{"id":787794,"date":"2024-08-25T06:41:50","date_gmt":"2024-08-25T11:41:50","guid":{"rendered":"http:\/\/spaceweekly.com\/?p=787794"},"modified":"2024-08-25T06:41:50","modified_gmt":"2024-08-25T11:41:50","slug":"our-1st-and-last-visit-to-neptune","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=787794","title":{"rendered":"Our 1st and last visit to Neptune"},"content":{"rendered":"<p> <br \/>\n<\/p>\n<div>\n<figure id=\"attachment_319612\" aria-describedby=\"caption-attachment-319612\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><figcaption id=\"caption-attachment-319612\" class=\"wp-caption-text\">Voyager 2 acquired this image fewer than 5 days before its closest approach to Neptune on August 25, 1989. You can see Neptune\u2019s Great Dark Spot \u2013 a storm in its atmosphere \u2013 and the bright, light-blue smudge of clouds that accompanies the storm. Image via NASA\/ JPL-Caltech.<\/figcaption><\/figure>\n<p>Reprinted from NASA.<\/p>\n<h3>Voyager 2 passes by Neptune, 35 years ago<\/h3>\n<p>Thirty-five years ago, on August 25, 1989, NASA\u2019s Voyager 2 spacecraft made a close flyby of Neptune. It gave humanity its 1st close-up of our solar system\u2019s 8th planet. It also marked the end of the Voyager mission\u2019s Grand Tour of the solar system\u2019s 4 giant planets, Jupiter, Saturn, Uranus and Neptune. No other spacecraft has visited Neptune since.<\/p>\n<p>Ed Stone, a professor of physics at Caltech and Voyager\u2019s project scientist since 1975, said:<\/p>\n<blockquote>\n<p>The Voyager planetary program really was an opportunity to show the public what science is all about. Every day we learned something new.<\/p>\n<\/blockquote>\n<p>Wrapped in teal and cobalt-colored bands of clouds, the planet that Voyager 2 revealed looked like a blue-hued sibling to Jupiter and Saturn. The blue on Neptune indicates the presence of methane. A massive, slate-colored storm was dubbed the Great Dark Spot, similar to Jupiter\u2019s Great Red Spot. Plus, Voyager 2 discovered six new moons and four rings.<\/p>\n<figure id=\"attachment_319615\" aria-describedby=\"caption-attachment-319615\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2019\/08\/neptune-rings-8-26-1989-voyager2.jpg\" alt=\"A split image with the bright planet itself hidden by an obscuring bar, and the rings visible.\" width=\"800\" height=\"585\" class=\"size-full wp-image-319615\" srcset=\"https:\/\/earthsky.org\/upl\/2019\/08\/neptune-rings-8-26-1989-voyager2.jpg 700w, https:\/\/earthsky.org\/upl\/2019\/08\/neptune-rings-8-26-1989-voyager2-300x219.jpg 300w, https:\/\/earthsky.org\/upl\/2019\/08\/neptune-rings-8-26-1989-voyager2-640x468.jpg 640w, https:\/\/earthsky.org\/upl\/2019\/08\/neptune-rings-8-26-1989-voyager2-190x139.jpg 190w, https:\/\/earthsky.org\/upl\/2019\/08\/neptune-rings-8-26-1989-voyager2-140x102.jpg 140w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\"\/><figcaption id=\"caption-attachment-319615\" class=\"wp-caption-text\">Voyager 2 took these 2 images of the rings of Neptune on August 26, 1989, just after closest approach. Neptune\u2019s 2 main rings are clearly visible. And 2 fainter rings are visible with the help of long exposure times and backlighting from the sun. Image via NASA PhotoJournal.<\/figcaption><\/figure>\n<h3>Voyager 2 also visited Triton<\/h3>\n<p>During the encounter, the engineering team carefully changed the probe\u2019s direction and speed so that it could do a close flyby of the planet\u2019s largest moon, Triton. The flyby showed evidence of geologically young surfaces and active geysers spewing material skyward. This indicated that Triton was not simply a solid ball of ice even though it had the lowest surface temperature of any natural body observed by Voyager: -391 degrees Fahrenheit (-235 degrees Celsius).<\/p>\n<h3>Voyager 2 onward to interstellar space<\/h3>\n<p>The conclusion of the Neptune flyby marked the beginning of the Voyager Interstellar Mission. Forty-seven years after launch, Voyager 2 and its twin, Voyager 1 (which had also flown by Jupiter and Saturn), continue to send back dispatches from the outer reaches of our solar system. At the time of the Neptune encounter, Voyager 2 was about 2.9 billion miles (4.7 billion km) from Earth. Today it is 12.7 billion miles (20 billion km) from us. The faster-moving Voyager 1 is 15.2 billion miles (24 billion km) from Earth. <\/p>\n<p><iframe loading=\"lazy\" title=\"VOYAGER 2 AT TRITON\" width=\"1110\" height=\"624\" src=\"https:\/\/www.youtube.com\/embed\/qhD_mpaEOu0?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<h3>Getting there<\/h3>\n<p>By the time Voyager 2 reached Neptune, the Voyager mission team had completed five planetary encounters. But the big blue planet still posed unique challenges.<\/p>\n<p>Neptune is about 30 times farther from the sun than Earth. So, the icy giant receives only about 0.001 times the amount of sunlight that Earth does. In such low light, Voyager 2\u2019s camera required longer exposures to get quality images. But the spacecraft would reach a maximum speed of about 60,000 mph (90,000 kph) relative to Earth. So, a long exposure time would make the image blurry. (Imagine trying to take a picture of a roadside sign from the window of a speeding car.)<\/p>\n<p>So the team programmed Voyager 2\u2019s thrusters to fire gently during the close approach, thus rotating the spacecraft to keep the camera focused on its target without interrupting the spacecraft\u2019s overall speed and direction.<\/p>\n<h3>Receiving the radio signals from Neptune<\/h3>\n<p>The probe\u2019s distance meant by the time radio signals from Voyager 2 reached Earth, they were weaker than other flybys. But the spacecraft had the advantage of time. The Voyagers communicate with Earth via the Deep Space Network, or DSN, which utilizes several radio antennas. They are in Madrid, Spain; Canberra, Australia; and Goldstone, California. During Voyager 2\u2019s Uranus encounter in 1986, the three largest DSN antennas were 64 meters (210 feet) wide. To assist with the Neptune encounter, the DSN expanded the dishes to 70 meters (230 feet). They also included nearby non-DSN antennas to collect data, including another 64-meter (210 feet) dish in Parkes, Australia. And multiple 25-meter (82 feet) antennas at the Very Large Array in New Mexico.<\/p>\n<p>The effort ensured that engineers could hear Voyager loud and clear. It also increased how much data could reach Earth in a given period, thus enabling the spacecraft to send back more pictures from the flyby. <\/p>\n<h3>Being there<\/h3>\n<p>In the week leading up to that August 1989 close encounter, the atmosphere was electric at NASA\u2019s Jet Propulsion Laboratory in Pasadena, California, which manages the Voyager mission. As images taken by Voyager 2 during its Neptune approach made the four-hour journey to Earth, Voyager team members would crowd around computer monitors around the Lab to see. Stone said:<\/p>\n<blockquote>\n<p>One of the things that made the Voyager planetary encounters different from missions today is that there was no internet that would have allowed the whole team and the whole world to see the pictures at the same time. The images were available in real time at a limited number of locations.<\/p>\n<\/blockquote>\n<p>But the team was committed to giving the public updates as quickly as possible. So from August 21 to August 29, they would share their discoveries with the world during daily press conferences. On August 24, a program called <em>Voyager All Night<\/em> broadcast regular updates from the probe\u2019s closest encounter with the planet, which took place at 4 a.m. GMT (9 p.m. in California on August 24).<\/p>\n<p>The next morning, Vice President Dan Quayle visited the lab to commend the Voyager team. That night, Chuck Berry, whose song Johnny B. Goode was included on the Golden Record that flew with both Voyagers, played at JPL\u2019s celebration of the feat.<\/p>\n<figure id=\"attachment_319617\" aria-describedby=\"caption-attachment-319617\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2019\/08\/chuck-berry-carl-sagan-august-1989-e1566592570684.jpg\" alt=\"White-suited man with guitar next to gesturing man in tan suit, microphone in front of the pair.\" width=\"800\" height=\"547\" class=\"size-full wp-image-319617\"\/><figcaption id=\"caption-attachment-319617\" class=\"wp-caption-text\">Chuck Berry (l) and Carl Sagan (r) at a Voyager 2 Neptune flyby celebration in August 1989. Berry\u2019s song Johnny B. Goode is the only rock \u2018n\u2019 roll song on the Golden Records currently traveling into interstellar space aboard Voyagers 1 and 2. Image via NASA.<\/figcaption><\/figure>\n<h3>Voyagers were successful and continue today<\/h3>\n<p>Of course, the Voyagers\u2019 achievements extend far beyond that historic week over three decades ago. Both probes have now entered interstellar space after exiting the heliosphere, the protective bubble around the planets created by a high-speed flow of particles and magnetic fields spewed outward by our sun.<\/p>\n<p>They are reporting back to Earth on the \u201cweather\u201d and conditions from this region filled with the debris from stars that exploded elsewhere in our galaxy. They have taken humanity\u2019s first tenuous step into the cosmic ocean where no other operating probes have flown.<\/p>\n<p>Voyager data also complement other missions, including NASA\u2019s Interstellar Boundary Explorer (IBEX), which is remotely sensing that boundary where particles from our sun collide with material from the rest of the galaxy. And NASA is preparing the Interstellar Mapping and Acceleration Probe (IMAP), due to launch in 2025, to capitalize on Voyager observations.<\/p>\n<p>The Voyagers send their findings back to DSN antennas with 13-watt transmitters, about enough power to run a refrigerator light bulb. Stone said:<\/p>\n<blockquote>\n<p>Every day they travel somewhere that human probes have never been before. Years after launch, and they\u2019re still exploring.<\/p>\n<\/blockquote>\n<p>More information about the Voyager mission<\/p>\n<p>More images of Neptune taken by Voyager 2<\/p>\n<figure id=\"attachment_204904\" aria-describedby=\"caption-attachment-204904\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2014\/08\/Neptune-and-Triton_Voyager-2-cp-e1566593992292.jpg\" alt=\"A large blue crescent Neptune, next to a tiny blue crescent Triton.\" width=\"800\" height=\"572\" class=\"size-full wp-image-204904\"\/><figcaption id=\"caption-attachment-204904\" class=\"wp-caption-text\">Neptune and its large moon Triton, via Voyager 2.<\/figcaption><\/figure>\n<p>Bottom line: It has been 35 years since Voyager 2 visited Neptune as part of the Voyagers\u2019 Grand Tour of our solar system\u2019s four giant planets. As of today, no other earthly spacecraft has returned to Neptune.<\/p>\n<p>Via NASA<\/p>\n<p>Where is Voyager 2 going? And when will it get there?<\/p>\n<p>Read more: Why are the Voyager spacecraft getting closer to Earth?<\/p>\n<p><span class=\"cp-load-after-post\"\/><\/div>\n<div>\n<div class=\"post-author\">\n<h4>Deborah Byrd<\/h4>\n<p>                    View Articles\n                  <\/p><\/div>\n<div class=\"post-tags\">\n<h6 data-udy-fe=\"text_7c58270d\">About the Author:<\/h6>\n<p>Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Prior to that, she had worked for the University of Texas McDonald Observatory since 1976, and created and produced their Star Date radio series. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. In 2020, she won the Education Prize from the American Astronomical Society, the largest organization of professional astronomers in North America. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. &#8220;Being an EarthSky editor is like hosting a big global party for cool nature-lovers,&#8221; she says.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<p><br \/>\n<br \/><a href=\"https:\/\/earthsky.org\/space\/voyager-2-neptune-flyby-august-25-1989\/?rand=772280\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Voyager 2 acquired this image fewer than 5 days before its closest approach to Neptune on August 25, 1989. You can see Neptune\u2019s Great Dark Spot \u2013 a storm in&hellip; <\/p>\n","protected":false},"author":1,"featured_media":787795,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-787794","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sky"],"_links":{"self":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/787794","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=787794"}],"version-history":[{"count":0,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/787794\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/media\/787795"}],"wp:attachment":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=787794"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=787794"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=787794"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}