A large diameter telescope provides two new basic capabilities that are not available with existing ground based telescopes and that cannot be delivered by the small telescopes in space or planned for the future:
- Improved spatial resolution, as long as the distorting effects of the Earth’s atmosphere are corrected for with an adaptive optics system; and
- Increased sensitivity
Sharper images allow us to see smaller objects and more detail; thus TMT will provide three times better resolution and detail than other telescopes. One example of new science that can be achieved with TMT’s tripled resolution is finding planets around other stars in the “habitable zone,” where the separation between the star and the exoplanet is similar to Earth and that allows for liquid water on the planet’s surface. Many other areas of science that TMT will explore require finer spatial resolution than is currently available. TMT will have a high performance adaptive optics system from day one.
TMT will also deliver a huge increase in sensitivity or image depth, thanks both to the larger area of the telescope and the sharper images. Increased sensitivity will finally allow us to detect the faintest, most distant galaxies and the smallest stars and planets. High sensitivity also means the properties of stars and galaxies are measured more quickly, allowing more objects to be studied and more rare objects to be found. The sensitivity for standard forms of observations is proportional to the telescope’s diameter (D) multiplied by itself 4 times (DxDxDxD). Today, large telescopes are typically 8 meters in diameter; in comparison, the TMT will be 200 times more sensitive, up to 200 times faster or able to detect objects 200 times fainter.
The TMT will be a general-purpose telescope, able to carry out different scientific investigations across many areas of astronomy, planetary science, and physics. The telescope will support a variety of instruments that work at different wavelengths of light (optical or infrared) and take images or spectral measurements. The instruments selected for early operations are versatile in nature.
A few key science areas that TMT will address far better than any existing facility include:
DARK MATTER AND DARK ENERGY:
TMT will study very distant “standard candle” supernovae that are magnified by the strong gravity of nearby galaxy clusters. The properties of these supernovae will allow TMT to test competing theories of Dark Energy and to determine how Dark Energy and Dark Matter have governed the evolution of our universe over cosmic time.