WASHINGTON • Nasa has published the first images of Jupiter's north pole and its southern aurora, taken during the Juno spacecraft's first orbital fly-by of the gaseous giant.
Juno came within 4,200km of Jupiter on Aug 27 during a six-hour transit from the north pole to the south.
"It looks like nothing we have seen or imagined before," said Dr Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio, on Friday.
"The largest planet in our solar system is truly unique. We have 36 more fly-bys to study just how unique it really is."
A camera dubbed the "JunoCam" took the high-definition images. It is one of the nine instruments on board the spacecraft. Juno notably sent the first infrared close-ups of the planet's north and south poles.
"These first infrared views of Jupiter's north and south poles are revealing warm and hot spots that have never been seen before," said Dr Alberto Adriani, of the Istituto di Astrofisica E Planetologia Spaziali in Rome.
Dr Adriani is one of the researchers who developed the Jovian Infrared Auroral Mapper that allowed scientists to acquire the images.
"While we knew that the first-ever infrared views of Jupiter's south pole could reveal the planet's southern aurora, we were amazed to see it for the first time," he said.
Auroras are streamers of light in the sky caused by energy from the sun and electrically charged particles trapped in the magnetic field. Another Juno instrument recorded sounds from Jupiter - "ghostly-sounding transmissions emanating from the planet", said Nasa.
Scientists have known about Jupiter's radio emissions since the 1950s, but had never analysed them from such a close distance.
"Jupiter is talking to us in a way only gas-giant worlds can," said Dr Bill Kurth, co-investigator from the University of Iowa.
Juno's main mission began in July and is scheduled to end in February 2018, when the probe will self-destruct by diving into the planet's atmosphere.
The US$1.1 billion (S$1.5 billion) project aims to peer beneath the clouds around Jupiter for the first time to learn more about the planet's atmosphere. Scientists want to know how much water the planet contains, because it can tell them a lot about when and how the planet formed. Juno will also probe how the planet's intense magnetic field is generated, and study the formation of auroras.
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