All these Sky Pixels Are Yours The evolution of telescopes and CCD Arrays: The Coming Data Nightmare
Once Upon a Time: Life Was Simple • One Big Telescope • One Thick Mirror • One Lousy Detector
Old School • But No QE
Thick Mirrors • Made the support structure of the telescopes very expensive • Capital Cost scaled as A3 • Would be limiting factor • Thermal Issues • 1948-1982
Solution: Develop Thin Mirrors • Lower Cost for Support Structures • Thermal Issues are less
Next: Combine Individual Light Sources • First done at the Multiple Mirror Telescope which was commissioned in 1982
Thin to Segmented Mirrors • Thin Mirror Technology (including Hubble) would dominate from 1982 to about 1998 • Keck 10 meter segmented mirror
What about Detectors? • Photographic/Film is horrible non linear and no QE • Need a digital detector • Boyle and Smith 1969 CCD Nobel Prize
Optical Interferometer • Can it work at short wavelengths to combine the light from many mirrors?
24.5 Meter Telescope Coming • Giant Magellan Telescope • 7 x 8.4 mirrors
The Next Big Thing • A 33 GigaPixel Digital Camera
But is Big Aperture = Big Science • Historically not – Historically its survey instruments that advance the field. • Here comes the LSST
LSST Concept • Single 8.4 M mirror • 3 degree FOV (!) • 80% encircled energy = 0.2” (Like HST) • 10s integration equivalent to 10hr integration with 200 inch telescope. • There are 40,000 square degrees in the sky • So …
But Can this Work? Each image = 132 Gbyte 240 Images per hour = 32 Terrabytes 10 hours = 320 TB 4 Day Survey = 1.28 PB Rinse and repeat and each pixel contains information!