{"id":16065,"date":"2018-12-11T05:09:18","date_gmt":"2018-12-11T05:09:18","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=16065"},"modified":"2020-06-09T12:47:29","modified_gmt":"2020-06-09T12:47:29","slug":"nasas-voyager-2-probe-enters-interstellar-space","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/nasas-voyager-2-probe-enters-interstellar-space\/","title":{"rendered":"NASA\u2019s Voyager 2 Probe Enters Interstellar Space"},"content":{"rendered":"\n
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For the second time in history, a human-made object has reached the space between the stars. NASA\u2019s\u00a0Voyager 2<\/a>\u00a0probe now has exited the heliosphere \u2013 the protective bubble of particles and magnetic fields created by the Sun.<\/p>\n\n\n\n

Members of NASA\u2019s Voyager team will discuss the findings at a news conference at 11 a.m. EST (8 a.m. PST) today at the meeting of the American Geophysical Union (AGU) in Washington. The news conference will stream live on the agency\u2019s\u00a0website<\/a>.<\/p>\n\n\n\n

Comparing data from different instruments aboard the trailblazing spacecraft, mission scientists determined the probe crossed the outer edge of the heliosphere on Nov. 5. This boundary, called the heliopause, is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Its twin,\u00a0Voyager 1<\/a>, crossed this boundary in 2012, but Voyager 2 carries a working instrument that will provide first-of-its-kind observations of the nature of this gateway into interstellar space.<\/p>\n\n\n\n

Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information \u2013 moving at the speed of light \u2013 takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.<\/p>\n\n\n\n

The most compelling evidence of Voyager 2\u2019s exit from the heliosphere came from its onboard Plasma Science Experiment (PLS<\/a>), an instrument that stopped working on Voyager 1 in 1980, long before that probe crossed the heliopause. Until recently, the space surrounding Voyager 2 was filled predominantly with plasma flowing out from our Sun. This outflow, called the solar wind, creates a bubble \u2013 the heliosphere \u2013 that envelopes the planets in our solar system. The PLS uses the electrical current of the plasma to detect the speed, density, temperature, pressure and flux of the solar wind. The PLS aboard Voyager 2 observed a steep decline in the speed of the solar wind particles on Nov. 5. Since that date, the plasma instrument has observed no solar wind flow in the environment around Voyager 2, which makes mission scientists confident the probe has left the heliosphere.<\/p>\n\n\n\n

\u201cWorking on Voyager makes me feel like an explorer, because everything we\u2019re seeing is new,\u201d said John Richardson, principal investigator for the PLS instrument and a principal research scientist at the Massachusetts Institute of Technology in Cambridge. \u201cEven though Voyager 1 crossed the heliopause in 2012, it did so at a different place and a different time, and without the PLS data. So we\u2019re still seeing things that no one has seen before.\u201d<\/p>\n\n\n\n

In addition to the plasma data, Voyager\u2019s science team members have seen evidence from three other onboard instruments \u2013 the cosmic ray subsystem, the low energy charged particle instrument and the magnetometer \u2013 that is consistent with the conclusion that Voyager 2 has crossed the heliopause. Voyager\u2019s team members are eager to continue to study the data from these other onboard instruments to get a clearer picture of the environment through which Voyager 2 is traveling.<\/p>\n\n\n\n

\u201cThere is still a lot to learn about the region of interstellar space immediately beyond the heliopause,\u201d said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California.\u00a0<\/p>\n\n\n\n

Together, the two Voyagers provide a detailed glimpse of how our heliosphere interacts with the constant interstellar wind flowing from beyond. Their observations complement data from NASA\u2019s Interstellar Boundary Explorer (IBEX<\/a>), a mission that is remotely sensing that boundary. NASA also is preparing an additional mission \u2013 the upcoming Interstellar Mapping and Acceleration Probe (IMAP<\/a>), due to launch in 2024 \u2013 to capitalize on the Voyagers\u2019 observations.<\/p>\n\n\n\n

\u201cVoyager has a very special place for us in our heliophysics fleet,\u201d said Nicola Fox, director of the Heliophysics Division at NASA Headquarters. \u201cOur studies start at the Sun and extend out to everything the solar wind touches. To have the Voyagers sending back information about the edge of the Sun\u2019s influence gives us an unprecedented glimpse of truly uncharted territory.\u201d<\/p>\n\n\n\n

While the probes have left the heliosphere, Voyager 1 and Voyager 2 have not yet left the solar system, and won\u2019t be leaving anytime soon. The boundary of the solar system is considered to be beyond the outer edge of the\u00a0Oort Cloud<\/a>, a collection of small objects that are still under the influence of the Sun\u2019s gravity. The width of the Oort Cloud is not known precisely, but it is estimated to begin at about 1,000 astronomical units (AU) from the Sun and to extend to about 100,000 AU. One AU is the distance from the Sun to Earth. It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud and possibly 30,000 years to fly beyond it.<\/p>\n\n\n\n

The Voyager probes are powered using heat from the decay of radioactive material, contained in a device called a radioisotope thermal generator (RTG<\/a>). The power output of the RTGs diminishes by about four watts per year, which means that various parts of the Voyagers, including the cameras on both spacecraft, have been turned off over time to manage power.<\/p>\n\n\n\n

\u201cI think we\u2019re all happy and relieved that the Voyager probes have both operated long enough to make it past this milestone,\u201d said Suzanne Dodd, Voyager project manager at NASA\u2019s Jet Propulsion Laboratory (JPL) in Pasadena, California. \u201cThis is what we’ve all been waiting for. Now we\u2019re looking forward to what we\u2019ll be able to learn from having both probes outside the heliopause.\u201d<\/p>\n\n\n\n

Voyager 2 launched in 1977, 16 days before Voyager 1, and both have traveled well beyond their original destinations. The spacecraft were built to last five years and conduct close-up studies of Jupiter and Saturn. However, as the mission continued, additional flybys of the two outermost giant planets, Uranus and Neptune, proved possible. As the spacecraft flew across the solar system, remote-control reprogramming was used to endow the Voyagers with greater capabilities than they possessed when they left Earth. Their two-planet mission became a four-planet mission. Their five-year lifespans have stretched to 41 years, making Voyager 2 NASA\u2019s longest running mission.<\/p>\n\n\n\n

The Voyager story has impacted not only generations of current and future scientists and engineers, but also Earth’s culture, including film, art and music. Each spacecraft carries a\u00a0Golden Record<\/a>\u00a0of Earth sounds, pictures and messages. Since the spacecraft could last billions of years, these circular time capsules could one day be the only traces of human civilization.<\/p>\n\n\n\n

Voyager\u2019s mission controllers communicate with the probes using NASA\u2019s Deep Space Network (DSN<\/a>), a global system for communicating with interplanetary spacecraft. The DSN consists of three clusters of antennas in Goldstone, California; Madrid, Spain; and Canberra, Australia.<\/p>\n\n\n\n

The Voyager Interstellar Mission is a part of NASA\u2019s Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA\u2019s Science Mission Directorate in Washington. JPL built and operates the twin Voyager spacecraft. NASA\u2019s DSN, managed by JPL, is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions. The Commonwealth Scientific and Industrial Research Organisation, Australia\u2019s national science agency, operates both the Canberra Deep Space Communication Complex, part of the DSN, and the Parkes Observatory, which NASA has been using to downlink data from Voyager 2 since Nov. 8.<\/p>\n

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For the second time in history, a human-made object has reached the space between the stars. NASA\u2019s\u00a0Voyager 2\u00a0probe now has exited the heliosphere \u2013 the protective bubble of particles and magnetic fields created by the Sun. Members of NASA\u2019s Voyager team will discuss the findings at a news conference at 11 a.m. EST (8 a.m. […]<\/p>\n","protected":false},"author":2,"featured_media":16066,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-16065","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",985,554,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas-200x200.png",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas-300x169.png",300,169,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas-768x432.png",750,422,true],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",750,422,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",985,554,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",985,554,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",985,554,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",870,489,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",600,337,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",600,337,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",760,427,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",550,309,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",95,53,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",640,360,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",96,54,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/12\/nas.png",150,84,false]},"author_info":{"info":["RevoScience"]},"category_info":"Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/16065","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=16065"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/16065\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/16066"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=16065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=16065"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=16065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}