Showing posts with label Stars. Show all posts
A star is a massive,
luminous sphere of plasma held together by its own gravity. The nearest star to
Earth is the Sun, which is the source of most of the planet's energy. Some
other stars are visible from Earth during the night, appearing as a multitude
of fixed luminous points due to their immense distance. Historically, the most
prominent stars were grouped into constellations and asterisms, and the
brightest stars gained proper names. Source
Cosmic dust
can be taken to be all dust in the cosmos, as its name implies, or limited to
space dust in the Solar System. It is for the most part a type of small dust
particles which are a few molecules to 0.1 µm in size. By one estimate, as
much as 40,000 tons of cosmic dust reaches the Earth's surface every year. In October 2011,
scientists reported that cosmic dust contains complex organic matter ("amorphous
organic solids with a mixed aromatic–aliphatic structure") that could be
created naturally, and rapidly, by stars. Source
A star is a massive, luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun, which is the source of most of the planet's energy. Some other stars are visible from Earth during the night, appearing as a multitude of fixed luminous points due to their immense distance. Historically, the most prominent stars were grouped into constellations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations. For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space. Source
