My recent article about comet ISON from The Conversation website.

Comet ISON fizzles … but there’s a sting in the tail

By Natalie Starkey, The Open University

If there is one thing we know about comets, it is that their behaviour is really hard to predict and that they will always surprise us – and sometimes disappoint.

Unfortunately it looks like comet ISON, or most of it, did not survive its terrifying encounter with the sun yesterday when it made a close approach at just 1.2 million kms from our closest star’s fiery surface. This distance may seem large but it is close enough to have subjected the comet to temperatures of around 2,700°C. To survive such a close shave with the sun may sound unlikely. But a few other sungrazing comets have been known to survive closer passes so there was immense hope it would perform a death-defying stunt and emerge intact.

ISON did not leave us without a final serving of mystery though. Soon after reaching its nearest point to the sun (known as perihelion), Twitter and news agencies were alight, lamenting its loss following no signs of it emerging. It was assumed to have disintegrated – RIP ISON.

But then, moments later, new images emerged showing a hint of something appearing on the other side of the sun. Was this still a diminished comet ISON or a ghostly version of its former self? Well, comet experts are not sure.

Whatever appeared after perihelion had enough matter in it to produce a tail, which started fading as it got farther from the sun. But to be able to say anymore, scientists need more data, which they don’t have.

This is because ISON is still too close to the sun and remains too faint for equipment to record what data will be needed. What can be said for certain is that whatever the size of the nucleus of the remnant, if it has one, it will be much smaller than a few weeks ago when it was visible to the naked eye from Earth.

Comet of the century

Comet ISON had been dubbed the Comet of the Century. Ever since it was first spotted in September 2012 scientists believed it had the potential to shine brighter than the Moon. Although ISON did not quite live up to these predictions, it has certainly put on a good show on its perilous journey from the Oort cloud, a region of icy comets lying nearly a light year from the sun, where it lived for 4.6 billion years.

In recent weeks ISON has been entertaining us with a show of varying levels of dust and ice streaming from its nucleus. As it got closer to the sun, the dust production of ISON has, at times, seemed to completely shut down. This led some worried scientists to suspect the comet had died very early, its shining light distinguished. But then ISON surprised us all by turning on again and the last sightings before perihelion suggested that it had not yet run out of juice.

Bright comets from the Oort cloud passing the Earth are extremely rare. Astronomers study these icy objects to learn more about the mysterious visitors from the outer solar system. ISON holds secrets 4.6 billion years old, including potential information about the earliest formed gases and dust in our solar system. But despite what has become of comet ISON, scientists have acquired lots of new data about the comet on its journey to the sun, which will help them understand, and hopefully better predict, the behaviour of future cometary visitors.

The rarity of this event explains why scientists have been unsure how to predict what the comet was going to do as they do not have much to compare it to. Passing the sun is certainly no easy manoeuvre: the extremes of gravity and heat acting to rip apart and explode the comet nucleus, possibly vaporising it in a split second.

We have probably been denied the opportunity to observe a beautiful comet blazing through our night skies in December. But it is not not all bad news. ISON’s curtailed life allowed us to learn more about the behaviour of these ancient icy dustballs. And, while scientists pore over new comet data, we can all anticipate the next one to be spotted hurtling toward the sun. It could be a good few years, but there’s one thing we can be assured – comets will always take us on a thrilling ride.

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This article was updated on December 1 to include the latest information about ISON.

Natalie Starkey receives funding from The Science and Technology Facilities Council. She is affiliated with Planetary and Space Sciences at The Open University.

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

I’ve just had a little article published on The Conversation website about space dust, and how we hoover it up when we clean.

Your house is full of space dust – it reveals the solar system’s story

By Natalie Starkey, The Open University

When you clean your house you are probably vacuuming up space dust. Not kidding. It is the same dust that was once part of comets and asteroids. You see that dust in the faint glow it helps create before sunrise and after sunset. As much as 40,000 tons of space dust arrives on Earth every year.

While that fact may not be in doubt, there is a lot of debate about where this dust comes from. Most of it, we know, spirals down from the interplanetary dust cloud, a vast swathe of dust extending in a disk-shape around the sun. But where exactly did this dust cloud originate?

Recent studies suggest that less than 10% of the dust comes from asteroids, but that a much larger portion originates from Jupiter-family comets. These comets, which are made up of ice and dust, orbit around the sun close to Jupiter. They most likely enter the inner solar system because of collisions with other comets in the Kuiper belt, a major comet belt found beyond Neptune.

When space dust falls to Earth, depending on its size and abundance, it can produce a meteor shower (shooting stars). In fact, the annual Perseids and Leonids meteor showers are produced by the Earth encountering the dusty debris left behind from comets Swift-Tuttle and Tempel-Tuttle. Comet dust travels at high speeds, sometimes more than 150,000kph. It is slowed by the Earth’s atmosphere, but the pressure created on bigger pieces is enough to cause it to burn up in a flash of light. Smaller particles are the lucky ones. They can deal with the sudden change in pressure when entering Earth’s atmosphere and make it all the way to the surface.

NASA regularly uses special ER2 aircraft, a research version of the U2 spy plane, to fly at stratospheric heights (around 20km, twice that of a commercial plane) to collect space dust. The collection technique itself is simple. When at cruising altitude in the stratosphere the pilot opens up some pods below the wing containing “sticky pads”, which collect pieces of space dust. Back on Earth NASA use an exceptionally clean laboratory to pick the space dust from the collectors for researchers, like myself, to study.

My research is based around these dust particles because they offer our best opportunity to sample comets. The ER2 is a much cheaper way of obtaining these samples. The other method involves launching a spacecraft to reach out to a comet, and ensuring it can come back after passing through a comet’s icy and dusty tail, or even landing on its surface. There has been only one comet sample return mission to date – NASA’s Stardust.

Such missions, despite their expense, provide the most pristine solar system samples we will ever get. The spacecraft acts like a cocoon, protecting the samples on their travel through space, and from the extreme heating effects of entering the Earth’s atmosphere that can otherwise cause irreversible changes to the sample.

Comets contain the initial dust that formed our solar system, and, because they stayed far away from the sun for most of their lives, they act as a deep freeze, preserving dust that is billions of years old. By studying this dust we can effectively travel back in time to the start of the solar system to understand the composition of everything we know, including early-formed organic matter and water.

Organic matter – chemical compounds containing carbon-hydrogen bonds – is actually ubiquitous throughout the universe. One of the big questions is whether organic compounds can be delivered to planets to form the basis for life. We are still not sure how life started on Earth. If this did happen, comets and asteroids are good candidates as a transport vehicle.

The same story applies to water. We clearly have a lot of it on Earth but understanding if it came from asteroid or comet collisions with Earth, or if it was present in Earth from the start, is a question we can try to answer with comet samples.

In a recent study, I measured different forms of the elements hydrogen, carbon, nitrogen and oxygen in the cometary dust samples collected by NASA. The relationships between these different elements reveal information about where the comet formed in relation to the sun. They also tell us what kind of life the comet has had. For instance, if it was ever subjected to high temperatures, that would tell us if it had travelled near to the sun.

These dust samples add a few pieces to our complicated jigsaw of the solar system, helping us to understand when and where the planets formed, and how water and organic matter fit into the picture. We will never complete the jigsaw in my lifetime but continued analysis of samples returned from the depths of the solar system will help us make progress to figuring out where we came from.

Natalie Starkey receives funding from The Science and Technology Facilities Council. She is affiliated with Planetary and Space Sciences at The Open University.

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

Some of my colleagues have been putting together a website to show people the meteorites we have available for outreach work here at Planetary and Space Science at The Open University. We’ll be updating the site to show you what we’ve done with the meteorites and who’s been lucky enough to see and hold them. We have some really cool samples in the collection including, amongst others, a very heavy piece of an iron meteorite called Gibeon, and a beautiful piece of Mars called Nakhla that has some very nice fusion crust on it.

Space Rocks: Meteorites on the road (Open University meteorites outreach collection)

Here’s a little piece I wrote about my British Science Association Media Fellowship placement for the ‘Engaging Research’ blog at The Open University.

We’re nearing the time that we might be able to see Comet ISON whizzing through the night sky. I’m reliably informed that over the next week or so we should, on a clear night, be able to start looking for the comet with the use of a telescope or even a simple pair of binoculars. I’m no astronomer so I’ll be using my trusty binoculars and trying to hold still enough to spot the comet. All we need now is some clear night skies and somewhere with little light pollution! I hear in the UK we have a big storm headed our way next week so I don’t think that’ll be a good time to look!

Some lucky people have already spotted ISON and here’s a blog that discusses some of the beautiful images they’ve obtained so far.

So, how do we find ISON if we aren’t quite as nifty as some of these astronomy-types? Well it’s already passed Mars very closely on October 1st and some grainy images were obtained by the Mars Reconnaissance Orbiter’s HiRISE camera. On Earth I hear that in late October ISON’s proximity to the Sun in our skies will make it very hard to view, but as we move into November we hope that ISON really comes into its own. The beginning of November sees the comet appear between Leo and Virgo. I would suggest getting one of the smartphone apps for finding these star systems if you don’t have a clue where to start. Again, I’m no expert on stars so this is what I have to do. Towards the end of November it starts heading towards the Sun again so will be hard to observe (and obviosuly don’t try looking at the Sun with a pair of binoculars!!). Perihelion (when the comet is closest to the Sun) occurs on November 28th so it’s fingers crossed that day that ISON doesn’t disintegrate!

Going into December we enter a bit of a ‘wait and see’ situation depending on how ISON reacted to the Sun at perihelion. I’ll post something in December depending on the outcome, but December 26-27th is when ISON would be thought to pass closest to Earth so if you’re bored with the Christmas TV then this is hopefully a good time to see the comet of the century!

As a cosmochemist I’m not the best qualified to speak about star gazing but I like to give it a go all the same, so here is a link to the Armagh Planetarium advice on how to find ISON if you don’t trust my advice.

Starkey, N. A., Franchi, I. A. and Alexander, C. M. O’D. (2013). A Raman spectroscopic study of organic matter in interplanetary dust particles and meteorites using multiple wavelength laser excitation. Meteoritics and Planetary Science, 48 (10), 1800-1822. 

My next paper is out now in the journal ‘Meteoritics and Planetary Science’ and it focusses on some work I did in collaboration with Ian Franchi (Open University) and Conel Alexander (Carnegie Institute of Washington). This research was the culmination of quite a few years of work and a lot of days spent in the lab, not my normal NanoSIMS lab though but in the Raman spectroscopy lab down the corridor. The Raman instrument uses a laser to analyse the type of bonding in samples and I was using it to look at the electronic configuration of the carbon present in comet and asteroid dust samples. The carbon can tell us about the type of history the sample has experienced – things like whether the rock was altered by being heated up or by interacting with water, we would say that this tells us how much ‘processing’ the sample has undergone. This is important for us to understand because it means we can start to piece together when and where the samples formed which allows us to build up a picture of the early Solar System.

The dust samples I analyse are called interplanetary dust particles (IDPs) and these are the dust samples collected by the NASA Cosmic Dust Lab using high-flying aircraft in the stratosphere. The majority of these IDP samples are thought to originate from Jupiter-family comets, but some may be from asteroids. Because of their potential cometary source, they are very important samples because we don’t have many comet samples on Earth (our only truly confirmed ones are from the NASA Stardust mission). These IDPs make up the bulk of my research but they are very tricky to analyse because they are so small (often only 10 microns in size), but they are important because of their rarity and what they can tell us about the early Solar System. Because we understand quite a lot about the processing history of meteorite samples, generally assumed to be from asteroids, from the other analyses we can perform on them using all manner of instruments, I decided to use meteorites to see if they could help me understand the IDPs, that are otherwise really hard to measure in many normal lab instruments because of their small size. I have managed to achieve a comparison between the two sets of samples in this paper and I show that the IDPs are very primitive because the Raman analyses show that their carbon is unlike that in the meteorite samples. This tells me that the comet samples have undoubtedly undergone very little processing and so retain pristine material from the early Solar System whereas the meteorites have undergone processing that has changed their original composition meaning they are not as good for telling us about the composition of the early Solar System. The primitive composition of IDPs is important because it means they reflect a starting point in terms of the composition of the Solar System so allow us to figure out how we got from there to where we are now. Although this finding is not particularly new in itself, my study shows that you can analyse the more well-known meteorites and use them as a framework to understand these very minute and rare dust samples so that we can glean more information from them. Raman is also a non-destructive analytical technique so my samples remain intact ready to go into the next instrument to reveal some more information about their history. I’ve already in fact analysed this batch of samples in the NanoSIMS and that work was published earlier this year (sorry, this paper is behind a paywall too)…it just took me a bit longer to write-up the Raman work.

Just when I thought it was all done, some more of the work I did on my British Science Association Media Fellows placement with The Guardian suddenly appeared online. It’s in relation to nuclear energy, I made a nice timeline, it’s linked below if you want to see it. I also worked with the Guardian Graphics people to make a world map of future nuclear energy. It felt a bit like researching a school project but then the Graphics people made it look much more swish.

UK nuclear energy timeline

Future world nuclear energy

A small blog about my blog on alien life in space dust which was spoken about on an Australian ABC programme called Media Watch. It’s really funny because they have an Australian woman quoting my website and she puts on a faux english accent. Made me chuckle somewhat. Click the link below to see the 3.5 minute video.

ABC Media Watch piece with Australian Dr Starkey.

The tagline for the show is ‘everyone loves it until they’re on it’ but luckily I’m not on it for my science but rather because I comment on someone else’s. Phew!

Some so-called ‘science’ has appeared in the media today that’s made scientists like myself very angry. I was called up earlier today by Sky News to appear on their evening show commenting on this particular story (I’ll get in to what the story is in a minute) of which I’d previously heard nothing about. After a quick google I found the science to which Sky were referring, on the Daily Mail website (say no more?!). I didn’t need to give it much of a read before I called them back almost instantly to refuse to comment on the work because I didn’t want to give this ‘science’ the airtime. I also asked Sky not to cover the story because, basically, it is a total load of codswallop. I now know I’m not the only scientist who was called by a media agency today to comment on this story. However, this doesn’t mean that journalists haven’t covered the story in their droves! I’d prefer to ignore this story but I feel like I need to vent my fury and re-educate all those journalists who mistakenly chose to cover it without asking for any independent scientific opinion on the matter (I’m looking at you Daily Mail and Independent…oh and I can now add The Telegraph to that list although they did make some attempt to add some other science in at the end of the story, but that hasn’t appeased me!).

So the story is published in The Journal of Cosmology and this is instantly where I start to get concerned. This journal has a history of publishing dubious science and all I can say is it’s not somewhere I would submit any of my work! The ‘new scientific research’ presented in the paper tells us that alien life forms have been discovered in stratospheric dust returned by space balloons. One of the scientists on the work, Prof Wickramasinghe, has cropped up before telling us that he found diatoms in a meteorite. The origin of this particular meteorite itself was slightly dubious and it may have lingered for some time in a river after it came to Earth meaning that if life was found in this meteorite then it might very much have a terrestrial origin. However, there’s no need to discuss the origin of any diatoms because they simply didn’t exist in the meteorite anyway, the findings presented in the paper were a load of rubbish. Essentially no one in the scientific community believes any of Wickramasinghe’s claims and no one will believe any of the new claims. When we look at the ‘evidence’ in the new paper we are even less convinced. Images show what I would say is probably a piece of terrestrial volcanic dust (I presume, but with no scale bar it is impossible to say, in fact there are no scale bars on any of the images). However, the researchers instead suggest the dust is a collapsed alien organism with a head, nose and sphincter ‘clearly’ on show (see the Daily Mail website for pics and then try to match the caption with the image…it’s quite fun). This is all obviously ridiculous and to make matters worse there are no analyses presented to tell us the composition of this material, presumably because if you were to analyse it you would find it was made of rock, not ‘life form’. Anyway, I have a confession, I’ve been a bad journalist here and I’ve not read the paper associated with this piece I’m writing. I believe I’m exempt in this situation though because the paper can’t be considered a ‘real’ scientific paper so there was no need to read it.

Anyway, I’m bored of writing about this bad science now. As readers of my website will know, I study space dust collected in the stratosphere by NASA and I’d prefer to trust NASA to do this job to ensure that the dust remains pristine with no contamination. I will continue to analyse space dust to understand the composition of, and the conditions in, the early Solar System (of which organic material, not diatoms and sphincters, was clearly a component). ‘Life forms’ have not been found in space dust, which is not to say there’s not life somewhere out there in the Solar System, or that it didn’t exist in the past, but, if life were to be found then we’d need a little more proof than just some microscope pictures. And it’d also help if the microscope pictures actually looked like what they were being suggested to be. Oh, and of course if life forms were found in meteorites then the work would be published in a well-respected peer-reviewed journal!

Finally we have some serious articles getting started in the press about the Rosetta mission to the unpronounceable Comet 67P/Churyumov-Gerasimenko. The first article focussing on the next phase of the Rosetta mission is by Jonathan Amos for the BBC and is available here, but I was also interviewed a few weeks ago for a Telegraph article which should appear soon. As the BBC article points out, it’s a good time for comets and we’re going to be hearing a lot about them what with Comet ISON happening soon too. I’ll blog about that in due course but from what I hear from my astronomy buddies, things are looking quite good for ISON at the moment.

Rosetta is a mission that has been travelling through space for nearly 10 years and the spacecraft even entered into hiberation in 2011 to save its precious battery power. It’s passed two asteroids during its journey – 2867 Steins (in 2008) and 21 Lutetia (in 2010) – and is set to land on the comet in November 2014. It’s first big step is waking up from its 2 year slumber and this is set to happen on January 20th 2014. It will then approach the comet in August 2014 before the Philae lander makes its landing attempt. This is the first time in history that any space agency has tried to land on a comet so it’s a really exciting test of the technologies required to do this. Once (hopefully) it’s safely harpooned on the comet surface Rosetta will carry out scientific experiments to find out what the comet is made of. As we all know (or those of you who read my blog anyway), comets contain the original building blocks of the Solar System, having preserved the earliest materials from the beginning of the Solar System in the deep freeze far from the Sun. We don’t often get to sample them so not only will Rosetta show us how to capture a comet, but it will also be able to reveal 4.6 billion year old Solar System secrets.

Here’s a video made by ESA showing an orbit around the comet. There’s more video’s and content about Rosetta available here.

Oh, and even more excitingly, the Open University have an instrument, called Ptolemy, on the Philae Lander. We’re hoping to measure the isotopic composition of the water and organic material in the comet. However, building space instruments to survive and work in these extreme conditions is no mean feat so fingers crossed Ptolemy performs and we can get some real science back. I will be using the new data to compare to the analyses of comet dust that I make on Earth as Rosetta will provide us with the ‘ground truth’ to understand what a real comet looks like in space. I can’t wait!!

I recorded an interview for the Guardian Science Weekly podcast with the Ptolemy engineers at the The Open University. That should be available soon so I’ll post it on here when it’s ready.