A false - color image of Ceres ' Occator Crater shows differences in surface composition . On Ceres , blue is generally consort with shiny textile , found in more than 130 locations , and seems to be ordered with salt , such as sulfates . It is probable that silicate materials are also present . Image credit : NASA / JPL - Caltech / UCLA / MPS / DLR / IDA
In 2007 , a Delta II rocket carrying a NASA spacecraft calledDawnlaunched from Cape Canaveral , Florida . In 2011 , it arrive at the asteroid Vesta , where it spent 14 month in range analyze that physical object . It then left , powered by ion engines . Two and half age later Dawn insert the compass of Ceres , a mysterious dwarf major planet characterized by a complex geomorphology , that is locate in the asteroid belt between Mars and Jupiter .
The spacecraft recently complete the low - altitude , ball-shaped mapping of every in of the nanus planet ’s aerofoil . It did this over four months through a series of orbit , scanning one comic strip of landed estate at a time at a resolution of 35 metre / pel . Thanks to this intensive scrutiny , we now have some new insights into some of Ceres ’s characteristic . And yet other aspects remain mysterious — and confounding .
“ This is a physical structure unlike than any we ’ve examined thus far , " Chris Russell said last workweek at the Lunar and Planetary Science Conference in The Woodlands , Texas . Russell is the master police detective of the Dawn delegacy . " It fills a crack in our understanding of major planet evolution . It may still be evolving . ”
WHAT ARE THOSE BRIGHT SPOTS?
The bright spots of Ceres ' Occator crater as captured by NASA ’s Dawn space vehicle on June 25 , 2015 . look-alike credit : NASA / JPL - Caltech / UCLA / MPS / DLR / IDA
If you ’ve heard of Ceres , it ’s likely because of those mysterious white spots that scientists say us are definitely not exotic cities . They exist in Occator Crater , a complex feature of speech that is 92 kilometers in diam , 3 klick deep , and 70 to 80 million years old . The crater ’s lip is irregular and scollop . Its floor is bluish and its wall are red hued . The different coloring suggest compositional and physical divergence in the composite materials . The famed central bunch of bright spot is 10 kilometers across and very bright at the center of attention , with a mysterious dome .
“ The Occator dome continue to becharm us , " Russell state . In gamey - solution view , this " ever intriguing " planetary splotch bears an uncanny resemblance to “ a drop bag of flour , ” Russell said , adding , " That undimmed point has continue to charm us . ”
Notably , there are bright speckle elsewhere on Ceres , and to the rightfulness of the smart cluster and dome are supplementary spots , which are dimmer by a broker of two . Whatever is at body of work in Occator is not a wholly unique process , but we do n’t know what that summons is yet .
HOW TO SCAN AN ALIEN WORLD
Dawn is charge with soft instruments to help decipher the dwarf planet ’s closed book . The Gamma Ray and Neutron Detector ( GRaND ) maps factor on the asteroid so that scientist can make sense of the control surface and mental process at work . The official document works like this . Galactic cosmic rays peck into the regolith ( the loose surface level ; on Earth , think : dirt ) , and interactions with the surface lead to emission of neutrons and Vasco da Gamma beam of light . GRaND observe these emission as they bounce into space . neutron at different energy grade correspond to unlike surface element .
NASA / JPL - Caltech / UCLA / ASI / INAF
During the regolith fundamental interaction , when the cosmic rays hit the nucleus of an mote , the nucleus explodes , sending neutron and protons in all directions . Some neutrons escape the regolith , some smash into other karyon . Here ’s where it gets interesting . If a neutron murder the nucleus of a hydrogen atom , it loses energy in the interaction , like to the way a discriminative stimulus Lucille Ball stop when it strike another globe in a biz of pool . When GRaND is counting neutrons , therefore , small numbers hint more hydrogen .
That ’s what is shown on the above map , which is colour - coded for the comportment of H . ( Blue is more ; red is less . ) The area in drab is the north celestial pole of Ceres , and as the map reveal , it ’s teeming with hydrogen , comparatively speak . This indicates the presence of water system ice — H2O — near the gnome planet ’s open . This is the first sentence such ice has been detected , and the finding is consistent with longstanding scientific predictions . Planetary scientists will go on psychoanalyze the data hoard by GRaND and other instrument for easily understand the origin and evolution of Ceres .
" We ’re try about a cadence below the surface , " said Thomas Prettyman of the Planetary Science Institute , who lead the GRaND squad . " So we ’re below the optical surface , which make it complementary to the optical mass spectrometer . " Because cosmic rays strike from every steering in space , these measurements can even be made in total swarthiness , further affix the optical instrument data .
They ’re also plan to take some color data on the surface , Russell said . “ We ’ll take color of choose region — we ca n’t do the whole body — and we ’ll be doing topography over the next few month . ”
SOLVING THE MYSTERY
There is some discussion as to whether Ceres , now assort as a dwarf planet , should still be turn over an asteroid . Such taxonomic debates mouth to the exciting forward march of planetary science . The more scientist find out , the blurrier the telephone circuit get , and there is metre yet for the lines to get blurrier still .
“ Our stay at Ceres will likely be through former 2017 , " said Carol Raymond , the deputy principal investigator ofDawn . " We still have quite a way to go to fill in lacuna at lowest height . We expect we ’ll get lots of interesting data point for a long meter to descend . ”
That data point will come in many forms . " We ’ve been focus on the television camera data point , " Raymond toldmental_floss , noting that in addition to the Framing Camera and GRaND , the Visible & Infrared Spectrometer ( VIR ) tool is judge methodically to capture data to fill in gaps , though that ’s a dull process . " We ca n’t always augur ahead while we ’re sequencing ; it ’s a secret plan of cat - and - mouse to beguile high - value areas . "
blank space has take its toll onDawnover these nine years , and the spacecraft ’s reaction wheel are no longer fully honest . The wheels , which act as a sort of gyro , help guide and position the spacecraft . This wo n’t end the missionary post , though it does n’t make the caper any well-situated . In the months and years to come , information sets will continue being built , analysis conducted , and models run .
Take a closer look at Ceres in the video below .
