• Introduction
    • Stardust-NExT

       

      Stardust-NExT


      After successfully completing its mission to collect interstellar dust and dust from the nucleus of comet Wild 2 and return the tiny particles safely to Earth, the Stardust spacecraft took on a new assignment. The Stardust New Exploration of Tempel 1, or NExT, project is tasked to fly by comet Tempel 1, the target of the Deep Impact mission in 2005. It’s the first time NASA has revisited a comet. This return trip in a new vehicle revealed changes to the comet's surface since the Deep Impact experiment and a close approach to the Sun and gave us a glimpse of the crater generated by the Deep Impact encounter. It also imaged new terrain not seen during the Deep Impact mission and took new dust measurements.

       

       

      Mission Management

       
      Dr. Joseph Veverka
      Dr. Joseph Veverka
      Principal Investigator

      Dr. Joseph Veverka of Cornell University, Ithaca, NY, is NExT's principal investigator. NASA’s Jet Propulsion Laboratory, Pasadena, CA, manages the project. Lockheed Martin Astronautics of Denver, CO, built the spacecraft.

       
       
         
         
         
       
  • Science Objectives
    • Stardust-NExT will flyby comet Tempel 1 on February 14, 2011, to extend the exploration initiated by Deep Impact by:

         

      obtaining high resolution images of the coma, nucleus, and jets at resolutions as high as 12 m/pixel

      measuring the composition, size, distribution, and flux of dust emitted into the coma

         

      If the flyby goes as planned, significant portions of the hemisphere studied by Deep Impact in 2005 will be viewed.

       

       

      The Deep Impact analysis
      The Deep Impact analysis of Tempel 1’s gas and dust coma images revealed asymmetric distributions of water, copernicium, C2 and dust. 
       
       
  • Details
    • The Stardust spacecraft launched on February 7, 1999, and collected interstellar dust particles during 2000 and 2002. On January 2, 2004, it flew within 149 miles of the nucleus of comet Wild 2 where it captured comet dust in its aerogel-filled collector grid and took detailed pictures of the comet's surface. Two years later the sample return capsule returned to Earth. Scientists analyzing the returned dust particles have been thrilled and surprised by their findings. Meanwhile, Stardust continued its journey through space. A maneuver was executed on October 10, 2007, sending the spacecraft toward its new target, comet Tempel 1.


      Meanwhile in another part of the solar system, celestial fireworks were took place on July 4, 2005, when the two-part Deep Impact spacecraft released an “impactor” into the path of comet Tempel 1. Scientists gained a vast amount of knowledge from this encounter and made discoveries that raise new questions. The new observations of Tempel 1 carried out by Stardust-NExT will be performed with a different set of instruments, offering an unprecedented opportunity to add to the body of cometary knowledge.


      On February 14, 2011, the Stardust spacecraft made its closest approach to Tempel 1 at 8:40 pm PT at a distance of 111 miles. Stardust took 72 high-resolution images of the comet. It also accumulated 468 kilobytes of data about the dust in its coma, the cloud that is a comet's atmosphere.


      views of Tempel 1
      These images show views of Tempel 1 from Deep Impact (left) and Stardust-NExT (right). Two craters, about 1,000 feet in diameter, help scientists locate the area hit by the impactor released by Deep Impact in July 2005. The dashed lines correlate the features. Stardust approached the comet from a different angle on Feb. 14, 2011.
      Image credit: NASA/JPL-Caltech/University of Maryland/Cornell
       
  • Results
    • The Stardust-NExT mission accomplished its goals, which included observing changes in surface features in areas previously photographed during the 2005 Deep Impact mission; imaging new terrain; and viewing the crater generated when the 2005 mission propelled an impactor at the comet.


      "This mission is 100 percent successful," said Joe Veverka, Stardust-NExT principal investigator. "We saw a lot of new things that we didn't expect, and we'll be working hard to figure out what Tempel 1 is trying to tell us." Several of the images provide tantalizing clues to the result of the Deep Impact mission's collision with Tempel 1.


      The images show a crater with a small mound in the center, and it appears that some of the ejecta went up and came right back down. According to co-investigator Pete Schultz of Brown University, Providence, RI, this tells us the cometary nucleus is fragile and weak based on how subdued the crater appears to be.


      Engineering telemetry downlinked after closest approach indicates the spacecraft flew through waves of disintegrating cometary particles, including a dozen impacts that penetrated more than one layer of its protective shielding. "The data indicate Stardust went through something similar to a B-17 bomber flying through flak in World War II," said Don Brownlee, Stardust-NExT co-investigator from the University of Washington in Seattle. "Instead of having a little stream of uniform particles coming out, they apparently came out in chunks and crumbled."


      The Stardust spacecraft, which has logged over 3.5 billion miles since launch, will continue to image the comet as long as the science team can gain useful information.

       


       




      changes in the surface of comet Tempel 1
      These images show changes in the surface of comet Tempel 1, observed first by the Deep Impact Mission in 2005 (top) and again by the Stardust-NExT mission in 2011 (bottom). Between the two visits, the comet made one trip around the Sun. The smooth terrain is at a higher elevation than the more textured surface around it. Scientists think that cliffs, illustrated with yellow lines to the right, are being eroded back to the left in this view. The cliffs appear to have eroded as much as 66 to 100 feet in some places since 2005. The box shows depressions that have merged together over time, also from erosion. This erosion is caused by volatile substances evaporating away from the comet.
      Image credit: NASA/JPL-Caltech/University of Maryland/Cornell
       
      a side of the nucleus
      This image shows a side of the nucleus not seen before. Three terraces of different elevations are visible, with dark, banded scarps, or slopes, separating them. The lowest terrace has two circular features that are about 500 feet in diameter. The inset at right shows a closer view.
      Credit: NASA/JPL-Caltech/Cornell
       

      A CAI particle found in the Stardust collection
      These images compare the area of Tempel 1 that was hit by the Deep Impact impactor. At left is a composite of images obtained by Deep Impact in July 2005 prior to impact. The image at right has arrows identifying the rim of the crater caused by the impactor. The crater is estimated to be 500 feet in diameter. This image also shows a brighter mound in the center of the crater likely created when material from the impact fell back into the crater.
      Credit: NASA/JPL-Caltech/University of Maryland/Cornell
       
       
         
       
       
  • Noteworthy
    • Out of thousands of comets in our solar system we’ve only seen close up views of five. Flybys of comets Halley, Borelly, Wild-2, Tempel 1, and Hartley 2 have given us more information about comets than we ever had. But the Stardust-NExT mission is doing something never done before – going back to a comet we have already flown by.  This unprecedented return trip provides an amazing opportunity to view both naturally occurring changes that have taken place on the comet’s surface since 2005 and the human-directed crater excavated by the Deep Impact impactor.  

      A montage of all five comets
      A montage of all five comets whose nuclei have been imaged directly by spacecraft, to scale with each other. Hartley 2 is the smallest comet ever visited by a spacecraft! Will Tempel 1 look different when Stardust-NExT flies by? (Click to enlarge)
      Credit: Halley: Russian Academy of Sciences/Ted Stryk. Tempel 1 and Hartley 2: NASA/JPL/UMD. Borrelly: NASA/JPL/Ted Stryk. Wild 2: NASA/JPL. Montage by Emily Lakdawalla
       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

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