Why an 8-meter mirror with a 3 degree field? Couldn’t a smaller telescope or an array of smaller telescopes do the same science in a somewhat longer time?
Some of the science can’t be done at all with a smaller telescope, or group of small telescopes. For instance, the near-Earth object (NEO) survey is looking for things that won’t sit still for a long exposure. An exposure longer than 10 or 20 seconds becomes ineffective, and so finding the vast majority of NEOs which are small and faint requires a telescope that can collect a lot of light in 10 or 20 seconds. Similarly, longer exposures on a smaller telescope will not help characterize faint transient objects lasting only seconds. In an array of smaller telescopes, longer exposures would be required (to reach sky-noise limit) as well as multiple Gigapixel cameras. Some of the science can be done on a smaller telescope in a longer time, but consider the numbers: The speed with which you can survey an area of sky for objects of a given faintness is proportional to throughput (collecting area times field of view in meters squared degrees squared). The LSST enables totally new windows on t
Related Questions
- Why an 8.4 meter mirror with a 3.5 degree field? Couldn a smaller telescope or an array of smaller telescopes do the same science in a somewhat longer time?
- Why an 8-meter mirror with a 3 degree field? Couldn’t a smaller telescope or an array of smaller telescopes do the same science in a somewhat longer time?
- Who invented the non-spherical mirror telescope?
