(Adopted from Universe, Ch.6, with some modifications)
| 01. | The four largest moons of Jupiter are roughly the same size as our Moon and are about 628 million kilometers from Earth at opposition. What is the size in kilometers of the smallest surface features that the Hubble Space Telescope (resolution of 0.1 arcsec) can detect? How does this compare with the smallest features that can be seen on the Moon with the unaided human eye (resolution of 1 arcmin)? |
| 02. | Can the Hubble Space Telescope distinguish any features on Pluto? Justify your answer. |
| 03. | A NASA project named ARISE (Advanced Radio Interferometry between Space and Earth) proposes to place a radio telescope into an even higher orbit than the Japanese HALCA telescope. Using this telescope in concert with the VLBA, baseline as long as 50,000 km may be obtainable. Astronomers want to use this combination to study radio emission at a frequency of 1665 MHz from distant objects called quasars. (a) What is the wavelength of this emission? (b) Taking the baseline to be the effective diameter of this radio-telescope array, what angular resolution can be achieved? |
| 04. | The mission of the Submillimeter Wave Astronomy Satellite (SWAS), launched in 1998, is to investigate interstellar clouds within which stars form. One of the frequencies at which it observes these clouds is 557 GHz, characteristic of the emission from interstellar water molecules. (a) What is the wavelength (in meters) of this emission? In what part of the electromagnetic spectrum is this? (b) SWAS has an angular resolution of 4 arcminutes. What is the diameter of its primary mirror? |