NASA's Juno spacecraft - currently orbiting Jupiter, flying close approaches to the planet and then out into the realm of the Jovian moons - and the InSight lander, now perched in Mars' equatorial region, have both received mission extensions, the space agency announced Jan. 8. Cornell astronomers serve key roles on both projects.
An independent review panel composed of science, operations and mission management experts said the Juno and InSight missions have "produced exceptional science," and have recommended that the space agency continue both missions, according to the announcement from NASA and the Jet Propulsion Laboratory, Pasadena, California.
The Juno mission was extended from August 2021 until September 2025, as NASA expects that the mission end-of-life may occur during this period. The InSight mission will run through December 2022.
"For Juno, the goal of the mission is to understand how giant planets like Jupiter work," said Jonathan Lunine, the David C. Duncan Professor in the Physical Sciences and chair of the Department of Astronomy, in the College of Arts and Sciences. He is a co-investigator on the mission, with significant involvement on four instruments: the JIRAM infrared spectrometer, the MWR microwave radiometer, the interiors working group and the SRU stellar reference unit.
The Juno spacecraft launched in 2011 and entered into Jupiter's orbit in 2016. It has examined the planet's interior structure, magnetic field and magnetosphere, and has found the planet's atmospheric dynamics to be far more complex than previously thought.
In one such discovery, published last summer, Lunine and other scientists were surprised to find lightning in Jupiter's upper atmosphere.
"How did the giant planets form, evolve and how do they behave today?" Lunine said, discussing why studying Jupiter is consequential. "While giant planets are very different from planets like Earth, computer simulations of solar system formation suggest that the growth and migration of Jupiter and Saturn through the early primordial solar system may have accelerated the formation of the terrestrial planets - including Earth."
Lunine, a member of Cornell's Carl Sagan Institute, said the spacecraft spends only a short portion of its 53-day orbit close to Jupiter, due to the planet's intense radiation belts.
The craft's closest approach point - called the perijove - gradually moves northward each orbit, he said.
Juno will continue observations of the Jovian system and it will use propulsive maneuvers and satellite-gravity assists to perform close flybys of Jupiter's moons Ganymede, Europa and Io. During the extended mission, Juno will explore major scientific questions related to Jupiter's interior, structure and atmosphere, including an examination of the polar vortices, the magnetic "Great Blue Spot," water abundance and the Jovian aurorae.
The targeted observations of Jupiter's moons enable searches for changes in the moon's geology since the Voyager and Galileo missions. The spacecraft will also obtain high-latitude observations of Jupiter's rings and the spacecraft's microwave radiometer will explore the moon Europa's ice shell.
"So the extended mission is a journey to the northern latitudes of Jupiter, where within five years we'll explore why the poles of Jupiter seem so different from the equatorial region in appearance," Lunine said. "Looking at a strange creature from different angles allows you to understand it better. This five-year extended mission will allow us to see inside Jupiter from an entirely different perspective."
For InSight - a craft designed to sit on the red planet's surface, studying its interior crust, mantle and core - its mission's extra two Earth years translates to one more Martian year of collecting data on the planet's atmospheric dynamics, magnetic field and interior structure.
InSight, which landed on Mars in 2018, has found robust tectonic activity, gravity waves, Mars quakes, surface swirling "dust devils" and the steady, low rumble of infrasound - pressure oscillations below 10 Hertz, found by the lander's sensors.
"Hopefully in the coming Mars year, we'll see some larger Marsquakes occur," said Don Banfield '87, principal research scientist in the Cornell Center for Astrophysics and Planetary Science, and the science lead for the InSight mission's Auxiliary Payload Sensor Suite. "If not, we'll still study the wobble of Mars, improve our understanding of the planet's internal structure and collect data on the small Marsquakes."
InSight's scientific team is internationally diverse, collegial and cohesive, according to Banfield: "We work together very well. InSight is exploring Mars not just for the United States, but for all the world's curious people."
