{"id":49240,"date":"2023-09-04T11:43:58","date_gmt":"2023-09-04T11:43:58","guid":{"rendered":"http:\/\/2f5b6898-65f2-426f-8c3c-ee6a2326c73a"},"modified":"2023-09-04T12:32:37","modified_gmt":"2023-09-04T12:32:37","slug":"what-sample-return-missions-like-osiris-rex-can-tell-us-about-the-solar-system","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/what-sample-return-missions-like-osiris-rex-can-tell-us-about-the-solar-system\/","title":{"rendered":"What sample-return missions like OSIRIS-REx can tell us about the Solar System"},"content":{"rendered":"

Returning samples of space rocks to Earth can help scientists piece together information about the Solar System. <\/p>

By Ezzy Pearson\n <\/p>

Published: Monday, 04 September 2023 at 11:43 AM<\/p>

\n\n

Sample return missions are key when it comes to our ability to understand our Solar System.<\/p>

And on 24 September 2023, NASA\u2019s OSIRIS-REx<\/a> mission will arrive home, the culmination of its seven-year-long journey to asteroid Bennu and back.<\/p>

The Origins Spectral Interpretation Resource Identification and Security \u2013 Regolith Explorer, to give OSIRIS-REx its full title, will be carrying with it an estimated 250g of dust and pebbles, which it carefully gathered from the asteroid\u2019s surface back in October 2020<\/a>.\u00a0<\/p>

The moment just before OSIRIS-REx touches down on asteroid Bennu’s surface to collect its sample, 20 October 2020. Credit: NASA\/Goddard\/University of Arizona<\/figcaption><\/figure>

This precious cargo is being eagerly anticipated by planetary geologists around the globe.<\/p>

It will be one of just a handful of pristine samples taken directly from another Solar System body.<\/p>

That may not be the case for long, though.<\/p>

Recent years have seen the number of such sample-return missions<\/a> increase, heralding a new age for this particular field of space science.<\/p>

These missions provide a hugely important piece in the puzzle of understanding our Solar System\u2019s history.<\/p>

\"OSIRIS
OSIRIS REX entered orbit around Bennu on 3 December 2018, and is now around 19km above the surface. Image Credit: NASA\/Goddard\/University of Arizona<\/figcaption><\/figure>

Four and a half billion years after its creation, our Solar System is still littered with the remnants of planets that never came to be, in the form of comets and asteroids like Bennu.<\/p>

Astronomers have spent centuries staring at these distant objects, while more recently orbiters and lander missions have offered a closer look.<\/p>

To really understand these space rocks, however, requires the use of advanced equipment that can only be found in labs here on Earth.<\/p>

\"Craig
Craig Walton, from the University of Cambridge\u2019s Department of Earth Sciences, prepares meteorite samples for analysis on a scanning electron microscope. Credit: University of Cambridge Department of Earth Sciences<\/figcaption><\/figure>

Why sample return missions are so important<\/strong><\/h2>

We have long been able, of course, to look at pieces of some asteroids<\/a> that have obligingly fallen to Earth as meteorites.<\/p>

For decades, these have been collected, catalogued and studied to give us our current picture of the disparate worlds of our Solar System.<\/p>

The problem is that as soon as a meteorite enters Earth\u2019s atmosphere it\u2019s contaminated by our environment.<\/p>

This limits its usefulness as a source of information.<\/p>

And unless the meteor was seen streaking through the sky, there\u2019s usually no indication as to where in space these rocks have spent the last four billion years before hitting Earth.\u00a0<\/p>

\u201cMy background is in geology, and one of the things our lecturers always say is it\u2019s so important to do fieldwork,\u201d says Sara Russell, head of planetary materials at the Natural History Museum.<\/p>

\u201cYou don\u2019t just analyse a rock; you have to know what all the rocks around it were, where it came from, what the environment was like.\u201d<\/p>

A brief history of sample-return missions<\/strong><\/h2>
\"Harrison
Harrison Schmitt collects a soil sample during an Apollo 17 EVA. Credit: NASA<\/figcaption><\/figure>

This is why a growing number of space agencies are working on sample-return missions, of which OSIRIS-REx is merely the most recent.<\/p>

The first such missions were the Apollo landings, which in total returned an astounding 382kg of Moon rocks.<\/p>

Here, the fieldwork was done by human astronauts who took detailed observations and records of the landscape as they went.\u00a0<\/p>

However, most sample-return missions have been robotic.<\/p>

\"A
A lunar sample captured during Apollo 15 that was nicknamed the Genesis Rock. The rock was actually a piece of the Moon\u2019s primordial crust and was returned to Earth for examination. Credit: NASA<\/figcaption><\/figure>

The earliest of these were the Soviet Union\u2019s Luna<\/a> 16, 20 and 24, which between them returned around 300g of material in the \u201870s.<\/p>

But their primitive cameras and sensors provided only limited context.<\/p>

It\u2019s taken 50 years for technology to develop to the point where spacecraft can operate as effective field geologists.<\/p>

This fieldwork is started as soon as the spacecraft are within sight of their intended target.<\/p>

When Japanese sample-return mission Hayabusa2<\/a> arrived at asteroid Ryugu in June 2018, it spent several months examining every part of the asteroid with its cameras.<\/p>

\"Sample
Sample of the Ryugu grains obtained by the Hayabusa2 spacecraft. Credit: JAXA<\/figcaption><\/figure>

What OSIRIS-REx will do<\/strong><\/h2>

Six months later, OSIRIS-REx began its own observations when it arrived at Bennu.\u00a0<\/p>

\u201cFrom that you can look at boulder size, distribution and shape,\u201d explains Russell.<\/p>

Specialised spectral cameras can even give some indication as to what minerals the rocks are made of. <\/p>

\u201cSo you can see whether the bodies are made of the same thing, or if there\u2019s a variety of different rocks.\u201d<\/p>

These measurements are a vital part of the mission.<\/p>

For OSIRIS-REx, they fulfil the \u2018Resource Identification\u2019 part of its moniker by helping to analyse what potentially useful compounds and minerals can be found on asteroids.<\/p>

\"\u201cThey
\u201cThey look like cornflakes\u201d: a view of the TAGSAM sampler, captured by the \u2018SamCam\u2019 camera on OSIRIS-REx on 22 October 2020, reveals flake-like particles escaping into space. Credit: NASA<\/figcaption><\/figure>

These may even be mined by future space explorers, but they also provide important context that geologists will call upon later.<\/p>

More immediately, they help the flight team pick out the ideal site to take their sample from.<\/p>

\u201cThe engineers always insist you pick the safest place,\u201d says Russell.<\/p>

“But the scientists want you to pick somewhere that\u2019s scientifically interesting.<\/p>

“In OSIRIS-REx\u2019s case, they picked a dark area because that might have more organic material in it.\u201d\u00a0<\/p>

What we can learn from spacerocks<\/strong><\/h2>