A Japanese probe reached Venus today and prepared to enter orbit on a two-year mission that will mark a major milestone for the country's space programme and could shed light on the climate of Earth's mysterious neighbour.

The probe, Akatsuki, which means "dawn", would be the first Japan has placed in orbit around another planet and comes after the country recently brought a probe back from a sample-catching trip to an asteroid.

Scientists said they would know later whether the probe had successfully entered its orbit. They said they briefly lost contact with the probe, but communication had been restored.

Akatsuki, which was launched on May 20, is designed to monitor volcanic activity on the planet and provide data on its climate and its thick cloud cover, including whether Venus has lightning. The probe is equipped with infrared cameras and other instruments to carry out its mission.

The £191 million probe is supposed to maintain an elliptical orbit around Venus, ranging from passes 190 miles from the planet's surface to outer swings 50,000 miles away that will allow it to comprehensively monitor Venusian weather patterns.

One of the mysteries scientists are hoping to clear up is the intensity of surface winds on Venus that are believed to reach up to speeds of 220mph.

Japan's space agency JAXA said the probe was to continue monitoring Venus from its orbit for two years.

Inserting the probe into orbit would be a big success for Japan, which previously failed in an effort to put probes around Mars. The Mars mission, called Nozomi, or "hope", failed after a series of technical glitches. That mission was launched in 1998.

Japan has been overshadowed in recent years by the big strides of China, which has put astronauts in space twice since 2003 and was the third country to send a human into orbit after Russia and the US,

However, Japan has long been one of the world's leading space-faring nations. It was the first Asian country to put a satellite in orbit around the Earth - in 1970 - and has developed a highly reliable booster rocket in its H-2 series.

Japan's space programme has never involved manned flight and instead operates on a shoestring budget that focuses primarily on small-scale scientific projects.

It got a big morale boost earlier this year with the successful return to Earth in June of the Hayabusa probe.

Hayabusa successfully captured dust from an asteroid for the first time in history, bringing back microscopic samples from an asteroid called Itokawa that could offer insight into the creation and makeup of the solar system.

It is only the fourth set of samples to be returned from space in history - including moon matter collected by the Apollo missions, comet material by Stardust, and solar matter from the Genesis mission.

The spacecraft's capsule landed successfully in the Australian Outback in June after a seven-year, four billion-mile journey.

The Venus mission also follows Japan's first lunar probe, which completed a 19-month mission last year. The lunar project gathered data for a detailed map of the moon's surface and examined its mineral distribution.