Is it correct that Cometary nuclei's Raii are around 4000km? also are low-density atmospheres?
2006-08-31 14:00:50 · 2 answers · asked by Jasmine 1 in Science & Mathematics ➔ Astronomy & Space
if cometary nuclei's radii is much smaller than 4000km, how about Asteroids? i thought Asteriods' radii is quite small too. I'm also wondering about the shape of it.
2006-08-31 15:51:16 · update #1
if cometary nuclei's radii is much smaller than 4000km, how about Asteroids? i thought Asteriods' radii is quite small too. I'm also wondering about the shape of it.
2006-08-31 15:51:36 · update #2
No, comets are much smaller than that. Maybe 40km, but not nearly as large as 4000km. And they have no real atmosphere.
2006-08-31 14:33:29 · answer #1 · answered by campbelp2002 7 · 0⤊ 0⤋
The nucleus of a comet is typically on the order of 10-20 km across, although it can vary quite a bit. Halley's comet is potato-shaped, 16 km length, 8 km width and depth.
Only when the nucleus gets closer to the Sun (about the distance of Jupiter's orbit) does it start to develop an atmosphere - the heat from the Sun is turning some of the ice into gas. This atmosphere is called the coma, which is the bright part that we see as the "head" of the comet when they come in towards the Sun. The coma is on the order of 1,000,000 km across (that's almost as large as the Sun!).
The tail of a comet can stretch more than 150 million km - that's the distance from Earth to the Sun!
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The largest asteroid is Ceres, which has a diameter of 950 km, so a radius of 475 km. Here's a list of the largest known asteroids: http://en.wikipedia.org/wiki/List_of_noteworthy_asteroids
2006-08-31 22:30:04 · answer #2 · answered by kris 6 · 2⤊ 0⤋