19 January 2014

from NewsSky Website





Scientists are comparing

Rosetta's mission to land on the hurtling ball of ice,

to a fly trying to land on a speeding bullet.





is hurtling through space at nearly 25,000mph


A spaceship is about to embark on one of the most technologically advanced missions ever attempted - by landing on a comet at 24,600mph. An internal alarm will wake the Rosetta craft at 10am today after two and a half years of deep-space hibernation.

It will then chase 67P/Churyumov-Gerasimenko as it begins to move closer to the Sun, before harpooning the 2.5-mile wide frozen dirtball and trying to make a landing.

Project scientist Matt Taylor, from the European Space Agency (ESA), compared the feat to the Bruce Willis film Armageddon in which Willis lands on an asteroid to save the world from destruction.

An ESA computer animation of the Rosetta spaceship

"It will be an amazing achievement for human Endeavour, an 'Armageddon' type thing," he told the Sunday Telegraph.

"We're not just landing on the Moon, we're dealing with something dynamic, which is kicking off tonnes of dust and gas every minute."

Rosetta was launched in March 2004, from Kourou, in French Guiana, and is now 500 million miles from Earth and close to the orbit of Jupiter.

The comet is travelling at 24,600mph - far faster than a space ship - so the ESA craft has spent the time since its launch using the gravitational pull of the Earth and Mars to act as a sling shot and allow it to accelerate.

"It flew almost 10 years in space and in the last two and a half years it was so far from the sun that we couldn't keep it completely active so we had to switch it off," said Dr Paolo Ferri, head of the ESA's mission operations department.


When Rosetta is near the comet, it will launch its lander craft

"We have no contact since two and a half years and on Monday we'll have the first signal since then."

Scientists compare Rosetta's mission to a fly trying to land on a speeding bullet.

It will arrive at 67P in August, where if all goes to plan, it will become the first spacecraft to orbit a comet and land a probe on its surface.

Comets are the primitive building blocks of the solar system, and are thought to have helped 'seed' Earth with water, and perhaps even life. Their icy surface is embedded with dust, grit and particles from space, NASA says.

They are left over from a planet-building time when our sun was just a spinning disc of dust and gas.


An ESA animation of the lander landing on the comet

By studying the comet's dust and gas, Rosetta will help scientists learn more about the evolution of the solar system, it is hoped.

"Over the millennia of the history of Earth, comets have actually affected our evolution, they probably have affected the evolution of life as well, from the start of life to the destruction of life," Dr Ferri said.

"There are many theories about comets hitting the earth and causing global catastrophes. So understanding comets is also important to see in the future what could be done to defend the earth from comets."