Credit & Copyright: Robert Gendler
Explanation:
How far can you see?
The most distant object easily visible to the unaided eye is
M31,
the great
Andromeda Galaxy
some two million light-years away.
Without a telescope, even this immense spiral galaxy appears
as an unremarkable, faint, nebulous cloud in the
constellation
Andromeda.
But a bright yellow nucleus, dark winding dustlanes, gorgeous blue
spiral arms and star clusters are recorded in this stunning
telescopic digital
mosaic of the nearby island universe.
While even casual
skygazers
are now inspired by the knowledge that there are
many distant galaxies like M31, astronomers
seriously debated
this fundamental concept only 80 years ago.
Were these "spiral nebulae" simply outlying components of our own
Milky Way Galaxy or were they instead "island universes" -- distant
systems of stars comparable to the Milky Way itself?
This question was central to the famous
Shapley-Curtis
debate
of 1920, which was later resolved by
observations of M31
in favor of Andromeda,
island
universe.
Tomorrow's picture: X-ray Moon, X-ray Star
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 |
Январь Февраль Март Апрель Май Июнь Июль Август Сентябрь Октябрь Ноябрь Декабрь |
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
|
Публикации с ключевыми словами:
спиральная галактика - Туманность Андромеды - universe - Andromeda - spiral galaxy - Вселенная - Галактика - M 31
Публикации со словами: спиральная галактика - Туманность Андромеды - universe - Andromeda - spiral galaxy - Вселенная - Галактика - M 31 | |
См. также:
Все публикации на ту же тему >> | |
