Space Sunday: metal rain and glass on Mars, HoloLens into orbit

Comet Siding Spring's passage through the solar system 2013-2014
Comet Siding Spring’s passage through the solar system 2014

In October 2014, I wrote about comet Sliding Spring and it’s close approach to Mars as it swung through the solar system.

The comet had been identified as coming from the Oort cloud (or the Öpik–Oort cloud, to give proper recognition both astronomers who initially and independently postulated its existence), a spherical cloud of debris left-over from the creation of the solar system, occupying a huge area starting some 2,000-5,000 AU (2,000 to 5,000 times the distance from the Earth to the Sun) and extending out to around 50-100,000 AU – or about one light year away.

There is nothing odd about comets from the Oort cloud per se, but Sliding Spring appeared to be making its very first journey into the inner solar system, and so astronomers were keen to try to study it as best they could. Given the close pass at Mars, the vehicles on and orbiting that planet stood to have something of a grandstand view of things – providing certain precautions were taken, as I noted at the time.

An artist's impression of MAVEN in orbit around Mars (NASA / JPL)
An artist’s impression of MAVEN in orbit around Mars

Now data released by NASA shows that the comet’s flight past Mars did result in something very unusual: the comet’s tail, which brushed the Martian atmosphere, resulted in a “rain of metal” over the planet.

The data was obtained by NASA’s Mars Atmosphere and Volatile EvolutioN Mission (MAVEN), which at the time of the comet’s passage was so recent an arrival at Mars, that all its instruments hadn’t been fully commissioned. Hence, in part, the delay in releasing the data – NASA wanted to be sure MAVEN was recording things accurately.

According to MAVEN, the direct detection of sodium, magnesium, aluminium, chromium, nickel, copper, zinc, iron and other metals high in the Martian atmosphere can be linked directly to material sloughing off of the comet as it passed.

“This must have been a mind-blowing meteor shower,” said Nick Schneider of the Laboratory of Atmospheric and Space Physics at the University of Colorado, commenting on the data returned by the orbiter. Such is the strength of the signal of magnesium and iron measurements, the hourly meteor rate overhead on Mars must have been tens of thousands of “shooting stars” per hour over a period of many hours.

An artist's impression of meteors resulting from comet Siding Spring in the sky over NASA's MSL Curiosity rover
An artist’s impression of meteors resulting from comet Siding Spring in the sky over NASA’s MSL Curiosity rover

“I’m not sure anyone alive has ever seen that,” Schneider added, “and the closest thing in human history might the the 1833 Leonids shower.” The metal ions were the remains of pebbles and other pieces shed from the comet that burned up, or “ablated” into individual atoms as they struck the Martian atmosphere at 56 kilometres per second (125,000 miles per hour).

What is particularly important about the event is that as scientists know the source of the dust particles, it’s speed, and key information about Mars’ upper atmosphere, it is possible to learn more about Mars’ ionosphere, the comet’s composition, and even the workings of Earth’s ionosphere when it is hit by comet or asteroid debris.

Impact Glass

There is glass on Mars, and it might just be the ideal place in which to find any evidence of past microbial life.

The type of glass in question is referred to as “impact glass”, and is formed as a result of the heat generated by the impact of a meteorite melts the surrounding rock into glass. when a meteorite strikes the surface of a planet or moon, melting the surrounding rock into glass, preserving and organic matter that existed on or in the rock prior to the meteorite impact occurring.

In 2014, a research team examining impact glass formed millions of years ago as a result of meteorite strikes in Antarctica form found organic molecules and plant matter within the glass. Their work spurred a group of planetary science graduates at Brown University, Rhode Island, to simulate the spectral composition of possible Martian impact glass by using chemicals, compounds and powders matching those known to compose the surface material on Mars, and then melting the mix at high temperatures to form glass, which they then subjected to spectrographic analysis.

The team then compared the results of their analysis with spectral analyses of the surface of Mars carried out by the Imaging Spectrometer aboard NASA’s Mars Reconnaissance Orbiter (MRO) – and found a very similar spectral signature in areas where such impact glass would be expected to form, such as around the central peaks of craters caused by meteorite impacts.

A spectrographic image of the central peak of the Alga Crater impact zone, taken by MRO. The green colours indicate the presence of impact glass
A spectrographic image of the central peak of the Alga Crater impact zone, taken by MRO. The green colours indicate the presence of impact glass

Coincidentally, one of the areas found to have spectral signature is near the 650-kilometre long (400 miles) depression of Nili Fossae.  This region has been of significant interest to scientists because it looks to have been created in part by water during Mars’ warm past. Furthermore, in the last eight years, MRO has shown rocks at Nili Fossae contain carbonate minerals together with aluminium smectite, iron/magnesium smecite, hydrated silica, kaolinite group minerals, and iron oxides; additional, methane plumes have been identified in the region. All of this has already made Nilli Fossae one of the candidate landing areas for the Mars 2020 rover mission; the discovery of impact glass there could add a little extra weight to it being selected.

SpaceX Loses CRS-7

Sunday, June 28th marked the launch of the 7th resupply mission to the International Space Station (ISS) to be flown by SpaceX Corporation. Carrying some 1.8 tonnes (4,000 lbs) of food, supplies and scientific experiments, the mission was also to be the third in SpaceX’s attempts to recover the first stage of the Falcon 9 booster by landing it vertically on the deck of an autonomous drone ship “parked” off the Florida coast.

Unfortunately, the mission didn’t go as planned. Some 2.5 minutes after launch the rocket, at an altitude of some 32 kilometres, some 13 kilometres downrange of the launch complex and travelling at one kilometre per second, exploded.

The reasons for the vheicle’s destruction are not entirely clear, although Elon Musk, Founder and CEO of SpaceX (and whose birthday falls on June 28th), stated in a tweet following the loss: “Falcon 9 experienced a problem shortly before first stage shutdown. Will provide more info as soon as we review the data.”

The mission marks the third resupply mission to end in the loss of the vehicle in the last 12 months. In October 2014, Orbital ATK’s Antares rocket exploded seconds after lift-off with the loss of that company’s third Cygnus resupply mission, and in May 2015 a Russian Progress resupply mission was lost when it fell back to Earth following the failure of its upper stage motors.

The Falcon 9 / Dragon resupply mission included included high-resolution cameras designed to observe and study meteors as they strike Earth’s atmosphere, and equipment designed to help researchers better understand which microbes are present inside the space station, and how these organisms change and adapt over time.  However, for SpaceX, it means yet another attempt to test the recovery / landing systems on the Falcon 9’s first stage has been scuppered.

Earlier in the week, the company has been asked why they were trying to make the rocket recoverable and reusable. Their reply was simple. “A jumbo jet costs about the same as one of our Falcon 9 rockets, but airlines don’t junk a plane after a one-way trip from LA to New York,” a SpaceX representatives stated. “Yet when it comes to space travel, rockets fly only once — even though the rocket itself represents the majority of launch cost.”

NASA Looks Through the HoloLens

A year ago, I touched on some of the ways VR is liable to be used within future space activities.   With project Sidekick, NASA is looking to put Microsoft’s “mixed reality” HoloLens front and centre of their immediate attempts to harness these various emerging technologies.

Microsoft's HoloLens: to be deployed to the International Space Station
Microsoft’s HoloLens: to be deployed to the International Space Station (image: Microsoft)

Project Sidekick aims to put the HoloLens on the International Space Station to provide assistance to crews there in two ways.  In the first, a “Remote Expert Mode” utilises the headset and its Skype capability to give someone on the ground a view of exactly what the astronaut is seeing. Thus, they can provide precise technical or other support to the astronaut, and can even provide notes and drawings to the astronaut in real time to assist them in carrying a task. In the second, the HoloLens can be used in a “Procedure Mode”, in which holographic animated images are overlaid on top of the real objects the astronaut is looking at, providing additional reference and information on what to do and what to expect while carrying a task.

The HoloLens has been extensively tested by NASA over the past several months, including flights aboard their C9 “reduced gravity” training aircraft, still affectionately referred to as the vomit comet by some, as a result of flights subjecting passengers to period of free-fall flowed by exposure to around 2 times normal Earth gravity. These flights were to help ensure the headsets and support systems would function correctly in free fall.

The first batch of HoloLens headsets had been scheduled for delivery to the ISS aboard SpaceX CRS-7 which, as noted above, was unfortunately lost when the launch vehicle exploded.

All images courtesy of NASA / JPL, unless otherwise stated. Videos via NASA / You Tube.