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Asteroids are identified and tracked with radio waves, not visible light, so I don't think sun glare is a major issue.

by jessriedel 10y ago

sxcurry 10y ago
I've never heard this before. Can you provide a reference for more info?
- jessriedel 10y ago
  Radar is how lots of asteroid imaging is done: https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_comets https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_... However, I wasn't aware of the optical methods mitchty was referring to.
LeoPanthera 10y ago
This is not correct. Optical telescopes are used, in conjunction with the WISE space telescope. https://www.nasa.gov/content/asteroid-grand-challenge/detect/how-do-we-detect-asteroids https://www.nasa.gov/content/asteroid-grand-challenge/detect...
CydeWeys 10y ago
Active radar is subject to n^4 (!!!) drop-off with distance and as such is not useful for astronomical observation of any sort. Only passive detection is useful, which has a much more manageable dropoff of n^2. And asteroids don't emit radio waves, but they do reflect the Sun's light.
- snrplfth 10y ago
  I think they're talking about the Goldstone Array: https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar It's used for high-res imaging of asteroids that pass close by.
  - CydeWeys 10y ago
    Interesting, though it appears to be useful for imaging, not so much detection.
mitchty 10y ago
Radio only works for relatively close asteroids. https://en.wikipedia.org/wiki/Sentinel_Space_Telescope https://en.wikipedia.org/wiki/Sentinel_Space_Telescope Which was sadly cancelled: http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-pulls-plug-killer-asteroid-hunter-Sentinel-mission-set-search-dangerous-space-rocks-loses-30-million-support.html http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-... But the principle was based off infrared: http://aviationweek.com/space/ball-aerospace-ramps-sentinel-asteroid-mission http://aviationweek.com/space/ball-aerospace-ramps-sentinel-... The canadian satellite also uses light: https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance_Satellite https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance... Visible light is only one fraction of the spectrum, infrared is far more valuable for detection. Most asteroids are detected via passive observation. Radio waves are not conducive to detecting asteroids.
- jessriedel 10y ago
  My mistake. Thank you for the correction.

Asteroids are identified and tracked with radio waves, not visible light, so I don't think sun glare is a major issue.

sxcurry 10y ago

I've never heard this before. Can you provide a reference for more info?

jessriedel 10y ago
Radar is how lots of asteroid imaging is done: https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_comets https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_... However, I wasn't aware of the optical methods mitchty was referring to.

LeoPanthera 10y ago

This is not correct. Optical telescopes are used, in conjunction with the WISE space telescope. https://www.nasa.gov/content/asteroid-grand-challenge/detect/how-do-we-detect-asteroids https://www.nasa.gov/content/asteroid-grand-challenge/detect...

CydeWeys 10y ago

Active radar is subject to n^4 (!!!) drop-off with distance and as such is not useful for astronomical observation of any sort. Only passive detection is useful, which has a much more manageable dropoff of n^2. And asteroids don't emit radio waves, but they do reflect the Sun's light.

snrplfth 10y ago
I think they're talking about the Goldstone Array: https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar It's used for high-res imaging of asteroids that pass close by.
- CydeWeys 10y ago
  Interesting, though it appears to be useful for imaging, not so much detection.

mitchty 10y ago

Radio only works for relatively close asteroids. https://en.wikipedia.org/wiki/Sentinel_Space_Telescope https://en.wikipedia.org/wiki/Sentinel_Space_Telescope Which was sadly cancelled: http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-pulls-plug-killer-asteroid-hunter-Sentinel-mission-set-search-dangerous-space-rocks-loses-30-million-support.html http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-... But the principle was based off infrared: http://aviationweek.com/space/ball-aerospace-ramps-sentinel-asteroid-mission http://aviationweek.com/space/ball-aerospace-ramps-sentinel-... The canadian satellite also uses light: https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance_Satellite https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance... Visible light is only one fraction of the spectrum, infrared is far more valuable for detection. Most asteroids are detected via passive observation. Radio waves are not conducive to detecting asteroids.

jessriedel 10y ago
My mistake. Thank you for the correction.