagined it would have looked like this,” Raymond says.The young sun could have boiled away much of the water if Ceres had formed in its present location. So, some scientists suspect it was born out past Jupiter and Saturn, only to be drawn in by the gas giants’ turbulent early gyrations. Dawn found a marker of this distant birthplace: ammonia, a volatile molecule that could have only formed in the outer solar system. NASA/JPL-CALTECH/UCLA/MPS/DLR/IDA Dawn also spotted a sign that Ceres remains geologically active: what looked like a lone volcano, 4 kilometers tall, that oozes a “lava” of water, salt, and other materials. Later observations spotted traces of 21 more volcanoes. And more than 100 bright spots rich in salt also suggested the subsurface ice finds its way to the surface here and there, as a slushy brine. One such spot, at Ernutet crater, showed signs of organic molecules—common in the outer solar system and not a signifier of life. But the discoveries have made Ceres a prime candidate for further exploration; a NASA study on a possible lander is expected to conclude next year.In its final months, Dawn settled into a tight orbit, just 35 kilometers from Ceres’s surface. The defunct craft could remain in orbit for a half-century or more, says Marc Rayman, Dawn’s mission director at JPL, “an inert celestial monument around the dwarf planet it helped unveil.”last_img

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