Anything and everything about space?

Question

Can people just write any detail at all about space (GCSE level please) particularly stars and comets and the big bang!!!
Ta muchly!

Answer 1

A comet is a small body in the solar system that orbits the Sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail — both primarily from the effects of solar radiation upon the comet's nucleus, which itself is a minor body composed of rock, dust, and ices. Comets' orbits are constantly changing: their origins are in the outer solar system, and they have a propensity to be highly affected (or perturbed) by relatively close approaches to the major planets. Some are moved into sungrazing orbits that destroy the comets when they near the Sun, while others are thrown out of the solar system forever.

Comets are usually discovered visually or photographically using a wide-field telescope or other optical means of magnification, such as binoculars. However, even without access to optical equipment, it is still possible to discover a sungrazing comet online with a computer and an Internet connection.

Most comets are believed to originate in a cloud (the Oort cloud) at large distances from the Sun consisting of debris left over from the condensation of the solar nebula; the outer edges of such nebulae are cool enough that water exists in a solid (rather than gaseous) state. Asteroids originate via a different process, but very old comets which have lost all their volatile materials may come to resemble asteroids.


In physical cosmology, the Big Bang is the scientific theory that the universe emerged from a tremendously dense and hot state about 13.7 billion years ago. The theory is based on the observations indicating the expansion of space in accord with the Robertson-Walker model of general relativity, as indicated by the Hubble redshift of distant galaxies taken together with the cosmological principle.

Extrapolated into the past, these observations show that the universe has expanded from a state in which all the matter and energy in the universe was at an immense temperature and density. Physicists do not widely agree on what happened before this, although general relativity predicts a gravitational singularity.

A star is a massive, luminous ball of plasma. Stars group together to form galaxies, and they dominate the visible universe. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth, including daylight. Other stars are visible in the night sky, when they are not outshone by the Sun. A star shines because nuclear fusion in its core releases energy which traverses the star's interior and then radiates into outer space. Without stars, life and most atomic elements present in the Universe would not exist.

Astronomers can determine the mass, age, chemical composition and many other properties of a star by observing its spectrum, luminosity and motion through space. The total mass of a star is the principal determinant in its evolution and eventual fate. Other characteristics of a star that are determined by its evolutionary history include the diameter, rotation, movement and temperature. A plot of the temperature of many stars against their luminosities, known as a Hertzsprung-Russell diagram (H-R diagram), allows the current age and evolutionary state of a particular star to be determined.

A star begins as a collapsing cloud of material that is composed primarily of hydrogen along with some helium and heavier trace elements. Once the stellar core is sufficiently dense, some of the hydrogen is steadily converted into helium through the process of nuclear fusion. The remainder of the star's interior carries energy away from the core through a combination of radiation and convective processes. These processes keep the star from collapsing upon itself and the energy generates a stellar wind at the surface and radiation into outer space.[1]

Once the hydrogen fuel at the core is exhausted, a star of at least 0.4 times the mass of the Sun[2] expands to become a red giant, fusing heavier elements at the core, or in shells around the core. It then evolves into a degenerate form, recycling a portion of the matter into the interstellar environment where it will form a new generation of stars with a higher proportion of heavy elements

Answer 2

How does energy somehow get somewhere that never existed, then blow up to create millions of planets and make a planet where it is perfectly made so that humans can exist and all of this works with the correct amount of O, CO2, N, and everything perfect, where there is plenty of food and water, made so people can live, all made up perfectly, a galaxy where every planet revolves around a giant star perfectly, to keep a planet at a perfect temperature, not too hot, not too cold... Sounds pretty crazy, doesn't it?

Answer 3

Hi. The first stars were almost all hydrogen with a little helium and perhaps a trace of lithium. Second generation stars formed from matter blown out by the death of the fist stars and had more 'metals'. (Anything not hydrogen of helium is a metal in astronomy.) This generation of stars has more metals and therefore the elements needed for life.

Answer 4

Uranus is made of mostly hot water; its ocean is 5000 miles deep and the temperature of the water is 8000 degrees F. It doesn't boil into gas because of the pressure of the ammonia-methane-hydrogen-helium atmosphere above it.

Answer 5

I suggest you do your own research, you may even find it interesting, To rely on some of the answers you will get on this site may well ensure that you will not pass diddly squat let alone a GCSE.

Answer 6

In space, no one can hear you scream.

Do your own homework.

Answer 7

space dot com website may help you here...