{
  "analysisId": 277,
  "status": "ready",
  "videoId": "4czjS9h4Fpg",
  "url": "https://www.youtube.com/watch?v=4czjS9h4Fpg",
  "title": "Perseverance Rover’s Descent and Touchdown on Mars (Official NASA Video)",
  "channel": "NASA",
  "posterUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg.jpg",
  "durationSeconds": 205,
  "mode": "smart",
  "analysis": {
    "overview": "This official NASA video presents the onboard camera views and mission control audio of the Perseverance rover's descent and touchdown on Mars.",
    "tldr": [
      "Parachute deployment confirmed with significant deceleration observed.",
      "Heat shield separates as Perseverance slows to subsonic speeds.",
      "Touchdown is confirmed, placing the rover safely on the Martian surface."
    ],
    "videoKind": "news_event",
    "keyPoints": [],
    "entities": [
      "NASA",
      "JPL",
      "Mars 2020",
      "Perseverance Rover",
      "MRO"
    ],
    "limitations": [],
    "coverage": "dense",
    "mode": "smart",
    "analyzedRanges": [
      {
        "startSeconds": 0,
        "endSeconds": 205,
        "kind": "initial"
      }
    ],
    "brief": [
      {
        "startSeconds": 14,
        "text": "Parachute deployment confirmed with significant deceleration observed.",
        "at": "0:14",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=14s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/14.jpg"
      },
      {
        "startSeconds": 33,
        "text": "Heat shield separates as Perseverance slows to subsonic speeds.",
        "at": "0:33",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=33s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/33.jpg"
      },
      {
        "startSeconds": 187,
        "text": "Touchdown is confirmed, placing the rover safely on the Martian surface.",
        "at": "3:07",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=187s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/187.jpg"
      }
    ],
    "facts": [
      {
        "startSeconds": 26,
        "label": "Velocity",
        "value": "450 meters per second",
        "source": "spoken",
        "at": "0:26",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=26s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/26.jpg"
      },
      {
        "startSeconds": 27,
        "label": "Altitude",
        "value": "12 kilometers",
        "source": "spoken",
        "at": "0:27",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=27s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/27.jpg"
      },
      {
        "startSeconds": 44,
        "label": "Velocity",
        "value": "145 meters per second",
        "source": "spoken",
        "at": "0:44",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=44s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/44.jpg"
      },
      {
        "startSeconds": 48,
        "label": "Altitude",
        "value": "9 and a half kilometers",
        "source": "spoken",
        "at": "0:48",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=48s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/48.jpg"
      },
      {
        "startSeconds": 69,
        "label": "Velocity solution",
        "value": "3.3 meters per second",
        "source": "spoken",
        "at": "1:09",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=69s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/69.jpg"
      },
      {
        "startSeconds": 71,
        "label": "Altitude",
        "value": "7.4 kilometers",
        "source": "spoken",
        "at": "1:11",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=71s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/71.jpg"
      },
      {
        "startSeconds": 76,
        "label": "Velocity",
        "value": "100 meters per second",
        "source": "spoken",
        "at": "1:16",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=76s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/76.jpg"
      },
      {
        "startSeconds": 79,
        "label": "Altitude",
        "value": "6.6 kilometers",
        "source": "spoken",
        "at": "1:19",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=79s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/79.jpg"
      },
      {
        "startSeconds": 96,
        "label": "Velocity",
        "value": "90 meters per second",
        "source": "spoken",
        "at": "1:36",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=96s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/96.jpg"
      },
      {
        "startSeconds": 98,
        "label": "Altitude",
        "value": "4.2 kilometers",
        "source": "spoken",
        "at": "1:38",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=98s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/98.jpg"
      },
      {
        "startSeconds": 127,
        "label": "Velocity",
        "value": "83 meters per second",
        "source": "spoken",
        "at": "2:07",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=127s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/127.jpg"
      },
      {
        "startSeconds": 130,
        "label": "Altitude",
        "value": "2.6 kilometers",
        "source": "spoken",
        "at": "2:10",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=130s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/130.jpg"
      },
      {
        "startSeconds": 140,
        "label": "Velocity",
        "value": "75 meters per second",
        "source": "spoken",
        "at": "2:20",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=140s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/140.jpg"
      },
      {
        "startSeconds": 142,
        "label": "Altitude",
        "value": "1 kilometer",
        "source": "spoken",
        "at": "2:22",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=142s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/142.jpg"
      },
      {
        "startSeconds": 152,
        "label": "Speed",
        "value": "30 meters per second",
        "source": "spoken",
        "at": "2:32",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=152s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/152.jpg"
      },
      {
        "startSeconds": 154,
        "label": "Altitude",
        "value": "300 meters",
        "source": "spoken",
        "at": "2:34",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=154s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/154.jpg"
      },
      {
        "startSeconds": 177,
        "label": "Distance off surface",
        "value": "20 meters",
        "source": "spoken",
        "at": "2:57",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=177s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/177.jpg"
      }
    ],
    "chapters": [
      {
        "title": "Parachute Deployment and Heat Shield Separation",
        "startSeconds": 0,
        "endSeconds": 67,
        "summary": "The spacecraft begins the straighten up and fly right maneuver, jettisoning entry balance masses to prepare for parachute deployment and roll over. Navigation confirms the parachute has deployed at a velocity of 450 meters per second and an altitude of about 12 kilometers. Perseverance then slows to subsonic speeds, leading to heat shield separation at 33 seconds, which allows the radar and cameras to view the Martian surface at a velocity of 145 meters per second and an altitude of 9.5 kilometers.",
        "takeaways": [
          "Parachute deployment successfully reduces descent velocity significantly in the Martian atmosphere.",
          "Heat shield separation provides onboard optics and radar with direct visibility of the terrain."
        ],
        "at": "0:00",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=0s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/5.jpg"
      },
      {
        "title": "Descent, Terrain Relative Navigation, and Touchdown",
        "startSeconds": 67,
        "endSeconds": 205,
        "summary": "Navigation confirms radar lock and nav filter convergence at 3.3 meters per second and 7.4 kilometers altitude. Terrain relative navigation initializes, landing engines prime, and the back shell separates at an altitude of 2.6 kilometers. The spacecraft performs a divert maneuver, reaching a speed of 30 meters per second at 300 meters altitude, before initiating the skycrane maneuver at 20 meters off the surface. Touchdown is successfully confirmed, landing the Perseverance rover safely on Mars.",
        "takeaways": [
          "Terrain relative navigation and landing engine priming enable precise hazard avoidance during descent.",
          "The skycrane maneuver safely lowers the rover onto the Martian surface for mission operations."
        ],
        "at": "1:07",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=67s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/72.jpg"
      }
    ],
    "evidence": [
      {
        "startSeconds": 1,
        "title": "Mission Control View",
        "description": "NASA Jet Propulsion Laboratory control room monitors the descent telemetry.",
        "onScreenText": "PERSEVERANCE ROVER’S DESCENT AND TOUCHDOWN ON MARS ONBOARD CAMERA VIEWS",
        "evidenceType": "both",
        "confidence": "high",
        "at": "0:01",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=1s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/1.jpg"
      },
      {
        "startSeconds": 13,
        "title": "Parachute Deployment Split View",
        "description": "Split screen showing 30 percent speed and real-time footage of parachute deployment.",
        "onScreenText": "30% speed real time",
        "evidenceType": "both",
        "confidence": "high",
        "at": "0:13",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=13s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/13.jpg"
      },
      {
        "startSeconds": 33,
        "title": "Heat Shield Separation",
        "description": "The heat shield separates and falls away, revealing the Martian surface below.",
        "onScreenText": "Heat shield sep.",
        "evidenceType": "both",
        "confidence": "high",
        "at": "0:33",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=33s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/33.jpg"
      },
      {
        "startSeconds": 126,
        "title": "Back Shell Separation",
        "description": "The back shell separates from the descending spacecraft.",
        "onScreenText": "Back shell sep.",
        "evidenceType": "both",
        "confidence": "high",
        "at": "2:06",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=126s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/126.jpg"
      },
      {
        "startSeconds": 172,
        "title": "Skycrane Maneuver",
        "description": "Multiple camera angles show the skycrane maneuver lowering the rover toward the surface.",
        "onScreenText": "",
        "evidenceType": "visual",
        "confidence": "high",
        "at": "2:52",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=172s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/172.jpg"
      },
      {
        "startSeconds": 187,
        "title": "Touchdown Confirmation",
        "description": "Mission control celebrates as touchdown is confirmed.",
        "onScreenText": "WE LANDED!",
        "evidenceType": "both",
        "confidence": "high",
        "at": "3:07",
        "youtubeUrl": "https://www.youtube.com/watch?v=4czjS9h4Fpg&t=187s",
        "frameUrl": "https://vidwords.com/img/yt/4czjS9h4Fpg/at/187.jpg"
      }
    ],
    "demonstratedSteps": []
  },
  "howToCite": "Cite moments as markdown links: [12:34](youtubeUrl) — each youtubeUrl opens the video at that second. frameUrl is a still of that moment."
}