快猫短视频

NASA鈥檚 going sunbathing. Next week it will fire a spacecraft towards the Sun
to soak up particles from the solar wind. And to ensure a soft landing for the
precious samples, two specially equipped helicopters will snatch the probe out
of the air as it returns to Earth.

The solar wind flows continuously from the Sun into space. Its mix of charged
particles comes from the outer layers of the Sun and reflects their composition,
which has hardly changed in the 5 billion years since the Sun formed from a
cloud of gas and dust. 鈥淏y sending this craft into space we hope to discover the
starting material of the Solar System,鈥� says Donald Burnett of the California
Institute of Technology in Pasadena, leader of the Genesis project.

Three months after its launch on 30 July, the spacecraft will position itself
at a spot in space between Earth and the Sun called Lagrangian point 1. A cover
over the main part of the spacecraft will then swing back to reveal arrays of
ultra-pure materials that will absorb ions from the solar wind. The craft also
has an electrostatic concentrator that will focus the lighter ions, such as
oxygen, for isotope analysis.

快猫短视频s are especially curious about oxygen, whose three isotopes occur in
different ratios in different parts of the Solar System. They hope that finding
out the ratio of oxygen isotopes in the Sun will help them understand how the
primordial cloud of dust and gas coalesced into the planets we see today.

When the craft returns to the Earth in 2004, NASA plans to avoid a bumpy
touchdown for the fragile samples. Two helicopters equipped with long booms will
hook the capsule鈥檚 parachute as it drifts to Earth after re-entry.