An irregular galaxy has an undefined shape and is full of young stars, dust, and gas.とは 意味・読み方・使い方

An irregular galaxy has an undefined shape and is full of young stars, dust, and gas.

Star formation is the process in which dense clouds of gas in space collapse and form new stars.

A galaxy is a cluster of stars, dust, and gas which is held together by gravity.

a quasi-stellar object that mistakenly appears in a photograph to be a star, called

The young stars are surrounded by disks of gas and dust.

a star that is too small to be a fixed star and too big to be a planet

a nebula that was once thought to be a star with its planets but is now thought to be a very hot star surrounded by an expanding envelope of ionized gases that emit a fluorescent glow because of intense radiation from the star

The area contains many comets and a few dwarf planets like Pluto.

interplanetary space including forms of energy and gas and dust

The neutron star in the Crab Nebula is rotating at high speed and releasing X-rays and gamma rays in pulses.

When some of the stars aged and eventually exploded, the elements were scattered through space.

a physical science called sidereal astronomy

Galaxies are scattered throughout the universe and they vary greatly in size.

Astronomy deals with the stars and planets.

But now Venus is a very hot planet and the situation is very different.

There are many small stars like Gliese 667C in our galaxy.

Planets and stars often are occulted by other celestial bodies

At the time of their birth 4.6 billion years ago, Venus and Earth were like sister planets.

The Crab Nebula is expanding at about 1,500 kilometers per second by absorbing surrounding gases.

a streak of light in the sky at night that results when a meteoroid hits the earth's atmosphere and air friction causes the meteoroid to melt or vaporize or explode

`extragalactic nebula' is a former name for `galaxy'

a giant planet that is surrounded by three planar concentric rings of ice particles

an immense cloud of gas (mainly hydrogen) and dust in interstellar space

Mars and Mercury are usually considered to have been formed by planetesimal accumulation.

Pluto has an elliptic orbit.

Gas-giants don't have solid surfaces.

a fixed star in the last stage of its evolution, when it is composed of neutrons

a major planet whose orbit is outside the asteroid belt (Jupiter, Saturn, Uranus, Neptune, Pluto)

On the surface of the moon and Mars there are countless craters, both big and small.

The size of a galaxy may be as little as a thousand light-years across or as much as a million light-years across.