Photo courtesy: Nasa
After successful expeditions to Mars and the Moon, NASA is now all set to conquer Jupiter. When Juno finally beeped from above Jupiter on July 4, 2016 after a 5-year long journey over 2.8 billion kilometres, it was a triumph of sorts for NASA’s scientists.
The spacecraft’s name, Juno is derived from the Roman Goddess, wife of Jupiter. In mythology, when Jupiter drew a veil of clouds around himself to hide his mischief, his wife, Goddess Juno, managed to peer through and discover him. JUNO the spacecraft, currently in polar orbit over Jupiter, aims to accomplish the same feat as regards planet Jupiter, and reveal the many secrets related to the planet’s composition, gravity and magnetic fields, and polar magnetosphere. JUNO will also probe into the origins of the giant planet, its core, the amount of water present within its atmosphere, the planet’s mass, its mysterious red spot, and its winds that can reach speeds of over 618 kilometres per hour (384 mph).
JUNO is the first spacecraft to orbit Jupiter since Galileo, which was deliberately crashed into the planet’s surface on September 21, 2003, to protect one of its discoveries, a possible ocean beneath Jupiter’s moon Europa
A NASA New Frontiers mission, JUNO was launched from Cape Canaveral Air Force Station on August 5, 2011, and is powered by solar arrays, commonly used by satellites orbiting the Earth and working in the inner solar system. Three solar array wings, the largest ever deployed on a planetary probe, played an integral role in stabilizing the spacecraft and generating power
Dr. J. J. Rawal, President of the Indian Planetary Society (IPS), Mumbai, speaking with G’nY correspondent point out that JUNO has been primarily launched to:
- Determine the ratio of oxygen to hydrogen on Jupiter, besides effectively measuring the abundance of water on the planet. This will help check the authenticity of prevailing theories linking Jupiter’s origins to the solar system.
- Obtain a better estimate of Jupiter’s core mass.
- Precisely map Jupiter’s gravitational field to assess the distribution of mass within Jupiter’s interiors, including its structure and dynamics.
- Precisely map Jupiter’s magnetic field to assess the origin, structure, and depth of Jupiter’s magnetic field. This can also help scientists understand the fundamental physics behind the dynamo theory.
- Map the variations in atmospheric composition, temperature, structure, cloud opacity and dynamics to pressures far greater than 100 bars (10 MPa; 1450 pound/sq inch) at all latitudes.
- Characterize and explore the 3-D structure of Jupiter’s polar magnetosphere and its auroras.
- Measure the orbital frame-dragging, known as Lense-Thirring precession caused by the angular momentum of Jupiter, and possibly a new test of general relativity effects connected with the Jovian rotation.
As per prevalent hypothesis, Jupiter is widely believed to harbour a solid core of rock and ice. However, as Dr. Anil Bhardwaj, Director of the Space Physics Laboratory, Vikram Sarabhai Space Centre, talking to G’nY points out, “this lacks proof. JUNO equipped with infrared cameras and an ultraviolet spectrometer, with which to send pictures to the respective space centres, can help resolve the uncertainty.”
“NASA would also be planning similar missions to the icy moons of Jupiter in search of water in the deep cores there, to check on the possibility or otherwise of life forms on the planet”, Bharadwaj told G’nY.
A huge gaseous sphere 11 times wider than the Earth and 300 times more massive, Jupiter is believed to have been the first planet that was formed in our solar system, and to hence hold clues to the evolution of our solar system. With multiple moons orbiting around it, Jupiter is looked upon as a ‘mini solar system’.
JUNO will circle Jupiter 37 times for 20 months, diving down to about 2,600 miles (4,100 km) above the planet’s dense clouds. It will orbit the poles and try to dodge the planet’s most hazardous radiation belts, even as its onboard cameras focus themselves to take spectacular colour images of the giant planet. To protect it from radiation JUNO has been equipped with a shielded electronics vault.
The Juno mission ends on February 20, 2018, when Juno is expected to crash into Jupiter.