... An artificial comet holds secrets to Earths life . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... space flight . ... Hubbleт??s lasting legacy and what the future might hold . ... I have often said that Hubble s true legacy will be realized when astronomers decades or even a century from now compare their data from those future observatories with Hubble data. ... Only registered members of Astronomy.com are allowed to comment on this article. ...