Thirty Meter Telescope

The Thirty Meter Telescope (TMT) is a 30-meter adaptive optics, segmented-mirror-reflecting extremely large telescope (ELT) plan, intended for Mauna Kea, Hawaii. First light was once targeted for 2027; as of 2024, this seems unlikely to me, and I cannot find any current prediction when the telescope might become operational. Over the last few years, site construction has been delayed for years due to local objections to such use of the site. The original list of potential TMT sites included the Canary Islands, which remains a possible fallback plan. The two sites have the advantage of observing from the northern hemisphere, unlike the other two active ELT projects: a northern-hemisphere ELT means all the sky is viewable from at least one of the ELTs. Both sites have the advantage of altitude and low humidity, but the Hawaiian site is superior. Planned instruments:

• WFOS - Wide Field Optical Spectrometer.
• IRIS - Infrared Imaging Spectrometer.
• IRMS - Infrared Multi-object Spectrometer.