Another image of Ultima Thule

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Ultima Thule again

The image on the right was released during this morning’s first briefing outlining the successful confirmation of New Horizons’ fly-by of Ultima Thule (still on-going as I post this). It, along with other data, has provided an explanation for why the scientists have not detected a significant variation in brightness: Our view is looking down at the object’s poles

Images taken during the spacecraft’s approach — which brought New Horizons to within just 2,200 miles (3,500 kilometers) of Ultima at 12:33 a.m. EST — revealed that the Kuiper Belt object may have a shape similar to a bowling pin, spinning end over end, with dimensions of approximately 20 by 10 miles (32 by 16 kilometers). Another possibility is Ultima could be two objects orbiting each other. Flyby data have already solved one of Ultima’s mysteries, showing that the Kuiper Belt object is spinning like a propeller with the axis pointing approximately toward New Horizons. This explains why, in earlier images taken before Ultima was resolved, its brightness didn’t appear to vary as it rotated. The team has still not determined the rotation period.

They note that the highest resolution images will not arrive until February, though they do expect some good images by tomorrow.


One comment

  • Kirk

    During this afternoon’s briefing, Alan Stern answered a question about the likelihood of success for the highest resolution LORRI (Long-Range Reconnaissance Imager) images:

    This was really a stretch goal for the spacecraft. If this is the target [holds up water bottle]. As we were screaming by at 32,000 miles an hour, we took a series of images along the pathway of the error ellipse [moves hand past bottle], but the spacecraft only had time to capture one row. And so unless the frames were perfectly centered on the target, we will have missed part, or potentially all of it. Because it is a stretch goal, we wanted to try it, and we hope that it worked out, and we’re going to find out somewhat later. But the images that will start to come down this week will already reveal the basic geology and structure of Ultima for us, and we’re going to start writing our first scientific paper next week.

    LORRI’s field of view is only 0.29 degrees, compared to 5.8 degrees for MVIC (Multispectral Visible Imaging Camera).

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