July is a celebratory month for the US space programme. I’ve already written about July 4th marking the 20th anniversary of America – and the world – having had a continuous robotic presence on or around Mars for 20 years. This week, July 16th and July 20th mark the anniversaries of perhaps the two most momentous days in human space flight – the Lift-off of the Apollo 11 mission to land men on the lunar surface and, on July 20th, the actual landing of the Lunar Excursion Module Eagle on the Sea of Tranquillity. Neil A. Armstrong and Edwin “Buzz” Aldrin spent 21.5 hours there, while their colleague Michael Collins (the “forgotten third man” of Apollo 11) orbited the Moon aboard the Command and Service Module Columbia, carrying out a range of science work as he awaited his compatriots’ ascent back to orbit.
The Apollo programme, although ultimately dedicated to meeting John F. Kennedy’s 1961 goal of “putting a man on the Moon and returning him safely to the Earth”, actually had its roots in President Dwight D. Eisenhower’s administration, when it was seen as a logical progression from America’s single-seat Mercury programme to a vehicle capable of carrying a crew of three on a range of mission types, including ferrying crews to a space station, performing circumlunar flights, and eventually forming part of manned lunar landings.
Apollo was a bold venture, particularly when you consider Kennedy’s directive that America commit itself to achieving a manned landing on the Moon before the end of the 1960s, given in a stirring address before Congress on May 25, 1961 came just twenty days after NASA had finally managed to pump a man – Alan Shephard – into space on a sub-orbital flight, while their first orbital success with John Glenn was still nine months in the future. It was a programme which was politically motivated to be sure, but which nevertheless yielded scientific and technological results which helped shape both our understanding of the solar system and helped improve ours lives on many levels. It raised the potential of human space exploration high in the public consciousness, and was illuminated by tremendous successes whilst also and shadowed by moments of tragedy and near-tragedy.
As well as the missions themselves and the hardware required to carry them out – the Command and Service Module, the Lunar Excursion Module, the Saturn family of rockets (including the mighty Saturn V), Apollo perhaps did more than any over programme to shape NASA. It gave rise to the massive launch infrastructure at Merritt Island, Florida – now known as the Kennedy Space Centre – including the historic launch pads of Launch Complex 39, used by both Apollo and the shuttle, and now used by SpaceX and (soon) by NASA’s massive Space Launch System rockets; the Vehicle Assembly Building (then called the Vertical Assembly Building), where the Saturn rockets were assembled ready for launch, the still-used Launch Control Complex, and more. At the same time, Apollo gave NASA its operational heart for human space missions – the Manned Spaceflight Centre (now called the Johnston Spaceflight Centre) on land just outside Houston, Texas, donated to NASA by Rice University.
The entire history of the programme is a fascinating read – the politics, both in Washington (Kennedy’s own s science advisor, Jerome Wiesner, was quite vociferous in opposing the idea of sending men to the Moon) and in NASA (where a fierce difference of opinion was apparent in how the mission should be carried out. It’s a story I may some day plumb in a Space Sunday “special”, but for now I’ll simply say that all things considered, Apollo was a success, albeit one very self-contained. Six missions to the surface of the Moon, nine missions to and around the Moon, and the opportunity to increase our understanding of Earth’s natural satellite both by a human presence there and afterwards, thanks to the equipment left behind.
New Horizons Pluto Flyby
July 14th marked the second anniversary of the New Horizons spacecraft’s flyby of Pluto and Charon – a high-speed dash between the two lasting mere hours, after a nine-and-a-half year flight simply to reach them. Brief though the encounter might have been, the spacecraft returned such a wealth of data and images that our view of Pluto and its companion has been forever changed, with Pluto in particular – as I’ve often referenced in these Space Sunday pieces – revealing itself to be an enigma wrapped in a puzzle, determined to shatter our understanding of small planetary bodies in the solar system.
Such is the wealth of data gathered by the probe, coupled with the distances involved and the rate at which it could transmit data back to Earth, it took 16 months of all of the information stored aboard New Horizons to be returned to scientists here on Earth.
To mark the second anniversary of New Horizons’ flyby, NASA released a new video using actual New Horizons data and digital elevation models of Pluto and Charon, to offer a unique flight across Pluto.
The movie starts over the highlands to the south-west of “Sputnik Planum’s” great nitrogen ice sheet (visible to the right as the movie progresses), with the track of the film passing directly over the chaotic cratered and mountain terrain of “Cthulhu Macula”. moving northwards, the flight passes over the fractured highlands of “Voyager Terra” then back southwards over Pioneer Terra, distinguished by pitting, before concluding over the bladed terrain of Tartarus Dorsa in the far east of the encounter hemisphere.
Jupiter’s Stormy “Eye”
On Tuesday, July 12th (UT), 2017, NASA’s Juno space craft, the core component of the Juno mission to study Jupiter, completed its seventh close pass over the giant planet’s cloud tops, and for the first time since its arrival in orbit around Jupiter, just over a year ago on July 5th, 2016, the spacecraft’s flight around the planet took it almost directly over Jupiter’s baleful, blood eye staring out into space – the Great Red Spot.
This massive anticyclonic storm, much bigger than Earth’s diameter, has been raging for centuries, although it now appears to be slowly shrinking. The intersection of Juno’s orbit with the passage of the storm around the planet had been something scientists has been anticipating since the spacecraft achieved orbit around the gas giant, and Juno’s full suite of instruments were active in order to image and probe the gigantic storm. Within hours of the overflight, the first sets of images and their accompanying data were received by NASA several hours later, and following initial processing, were made available on-line to “citizen scientists” who could then process images and data with greater care to produce remarkable colour images and videos of the mighty storm.
Jupiter’s Great Red Spot, Seán Doran, from a video by Gerald Eichstädt July 2017. Click to go to video. Credit: NASA / SwRI / MSSS / Gerald Eichstädt / Seán Doran
Commenting on the alignment between overflight and storm, Scott Bolton the Principle Investigator (PI) of the Juno mission, said, “For generations people from all over the world and all walks of life have marvelled over the Great Red Spot. Now we are finally going to see what this storm looks like up close and personal.”
Some of the most remarkable images of the storm have been produced by Gerald Eichstädt, who initially processed the images into an enhanced colour version and then put them together in an animated video he posted to YouTube, together with information on how he put it together. Seán Doran, a favourite artist of mine on Flickr, further refined and then slowed Gerald’s original video to produce the film above (click the image to go to the movie on Flickr), complete with a nod to the classic science fiction movie, 2001: A Space Odyssey through the inclusion of an extract of György Ligeti’s Lux Aeterna.
Juno reached perijove – the point in its orbit where it is closest to Jupiter’s centre – at 02:55 UT on Tuesday, July 11th (18:55 PDT / 21:55 EDT, Monday, July 10th). At that time, it was about 3,500 km (2,200 mi) above Jupiter’s cloud tops. Eleven minutes and 33 seconds later, it was passing over the Great Red Spot a distance of about 9,000 km (5,600 mi); at which time, all eight of its instruments were trained on the feature, and the data they gathered is now being analysed.
Jupiter’s Great Red Spot seen under approximated local lighting conditions Seán Doran, July 2017
New Theory for Finding “Planet 9”
Ever since Mike Brown and Konstantin Batygin published their theory on “Planet Nine” in 2016 (see here for the my original article), their work has been challenged as being biased / at fault, rather than demonstrating there is a massive, far off planet darkly orbiting the Sun.
Brown and Batygin based their theory for “Planet 9” on the highly eccentric orbits of six trans-Neptunian objects (TNOs) – large asteroid / cometary bodies located in what is called the scattered disk, a sparsely populated region of space between 30 and 100 AU from the sun. Essentially, they suggested that the objects have been “pushed” into their orbits by the presence of a massive planetary body orbiting the Sun at about 200 AU. However, sceptics maintain that such a body wouldn’t be able to keep the objects in their extreme orbits, and that Brown and Batygin are suffering observational bias: they believe “Planet 9” is out there, they appear to find evidence of its influence and determine it is proof of their mysterious planet, rather than investigating other possible causes for what they are seeing.
However, at the start of 2017, Brown and Batygin received a boost when a team of astronomers announced that two distant asteroids, 2004 VN112 and 2013 RF98, shared the same properties. These rocks, part of a body of rocky object known as Extreme Trans Neptunian Objects (ETNOs), appeared to have once been a binary asteroid pair, formed from the same material and once in orbit around one another – until the gravitational of a massive body slowly prised them apart over the aeons, until the reached their respective obits seen today, clearly separate from one another.
Now, pair of astronomers from the Complutense University of Madrid (UCM), have proposed another way ETNOs might help make the case for “Planet 9”. They suggest the distances between the ETNOs nodes – the two points at which the orbit of a celestial body crosses the plane of the Solar System – and the Sun may point the way towards Planet 9.
It is at these nodes that the chances of ETNOs interacting with other bodies in the Solar System is the greatest, and where they are most likely to experience a drastic change in their orbits. By measuring where these nodes are, the pair – Doctors Carlos and Raul de la Fuente Marcos – theorised they could tell if the ETNOs are being perturbed by another object in the area – if there was nothing to perturb them, the nodes should be uniformly distributed. However, if there is something perturbing their motion about the Sun, then it is possible they could collectively have one of their nodes pulled close to the orbit of the hypothetical observer – and thus act as a pointer to where part of the perturber’s obit around the Sun lay.
In all they studied the nodes of 28 ETNOs and 24 extreme Centaurs (which also orbit the Sun at average distances of more than 150 AUs). They found that both populations of asteroid-like rocks become clustered at certain distances from the Sun, and also noted a correlation between the positions of the nodes and the inclination of the objects.
This latter find was especially unexpected, and does suggest that the orbits of these populations were being affected by the presence of another body – much in the same way that the orbits of comets within our Solar System have been found to be affected by the way they interact with Jupiter. What’s particularly important here is that the large number of ETNOs and extreme Centaurs observed to have these nodal clusters precludes the idea that the team’s finding are simply a matter of observational bias; rather it points more to a massive body exerting an influence on these objects, and the astronomers are confident that further observations will reveal more ETNOs sharing the same clustering, and further narrow the search for “Planet 9”.