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.
“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.
“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.
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.
Despite also being sceptical about the signal being artificial, the SETI Institute listened for the signal over the course of an entire weekend – long enough to detect it if the signal is either radial in nature or being directed at us – which may also have fuelled the excitement about the signal being “alien” in origin. They did so using an array of radio telescopes far more sensitive than RATAN-600, and heard nothing. A check back through their archive of scans of the same region of the sky also revealed nothing exceptional had ever been recorded. And so like the famous “Wow!” signal of 1977, the RATAN signal had been heard once, and vanished.
While this doesn’t entirely rule out the potential the signal might have been artificial – as the late Carl Sagan famously said, “absence of evidence is not evidence of absence” – it would seem to indicate that something other than alien intelligence was responsible for the signal.
Part of the problem here is that there are any number of natural space objects, such as pulsating quasars, or even items of terrestrial origin which could have just as easily cause the signal, and the RATAN-600 array has such a broad bandwidth, actually identifying the exact point of origin for the signal is hard. Hence the e-mail asking for help in identifying possible causes.
Until the signal is detected again – if it ever is – it is impossible to determine what may have caused it. However, due to the recent excitement, the Russian Academy of Sciences carried out further analysis of the signal, and concluded its origin is likely to be Earth-bound radio interference:
In the framework of this program, an interesting radio signal at a wavelength of 2.7 cm was detected in the direction of one of the objects (star system HD164595 in Hercules) in 2015. Subsequent processing and analysis of the signal revealed its most probable terrestrial origin.
As for the other objects of the RATAN-600 survey, it is too early to claim about any reliable scientific results. Using the obtained measurements, we are only able to estimate the upper limit of the detection of the studied areas. It can be said with confidence that no sought-for signal has been detected yet.
In this, it is worth pointing out that radio telescopes can be extremely susceptible to terrestrial interference. Astronomers at the Parkes radio telescope in Australia, for example, were left baffled for 17 years by strange, intermittent radio signals they dubbed perytons. First detected in 1998, it wasn’t until 2015 that the culprit was found: the microwave oven in the observatory’s kitchen. If a member of staff opened the door before it had finished heating, rather than waiting for the timer to expire, the microwave element would cut out as it should, but it would generate a sudden burst of interference, which the telescope would pick up.
As a result of this discovery, the Chinese authorities have implemented a 5 kilometre (3 mile) “exclusion zone” around their new super radio telescope, relocating 9,200 in the process, to ensure the risk of similar interference is minimised.
SpaceX Suffers Launch Pad Loss
After a string of successes with launches and booster recoveries, SpaceX suffered a significant setback on Thursday, September 1st, when a malfunction during what is called a static-fire test resulted in the complete loss of a Falcon 9 booster and its payload.
These tests are unique to SpaceX, and take place when the rocket is on the pad ahead of a launch (the vehicle in question had been due to launch the Amos 6 Israeli Earth communications satellite on September 3rd). They are essentially a full dress rehearsal for a launch, including fuelling the rocket and briefly firing the first stage engines.
The explosion came at 09:07 local time on the morning of September 1st, when the Falcon 9 rocket was being fuelled for the test. There was a brief flash in the rocket’s upper stage, which then exploded. Seconds later, the first stage blew up, completely destroying the rocket and its US $200 million payload, which Facebook /Eutelsat would have been using, at a cost of US $95 million, to support Internet.org activities in Africa. It’s not clear how much damage the launch pad, operated by the US Air Force 45th Space Wing at Canaveral Air Force Station, suffered.
This is the second loss of a Falcon booster in a little over a year – SpaceX previously lost a vehicle shortly after lift-off during a resupply mission to the ISS on June 28th, 2015 – and it means that all launches of the rocket are now suspended while the loss is investigated.
Interestingly, following the incident, SpaceX did not refer to the initial anomaly seen in the upper stage of the rocket as an “explosion”, but as a “fast fire” resulting in an explosion. This suggests there may be a suspicion something happened within the fuelling process, rather than a failure with the rocket itself, that caused the loss.
The suspension of Falcon 9 operations means that SpaceX will be unable to continue with its schedule of planned commercial launches and ISS resupply missions. Further, and depending on the length of the investigation and on its findings, the planned launch of the first Falcon Heavy, loosely slated for January / February 2017, and which uses the Falcon 9 as its core stage, may also be impacted.
OSIRIS-REx Readies for Launch
NASA and United Launch Alliance (ULA) are getting ready for the lift-off of America’s first attempt to gather samples off the surface of an asteroid and return them to Earth for study.
The Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer (OSIRIS-REx) mission is due to be launched from Complex 41 at Canaveral Air Force Station on Thursday, September 8th, atop a ULA Atlas V booster. If all goes according to plan, the spacecraft will rendezvous with near-Earth asteroid 101955 Bennu in August 2018, and commence a 12-month survey of the asteroid.
As a part of this survey, mission mangers will select a number of target locations on Bennu, and the vehicle will be instructed to slowly close on the asteroid so that a “touch and go” sampling arm can make contact with the surface of Bennu for around 5 seconds, during which a bust of nitrogen gas will stir up rocks and surface regolith, allowing them to be caught in the sampling mechanism. The spacecraft has enough nitrogen to allow three such sampling attempts, which will hopefully collect between 60 and 2000 grams (2–70 ounces) of material.
In March 2021, the window for departure from the asteroid will open, and OSIRIS-REx will begin its return journey to Earth, arriving in September 2023. A re-entry unit containing the gathered samples will then detach for a landing at the Utah Test and Training Range, where they will be recovered for detailed analysis.
Bennu, which is approximately 492 m (1,614 ft) in diameter, has been chosen due to it being a carbonaceous asteroid passing relatively close to Earth in its orbit around the Sun. Carbonaceous material is of significant interest to scientists as it is a key element in organic molecules necessary for life, as well as being representative of matter from before the formation of Earth. Organic molecules, such as amino acids, have previously been found in meteorite and comet samples, indicating that some ingredients necessary for life can be naturally synthesized in outer space.
Another reason for visiting Bennu is that there is a very small chance it could collide with Earth towards the end of the 22nd Century. By analysing the thermal absorption and emissions of the asteroid, scientist can better predict its future orbits and the potential of a future collision. This knowledge could also be used to better predict the orbits of other near-Earth asteroids.
In addition to the science payload, OSIRIS-REx will carry two microchips. One contains 442,000 names submitted to NASA through the 2014 “Messages to Bennu” campaign; the second containing sketches, photographs, graphics, poems, songs, and short videos submitted by the public from around the world under the We The Explorers campaign, and which reflect personal views on what it means to be an explorer.
Should the initial launch opportunity be missed on September 8th, the window will remain open for a further 33 days in which further attempts can be made.