Secret Behind Jupiter's Giant Size

Jupiter is the largest planet in the solar system. 120 times the size of Earth. However, recent measurements by the spacecraft reveal the planet’s core at most 10 times the size of the planet we inhabit.Recent studies found that about Jupiter, the giant planet has a core of very small compared with the size. Scientists believe, so the planet Jupiter, the largest in the Milky Way Galaxy because he swallowed the other small planets, before the swell.

As disclosed in the site of science, New Scientist, the core of Jupiter thought to have greater evaporation in a collision with a planet the size 10 times the size of Earth. This study provides new insight into a process that is fierce in the early formation of our solar system.Researchers from Peking University, China has to imitate what might happen in the event that the collision. The simulation results show, rocky planets closer to Jupiter will be demolished as it hit the giant planet’s atmosphere.

Half an hour later, the planet would fall into the core of Jupiter. Heavy elements in the core as the metal will evaporate and then mixed with hydrogen and helium in the atmosphere of Jupiter. Scientists believe this may explain why the core of Jupiter is very small but extremely dense atmosphere.Douglas Lin of the University of California, said that while the smaller planet does not bump into him, Jupiter will continue to grow into a giant planet itself.

The research team said, elements in the planet Saturn may also be caused by something similar, a collision with a smaller planet.The planets in our solar system created by collisions between dwarf planets that orbit the Sun, who was also born. In the process the impact, small planets to melt and form planets is greater.

Earth and Moon are the result of a collision between two giant planets about the size of Mars and Venus.Collision process occurs in less than 24 hours, and the temperature of the earth at that time was very high, around 7000 degrees Celsius, where rock and metal can be melted.

Astronomers find loads of water-ice on big asteroid

A slushy cocktail of water-ice and organic materials has been directly detected on the surface of an asteroid for the first time. The finding strengthens the theory that asteroids delivered the ingredients for Earth’s oceans and life, and could make astronomers rethink conventional models for how the Solar System evolved.

It has long been thought that asteroids, which lie in a belt between Mars and Jupiter, are rocky bodies that sit too close to the Sun to retain ice. By contrast, comets, which form further out beyond Neptune, are ice-rich bodies that develop distinctive tails of vaporized gas and dust when they approach the Sun. However, this distinction was blurred in 2006 by the discovery of small objects with comet-like tails in the asteroid belt1, says astronomer Andrew Rivkin of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.To investigate the composition of these ‘main-belt comets’, Rivkin and his colleague Joshua Emery, of the University of Tennessee in Knoxville, turned the infra-red telescope at Mauna Kea, Hawaii, onto the asteroid 24 Themis — the parent body from which two of the smaller comet-like asteroids observed in 2006 were chipped. Emery and Rivkin took seven measurements of 24 Themis over a period of six years, each time looking at a different face of the asteroid as it travelled around its orbit. They consistently found a band in the absorption spectrum of light reflected from its surface that indicated the presence of grains coated in water ice, as well as the signature of carbon-to-hydrogen chemical bonds — as found in organic materials. Rivkin and Emery’s work is published in this week’s Nature2.

“Astronomers have looked at dozens of asteroids with this technique, but this is the first time we’ve seen ice on the surface and organics,” says Rivkin. The result was independently confirmed by a team led by Humberto Campins at the University of Central Florida in Orlando. He and his colleagues observed 24 Themis for 7 hours one night, as it almost fully rotated on its axis. “Between us, we have seen the asteroid from almost every angle and we see global coverage,” says Campins. He and his team also publish their findings in this week’s Nature3.

Julie Castillo-Rogez, an astrophysicist at NASA’s Jet Propulsion Laboratory in Pasadena, California, describes the findings as “huge”. “This answers the long-term question of whether there is free water in the asteroid belt,” she says.
Icy interloper

Because 24 Themis lies only about 479 million kilometres from the Sun (roughly three times the mean distance from Earth to the Sun), it is surprising that the surface ice has not all been vaporized. Both teams speculate that more ice may be held in a reservoir beneath the asteroid’s surface, shielded from the Sun, and that this ice is slowly churned up as the asteroid is struck by small bodies in the belt, thus replenishing the surface ice.The findings lend weight to the idea that asteroids and comets are the source of Earth’s water and organic material. Geochemists think that the early Earth went through a molten phase when any organic molecules would have dissociated, so new organic material would have had to be delivered to the planet at a later time, says Campins. “I believe our findings are linked to the origin of life on Earth,” he says.To assess the plausibility of this scenario, astronomers must determine whether the make-up of 24 Themis is typical of other asteroids and, if so, what exactly they hold, says Castillo-Rogez. A priority should be to search for water ice on near-Earth asteroids that could be targeted by NASA’s planned robotic and manned missions. “If we find ice samples that contain the same ratio of deuterium [‘heavy hydrogen’ made up of one neutron and one proton] to hydrogen as seen on Earth, that would be a strong pointer,” she says.

However, 24 Themis may not be a typical member of the belt it could be an interloper that formed beyond Neptune, along with the comets, which was later knocked inwards, says Rivkin. If so, this would fit well with the controversial ‘Nice model’ of the evolution of the Solar System. Proposed in 2005, this model suggests that the giant planets Jupiter, Saturn, Uranus and Neptune and asteroids migrated to their present orbits after formation4. Either way, says Rivkin, “The old-fashioned picture of the Solar System in which asteroids are asteroids and comets are comets is getting harder to sustain.”(nature)

Saturn's mysterious hexagon

Saturn Hexagon

Stunning images of the intriguing hexagon shape crowning Saturn have been captured by Nasa’s Cassini spacecraft.Scientists have waited nearly 30 years for the Sun to illuminate the ringed planet’s north pole, which heralds the arrival of spring on Saturn.It has allowed them to take the most detailed pictures yet of the hexagon phenomenon, which has a diameter wider than two Earths. The images, taken from 475,000 miles away, have revealed concentric circles, curlicues, walls and streamers within the hexagon.

The data will help shed light on space weather and unanswered questions about the same processes on Earth.The unusual shape is created by a jet stream flowing around the north pole, but scientists are baffled by what causes the hexagon and where it sucks in and expels its energy.They are also intrigued by how it has managed to stay organised for so long. The last visible-light images of the entire hexagon were captured by Nasa’s Voyager spacecraft nearly 30 years ago, the last time spring began on Saturn.

A view of Saturn from the Cassini spacecraft taken today

The hexagon was originally discovered in images taken by the Voyager spacecraft in the early 1980s. It encircles Saturn at about 77 degrees north latitude. The jet stream is believed to whip along the hexagon at around 220 miles per hour.Saturn should give scientists a good model to study the physics of circulation patterns and atmosphere, before it does not have land masses or oceans on its surface to complicate weather the way Earth does.

Cassini has shown Saturn's region of space to be active

Nasa scientist Kevin Baines has studied the hexagon with Cassini’s visual and infrared mapping spectrometer.He said: ‘Now that we can see undulations and circular features instead of blobs in the hexagon, we can start trying to solve some of the unanswered questions about one of the most bizarre things we’ve ever seen in the solar system.

‘Solving these unanswered questions about the hexagon will help us answer basic questions about weather that we’re still asking about our own planet.’

The Cassini team plan to search the new images for clues, taking an especially close look at the newly identified waves that radiate from the corners of the hexagon – where the jet takes its hardest turns – and the multi-walled structure that extends to the top of Saturn’s cloud layer in each of the hexagon’s six sides.

Scientists are also particularly intrigued by a large dark spot that appeared in a different position in a previous infrared image from Cassini. In the latest images, the spot appears in the 2 o’clock position.The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.