This day in history | 1967 Soviets glimpse beneath clouds of Venus

The Soviet Union has successfully sent a space probe into the atmosphere of the planet Venus for the first time.
After its four-month journey from Earth, Venera 4 plunged through the planet’s dense cloud cover and down towards the surface.
Almost immediately it began sending back coded bleeps carrying details of the gases that make up the air around Venus, as well as readings for temperatures and pressure.
It is the first time any measurements have been taken from inside the planet’s atmosphere.
The Soviet Union had hoped to attempt a “soft” landing on the surface of Venus, and Venera 4 carried equipment designed to allow communications even while submerged beneath any oceans which it was suspected there might be on the surface.
But contact was lost 94 minutes after the probe entered the atmosphere, when it would still have been about 15 miles (25 km) above the planet itself.
The signals sent back from Venera 4 were picked up by the radio telescope at Jodrell Bank in Cheshire.
The observatory was invited to take part in the mission to Venus by the Soviet Academy of Scientists.
The director of Jodrell Bank, Professor Sir Bernard Lovell, said the radio signals sent back from Venera 4 confirmed that it was unlikely and almost impossible that there was life on the planet.
At a news conference, Professor Lovell said Jodrell Bank was delighted to help the Soviet Union in tracking the spacecraft.
“This appears … as a rational common-sense attitude, the sort of thing one always hopes will emerge in these colossal, expensive space enterprises,” he said.
Venera 4 is the first successful attempt to reach Venus after three failed Soviet missions.
Venera 3 came closest, and successfully reached the planet, but communications had already failed, making the mission a failure.
Within the next few days, the American spacecraft Mariner 5 is also expected to arrive at Venus.
It is not, however, planning to attempt a landing, but will fly past at about 2,500 miles (4,000 km) from the planet while instruments on board measure the atmosphere and magnetic fields.
A previous American mission, Mariner 2, was the first to fly by Venus and scan its features in December 1962.
Data sent back from that mission suggested that Venus has hot surface temperatures and an atmosphere dominated by carbon dioxide.

Courtesy BBC News

In context

The American spacecraft, Mariner 5, performed its fly-by of Venus successfully the following day.
Its measurements revealed why Venera 4 had come to such a sudden end.
Pressures under the continuous cloud cover around Venus were measured at about 90 times that of Earth – the equivalent of those about 3,000 feet (900 metres) below the oceans on Earth.
It is likely that Venera 4 was crushed before it reached the surface.
Even had it arrived, it would have been destroyed by surface temperatures measured at 480 degrees C – hot enough to melt lead.
There were another 12 Soviet Venera missions. Venera 7 became the first space probe to land successfully on Venus in August 1970.
In 1989, Nasa launched the Magellan spacecraft from the space shuttle.
Between 1990 and 1994 it orbited the planet, successfully mapping the majority of the surface in unprecedented detail before plunging into the atmosphere and disintegrating under the massive pressures.
The European Space Agency is planning to launch a further mission, known as the Venus Express, in October 2005.