In July I spoke at the Annual Prize Giving at the beautiful Claremont Fan Court School in Esher, Surrey where I also had the pleasure of judging the Rocket and Space Station building competition for the pre-prep and prep schools. The main requirement was that the designs had to float on water and they were all launched into the swimming pool for judging. The children really enjoyed it (and the parents too!) and none of the 25 designs sank (that I saw anyway!), some even contained teddy bear astronauts!

I also took along the outreach meteorites and spoke to GCSE and A-level students (and lots of their parents) about meteorites and space missions. A really fun and sunny day out, lots of fun.

I just finalised a book chapter for ‘Patrick Moore’s Yearbook of Astronomy 2016’ which will be published by Pan Macmillan. I focussed on the Rosetta story so far. But how do you summarise 20 years of a space mission in 5000 words?!…obviously there was so much to cover so I hope I did it justice. It’s gone to print now so I can’t wait to see a copy. The book is still edited Dr John Mason as it always has been, despite Sir Patrick Moore no longer being with us. It’s a lovely legacy for him though so I hope it continues for years to come – and I’m interested to see who else has written chapters for it.

I recently did some filming for a new BBC series where I was brought back down to Earth by putting on my ‘geologist’ hat to chat volcanoes and holes in the ground (more details when it’s released). It sounds like an exciting programme though and I should appear in 2 separate episodes. I even got my favourite pet rock into the filming – a piece of Icelandic basalt if you must know – I hope he makes the cut!

I’m a bit late posting this one as the original paper in Nature has been out for a while but I thought this IFL article covered the science really nicely. It’s good to have some idea where my Interplanetary Dust Particle (IDP) samples might actually come from…comets!! Thank goodness 🙂 And good work Rosetta, keep it up!

Rosetta Witnesses The Origins of Meteors | IFLScience.

Is iron rain the reason why Earth and the moon are so different?

Simon Redfern, University of Cambridge

New experiments show that the asteroids that slammed into Earth and the moon more than 4 billion years ago were vaporised into a mist of iron. The findings, published in Nature Geoscience, suggest that the iron mist thrown up from the high velocity impacts of these asteroids travelled fast enough to escape the moon’s gravity, but stayed gravitationally stuck on more massive Earth. And these results may help explain why the chemistry of the Earth and the moon differ.

When and how Earth’s metallic core formed is uncertain. Clues come from known differences in the preferences of certain elements incorporated in the silicate mantle or the metal core. In a mixture of silicate rock and iron metal, the atoms of certain elements, such as gold and platinum, tend to prefer to enter the metal, while others, such as hafnium, prefer the silicate.

As Earth’s iron-rich core formed it “sucked” the metal-loving elements out of the planet’s rocky mantle. However, measurements of the silicate mantle by James Day have previously shown that there are more of them left in the shallower Earth than would be expected. This has often been attributed to a late veneer of asteroids that delivered an extra dose of metal-loving elements to the rocky mantle.

One problem with this picture has been that the abundance of the metal-loving elements on Earth is ten to a hundred times greater than that measured on the moon, which should by this argument have the same veneer. The chemical difference between Earth and the moon has been perplexing, and casts a shadow over the prevalent idea that the moon formed from the same stuff as Earth after an impact from a Mars-sized planet early in the history of the Solar System.

Mighty Earth attracts more metal

The new paper seems to reconcile these differences. The experiment relied on Sandia National Laboratory’s “Z-machine”: a huge electromagnetic gun – twice as powerful as the world’s total generating capacity – that can launch projectiles into iron targets at ultra-high velocity.

The impact experiments by Richard Kraus and colleagues show that iron vaporises under the conditions created when an asteroid crashes into Earth or the moon. A cloud of iron mist will have wrapped around the globe after any such collision, falling to Earth as metal rain. These well-mixed droplets will have become incorporated into the mantle, delivering the excess metal-loving chemicals.

The same experiments, however, indicate that the velocity of the iron rain droplets will have been greater than the escape velocity on the moon, but below that of Earth. Earth would therefore have captured the metal cores of colliding asteroids, while the moon will have failed to. William Anderson of Los Alamos National Laboratory, US, said: “The moon may have received, but not retained, a significant portion of the late veneer.”

The results could imply that models for estimating the time scales of Earth’s core formation could be out by as much as a factor of ten, with the core forming much earlier in Earth’s history than previously recognised.

This article was originally published on The Conversation.
Read the original article.

Dawn breaks over distant Ceres … and perhaps reveals signs of habitability

Monica Grady, The Open University

NASA’s Dawn spacecraft is about to start its investigation of the largest member of the asteroid belt, 1 Ceres. It will take detailed images of the dwarf planet, and produce a geological map of its entire surface. But even before the spacecraft has reached its optimum orbit, the preliminary results just released are already surprising and delighting planetary scientists.

Up until February 2015, the best images taken of Ceres were from the Hubble space telescope, showing a near-spherical body with one area that was much brighter than the rest of the surface. As Dawn approached Ceres, its camera acquired some remarkable images, at about three times the resolution of those from Hubble. The pictures verified that there was indeed a brighter region.

Even better, close examination of the images showed that the area varied in brightness over the course of Ceres’ day (which is only about nine hours long), growing dimmer as the dwarf planet moved into darkness. It is interpretation of this variability that has planetary scientists buzzing.

As if that were not enough, a further series of pictures appear to show a plume emanating from the surface. Is Ceres active? Does it have a layer of water or ice below a thin crust of rock? Could it be a ball of mud, overlain by a muddy ocean, on top of which is another thin muddy crust? The exact structure of Ceres is not yet known, although it is clear that it’s not rocky all the way through – its density is too low, so there must be at least some water or ice present.
Suggestions at the 46th Lunar and Planetary Science Conference in Houston, Texas, of icy volcanism on Ceres have led to speculation that the dwarf planet could potentially be habitable. Although Ceres does not have an atmosphere, life might exist in a subsurface ocean, as has been suggested for Europa or Enceladus, moons orbiting Jupiter and Saturn respectively.

Cryovolcanism – the presence of ice volcanoes – is not the only mechanism that can produce a plume of dust and ice from a planetary surface. The Rosetta mission has delivered amazing images of plumes coming from comet P/67 Churyumov-Gerasimenko, caused by sublimation of ice that releases dust and gas trapped inside the ice. Could the bright spot be an icy plume caused by the vaporisation of Ceres’ surface as it turns towards the sun’s heat, and then dropping away as night falls? Corridor talk at the conference speculates that Ceres might be closer to a comet than the asteroid it is usually regarded as.

Fortunately, we won’t have to wait much longer before we get some more definitive answers to questions of Ceres’ physical structure and heritage. By the beginning of April, the Dawn spacecraft will be much closer and will start its imaging campaign in earnest, at which point we will start seeing craters and other surface features at better resolution.

In preparation for descriptions of such features, and bearing in mind that Ceres was the Roman goddess of the harvest, the International Astronomical Union has ruled that craters on Ceres should be named after international deities of agriculture and vegetation, while other features will be named after agricultural festivals of the world.

I’m not sure just how many of these there are, or how memorable their names will turn out to be. But as the Dawn mission’s principal investigator Chris Russell pointed out, there is one Mayan deity named Yum (Yum Kaax, god of agriculture and the jungle), who should readily be remembered. One can only hope the mission scientists find a suitably delicious feature on Ceres to give that name.

This article was originally published on The Conversation.
Read the original article.

Eureka! We’ve found Beagle2 – now, where did Philae go?

By Monica Grady, The Open University

Landing a spacecraft on a celestial body, whether it be the moon, Mars or a comet, is not easy. The European Space Agency found out the hard way in 2003 when its robot Beagle2, which was supposed to send back a signal after landing on Mars, didn’t do so.

But more than a decade after it went missing, the UK Space Agency has announced that the Beagle2 the elusive lander has been re-discovered.

Beagle2 was ejected from the Mars Express spacecraft on December 19, 2003, and was scheduled to land on December 25. The landing had Beagle2 protected by inflated airbags, which would be released from the lander and roll away before deflating. Beagle2 would then deploy its solar panels, before communicating with orbiting craft. Unfortunately, no signal was received, and after desperate attempts to communicate with Beagle2, it was sadly concluded that the lander had been lost.

The subsequent inquiry found that the most likely causes of the loss were either a problem with the Entry, Descent and Landing System (EDLS) or sheer bad luck. It now looks as though the EDLS worked – so that leaves bad luck.

The images that have sparked the news come from the HiRise camera on board NASA’s Mars Reconnaissance Oriter. This is an instrument which is able to take very high resolution images of Mars’ surface. The scientists leading the search for the missing Beagle2 were looking for “something that wasn’t red, and wasn’t a pointy rock”. Given that this doesn’t narrow the field down very much, it is testament to the amazing perseverance and talents of the individuals concerned that they have managed to locate the lander.

It is poignant that the information comes at this time – Colin Pillinger was very much the driving force behind Beagle2, and one of the leaders of the Rosetta mission. His premature death last year deprived the scientific community of one of its most charismatic members. How he would have gloried in the re-discovery of Beagle2.

In contrast to the finding of Beagle2 comes news of another of ESA’s landers: Philae. Getting Rosetta spacecraft to drop Philae was an exciting and nerve-wracking time – the lander successfully sent an arrival signal, but subsequent information showed that Philae hadn’t landed where it was supposed to.

Since the mid-November landing, there have been several possible sightings of Philae from cameras on-board Rosetta. But none has been confirmed as the lander. Rosetta is continuing its science mission – which means that it has moved further away from the nucleus of comet 67P Churyumov-Gerasimenko. It is now taking wider-field images of the comet’s nucleus, to search for signs of developing surface activity, rather than the more narrow, specific area images that were being acquired in the search for Philae.

Even though the exact location of Philae is unknown, the lander is not lost. It is misplaced, and there is hope that when Rosetta next approaches close to the nucleus, in mid-February, it will once again be able to resume scanning for its delinquent child.

And what of ESA’s third lander – the hugely successful Huygens spacecraft? This is also celebrating its anniversary. It landed on Saturn’s moon, Titan, in January 2005. It did everything that was asked of it, landed where it was supposed to land, acquired the data it was supposed to acquire, and then, on time and with no fuss, quietly went to sleep. A lesson for other landers to learn?

So if you kept score, ESA Landers: Mission accomplished 1, Lost 1, Found 1.

This article was originally published on The Conversation.
Read the original article.

On Monday 13^th January I visited Stowe School in Buckingham to speak to the GCSE and A-level students about my research, namely comets and asteroids. I took along the meteorite collection and there was much excitement from the students and teachers when they got to hold a little piece of Mars. Gibeon was also a clear favourite purely because of its size and weight! The students were full of questions at the end of my talks and it was great to see so much enthusiasm for space science. I finished up by speaking about the exciting Rosetta results that have started coming out and even left some of the students with some homework research as they were interested to learn more about oxygen isotopes. In summary, a lovely evening in a beautiful school, and I even got a delicious dinner too, with ‘Stowe School’ personalised after dinner mints (see pic)!

Here’s a great little article I just read about the Hayabusa-2 mission. I’ve just republished this from The Conversation…saves me writing a blog on here about it…must get on with paper writing instead!

 

After Rosetta, Japanese mission aims for an asteroid in search of origins of Earth’s water

By Elizabeth Tasker, Hokkaido University

The European Space Agency’s Rosetta mission to land on comet 67P was one of the most audacious in space history. The idea of landing on a small chunk of icy rock 300m kilometres away from Earth and hurtling towards the sun at speeds approaching 135,000km/hour is incredible – made more so by the fact they actually achieved it.

What scientists have learned from the data returned by Rosetta supports the need for another ambitious space mission that has just begun: the Japanese Aerospace Exploration Agency (JAXA) Hayabusa2 mission will intercept not a comet, but an asteroid, landing on its surface no fewer than three times.

Data returned by the Rosetta mission has already provided us with many surprises, including the results now published in the journal Science, which reveal that the nature of the water found on comet 67P does not match that found on Earth.

Examining the vaporous cloud that encloses the comet nucleus, Rosetta measured the ratio of hydrogen to its heavier form, deuterium, and found it was three times higher than that found on Earth. This is an important discovery, since while water is vital to our existence on Earth, it is not at all obvious where it came from.

In the beginning

The Earth was formed from small rocky planetesimals that circled the young sun, coalescing into a planet that was most likely born a dry world. Ices are not found in the planetary formation process until we reach lower temperatures much further out into the solar system. This means that the Earth must have had a water delivery at a later time.

One hypothesis is that water came via comet impacts. Comets are formed in the chilly reaches around the giant planets of Jupiter, Saturn, Uranus and Neptune and are heavy in ice. During the end of our solar system’s formation, a large number of these were scattered towards the inner planets via gravitational kicks from their mammoth planetary neighbours. Striking our dry world, their icy contents could have begun the formation of our oceans.

But Rosetta’s analysis of comet 67P suggests that our oceans are not filled with fresh comet water. What we need is an alternative source, which leads us to Hayabusa2’s mission to the asteroids.

Answers from asteroids

The JAXA Hayabusa2 mission, which launched in early December, aims to intercept asteroid 1999 JU3, touch down on its surface three times, deploy a lander with a trio of rovers and return to Earth with the asteroid samples in 2020. In short, it is a worthy successor to Rosetta.

Both comets and asteroids are left-over rocky parts from the planet formation process, but asteroids sit much closer to the Earth. The majority form a band orbiting the sun beyond Mars, known as the asteroid belt, but Hayabusa2’s target is far closer, currently orbiting the sun between the Earth and Mars.

Asteroids come in different flavours. The S-type group have been heated during their lifetime in processes that alter their original composition, while C-type asteroids – the target of Hayabusa2 – are thought to have changed very little since their original formation.

As its name implies, Hayabusa2 has a predecessor that visited the S-type asteroid, Itokawa, which showed evidence of experiencing heating up to 800°C. While its exploration illuminated much about the evolution of such space rocks, it held no answers as to the arrival of water on Earth.

Answers in clay

At only around 1km across, 1999 JU3 has insufficient gravity to hold liquid water, but observations suggest it contains clays, which require water to form. This, and its current unstable orbit, implies that it was once part of a larger object that broke apart.

After completing an initial analysis, Hayabusa2’s first touchdown will be at the site of the discovered clays. While Rosetta deployed a lander to reach the comet surface, Hayabusa2 will itself make contact with the asteroid, firing a bullet as it descends to break up surface material that it can gather. It will do this twice more at different locations; the third descent will preceded by the firing of a larger missile to bring up rocky debris from beneath the surface of the asteroid. While making a direct landing is risky, the advantage is that these samples can be brought back to Earth for thorough analysis.

Despite touching down itself, Hayabusa2 will also deploy a lander. Developed by the same German and French teams that built the Rosetta lander, Philae, Hayabusa2’s MASCOT (Mobile Asteroid Surface SCout) will run on a 15-hour battery and dispatch three small rovers to explore the surface.

Life’s building blocks in space

However, water may be only one part of the secrets to be discovered on 1999 JU3. Previous research has suggested that reactions with water on asteroids are linked to the production of amino acids: the organic building blocks for life. Not only this, but these amino acids seem to be predominantly left-handed; a distinctive feature of those in life on Earth.

While amino acids created in the laboratory appear equally as both left- and right-handed mirror images, biology strongly favours the left-handed version. We don’t know the reason for this preference, making the suggestion that such selectivity could have begun in space extremely exciting. If this turns out to be true, then scientists opening Hayabusa2’s sample jar in six years time may not only find the source of our water, but perhaps also the very beginnings of life.

This article was originally published on The Conversation.
Read the original article.

So one of the Rosetta instruments is looking at the dust in the environment around comet 67P. There’s a blog on the ESA site here about this. In summary, they’re looking for the really small dust, less than 1 micron in size, but they’ve sampled something a bit larger which broke the tip of their instrument, an Atomic Force Microscope (AFM). Fear not though, they have other tips so the plan is now to re-image the big piece of dust, which looks to be around 10 micron in size, and see what it’s like. On first pass it looks quite fluffy so I’m thinking it’s not dissimilar to the interplanetary dust particles that I’m measuring in the lab this week. Can’t wait to see more results. There’s been lots of Rosetta information flooding out the American Geophysical Union (AGU) meeting this week in San Francisco and I’m sad I wasn’t there because lots of data and pictures were shown which we’ll now have to wait until publication to see! Hopefully it won’t take too long until it’s all out in a journal for us to look at.