APOD and General Astronomy Discussion Forum
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.Not blurred, but dimmed. Only a tiny portion of the light from M101 reaches Earth. Imagine the Earth intersecting the surface of a sphere of 27 million light years radius around M101. The surface area of the sphere represents all the light emitted by M101 in an instant, but the Earth occupies only the tiniest portion of that surface area, so we can only observe a tiny fraction of its light.DavidLeodis wrote:I wonder how much the image 'light' of M101 has spread out since it first came our way such perhaps that our view of M101 is blurred (like the light from a torch spreads out as it goes further from the torch).
. Your "dimmed" is a more appropriate word than my "blurred".It is interesting to consider true blurring and aberration, as well. The intervening space is not flat, but gravitationally "lumpy", and crisscrossed with gravitational waves. So there's actually some optical aberration, although over a mere 20 or 30 million light years, without any large intervening mass, that distortion is probably beyond our ability to measure, and certainly too small to be visible to our eyes in an image. But it's there.Nitpicker wrote:Not blurred, but dimmed. Only a tiny portion of the light from M101 reaches Earth. Imagine the Earth intersecting the surface of a sphere of 27 million light years radius around M101. The surface area of the sphere represents all the light emitted by M101 in an instant, but the Earth occupies only the tiniest portion of that surface area, so we can only observe a tiny fraction of its light.DavidLeodis wrote:I wonder how much the image 'light' of M101 has spread out since it first came our way such perhaps that our view of M101 is blurred (like the light from a torch spreads out as it goes further from the torch).
Not for galaxies, but the parallax method from Jupiter would allow us to measure accurate distances to more nearby stars (a bit further away), than the current Earth-bound parallax methods.ta152h0 wrote:would distances be more accurately calculated from distances, let's say Jupiter's orbit and 180 degrees apart ?
While New Horizons is biding its time out around ~40 AU it would be nice for it to use LORRI's ~1 arcsec resolution to take some stereo images of nearby stars (i.e., stars <40 parsecs distant in directions more or less perpendicular to the direction of 2014 MU69).Nitpicker wrote:Not for galaxies, but the parallax method from Jupiter would allow us to measure accurate distances to more nearby stars (a bit further away), than the current Earth-bound parallax methods.ta152h0 wrote:
would distances be more accurately calculated from distances, let's say Jupiter's orbit and 180 degrees apart ?
https://en.wikipedia.org/wiki/New_Horizons#Long-Range_Reconnaissance_Imager_.28LORRI.29 wrote:
<<New Horizons has maneuvered for a January 1, 2019 flyby of Kuiper belt object 2014 MU69 when it is 43.4 AU from the Sun. The Long-Range Reconnaissance Imager (LORRI) is a long-focal-length imager designed for high resolution and responsivity at visible wavelengths. The instrument is equipped with a 1024×1024 pixel by 12-bits-per-pixel monochromatic CCD imager with a 208.3 mm (8.20 in) aperture giving a resolution of 5 μrad (~1 arcsec).
In August 2013, it was proposed to use the radio-tracking data from New Horizons to discover indications on the position of a hypothesized trans-Neptunian planetary-sized body.>>