50 New Exoplanets Found, Billions More Await 208
The Bad Astronomer writes "Astronomers using a sensitive spectrograph have just announced the existence of 50 more planets orbiting nearby Sun-like stars. The important things to note: 1) Sixteen of them are super-Earths, and 2) 40% of all Sun-like stars appear to have at least one planet with less mass than Saturn."
Re:Great Super Earths. (Score:3, Informative)
I'm guessing that you're either being silly or haven't taken your medication, but since there are no stupid questions and lots of other people are probably wondering about this, the second link points out that the increase in gravity isn't all that much: "For example, a planet with 5 times Earth’s mass but twice the radius would have a surface gravity only 20% higher than Earth; if you weighed 150 pounds here you’d weigh 180 pounds there."
That being said, there's always the anthropic principle to consider. It's possible there's something about planets with gravity that differs more than a few percent from ours screws up chemical evolution. Not likely, but not yet possible to rule out.
This is all in ignorance of any knowledge of whether or not these planets are in the habitable zone (hey; I've got classes tomorrow, I don't have that much time to RTFA.)
about HARPS (Score:5, Informative)
This is likely to be informative:
"HARPS is the ESO facility for the measurement of radial velocities with the highest accuracy currently available. It is fibre-fed by the Cassegrain focus of the 3.6m telescope in La Silla.
The instrument is built to obtain very high long term radial velocity accuracy (on the order of 1 m/s). To achieve this goal, HARPS is designed as an echelle spectrograph fed by a pair of fibres and optimised for mechanical stability. It is contained in a vacuum vessel to avoid spectral drift due to temperature and air pressure variations. One of the two fibres collects the star light, while the second is used to either record simultaneously a Th-Ar reference spectrum or the background sky. The two HARPS fibres (object + sky or Th-Ar) have an aperture on the sky of 1"; this produces a resolving power of 115,000 in the spectrograph. Both fibres are equipped with an image scrambler to provide a uniform spectrograph pupil illumination, independent of pointing decentering."
1.) It's an optical telescope.
2.) It's on the face of the earth (I find this amazing.)
I got the impression from Frank Drake's book that astronomy was 'best done' by satellite radio telescope.