Astronomy

I have been interested in astronomy for a very long time. I'm unavoidably handicapped in admiring the stars myself by bad short-sightedness: my glasses help, but it's impressive enough that they can give me sharp vision at arm's length that I don't complain that the stars are not pin-points, and that (since the light is spread out) the faint stars aren't there.

I had the good fortune to encounter Voyager's pictures of Jupiter, Saturn, Uranus and Neptune at an impressionable age; this has given me a bias toward the sort of astronomy which talks about rock formations on Mars and away from the Big Picture of cosmology. Though space travel is still so expensive that it's unlikely we'll be colonising the void any time soon, I feel privileged to be living in a period when each probe we send finds out something new about the Solar System, and helps make Gaspra and Triton seem places no different in kind from Greenland or the Himalayas.

There are lots of astronomy sites on the Internet, ranging from collections of pictures of interesting objects, through the home pages of organisations like NASA, through to sites which inform you exactly how to write a research proposal for the use of their big telescopes.

Because of my planetary bias, I think that one of the greatest recent discoveries has been that there are a profusion of objects orbiting other stars which at least partially resemble planets. They are discovered in a very indirect way (as they orbit the star, the star wobbles, so the lines in its spectrum move backwards and forwards); for more information, and for an up-to-date list of them, try OBSPM, home of one of the planet-discovering teams.

Another interesting ongoing discovery, made possible by new detectors and large telescopes, is the Kuiper belt of asteroid-like objects orbiting outside the orbit of Neptune. Jewitt's site is the best I've encountered. Finding these objects is a heroic task: they're incredibly faint and, since they tend to move in orbits rather inclined to the plane of the ecliptic, you have to search the whole sky to look for them. The instruments used rise to the challenge: the Canada-France-Hawaii telescope was used with a hundred-million-pixel CCD detector the size of a sheet of A4 paper in one case. There is a catalogue of KB objects here.

Astronomy links

Science@NASA headlines the newest discoveries in astronomy and space science; space.com is a rather more wide-ranging news service.

The Views of the Solar System and The Nine Planets are very similar run-throughs of the planets in our solar system; look at both and compare them.

Instruments

• The Space Telescope Science Institute, with its large archive of stunning pictures from the Hubble telescope.
• Sloan Digital Sky Survey - examining a fair chunk of the whole sky with a large CCD array, looking for new classes of objects and unassailable statistics on old classes.
• NGST - the Next Generation Space Telescope. Eight metres wide, located at the Sun-Earth L2 point, and capable of seeing back to the dawn of the Universe.
• Chandra - the X-ray analogue of the Hubble Space Telescope.
• NASA's roadmap for instruments capable of finding new planetary systems. Fascinating - and suggesting that, with 'finite-but-large' funding, we could have images of other solar systems before my 40th birthday and resolved images of the planets there before my 60th.
• The Keck Telescopes - two ten-metre telescopes on the top of Mauna Kea in Hawaii.
• The Gemini Observatory - an eight-metre telescope in Hawaii and an identical instrument in Chile, to provide complete coverage of the Northern and Southern skies. Both telescopes are designed to use adaptive optics for the best possible Earth-bound images.
• The Future of Filled-Aperture Telescopes - laying the ground for a possible hundred-metre telescope, with a collecting area ten times the combined total of every large optical telescope ever built, to take astronomy into a new and unexplored region. The simulated views of galaxies in the Hubble Deep Field are as good as the views Hubble gets of galaxies in the Virgo Cluster. Once again, the price tag is finite but large.
• The Hobby-Eberly Telescope - a gigantic spectroscopic-survey instrument built at an order of magnitude cheaper price than any other telescope its size.

Missions to the Solar System

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• Mars Pathfinder (the little rover) - this mission is now over, but the pictures are up and are impressive. It gives you a real feeling of being there, on the orange deserts of Mars
• Mars Global Surveyor (mapping Mars) - the spacecraft has reached Mars, but is not yet in the correct orbit, and won't get there until about March 1999. However, it's taken some interesting pictures already.
• Galileo (Jupiter orbiter) - the original mission is now over, and Galileo is surveying Europa very carefully before a final suicidal plunge towards Io, hopefully producing amazing images of Io's volcanoes.
• Cassini (Saturn orbiter) - launched October 15^th 1997, will arrive at Saturn in 2004.
• Missions Yet to Come - Europa orbiter, Pluto flyby and a visit to within 2 million kilometres of the surface of the Sun

New ways of getting about in space

• Sailing the Proton Wind - using large current-carrying loops to divert particles from the solar wind for propulsion
• Thermonuclear Fusion Rockets - think of a fusion reactor open at one end, using the stream of incredibly hot ⁴He atoms to provide reaction mass. The amusing part is that NASA have something close to an experimental testbed for this, here.

Amateur astronomy

• The Amateur Sky Survey - building cheap wide-field CCD cameras, with the intention of discovering vast numbers of asteroids and variable stars.
• The Large Amateur Telescope - a group of researchers at HP building a 70-inch telescope on their own.