When you want to see the stars, find someplace dark
A beautiful image of Mauna Kea taken from the International Space Station. The image was taken using a Nikon D4 DLSR using an 800 millimeter lens. At the time the ISS was at an altitude of 215 nautical miles (398km) over the island.
Taken in the afternoon the low Sun angle causes the terrain to cast long shadows. The summit pu’u each stand out strongly in relief and the summit observatories are easily visible.
With the controversy again raging over the TMT we are again seeing complete mis-representation of astronomy in the press and social media. These postings and comments make interesting reading. These show the wide range of feelings in the community. There also seems to be a misunderstanding about the roles of large telescopes in general.
One of the themes that popped up in the comments several times was the idea that space telescopes are where to put the money and the belief that ground telescopes were “obsolete’, thus projects like TMT are not needed. This could not be further from the truth. Yes there are advantages to space telescopes with respect to interference from the atmosphere. But space telescopes face several severe and inherent disadvantages.
Space telescopes are hugely expensive for what you get. Hubble is a mere 2 meter class telescope. Very small in the terms of modern telescopes. This limits the performance drastically. Hubble can only collect a little more light than a single segment of the current Keck telescope, and Keck has 36 segments in it’s 10 meter mirror. Work out the math and you find that Keck gathers 25 times more light than than Hubble. The new James Webb Space Telescope will be a 6.5 meter telescope. The Thirty Meter Telescope will be 30 meters with 492 segments, thus will gather 28 times more light than JWST.
Continue reading “TMT versus Space Based Alternatives”
Planets, Stars, and How to Live on a Space Station
May 23rd Astronomy Program
Kailua Kona Library
3:30 PM to 4:30 PM
Allan Honey, a program engineer at Keck Observatory, will talk about the different distances in space between stars and planets. Allan’s son, Ben Honey, a flight controller for the International Space Station at the Johnson Space Center in Houston, will explain what happens when astronauts live and work in space. Allan Honey has worked at the Keck Observatory for more than 26 years, and Ben Honey grew up on the Big Island before leaving to study at Embry-Riddle Aeronautical University
Waimea was living up to reputation with a gusty wind and blowing mist. But this did little to dampen the Waimea Planet Walk sponsored by Keck and CFHT Observatories. A steady stream of parents and kids walked the length of the main street to visit the booths representing a scale model of the solar system.
The Sun and the inner solar system… Mercury, Venus Earth and Mars, all occupied the lawn directly in front of the Keck lobby. Each location was measured properly to achieve the correct position, each booth had a scale model of the planet to correctly interpret the scale of the entire solar system. This meant the Sun was about 8 inches (20cm) in diameter and the Earth a small dot mounted to a piece of wood. In the far corner of the Keck lawn, several hundred feet from the Sun, sat Jupiter represented by a 1/2-inch (1cm) ball bearing.
To visit the remainder of the solar system it was necessary to walk down Mamalahoa highway. Saturn sat in the upper corner of the KTA parking lot, beside the historic cemetery. Uranus was located in the lower corner of the KTA parking lot. Neptune in the park across the street from the library. At the end of the walk, Pluto and the rest of the TNO’s in the lawn of CFHT.
Everyone, volunteers and guests, seemed to be having a great time learning. All up and down the street walked parents and kids from station to station. It is always interesting to see the entire solar system represented to scale like this, even if you have seen it before. The experience is the first step to seeing just how big space is…
There is an article on the TMT in yesterdays’s Honolulu Advertiser. While the article shows growing community awareness of the Thirty Meter Telescope project and puts forth some of the basics, it concentrates on some of the political issues. Those are, as typical for Hawai’i, rather fractious, showing the very polarized nature of political discourse in the state.
One of the themes that popped up in the comments several times was the idea that space telescopes are where to put the money and the belief that ground telescopes were “obsolete’, thus projects like TMT are not needed. This could not be further from the truth. Yes there are advantages to space telescopes with respect to interference from the atmosphere. But space telescopes face several severe and inherent disadvantages.