Snworld

Why aren’t our Solar System’s planets and moons made from the same material? the solar system formed from the collapse of a molecular cloud consisting mostly of hydrogen, but also containing heavier elements. As the cloud collapsed, its central region began to heat up until eventually the hot ‘proto-sun’ was formed. the planets formed by the accretion of material from within this cloud. due to their high boiling points, only metals and silicates could exist in solid form in the hot, inner regions of the early solar system. More volatile elements either remained gaseous or were blown away by the sun’s energy. since this heavy material existed mainly in the inner regions of the solar system, the planets that formed there are small and rocky. in the cold outer reaches of the solar system, compounds with low melting points could remain in solid form. these ices were also much more abundant than the heavier elements. the outer planets were therefore able to grow much larger, and he...

To kick off the ‘Summer of Mars’ events programme at the Kennedy Space Center in Florida, NASA recently unveiled an 8.5m-long concept Martian rover that wouldn’t look out of place in the Batcave. The vehicle consists of a detachable rear section housing a science laboratory, and a front section that’s equipped with radio and GPS. Sadly, it is only a concept: according to the latest information on NASA’s website, the actual rover used in the Mars 2020 mission is likely to be similar in size and appearance to Curiosity, the 3m-long rover that’s been busy exploring the Red Planet’s surface since 2012.

IS THERE A TENTH PLANET? It seems the Solar System may be a little more crowded than we thought: a planet around the size of Mars could be hidden among its outer fringes. A team from the University of Arizona has discovered a mysterious mass, dubbed Planet Ten, that appears to be tugging at the orbits of a population of space rocks known as the Kuiper Belt in the icy outskirts of the Solar System. The Kuiper Belt lies beyond the orbit of Neptune and extends to a few hundred Astronomical Units (AU), with one AU representing the distance between Earth and the Sun. The Earth and the other major planets all orbit the Sun in roughly the same plane. However, Kuiper Belt Objects (KBOs) are far enough away from the gravitational attraction of the gas giants to be tilted away from this plane, and are affected by interactions with one another. This angle, known as the inclination, can be calculated. If the observed angle differs from the one calculated, then it’s possible that the smalle...

Stars die because they exhaust their nuclear fuel. The events at the end of a star’s life depend on its mass. Really massive stars use up their hydrogen fuel quickly, but are hot enough to fuse heavier elements such as helium and carbon. Once there is no fuel left, the star collapses and the outer layers explode as a ‘supernova’. What’s left over after a supernova explosion is a ‘neutron star’ – the collapsed core of the star – or, if there’s sufficient mass, a black hole. Average-sized stars (up to about 1.4 times the mass of the Sun) will die less dramatically. As their hydrogen is used up, they swell to become red giants, fusing helium in their cores, before shedding their outer layers, often forming a ‘planetary nebula’. The star’s core remains as a ‘white dwarf’, which cools off over billions of years. The tiniest stars, known as ‘red dwarfs’, burn their nuclear fuel so slowly that they might live to be 100 billion years old – much older than the current age of the Universe....

Since the Martian atmosphere is about 100 times less dense than Earth’s, the ‘lift’ a frisbee experiences would also be about 100 times less. But the gravitational force on Mars is about a third of that on Earth, so a frisbee on Mars would act as if it is about 33 times heavier (100/3). Since the lift depends on the size of the frisbee, the angle of attack and the velocity it is thrown (as well as the air density), it would still be possible to make a frisbee glide, but it would require much more effort on the part of the thrower.

The reason of rockets follow parabola Students have long been taught that all projectiles follow a curved path known as a parabola. The explanation is that, as they fly, they cover distance both horizontally and vertically – but only the latter is affected by the force of gravity, which bends the path of the projectile into a parabola. For longrange rockets, things are more complex. For example, air resistance must be taken into account. But, even ignoring that, a projectile doesn’t really follow a parabola – because the Earth isn’t flat. This means that gravity doesn’t simply pull objects straight back down. Instead, it pulls them towards the centre of the Earth, whose direction changes as the projectile moves further down-range, away from the launch site. Detailed calculations then reveal that the true trajectory is not a parabola, but part of an ellipse

TEN BIGGEST BANGS ON EARTH Seattle Kingdome demolition  When: 26 March 2000 Holding up to 66,000 sports fans in its 19.821 million m3 capacity, this stadium became the largest building to be demolished by explosives when it was destroyed in 2000. Chicxulub Impact When: 65 million years ago The chicxulub crater in mexico, a staggering 180km wide, was created when a 10km-wide meteorite crashed into earth. the impact is believed to have been a major contributing factor in the extinction of the dinosaurs. Heligoland explosion When: 18 April 1947 The royal navy tried – and failed – to blow up a whole north sea island and the huge German naval base it carried by detonating around 4,000 tonnes of explosives, one of the world’s biggestever single detonations. Despite that, the island remained intact. Mt Toba When: 75,000 years ago When the supervolcano mt toba erupted, it launched at least 2,800km3 of magma and ash into the atmosphere, causing a six-year volcanic win...

TEN BIG BLUNDERS & FALSE CLAIMS Mars mission malfunction NASA spent $327 million launching the Mars Climate Orbiter, which reached the red planet on 23 September 1999 – only to be lost in the Martian atmosphere. A navigation malfunction in its navigation systems was discovered to be the result of a basic error: the orbiter had been engineered using imperial measurements, but was guided using technology that followed the metric system. The universe revolves around us the influential (and groundbreaking) Grecoroman mathematician and geographer Ptolemy developed an astronomical model in which earth sat at the centre of the cosmos. His geocentric model went uncorrected until copernicus proposed his heliocentric theory in 1543 – nearly 1,500 years later. Dna is a triple helix American scientist linus Pauling was a nobel-winning chemist – but erred in 1953 when suggesting that DnA has a triple helix structure. later that year, francis Watson and James crick discovered t...

10 FAMOUS ASTRONOMERS galileo galilei 1564–1642 Supported heliocentricism, discovered Jupiter’s moons and developed telescopes Galileo’s support of the copernican heliocentric model saw his ideas investigated by the roman inquisition of 1615. But the italian’s own achievements were formidable, including developing telescopes enabling good views of the milky Way and Jupiter’s moons. eratosthenes 276–194BC Measured the circumference of the earth eratosthenes – born in cyrene, now in libya – used the angle of the noonday sun at different places in egypt to estimate the circumference of earth. His figure was remarkably accurate – in fact, according to some commentators, he was out by less than 2%. William Herschel 1738–1822 Discovered uranus and its moons Born in Germany Herschel moved to england as a teenager. He became famous for discovering uranus and two of its major moons, titania and oberon, as well as two of saturn’s moons. He also discovered infrared radiation. Joha...

10 IMMENSE THINGS IN SPACE 01 Biggest asteroid  ceres 950km diameter (average) Discovered in 1801, ceres makes up a third of the total mass of the asteroid belt between mars and Jupiter. 02 Biggest object in our solar system sun 1,392,000km diameter the yellow dwarf star around which we orbit comprises over 99.8 per cent of the total mass of our solar system. 03 Biggest known planet  GQ Lup b 30 times the radius of Jupiter this huge exoplanet, detected orbiting a star some 457 light-years from earth, may have a mass up to 36 times that of Jupiter and is fiercely hot – possibly 2,650 kelvin. 04 Largest structure in the universe Huge Large Quasar Group (Huge-LQG ) 4 billion light-years across in 2013, an international team detected a chain of some 73 quasars stretching so far that its existence challenges the fundamental cosmological Principle. 05 Biggest black hole   centre of ngc 1277 17 billion solar mass this supermassive black...

10 BIGGEST MOONS IN OUR SOLAR SYSTEM 01 ganymede radius: 2,631km satellite of: Jupiter 02 titan radius: 2,576km satellite of: saturn 03 callisto radius: 2,410km satellite of: Jupiter 04 io radius: 1,821km satellite of: Jupiter 05 Moon radius: 1,737km satellite of: earth 06 europa radius: 1,561km satellite of: Jupiter 07 triton radius: 1,353km satellite of: Neptune 08 titania Radius: 788km satellite of: uranus 09 rhea Radius: 764km satellite of: saturn 10 oberon radius: 761km Satellite of: uranus

 10 LONGEST HUMAN SPACE FLIGHTS 01 Valeri Polyakov russia Mission: Mir Space Station Duration: 437 days 8 January 1994– 22 March 1995. 02 Sergei Avdeyev soviet union Mission: Mir Space Station Duration: 379 days 13 August 1988– 28 August 1989. 03 Vladimir titov & Musa Manarov soviet union mission: mir space station Duration: 365 days 21 December 1987– 21 December 1988. 04 Yuri Romanenko soviet union mission: mir space station Duration: 326 days 6 february 1987– 29 December 1988. 05 Sergei Krikalev Soviet Union/ russia mission: mir space station Duration 312 days 19 may 1991– 25 march 1992. 06 Valeri Polyakov soviet union Mission: Mir Space Station Duration: 240 days 29 August 1988– 7 April 1989. 07 Leonid Kizim, Vladimir Solovyov & Oleg Atkov soviet union mission: salyut 7 space station Duration: 237 days 8 february 1984– 2 october 1984. 08 mikhail tyurin & michael lópezAllegria russia & usA mission: international space station Dura...

10 SPACE FIRSTS First man in orbit Yuri Gagarin Launch date: 12 April 1961 The Russian cosmonaut completed an orbit of earth during his 108-minute spaceflight aboard Vostok I. Being the first human in space, he later explained the experience of weightlessness: “You feel as if you were hanging in a horizontal position in straps. You feel as if you are suspended.” After landing back on earth, Gagarin became an instant celebrity, touring the world to tell the adoring public about his big adventure. It was to be his only mission into space and he died in a plane crash in 1968 during a routine flight. His ashes are buried in the walls of the Kremlin in Moscow. First woman in orbit Valentina Tereshkova  16 June 1963 the russian orbited the earth 48 times during her nearthree-day spell aboard Vostok 6. First space walk Alexey Leonov  18 March 1965 Another russian cosmonaut, leonov undertook a 12-minute period of ‘extravehicular activity’ (space walk) during the Vosk...