Captured at a distance of 78,000 km (48,000 mi) from Jupiter by JunoCam, this image reveals the pale bluish region of Jupiter’s north polar region, speckled by hurricane-like cloud formations. Credit: NASA/JPL / SwRI / MSSS
NASA’s Juno spacecraft has continued to return data and images from its second pass around Jupiter on August 27th, 2016. Images in visible and infra-red light have been received as a part of the data – together with the sound of Jupiter’s “voice”.
Of particular interest are the images of Jupiter’s north pole – which has never been seen by human eyes, and is revealed as being vastly different to the rest of the planet, together with detailed images of the planet’s south pole, only previously briefly seen by the Cassini mission in 2008, whilst en route to Saturn.
“First glimpse of Jupiter’s north pole, and it looks like nothing we have seen or imagined before,” said the Juno mission’s principal investigator Scott Bolton on the release of the most recently received images and data on Friday, September 2nd.
An enhanced view of the north polar hurricane-like clouds images by Juno on August 27th, 2016, together with the blue tingle of the polar atmosphere. Credit: NASA/JPL / SwRI / MSSS
“It’s bluer in colour up there than other parts of the planet, and there are a lot of storms. There is no sign of the latitudinal bands or zone and belts that we are used to—this image is hardly recognisable as Jupiter. We’re seeing signs that the clouds have shadows, possibly indicating that the clouds are at a higher altitude than other features.”
All of Juno’s science instruments were active during the flyby,gathering some 6 Mb of data, images and sounds, which was transmitted back to Earth over a period of a day and a half once the space vehicle had moved away from Jupiter once more. Among this data were images from the Italian-built Jovian Infra-red Auroral Mapper (JIRAM), which returned the first ever close-up infra-red images of Jupiter’s massive aurora.
A mosaic of three infra-red images of Jupiter’s southern aurora taken some 4 hours after the closest point of the flyby. The images were captured by the Jovian Infra-red Auroral Mapper (JIRAM) camera aboard Juno
at wavelengths ranging from 3.3 to 3.6 microns — the wavelengths of light emitted by excited hydrogen ions. Credit: NASA/JPL / SwRI / IAPS
“JIRAM is getting under Jupiter’s skin, giving us our first infra-red close-ups of the planet,” said Alberto Adriani, JIRAM co-investigator from Istituto di Astrofisica e Planetologia Spaziali, Rome. “These views of Jupiter’s north and south poles are revealing warm and hot spots that have never been seen before.
“No other instruments, both from Earth or space, have been able to see the southern aurora,” he continued. “Now, with JIRAM, we see that it appears to be very bright and well-structured. The high level of detail in the images will tell us more about the aurora’s morphology and dynamics.”
Juno doesn’t only have eyes, it has ears as well. We’ve known for a long time that Jupiter can be quite “vocal”, and the flyby allowed Juno’s Radio/Plasma Wave Experiment (WAVE) to capture the sound of the planet’s aurorae.
“Jupiter is talking to us in a way only gas-giant worlds can,” said Bill Kurth, co-investigator for WAVE. “We detected the signature emissions of the energetic particles that generate the massive auroras which encircle Jupiter’s north pole. These emissions are the strongest in the solar system. Now we are going to try to figure out where the electrons come from that are generating them.”
Juno is now heading back away from Jupiter on the second of its “long” orbits of the planet. On October 19th, the spacecraft will once again skim over Jupiter’s cloud tops, where it will perform a further braking manoeuvre to reduce its orbital period around the planet to just 14 days.
Did ET Call Us? Mostly Likely Not
The end of August saw various media outlets a-buzz with news about Russian scientists having detected a “strong” radio signal from deep space, with muttering and speculations about aliens, despite cautionary notes from assorted space-related outlets and organisations.
The signal was actually detected in May 2015 by the RATAN-600 radio telescope in Zelenchukskaya, south-western Russia. At the time, the telescope was conducting a survey of astronomical objects in the framework of the SETI (Search for Extraterrestrial Intelligence) programme. It seemed to come from the general direction of the star HD 164595, a star around 95 light years away which is very similar to our own Sun but about 1.5 billion years older, and known to have at least one planet – a gas giant roughly the mass of Neptune – orbiting it.
News about it reached a wider audience in August when a member of the team behind the survey decided to e-mail data on it to colleagues asking for thoughts on what it might be, and suggesting the region of the sky containing HD 164595 should be monitored for further indications of the signal and possible causes.
The RATAN-600 radio telescope. Credit: Russian Academy of Sciences
This request was picked up by science and technology writer Paul Gilster, who blogged about it on his website Centauri Dreams. While Gilster clearly stated there was no evidence of the signal being the work of an extra-terrestrial civilisation, he did couch his post in terms of the power requirements and possible technological status of such a civilisation were the signal to prove to be artificial in nature.
The information was also received by the SETI Institute in California. Their senior astronomer, Seth Shostak, estimated that if transmitting in all directions, the signal would require energy on the order of 10^20 watts – or more energy than the Earth receives from the Sun – making the originating species a Type II civilisation on the Kardashev scale. If directed solely towards Earth, Shostak estimated the energy requirement would “only” be around 10^13 watts – roughly equivalent to all of the energy used by humanity here on Earth, putting the aliens at a Type I civilisation on the Kardashev scale – that is, equal to or slightly more advanced than we are.