Raw images of the moment Saturn¹ reached its equinox have been beamed to Earth by the US Cassini spacecraft.

木星到达昼夜平分点的原始照片被美国卡西尼号宇宙飞船拍摄到并发回地球。

Scientists are studying the unprocessed（未加工的） pictures to uncover new discoveries in the gas giant's ring system.

Equinox is the moment when the Sun crosses a planet's equator（赤道）, making day and night the same length.

During this time, the Sun's angle over Saturn is lowered, showing new objects and irregular structures as shadows on the otherwise flat plane of the rings.

Saturn's orbit is so vast that Equinox happens only once every 15 Earth years.

At the moment of equinox（昼夜平分点）, the rings turn edge-on to the Sun and reflect almost no sunlight.

This is the first equinox since 1994 and the first time there has been an observer, in the shape of the joint² US and European spacecraft, Cassini.

In an email, Dr Carolyn Porco, leader of Cassini's imaging team, said the long-awaited images did not disappoint: "Even a cursory³（草率的，粗略的） examination of them reveals strange new phenomena⁴ we hadn't fully⁵ anticipated.

"Over the next week or two, the [Cassini] imaging team will be poring（熟读，熟视） over these precious gems⁶（宝石） to see what other surprises await us, and, as usual, we will announce what we have found as soon as we can."

Cassini was launched in October 1997 from Florida's Cape⁷ Canaveral Air Force Station. It arrived at Saturn in July 2004 to embark⁸ on a four-year mission of exploration around the planet and its moons.

The spacecraft is still operating well and has been re-programmed to carry out new tasks. Its current mission is to answer some of the questions raised by its earlier observations.