Comments by "H. de Jong" (@h.dejong2531) on "For the Last 33 Years, Hubble Has Been Seeing Something It Wasn't Designed For | Hubble Supercut" video.

  1. We've done something better than that: most of the planets in our solar system have been visited by spacecraft, which orbited those planets for years. We have photos showing far more detail than Hubble is capable of, of Mercury, Venus, Mars, Jupiter and Saturn. What Hubble brings in this case is that Saturn's orbiter Cassini is no longer in service.
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  2. The practical limit is set by the diameter of the mirror. This is called the diffraction limit, and there's a formula that calculates the best possible resolution based on mirror size and wavelength. If I remember correctly, Hubble's current cameras are already pretty close to that limit. Adding more pixels won't improve the image.
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  3. New Horizons took thousands of photos of Pluto. Hubble can't resolve Pluto very well: Pluto's size occupies only 10 pixels on Hubble's camera sensors.
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  4. Orbital spacecraft are an order of magnitude more expensive than a flyby. There are proposals to do an Uranus orbiter mission, but with the way NASA's planetary science budget is going, it will take a while for such a mission to get approved.
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  5. The impact caused a lot of gas from the lower atmosphere to mix with the upper atmospheric layers. The different colors of those gases cause the crater-like appearance.
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  6. Hubble produces some great photos, you mean. It's a camera. Not a guy drawing stuff.
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  7. The optics are similar, but the instruments are very different: KH is optimized for looking at the very bright daylit Earth, Hubble looks at very faint starlight. And Hubble has spectrocopic instruments, which the KHs don't need.
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  8. Nope. You imagine space is filled with far more matter than is there in reality. i.e. light travels farther than you think.
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  9.  @petethewrist  Space is not filled with slits either.
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  10. We have taken such pictures. Both LRO and Chandrayaan-2 photographed the Apollo landing sites from lunar orbit.
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  11. Hubble's resolution looking at Earth is around 30 cm/pixel.
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  12. Hubble's current cameras are already pretty close to the limit set by the mirror size.
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  13. Hubble doesn't have the resolution to do that. We do have several spacecraft orbiting the moon that have photographed the landing sites with enough resolution to see astronaut foot tracks.
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  14. Hubble takes photos, not "computer generated images".
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  15.  @petethewrist  Photons travel until they encounter an obstacle. Space is so empty that enough photons even from remote galaxies arrive here without encountering any obstacle.
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  16. JWST has looked at several of the outer planets already.
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  17. Eh, no. Hubble got a new mirror to a very different design to that used for spy satellites. Crucially, Hubble's mirror was a lot larger than previous mirrors made by Perkin-Elmer for spy satellites. PE modified the instrument they used for checking the mirror shape, but they did this incorrectly. Worse, they checked the mirror with a second, older instrument which indicated that the mirror shape was incorrect, but instead of realising there was a problem with a mirror, they assumed the older instrument wasn't working correctly. So the mirror was sent off for inclusion in Hubble. NASA didn't check the mirror again (relying on PE's previous checks), and launched the faulty mirror.
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  18.  @mcrick8931  There are articles online that have annotated photos of each landing site.
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  19.  @PtolemyJones  If you want to know how we can determine that: the diffraction limit tells us the upper limit of resolution for any optical system.
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  20. Learning more about the universe is never useless.
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  21. None of them. And as we know now, those aren't elements.
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  22. gravitational slingshot, you mean?
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  23. Our eyes are very ingenious. They adjust to the ambient light level, mostly without you noticing anything. The night sky is 9 orders of magnitude darker than a sunny noon. Hubble photos are bright because a. Hubble observes targets for long periods, and b. the brightness of the image is adjusted to a level we can see easily on a screen.
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  24.  @xaviercostar6554  yes. Earth's and Venus' orbits are both inclined, so most times, when Venus passes between us and the Sun it will go above or below the sun from our point of view.
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  25. We do have a satellite orbiting Jupiter right now: Juno. We used to have one at Saturn too: Cassini. So your argument holds no water.
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  26. New Horizons took thousands of pictures of Pluto.
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  27. HST has looked at Pluto, but it's so small it can't resolve any detail on the surface.
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