Juno reaches Jupiter ~ it carries three 1.5-inch Lego figurines (Galileo Galilei)

Do you why these legos are so special … !  Lego  is a line of plastic construction toys that are manufactured by  Lego Group, a privately held company based in Billund, Denmark.

Humans will be knowing more and reading more about “ Io, Europa, Ganymede, and Callisto” – they are the “Galilean moons” - the four largest moons of Jupiter . They were discovered by Galileo Galilei around January 1610 and were the first group of objects found to orbit another planet. Galileo's discovery showed the importance of the telescope as a tool for astronomers by proving that there were objects in space that cannot be seen by the naked eye. The fifth planet from the sun and the heftiest in the solar system, Jupiter is known as a gas giant — a ball of mainly hydrogen and helium — unlike rocky Earth and Mars. It is 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.

Today is significant day in the history of astronomy for NASA has confirmed having 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. "Welcome to Jupiter!" flashed on screens at mission control at NASA's Jet Propulsion Lab in Pasadena, California.  The Juno team cheered and hugged.

Juno is a NASA New Frontiers mission currently orbiting the planet Jupiter. Juno was launched from Cape Canaveral Air Force Station on August 5, 2011 and reached destination today ~5^th July 2016.  The spacecraft is in a polar orbit to study Jupiter's composition, gravity field, magnetic field, and polar magnetosphere. Juno will also search for clues about how the planet formed, including whether it has a rocky core, the amount of water present within the deep atmosphere, mass distribution, and its deep winds, which can reach speeds of 618 kilometers per hour (384 mph).  Still June is not the first, which credit goes to Galileo probe which orbited from 1995–2003.

The Juno spacecraft is powered by solar arrays, commonly used by satellites orbiting Earth and working in the inner Solar System, whereas radioisotope thermoelectric generators are commonly used for missions to the outer Solar System and beyond. The spacecraft's name comes from Greco-Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, but his wife, the goddess Juno, was able to peer through the clouds and see Jupiter's true nature. The mission had previously been referred to by the backronym JUpiter Near-polar Orbiter in a list of NASA acronyms.

Today marks the culmination of a journey that commenced almost 5 years ago – its predecessor Galileo was deliberately crashed into Jupiter on September 21, 2003, to protect one of its discoveries -- a possible ocean beneath Jupiter's moon Europa.  Juno will help answer  lot of questions by looking at Jupiter's interior. The spacecraft will orbit the poles and try to dodge the planet's most hazardous radiation belts. To protect the spacecraft from the radiation, Juno has a shielded electronics vault.

Juno is a spinning, robotic probe as wide as a basketball court. It will circle Jupiter 37 times for 20 months, diving down to about 2,600 miles (4,100 kilometers) above the planet's dense clouds. The seven science instruments on board will study Jupiter's auroras and help scientists better understand the planet's origins, structure, atmosphere and magnetosphere. An onboard color camera called JunoCam will take "spectacular close-up, color images" of Jupiter, according to NASA. The space agency is asking the public to help decide where to point the camera.

Interestingly, three 1.5-inch Lego figurines are also on board Juno. One is a likeness of Galileo Galilei -- the scientist who discovered Jupiter's four largest moons. The other two represent the Roman god Jupiter and his wife Juno. They were included to inspire children to study science and math. Nasa is using the aluminium Lego figures to inspire children to explore science, technology and engineering.

Nasa's Juno spacecraft fired its main rocket engine to slow itself down from a speed of 165,000 mph (265,000 kph) and slip into orbit around Jupiter. In Greek and Roman mythology, Jupiter drew a veil of clouds around himself to hide his mischief. From Mount Olympus, Juno was able to peer through the clouds and reveal Jupiter's true nature. Juno holds a magnifying glass to signify her search for the truth, while her husband holds a lightning bolt. The third Lego crew member is Galileo Galilei, who made several important discoveries about Jupiter. Even as NASA attempts to inspire the next generation of spacecraft engineers by encouraging children to explore subjects such as science and technology – the legos are on a  suicide mission. Juno, along with its three passengers, meets its demise in 2018 when it deliberately dives into Jupiter's atmosphere and disintegrates — a necessary sacrifice to prevent any chance of accidentally crashing into the planet's potentially habitable moons.

If successful, scientists will for the first time be able to see what lies beneath Jupiter's atmosphere, and help unlock secrets about how the solar system formed.  

With regards – S. Sampathkumar

5^th July 2016.