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LORRI has a 8" primary mirror, not 3. Ralph has a 75mm mirror, but that's the secondary telescope; it does multispectral photography (6 bands) and infrared spec
by nwallin 8y ago
LORRI has a 8" primary mirror, not 3. Ralph has a 75mm mirror, but that's the secondary telescope; it does multispectral photography (6 bands) and infrared spectrometry.
Even with such a small primary mirror, New Horizons has a number of advantages. First, Ultima Thule is larger than Manhattan. Not exactly large, but certainly bigger than the Empire State Building.
Second, the mount is incredibly stable. There are basically no vibrations to speak of. As an amateur astronomer, I can tell you that the mount is one of the most important pieces of equipment in astrophotography. A mediocre telescope on a good mount will give good images. A good telescope on a mediocre mount will give mediocre images.
Third, the mirror itself is much better designed and manufactured than the average amateur astronomer's scope. Certainly better than any of mine.
Fourth, the sensor is cooled to very low temperatures, so it is way less noisy than the average consumer sensor.
Fifth, there is no atmosphere in the way. This is a huge advantage.
When all is said and done, LORRI will have a resolution on Ultima Thule's surface of about 60 feet. Certainly no Google Earth, but plenty good enough for the science objects of the flyby.
- AndrewKemendo 8y agoAh, didn't know the LORRI was the primary and not the Ralph, thanks. So when do you think we'll see the LORRI images of Ultima Thule? My point remains though, and it was just a general metaphor about how astounding the stuff they are trying to do is from an imaging perspective.
- azernik 8y agoThe images are LORRI images; however, because of bandwidth constraints (about 1000bps), these are lower-resolution versions of the LORRI images for press and initial science work. e.g. a one-tenth-resolution image takes about 3 hours to download. See here for a description of the sequence of transmissions: https://youtu.be/ymJRlUQfPfQ?t=586 https://youtu.be/ymJRlUQfPfQ?t=586 EDIT: The full download of the gigabytes of data from the flyby will take 20 months to download.
- Agathos 8y agoEmily Lakdawalla wrote a great timeline here. http://www.planetary.org/blogs/emily-lakdawalla/2018/what-to-expect-new-horizons-mu69-ultima-thule.html http://www.planetary.org/blogs/emily-lakdawalla/2018/what-to... The best shots won't be for a while, but hopefully the team received some informative images today or tonight and will be able to share them at tomorrow's press conference. As she notes, there is a chance that the first downloads will miss Ultima Thule entirely. The encounter was just that difficult. As for LORRI and Ralph, can't we call them both "primary?" Only Ralph produces color images, so most color shots of Pluto are Ralph's (https://solarsystem.nasa.gov/resources/639/the-frozen-canyons-of-plutos-north-pole/?category=planets/dwarf-planets_pluto https://solarsystem.nasa.gov/resources/639/the-frozen-canyon...). LORRI has higher resolution, which is why some of the most stunning shots of Pluto are black and white (https://solarsystem.nasa.gov/resources/652/plutos-majestic-mountains-frozen-plains-and-foggy-hazes/?category=planets/dwarf-planets_pluto https://solarsystem.nasa.gov/resources/652/plutos-majestic-m...). Some images were produced by "painting" Ralph's colors onto LORRI's high resolution features (https://solarsystem.nasa.gov/resources/699/pluto-dazzles-in-false-color/?category=planets/dwarf-planets_pluto https://solarsystem.nasa.gov/resources/699/pluto-dazzles-in-...).
- jessriedel 8y agoI really enjoyed this comment, thank you.