Wednesday, 25 March 2015

spcae facts-3

  • 51. Planets have magnetic field around them because of the liquid iron in their cores. As the planets rotate, so the iron swirls, generating electric currents that create the magnetic field.
  • 52. Earth’s atmosphere is the only atmosphere discovered till date that human can breathe in.
  • 53. Earth’s atmosphere was formed from gases pouring out from volcanoes.
  • 54. Jupiter has no surface for a spacecraft to land on because it is made mostly from helium gas and hydrogen. The massive pull of Jupiter’s gravity squeezes the hydrogen so hard that it is liquid.
  • 55. Jupiter spins right round in less than 10 hours which means that the planet’s surface is moving at nearly 50,000 km/hr.
  • 56. The first successful planetary space probe was the USA’s Mariner 2, which flew past Venus in 1962.
  • 57. Voyager 2 has flown over 6 billion km and is heading out of the solar system after passing close to Neptune in 1989.
  • 58. To save fuel on journeys to distant planets, space probes may use a nearby planet’s gravity to catapult them on their way. This is called slingshot.
  • 59. Hubble’s law showed that Universe is getting bigger – and so must have started very small. This led to the idea of Big Bang.
  • 60. It’s believed that it was the impact of a big meteorite may have chilled the earth and wiped out all the dinosaurs.
  • 61. The first astronomers thought the regular pulses from far space might be signals from aliens, and pulsars were jokingly called LGMs (short for Little Green Men).
  • 62. Pulsars probably result from a supernova explosion - that is why most are found in the flat disc of the Milky Way, where supernovae occur.
  • 63. Three moons have yet been found to have their own moons: Saturn’s moon Titan, Jupiter’s Lo, and Neptune’s Triton.
  • 64. The largest moon in the Solar System is the Jupiter’s moon Ganymede.
  • 65. Saturn is not solid, but is made almost entirely of gas – mostly liquid hydrogen and helium. Only in the planet’s very small core is there any rock.
  • 66. Winds ten times stronger than a hurricane on Earth swirl around Saturn’s equator reaching up to 1100 km/h – and they never let up: even for a moment.
  • 67. The first space station was the Soviet Salyut 1 launched in April 1971; its low orbit meant it stayed up only five months.
  • 68. In April 2001, Dennis Tito became the first space tourist, ferried up to the ISS by the Russian Soyuz space shuttle.
  • 69. Einstein’s theory of general relativity shows that gravity not only pulls on matter, but also space and even ‘Time’ itself.
  • 70. Since the star Deneb is 1800 light years away, we see it as it was when the emperor Septimus Severius was ruling the Rome (AD 200).
  • 71. With powerful telescopes, astronomers can see galaxies 2 billion light years away. This means we see them as they were when the only life forms in Earth were bacteria.
  • 72. The slowest rotating planet is Venus, which takes 243.01 days to turn around.
  • 73. The fastest spinning objects in the Universe are neutron stars – these can rotate 500 times in just 1 second.
  • 74. In summer in Uranus, the sun does not set for 20 years. In winter, darkness lasts for 20 years. In autumn, the sun rises and sets every 9 hours.
  • 75. Uranus’s moon Miranda is the weirdest moon of all. It seems to have been blasted apart, and then put together again.