Watching the Skies

29 November 2016 2595 view(s) 3 min read
Watching the Skies

Here at the Space Collective, we have a healthy respect for all aspects of human and robotic space missions. Over the past few months our blogs have focused on many elements of this, both current and historical, but what about the other areas of space? Astronomy and space science are intertwined with our missions and exploration. Apollo 9's Rusty Schweickart, is a prime example of an astronaut who does a lot of work with the astronomical community, specifically in the threat from space of meteorites.

meteorite crater in arizona, united states of america

The B612 Foundation of which Schweickart is a key part, looks at ways to mitigate what can only be described as the only truly global threat to civilisation as we know it. You only have to see the movies made in the wake of Comet Shoemaker-Levy 9 in the mid 1990's "Deep Impact" and "Armageddon" to realise just how bad Hollywood movies can be, but on a more serious note, the scale of the threat we face from these space hazards.

tissint martian meteorite segmentTissint Martian Meteorite

An object the size of a grain of sand is what we see when looking up and seeing shooting stars. Hitting our upper atmosphere at around 25000 mph, they glow with the same light that causes the bottom of an Apollo capsule heat shield to glow, with air frictional forces causing ablation of the material, in essence "burning it" away, for want of a better term.

In fact, the study of meteorites was what led to elements of the development in Mercury, Gemini and Apollo heat shield technology, that continues to this day with Mars landers and the Orion spacecraft.

Here at the Space Collective, we have a few of the remnants of the early solar system for you. Moon rocks, Mars rocks, a few from the asteroid Vesta and even one which "may" have originated on the planet Mercury. "How do we know these came from these locations?", is a common question we are asked.

mars rover and lander concept artworkMars Lander and Rover Concept

Well with the Moon rocks, the over 840 lbs of Apollo samples returned between 1969 and 1972 give us a perfect way to cross match against rocks blasted off the lunar surface by meteorite impacts, that eventually found their way to our planet. Some of the rarest meteorites available, they fetch a higher price than the average meteorite, but for good reason. Imagine the thrill of holding a piece of the Moon, when looking up at it... and legally (as owning Apollo samples is a Federal offence and can land you in jail for up to 7 years).

With Mars, it's equally solid science that lets us state with absolute certainty that the rocks originated from the red planet. From the Viking landers in 1976 through Pathfinder, Phoenix, Spirit and Opportunity and now MSL, we have a range of "ground truth" spacecraft on the surface, giving us spectroscopic analysis which matches these rocks 100%, even in some cases, showing the evidence of past water on the Martian surface.

Vesta, we have data from the DAWN spacecraft as evidence. This orbited Vesta for a considerable period a few years ago, gaining vast amounts of spectral data from orbit which again matched with the "HED" type of Meteorites (Howardites, Eucrites, Diogenites) which are all believed to come from Vesta.

Mercury a bit trickier, which is why we say "possibly" as only the data from Messenger spacecraft has given us any indicated of their possible origin.

With Christmas fast approaching, we do think these little space rocks make perfect gifts, and to see the look on a child's face (which we have so many times at events) when they realise they are holding something older than the planet they are stood on, is something to behold.

Keep looking up...