Explanation:
Stars remain where they are. Nebulas appear the same. Day after day. Year after
year.
Given the vast distances in astronomy, even fast moving objects will not appear to
change their appearance in a
human
lifetime. Typically.
A recent spectacular exception to this, however, is the supersonic jet in the star
forming
Herbig Haro 47.
HH 47
is so close -- and the jets are moving so fast -- that images from the
Hubble Space Telescope from 1994 to 2008 have been combined
into a time-lapse movie that actually shows a powerful jet expanding.
Visible above, jets of plasma extending over 10,000 times the Earth-Sun distance
shoot out from a forming star at speeds in excess of 150 kilometers per second.
Studying how these
jets evolve gives clues not only to how the star in HH 47 is forming, but how stars like our Sun formed billions of years ago.
HH 47 is located about 1,500 light years away toward
the constellation of Sails of a Ship
(Vela).
