Space Sunday: Flying over Mars, JUICE for Jupiter and black holes

An impact crater which formed between July 2010 and May 2012 and imaged by the HiRISE camera on the Mars Reconnaissance Orbiter, is one of the locations featured in “A Fictive Flight Above Real Mars” by Jan Fröjdman. Credit: Jan Fröjdman; original anaglyph image NASA/JPL / University of Arizona

Ever wondered what it would be like to actually fly over Mars? I have – although I admit, I’m utterly entranced by that red world and the potentials it presents. Finnish film-maker Jan Fröjdman has as well – only he’s taken the idea a step further and produced a remarkable video,  A Fictive Flight Above Real Mars. Last just over 4.5 minutes, the film takes us on a flight over some of the must remarkable scenery imaginable, using high-resolution images and data returned by NASA’s Mars Reconnaissance Orbiter (MRO).

It’s a stunning piece showing many of the more intriguing features of Mars: the recent impact crater see in the still at the top of this article; the ice walls and melt holes of the Martian poles; gullies and cliffs rutted and marked by RSLs – recurring slope lineae – which might or might not be the result of liquid activity; the ripples of sand dunes, and the winding forms of channels which might have been shaped by the passage of water.

To make the film, Fröjdman used 3-D anaglyph images from HiRISE (the High Resolution Science Imaging Experiment aboard MRO), which contain information about the topography of Mars surface. The work involved manually picking more than 33,000 reference points in the anaglyph images, and then processing the results through six pieces of software to achieve a sense of motion and panning across the surface of Mars.

In putting the film together, Fröjdman  wanted to create a real feeling of flying over Mars and of recapturing the feel of video footage shot by the Apollo astronauts as they orbited the Moon. To help with the latter, he overlaid the video with image cross-hairs of the kind seen in some of the Apollo footage, and added little bursts of thruster firings to simulate a vehicle manoeuvring in the thin atmosphere. The film concludes with a main engine firing, presumably to lift the vehicle back into orbit.

NASA and SpaceX Consider Red Dragon Landing Site

And staying with Mars: NASA and SpaceX have started the process of selecting a landing site for SpaceX’s planned Red Dragon mission to Mars in 2020. The ambitious mission will see the company attempt to land a 10-tonne Red Dragon capsule on Mars purely by propulsive means. While paid for entirely by the company, the mission will feature a science suite provided by NASA.

There are two major criteria governing any landing site location: scientific interest, and the potential for colonisation – the 2020 mission being the first of a number which SpaceX plans to uses as precursors for human missions to Mars. As such, it had initially been decided that any landing sites put forward must be near the equator, for solar power; near large quantities of ice, for water and at low elevation, for better thermal conditions.

NASA initially identified four potential locations on Mars’ northern hemisphere which meet the broad criteria for the mission – but examination of three of them using the HiRISE system on the Mars Reconnaissance Orbiter showed they are rocky enough to pose a threat to landing a vehicle the size and mass of Red Dragon. This currently leaves a short-list of one, in the shape of Arcadia Planitia, a smooth plain containing fresh lava flows and which has a large region that was shaped by periglacial processes which suggest that ice is present just beneath the surface.

Acadia Planitia is the current sole contender to be the landing site for the SpaceX Mars 2020 mission

However, negating this is the plain’s relatively high northern latitude (40-60 degrees north), which would reduce the amount of sunlight a base of operations there would receive in the winter months. While Amazonis Planitia to the south offers a similar youthful surface, much of which is relatively smooth, it is largely volcanic in origin and unlikely to harbour sub-surface water ice which can be easily accessed.

Given both of these point, it is likely other possible landing sites will be proposed in the coming months.

Curiosity Reveals More Wheel Damage

It’s been a while since my last report on NASA’s Mars Science Laboratory rover, Curiosity. This is mostly being the updates coming out of JPL have slowed mightily in recent months.

At present, Curiosity is examining sand dunes on the lower slopes of “Mount Sharp”. Once finished, it will proceed up higher to a feature known as “Vera Rubin Ridge”, inspecting a layer that is rich in the mineral hematite. From there, it will proceeded to even higher elevations to inspect layers that contain clays and sulphates. This will require a drive of some 6 km (3.7 mi) uphill, and so will require time to complete.

A recurring area of concern for the mission – albeit not serious at this point – is the wear and tear on the rover’s wheels. In 2013, Curiosity suffered greater than expected damage to its six wheels while traversing some exceptionally rough terrain.  Although the damage was nowhere near severe enough to impeded the rover’s driving abilities, it did result in engineers keeping a much closer eye on the condition of Curiosity’s wheels using the imaging system mounted on the rover’s robot arm.

The latest of these checks was performed on  Sunday, March 19th, 2017, and it revealed two small breaks in the raised treads (“grousers”) on the rover’s left middle wheel. These seem to have occurred since the last wheel check at the end of January, 2017. These treads perform two major tasks: bearing the brunt of the rover’s weight and providing most of the traction for a wheel.

The broken “grousers” (“treads”) on one of Curiosity’s six wheels, together with older puncture holes through the wheel, as imaged on March 19th, 2017. Credit: NASA/JPL

Following the 2013 damage, testing on Earth suggested that significant breaks in three “grousers” on a wheel would indicate it has passed 60% of its expected lifespan. However, the mission team emphasise the rover has already driven more than 60% of the total distance needed for it to make it to all of its scientific destinations. As such, while the breaks will be monitored, they are not a cause for immediate or grave concern.

Overall, confidence remains high that Curiosity will achieve all of its expected science goals and will likely make an extended traverse up the side of “Mount Sharp”.

A rover’s progress: the 16 km (10 mi) travelled by Curiosity so far, and potential for future explorations up the side of Aeolis Mons. Credit: NASA/JPL / T. Reyes

Juno ready for another close-up; JUICE gets a Green Light

NASA’s Juno spacecraft will perform its fourth science flyby of Jupiter – the fifth since it arrived at the planet on July 4th, 2016. The flyby will again see the vehicle pass just 4,400 km (2,700 miles) above the giant planet’s cloud tops as it swings from pole-to-pole around the planet before heading back out into space on another 53.5 day orbit.

Juno has already revealed that Jupiter’s magnetic fields are more complicated than originally thought, and that the belts and zones that give the planet’s cloud tops their distinctive look extend deep into the its interior. In addition, observations of the energetic particles that create the incandescent auroras suggest a complicated current system involving charged material lofted from volcanoes on Jupiter’s moon Io, suggesting the pairing between Jupiter and Io is more complex than had been thought.

An enhanced colour image of Jupiter’s clouds, captured during the February 2nd, 2017 perijove (point of closest approach to the planet), reveal a complex interaction of storms and atmospheric currents. Credits: NASA/JPL / SwRI /MSSS / Roman Tkachenko

However, it has been the imaging system aboard the space vehicle which has captured the imaginations of those following the mission, revealing as it has remarkable images of parts of the planet never before see in detail. The camera system is part of a NASA Citizen Scientist programme, which encourages people to participate in the mission.

As I’ve recently reported, Jupiter and its retinue of four Galilean moons – Io, Europa, Ganyemede and Callisto – is the subject of deep interest for astronomers and planetary scientists. While it will not reach Jupiter’s vicinity until long after Juno has met its end, NASA’s Europa Clipper is set to undertake a similar style of mission, repeatedly looping close to Jupiter and then moving away again to avoid long periods of exposure in the planet’s massive radiation fields. However, as I’ve also reported, the focus of the mission will not be Jupiter, but the icy Moon Europa.

An artist’s impression of Europe’s JUICE mission, which will encounter Callisto and Europa, and study Ganymede, using Jupiter a means of additional propulsion. Credit: ESA

Depending on the launch vehicle used, Europa Clipper could reach Jupiter between 3 and 6 years after launch, which is provisionally set for either 2020 or 2022. As such, it will be “partnered” by the European JUpiter ICy moon Explorer (JUICE), a massive 5.3 tonne vehicle set to be launched in 2022, and which will target not only Europa, but Jupiter’s other two icy moons, Ganymede and Callisto – with the focus of the mission firmly on Ganymede.

JUICE took a significant step forward on Friday, March 24th, 2017 whenESA announced the mission had cleared its preliminary design review. Prime contractor Airbus and its partners can now start building a prototype spacecraft to test systems for the mission, which is expected to cost some €1.5 billion (US $1.6 billion). Once launched, the solar-powered vehicle will take around seven years to reach Jupiter.

The reason for the long journey times for both Europa Clipper and JUICE is because neither vehicle can fly directly from the surface of the Earth to Jupiter. Instead, they have to use “gravity assists” – looping around the Earth (and sometimes Venus) to both accelerate them and “slingshot” them around onto trajectories which will intercept the orbits of their targets. How many such gravity assists are needed depends on a number of factors, but as it may be able to use America’s Space Launch System launch – significantly more powerful than Europe’s Ariane rocket – Europa Clipper holds an advantage which as noted, could see it reach Jupiter in just 3 years from launch.

Ganymede, lower left, compared to Earth and our Moon. It is of particular interest to planetary scientists as it many have a water ocean under its frozen crust with around 15 times all of the water to be found on Earth.. Credit: Wikipedia

Once at Jupiter, JUICE will also use the massive planet’s gravity to its own advantage, allowing it to undertake multiple flybys of Callisto, Ganymede and Europa before finally allowing Jupiter to push it into an orbit were it can focus on Ganymede for around eight months, seeking to unlock the secrets of the moon’s sub-surface ocean.

The Rogue Supermassive Black Hole

Astronomers using the Hubble Space Telescope have uncovered a supermassive black hole (SMBH) more than one billion times more massive than our own sun, that has been propelled out of the centre of a galaxy far, far away (i.e. around eight billion light-years away from our own).

A artist’s impression of a supermassive black hole and its surrounding disc of gases. Credit: NASA

Almost all galaxies are thought to have a massive black hole at their centre, which is seen as a quasar – light emitted by the hot gasses surrounding the black hole. What makes this one special is the fact it is being booted out of its own galaxy at a speed of around 8 million km/h (5 million mph) – that’s around 2080 kilometres (1300 miles) every second.

Such a phenomenon has been predicted, but this seems to be the first time it has apparently been observed. In short, it is believed to be the result of two galaxies colliding, causing their central black holes to merge. However, because the black holes were in some way unequal, the merger resulted in the new massive black hole having an adverse reaction to the gravitational waves (themselves only confirmed in 2016 – see Space Sunday: of Einstein, waves, landers and honours) generated as a part of the merger. I’ll let Katrina Jackson from NASA Goddard Space Flight Centre explain further.

If the theory for this particular black hole is correct, it’ll be further evidence of gravitational waves, and the first direct evidence of what can happen when two unequal supermassive black holes merge.


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