Snipfact:

  The USSR's Sputnik I was the first artificial satellite to enter Earth's orbit. This 83.6 kg (184 lb) metal sphere transmitted signals back to Earth for three weeks before its batteries failed. In 1958 the USA began to launch its own satellites. Five went into orbit. All of the earliest satellites have since crashed back to Earth, expect Vanguard 1 (USA, 1958) Which is still in space and likely to remain so for another 200 years.

  About 100-200 objects, each larger than a football, re-enter every year, but there are still many pieces of space junk in orbit. A survey carried out in June 2000 calculated that there are 90 space probes and 2,671 satellites still in space. There are as many as 100,000 objects larger than 10cm including parts of rockets: an Ariane rocket booster exploded in 1986, scattering 400 fragments large enough to be tracked. In 1991 space shuttle Discovery STS-48 narrowly avoided a discarded Soviet rocket.

  Thrust is the force required to lift a vehicle such as an aircraft or rocket off the ground. Rockets often have several stages. Each one provides a proportion of the thrust required to carry a satellite, space shuttle or other vehicle into orbit or into space, dropping away as their propellant has been used so their propellant has been used so that their weight no longer need to be carried.

  The 69 ton Skylab re-entered in 1979, scattering large chunks in the Australian desert, and Russia’s Mir space station, which weighed 120 tones, came down in the Pacific.

  When satellites reach the end of their useful life, they may be deliberately directed back in such a way that they burn up as they re-enter the Earth’s atmosphere or come down in the oceans or away from places where they could cause damage. So far, no one has been killed or seriously injured by space debris.

  On 1 February 2003, space shuttle Columbia STS-107 broke up on re-entry and its crew were killed. On-board animal experiments involving silkworms, spiders, carpenter bees, harverster ants and Japanese killfish were destroyed, but amazingly, canisters of worms were found alive.

  The STS-90 mission of space shuttle Columbia (April/May 1998) contained the Neurolab –a space menagerie with 170 baby rats, 18 mice, 229 swordtail fish, 135 snails, four oyster toad fish and 1,514 cricket eggs and larvae.

  Arabella, a garden spider went to the US Skylab-3 in July 1973. She spent almost 60 days in orbit in an experiment to test the effect of weightlessness on her web-weaving skills.

  In November 1970, the USA’s Orbiting Frog Otolith satellite (OFO-A) launched two bullfrogs into built for a week. In December 1990. Toyohiro Akiyama, a Japanese journalist, took six green three frogs to the Soviet Mir space station to conduct weightlessness experiments.

  Able, a female rhesus monkey, and Baker, a female squirrel monkey, were launched by the USA in may 1959. They did not orbit and successfully returned to Earth. In November 1961 Enos, a male chimpanzee, completed two orbits and survived. The USSR’s first space primates were monkeys Abrek and Bion, who orbited in December 1983 in one of  a series of Bion satellite experiments.

  Laika, a female Samoyed husky, became the first animal in orbit after being launched by the USSR in Sputnik 2 in November 1957. There was no way to bring her down and she died after ten days in space. Two female huskies, Belka and Strelka, orbited successfully in August 1960. Strelka later gave birth to puppies, one of which was given to US President John F. Kennedy. In October 1963, a French Veronique AGI rocket put a cat called Felix into space and returned him safely to Earth by parachute.

  Before humans went into space animals were used to test equipment to be sent up in a rocket – but not into space – was Albert 1, a male rhesus monkey, in 1948. He and his successor, Albert 2, died during the tests. However , on September 1951, a monkey and 11 mice were recovered after a launch in a US Aerobee rocket. Many further animal experiments were carried out before the first manned space flight.  

  1978 Space probes Pioneer 1 and 2 reach Venus 1980 Voyager1 explores Saturn 1985-89 Voyager 2 discovers moons of Uranus and Neptune 1994 Comet Shoemaker-Levy observed crashing into Jupiter 1995 Galileo probe reaches Jupiter 1997 Mars Pathfinder lands 1997 Cassini probe launched to Saturn 1998 International Space Station construction starts 1999 Chandra X-Ray Observatory launched 2003 Galileo probe deliberately crash-landed on Jupiter 2006 New Horizons space probe launched to Pluto 2008 Phoenix mission to Mars landed on the planet

    1905 Einstein’s Special Theory of Relativity first proposed 1908 Giant and dwarf stars described 1923 Galaxies beyond the Milky way proved 1927 Big Bang theory proposed 1930 Pluto discovered by Clyde Tombaugh 1959 First photographs of the far side of the Moon by Soviet satellite Luna3 1961 First quasars discovered 1967 First pulsars identified 1971 Black hole first detected 1971 Mariner 9 spacecraft maps Mars 1973 Skylab space laboratory launched 1976 Rings of Uranus are discovered 1977 Voyager deep space probes are launched 1980 Voyager 1 explores Saturn

  1801 First asteroid, Ceres, discovered by Giuseppe Piazzi 1846 Johann Galle and Urbain Le Verrier discover 8th planet Neptune 1787-89 Herschel finds two moons of Uranus and two Saturn 1839-40 First photographs of the Moon 1894 Flagstaff Observatory, Arizona, founded

  1609 Johannes Kepler describes laws of planetary motion 1610 Galileo Galilei discovers moons of Jupiter 1655 Christian Huygens discovers Titan, moon of Saturn 1668 Isaac Newton builds first reflecting telescope 1687 Isaac Newton publishes theories of motions of planets, etc 1705 Edmond Hailey predicts return of comet 1671-84 Giovanni Cassini discovers four moon of Saturn 1774 Charles Messier compiles star catalogue 1781 william Herschel discovers 7th planet, Uranus

  Astronomy is the scientific study of the Universe and the bodies it contains(excluding Earth). Astronomers are the scientists who study astronomy. 585 BC First prediction of eclipse of the Sun. 130 BC Hipparchus calculates distance and size of Moon. AD 1543 Copernicus shows that the Sun is at the centre of the Solar System.

    The Large Binocular Telescope, completed in 2007, is the largest and most advanced optical telescope ever built. Sited at the Mount Graham International Observatory, it has two 8.4 m (27.5 ft) mirrors, giving a total area equal to one giant 11.4 m (37.4 ft) diameter mirror. It is expected to produce images as much as 10 times the resolution of those produced by the much smaller Hubble Space Telescope.

    This telescope is designed to collect light for spectrum analysis rather than for visual exploration. It has been in operation since 1999, and has an overall diameter of 11 m (36.1 ft), making it one of the largest ever optical telescopes.

    The two Keck telescopes were opened in 1992-96. They are situated 4,000 m (13,123 ft) up a Hawaiian mountain, so above 40 percent of the Earth’s atmosphere. They are the world’s most powerful ground-based instruments, with a 10.82 m (35.5 ft) total aperture made up of 36 hexagonal mirrors.

  The Hubble Space Telescope was launched in 1990 and orbits 600 km (372.8 miles) above Earth’s atmosphere. It can photograph distant objects with ten times the detail possible with ground-based telescopes.

  Completed in 1963, this is the world’s  most powerful radio telescope. Its uses include searching for pulsars and quasars and the search for alien life forms under the SETI (Search for Extra-Terrestrial Intelligence) programme. Its giant 305m (1,000,65 ft) dish features in the final scenes of the James Bond film Golden Eye (1995).

  Britain’s first, and once the world’s largest radio telescope, with a 76 m (249.3 ft) dish began operating in 1957.

    The Hale’s 5 m (16.4 ft) telescope was first used in 1949.

    The Telescope was installed in 1917 with a mirror size of 2.5 m (8.2 ft). It was the world’s largest until the Hale.

    This 1 m (3.25 ft) telescope is the biggest refracting instrument made up to this time. It was completed in 1897.

    A giant telescope built in 1788 with a 1.2 m (3.9 ft) mirror. It is also known as Herschel’s “Forty-foot” reflector.

    The Earl of Rosse’s 1.8 m 5.9 ft) reflecting telescope, built in 1845, was used to discover the spiral form of galaxies. It was the world’s largest until the opening of Mount Wilson.