Welcome to Jupiter!

NASA's Juno space probe arrives at giant planet

Personally, I think manned exploration is dangerous, silly, and way too expensive.

Computers and robotics make it totally unnecessary and frivolous.

But this stuff is great fun.

While American satellite news radio dwelt endlessly and repetitively on the presser by the FBI Director concerning Hillary's emails, the biggest story on BBC World Service was this one.

NASA says it has received a signal from 540 million miles across the solar system, confirming its Juno spacecraft has successfully started orbiting Jupiter, the largest planet in our solar system.

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The probe had to conduct a tricky maneuver to slow down enough to allow it to be pulled into orbit: 

It fired its main engine for 35 minutes, effectively hitting the brakes to slow the spacecraft by about 1,212 miles per hour (542 meters per second).

"NASA did it again," said Scott Bolton, Juno principal investigator.

"We're there, we're in orbit. We conquered Jupiter."

"Through tones Juno sang to us and it was a song of perfection," said Rick Nybakken, 

Juno was launched nearly five years ago on a mission to study Jupiter's composition and evolution.

It's the first spacecraft to orbit Jupiter since Galileo. 

Galileo was deliberately crashed into Jupiter on September 21, 2003.

. . . .

The largest planet in our solar system, Jupiter is a huge ball of gas 11 times wider than Earth and 300 times more massive than our planet.

Researchers think it was the first planet to form and that it holds clues to how the solar system evolved.

Spacecraft have been to Jupiter before. 

But scientists still are puzzled by the gas giant.

What's going on under Jupiter's dense clouds?

 Does it have a solid core?

 How much water is in its atmosphere?

 And how deep are those colorful bands and that mysterious giant red spot?

Juno will help answer those questions by looking at Jupiter's interior. 

The spacecraft will orbit the poles and try to dodge the planet's most hazardous radiation belts. 

. . . .

Juno's main spacecraft body measures 11.5 feet (3.5 meters) tall and 11.5 feet in diameter. 

But with its three solar panels open, it spans about 66 feet (20 meters). 

For comparison, an NBA basketball court is 50 feet wide and 94 feet long.

Jupiter was 445 million miles (716 million kilometers) from Earth when Juno was launched from Cape Canaveral on August 5, 2011. 

But the probe has traveled a total distance of 1,740 million miles (2,800 million kilometers) to reach the gaseous planet, making a flyby of Earth to help pick up speed.

"After a 1.7 billion mile journey, we hit our burn targets within one second, on a target that was just tens of kilometers large," said Nybakken. 

"That's how well the Juno spacecraft performed tonight."

The Juno mission ends on February 20, 2018, when Juno is expected to crash into Jupiter.