La nave espacial Juno de la NASA hará un sobrevuelo cercano de la luna helada Europa de Júpiter

Impresión artística de la nave espacial Juno orbitando Júpiter. Crédito: NASA

A medida que la nave espacial Juno se acerque a la luna Europa, debería proporcionar ciencia valiosa, e imágenes notables, para[{” attribute=””>NASA’s upcoming Europa Clipper mission.

In less than three days, on Thursday, September 29, at 2:36 a.m. PDT (5:36 a.m. EDT), NASA’s Juno spacecraft will come within 222 miles (358 kilometers) of the surface of Jupiter’s ice-covered moon, Europa. During the close flyby, the solar-powered spacecraft is expected to obtain some of the highest-resolution images ever taken of portions of Europa’s surface. It will also collect valuable data on the moon’s interior, surface composition, and ionosphere, along with its interaction with Jupiter’s magnetosphere.

Future missions could benefit greatly from this detailed information. One such mission is Europa Clipper, which is set to launch in 2024 to study the icy moon. “Europa is such an intriguing Jovian moon, it is the focus of its own future NASA mission,” said Juno Principal Investigator Scott Bolton of the Southwest Research Institute in San Antonio. “We’re happy to provide data that may help the Europa Clipper team with mission planning, as well as provide new scientific insights into this icy world.”

This image of Jupiter’s moon Europa was taken by the JunoCam imager aboard NASA’s Juno spacecraft on Oct. 16, 2021, from a distance of about 51,000 miles (82,000 kilometers). Credit: Image data: NASA/JPL-Caltech/SwRI/MSSS, Image processing: Andrea Luck CC BY

Europa is about 90% the size of Earth’s Moon, with an equatorial diameter of 1,940 miles (3,100 kilometers). Researchers believe a salty ocean lies below a miles-thick ice shell, sparking questions about potential conditions capable of supporting life underneath Europa’s surface.

Gravitational forces from the close flyby will modify Juno’s trajectory, reducing the time it takes to orbit Jupiter from 43 to 38 days. It will be the closest a NASA spacecraft has approached Europa in over 22 years, since Galileo came within 218 miles (351 kilometers) on January 3, 2000. Additionally, this flyby marks the second encounter with a Galilean moon during Juno’s extended mission. In June 2021, the mission explored Ganymede and plans include making close approaches of Io in 2023 and 2024.

Data collection on the spacecraft will begin an hour prior to closest approach, when the Juno is 51,820 miles (83,397 kilometers) from Europa.

“The relative velocity between spacecraft and moon will be 14.7 miles per second (23.6 kilometers per second), so we are screaming by pretty fast,” said John Bordi, Juno deputy mission manager at JPL. “All steps have to go like clockwork to successfully acquire our planned data, because soon after the flyby is complete, the spacecraft needs to be reoriented for our upcoming close approach of Jupiter, which happens only 7 ½ hours later.”

Juno’s extended mission includes flybys of the moons Ganymede, Europa, and Io. This graphic depicts the spacecraft’s orbits of Jupiter – labeled “PJ” for perijove, or point of closest approach to the planet – from its prime mission in gray to the 42 orbits of its extended mission in shades of blue and purple. Credit: NASA/JPL-Caltech/SwRI

Juno’s full suite of instruments and sensors will be activated for the Europa encounter. The spacecraft’s Jupiter Energetic-Particle Detector Instrument (JEDI) and its medium-gain (X-band) radio antenna will collect data on Europa’s ionosphere. Its Waves, Jovian Auroral Distributions Experiment (JADE), and Magnetometer (MAG) experiments will measure plasma in the moon’s wake as Juno explores Europa’s interaction with Jupiter’s magnetosphere.

MAG and Waves will also search for possible water plumes above Europa’s surface. “We have the right equipment to do the job, but to capture a plume will require a lot of luck,” said Bolton. “We have to be at the right place at just the right time, but if we are so fortunate, it’s a home run for sure.”

Inside and Out

Juno’s Microwave Radiometer (MWR) will gaze into Europa’s water-ice crust to obtain data on its composition and temperature. This is the first time that data like this will be gathered to study the moon’s icy shell.

Additionally, during the flyby the mission expects to take four visible-light images of the moon with JunoCam (a public-engagement camera). The Juno science team will compare them to images from previous missions, so they can find any changes in Europa’s surface features that might have occurred over the past two decades. These visible-light images will have an expected resolution of better than 0.6 miles (1 kilometer) per pixel.

Esta película se generó a partir de imágenes recopiladas el 29 de octubre de 2018, durante el 16° perijove de Juno (el punto en el que una órbita se acerca más al centro de Júpiter). El científico ciudadano Gerald Eichstädt creó esta película utilizando datos del generador de imágenes JunoCam de la nave espacial. Crédito: Imagen mejorada por Gerald Eichstädt basada en imágenes cortesía de NASA/JPL-Caltech/SwRI/MSSS

Juno estará a la sombra de Europa más cercana a la luna. Sin embargo, la atmósfera de Júpiter reflejará suficiente luz solar para que los generadores de imágenes de luz visible de Juno recopilen datos. La cámara destacada de la misión (llamada Unidad de referencia estelar) tomará una imagen en blanco y negro de alta resolución de la superficie de Europa. Fue diseñado para tomar imágenes de campos de estrellas y buscar estrellas brillantes con posiciones conocidas para ayudar a Juno a orientarse. Mientras tanto, el Jovian Infrared Auroral Mapper (JIRAM) intentará capturar imágenes infrarrojas de su superficie.

Las vistas de cerca de Juno y los datos de su instrumento MWR informarán a la misión Europa Clipper, que realizará casi 50 sobrevuelos de la luna helada después de que llegue a Europa en 2030. Europa Clipper recopilará datos sobre la atmósfera, la superficie y el interior de la luna. Con esta información, los científicos esperan comprender mejor el océano subterráneo global de Europa, el grosor de su capa de hielo y cualquier columna que pueda descargar agua subterránea al espacio.

Más información sobre la misión

El Laboratorio de Propulsión a Chorro (JPL) de la NASA, una división de Caltech en Pasadena, California, administra la misión Juno para el investigador principal Scott J. Bolton del Southwest Research Institute en San Antonio. Juno es parte del programa Nuevas Fronteras de la NASA, que se administra en el Centro Marshall de Vuelos Espaciales de la NASA en Huntsville, Alabama, para la dirección de las misiones científicas de la agencia en Washington. Lockheed Martin Space en Denver construyó y opera la nave espacial.