A red giant is a star that has exhausted the supply of hydrogen in its core and has begun thermonuclear fusion of hydrogen in a shell surrounding the core. They have radii tens to hundreds of times larger than that of the Sun. However, their outer envelope is lower in temperature, giving them a reddish-orange hue. Despite the lower energy density of their envelope, red giants are many times more luminous than the Sun because of their great size. Red-giant-branch stars have luminosities up to nearly three thousand times that of the Sun (L☉), spectral types of K or M, have surface temperatures of 3,000–4,000 K, and radii up to about 200 times the Sun (R☉). Stars on the horizontal branch are hotter, with only a small range of luminosities around 75 L☉. Asymptotic-giant-branch stars range from similar luminosities as the brighter stars of the red giant branch, up to several times more luminous at the end of the thermal pulsing phase.
The Solar System formed 4. 6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system’s mass is in the Sun, with the majority of the remaining mass contained in Jupiter. The four smaller inner planets, Mercury, Venus, Earth and Mars, are terrestrial planets, being primarily composed of rock and metal. The four outer planets are giant planets, being substantially more massive than the terrestrials. The two largest, Jupiter and Saturn, are gas giants, being composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are ice giants, being composed mostly of substances with relatively high melting points compared with hydrogen and helium, called volatiles, such as water, ammonia and methane. All eight planets have almost circular orbits that lie within a nearly flat disc called the ecliptic.
The format of a special report or breaking news event on television commonly consists of the current non-news programming (or, in some cases, regularly scheduled newscasts) suddenly switching to a reverse countdown, usually from 5 seconds, to allow any affiliated stations to switch to the network news feed (television stations typically do not provide these countdowns for local coverage, normally leading with a graphic and/or voiceover announcing the cut-in). If a national network newscast is in progress when the breaking news event occurs, the newscast will pause temporarily to allow other network affiliates to join the network news feed.
There is then an opening graphic, featuring music (such as NBC’s “The Pulse of Events”, composed by John Williams) which adds an emphasis on the importance of the event. This is usually followed by the introduction of a news anchor, who welcomes the viewer to the broadcast and introduces the story at hand. Lower thirds and other graphics may also be altered to convey a sense of urgency.