Outdoor Solar Lights

We all know that the New Horizons mission will give us the first close up views of Pluto and Charon’s surfaces. But my question is how can the Hubble Space Telescope see galaxies trillions of light years away, but not even see a planet clearly, that is in our own solar system? I realize that Pluto is smal, but come on..

Well, first of all, we can’t see anything more than 13.7 billion lightyears away.

Second, galaxies are really big. The smallest have an angular size that is a few seconds of arc, whereas Pluto is well under a second of arc—a tenth of an arcsecond at best. That’s approximately equal to the diffraction-limited resolution of the Hubble (which is, after all, not a very big telescope).

Third, "cosmological magnification" enlarges objects at extremely large distances, due to a relativistic effect. Objects more than 8 billion lightyears away actually appear bigger than objects that are, say, 4 billion lightyears away.

Related posts:

1. Could telescopes eventually clearly show extra-solar planets?
2. One question that is very important to understand actual existence of dark matter?
3. Should I buy a neutral density moon filter in order to view the moon through my telescope?
4. Should I buy a neutral density moon filter in order to view the moon through my telescope?
5. Hubble Telescope question?

This entry was posted on Monday, October 26th, 2009 at 9:48 am and is filed under mission solar lights. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.