Michael Lloyd-Hart and Roger Angel
The ultimate solution is to get above the atmosphere by putting a large telescope in space. Unfortunately, the existing Hubble Telescope is too small, and its mirrors emit heat. The diffraction-limited resolution provided by its 2.4 m aperture is not high enough to separate star
and planet in the infrared, even were it equipped with detectors in the 5 to 10 micron range, and in the visible, it simply does not collect enough light. NASA’s Next Generation Space Telescope
(NGST), on the other hand,
with a diameter of 8 m, is
specifically targeted for
observations at the right
wavelengths. NGST will be able to see giant planets orbiting at large separations around other stars, but it will not be operational for about a decade. Now in the planning stages is another NASA mission called Terrestrial Planet Finder, or TPF, which will extend the search to smaller Earth-like planets, and will look for key features in the spectra of any that it finds. In the case of our Earth, the infrared spectrum shows strong features of water, indicating the presence of oceans, and ozone. As far as we know, life is the only process that can maintain such a high abundance of ozone in the
atmosphere. If we found another Earth-like planet with a similar spectrum, we would strongly suspect that it also supported life.
Log in or Become a member to view the full text of this article.
This article may be available for purchase via the search at www.osapublishing.org.
OSA Members get the full text of Optics & Photonics News, plus a variety of other member benefits.
Publish Date: 01 October 2000
Towards the Ultimate Control of Light: Optical frequency metrology and the phase control of femtosecond pulses
Photonic Crystals: Towards Large-Scale Integration of Optical and Optoelectronic Circuits
The Clearest Glass in the World
Imaging the Sun: In Extreme Ultraviolet and in X-Rays with Space borne Instruments
“Spiked” Semiconductors for Clean Hydrogen Production
Self-Organized 3D Integrated Optical Interconnects
Tuning Quantum Light in Both Time and Space