One advantage of the Hubble Space Telescope over ground based ones is that
A) it can make better observations of the ozone layer.
B) it can better focus X-ray images.
C) its adaptive optics controls atmospheric blurring better.
D) in orbit, it can operate close to its diffraction limit at visible wavelengths.
E) it is larger than any Earth-based telescopes.
Question 2
The Hipparcos data give us
A) parallaxes to the nearest galaxies.
B) parallaxes as small as 0.005.
C) an accurate distance to the Moon.
D) distances to about 100 billion stars, practically everything in the Milky Way Galaxy.
E) information on only the 6,000 brightest stars.