NASA's Mission to Pluto and the Kuiper Belt
NASA's New Horizons spacecraft doesn't zoom past its next science target until New Year's Day 2019, but the Kuiper Belt object, known as 2014 MU69, is already revealing surprises.
Observers Kai Getrost and Alex Parker wait to collect 2014 MU69 stellar occultation data in Argentina on June 3, 2017. Several New Horizons team members and collaborators will return to the country on July 17 for this summer's third and final MU69 occultation observation opportunity. (Image credit: Kai Getrost)
Scientists have been sifting through data gathered from observing the object's quick pass in front of a star – an astronomical event known as an occultation – on June 3. More than 50 mission team members and collaborators set up telescopes across South Africa and Argentina, along a predicted track of the narrow shadow of MU69 that the occultation would create on Earth's surface, aiming to catch a two-second glimpse of the object's shadow as it raced across the Earth. Accomplishing the observations of that occultation was made possible with the help of NASA's Hubble Space Telescope and Gaia, a space observatory of the European Space Agency (ESA).
Combined, the pre-positioned mobile telescopes captured more than 100,000 images of the occultation star that can be used to assess the environment around this Kuiper Belt object (KBO). While MU69 itself eluded direct detection, the June 3 data provided valuable and unexpected insights that have already helped New Horizons.
"These data show that MU69 might not be as dark or as large as some expected," said occultation team leader Marc Buie, a New Horizons science team member from Southwest Research Institute (SwRI) in Boulder, Colorado.
Initial estimates of MU69's diameter, based primarily on data taken by the Hubble Space Telescope since the KBO's discovery in 2014, fall in the 12-25-mile (20-40-kilometer) range – though data from this summer's ground-based occultation observations might imply it's at or even below the smallest sizes expected before the June 3 occultation.
Besides MU69's size, the readings offer details on other aspects of the Kuiper Belt object.
"These results are telling us something really interesting," said New Horizons Principal Investigator Alan Stern, of SwRI. "The fact that we accomplished the occultation observations from every planned observing site but didn't detect the object itself likely means that either MU69 is highly reflective and smaller than some expected, or it may be a binary or even a swarm of smaller bodies left from the time when the planets in our solar system formed."
More data are on the way, with additional occultations of MU69 occurring on July 10 and July 17. On July 10, NASA's airborne Stratospheric Observatory for Infrared Astronomy (SOFIA) will use its powerful 100-inch (2.5-meter) telescope to probe the space around MU69 for debris that might present a hazard to New Horizons as it flies by in 18 months.
On July 17, the Hubble Space Telescope also will check for debris around MU69, while team members set up another groundbased "fence line" of small mobile telescopes along the predicted ground track of the occultation shadow in southern Argentina to try to better constrain, or even determine, the size of MU69.
Check out the star brightness, predicted shadow path and other tech specs for the July 10 and July 17 occultation events.
NASA imesema kuwa ndege ya New Horizons ya NASA haitaweza kusafiri hadi kwenye eneo la kwanza la uchunguzi wa sayari ya Pluto, lakini imesema kuwa ndege ya Kuiper Belt inayoitwa 2014 MU69 itaonekana katika eneo hilo. Watafiti wa NASA Kai Getrost na Alex Parker wanatarajia kukusanya data ya 2014 MU69 katika Argentina mnamo Juni 3, 2017. Washiriki kadhaa wa New Horizons wataanza safari ya kwanza ya uchunguzi wa MU69 Julai 17. "Kama ilivyoelezwa hapo juu, wanasayansi wamekuwa wakichunguza data zilizokusanywa kutoka kwa kuchunguza kupita kwa haraka kwa kitu hicho mbele ya nyota - tukio la angani linalojulikana kama ""kuficha"" - Juni 3. """ Zaidi ya wanachama 50 wa timu ya misheni na washirika waliweka darubini kote Afrika Kusini na Argentina, kando ya njia iliyotarajiwa ya kivuli cha MU69 ambacho kufichwa kwa jua kutatengeneza kwenye uso wa Dunia, na lengo la kukamata picha ya sekunde mbili ya kivuli cha kitu hicho wakati kinapiga mbio duniani. Utafiti huo ulifanywa kwa msaada wa darubini ya Hubble ya NASA na Gaia, kituo cha uchunguzi wa anga cha Shirika la Anga la Ulaya. Teleskopi hizo mbili zilizowekwa tayari zimepata picha zaidi ya 100,000 za nyota hiyo ambayo inaweza kutumiwa kutathmini mazingira ya karibu na kitu hiki cha Kuiper Belt. MU69 haikuonekana moja kwa moja, lakini data ya Juni 3 ilitoa ufahamu muhimu na usiotazamiwa ambao tayari umesaidia New Horizons. "Hii inaonyesha kwamba MU69 inaweza kuwa si giza au kubwa kama baadhi ya kutarajiwa, ""alisema kiongozi wa timu ya occultation Marc Buie, New Horizons sayansi timu mwanachama kutoka Southwest Research Institute (SWRI) katika Boulder, Colorado." Takwimu za awali za kipenyo cha MU69 zinategemea data zilizochukuliwa na darubini ya anga ya Hubble tangu kugunduliwa kwa KBO mnamo 2014, na zinaanguka katika safu ya kilomita 12-25 (mwisho wa data kutoka kwa uchunguzi wa jua wa jua wa majira ya joto) inaweza kuashiria kuwa iko katika au hata chini ya ukubwa mdogo unaotarajiwa kabla ya jua kupotea Juni 3. Mbali na ukubwa wa MU69, uchunguzi huo unatoa maelezo zaidi kuhusu sehemu nyingine za kiumbe hicho cha Kuiper Belt. "Hizi matokeo ni kutuambia kitu kweli ya kuvutia", alisema New Horizons Mkuu Mtafiti Alan Stern, wa SwRI. "Ukweli kwamba tulifanya uchunguzi wa kufichwa kutoka kila tovuti iliyopangwa ya uchunguzi lakini hatukuona kitu hicho mwenyewe, inawezekana inamaanisha kwamba ama MU69 ni ya kutafakari sana na ndogo kuliko wengine walivyotarajia, au inaweza kuwa binary au hata kundi la miili midogo iliyobaki kutoka wakati ambapo sayari katika mfumo wetu wa jua ziliundwa. """ Kwa mujibu wa taarifa ya shirika la habari la AFP, uchunguzi wa zaidi wa MU69 ulifanyika Julai 10 na 17. Mnamo Julai 10, NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) itatumia darubini yake yenye nguvu ya inchi 100 (mita 2.5) kuchunguza nafasi karibu na MU69 kwa mabaki ambayo yanaweza kuwa hatari kwa New Horizons wakati inapita katika miezi 18. "Jumapili, Hubble Space Telescope pia itaangalia kwa mabaki karibu na MU69, wakati wanachama wa timu hiyo wanaweka ""mstari wa uzio"" mwingine wa ardhi wa darubini ndogo za rununu kando ya njia ya ardhi iliyotabiriwa ya kivuli cha kuficha kusini mwa Argentina kujaribu kuzuia vizuri, au hata kuamua, ukubwa wa MU69." Angalia mwangaza wa nyota, njia ya kivuli iliyotarajiwa na vipimo vingine vya teknolojia kwa matukio ya kuficha ya Julai 10 na Julai 17.