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IS MERCURY’S CORE liquid or solid, and why – on the smallest planet in our solar system – is it so big? What can the planet closest to the Sun tell us about how our solar system came into being?
An unmanned European-Japanese space mission, dubbed BepiColombo, blasted off early this morning from French Guiana, to probe these and other mysteries.
“BepiColombo is coming like a white knight with better and more precise data,” said Alain Doressoundiram, an astronomer at the Paris Observatory.
“To understand how Earth was formed, we need to understand how all rocky planets formed,” including Venus and Mars, he told AFP.
“Mercury stands apart and we don’t know why.”
First, however, the suite of instruments on board the Ariane 5 rocket will have to travel seven years and nine million kilometres to reach their destination.
In a statement after the launch, ArianeGroup said the satellite had successfully escaped Earth’s gravity field and was beginning its long journey where it will reach speeds of up to 40,000 kilometres an hour.
According to Pierre Bousquet, an engineer at France’s National Centre for Space Research and head of the French team contributing to the mission, Mercury is “abnormally small,” leading to speculation that it survived a massive collision in its youth. ”
A huge crater visible on its surface could be the scar left over from that encounter,” Bousquet told AFP. Finding out if this is true is on BepiColombo’s ‘to do’ list.
Going hot and cold
This scenario would explain why Mercury’s core accounts for a whopping 55% of its mass, compared to 30% for Earth.
Mercury is also the only rocky planet orbiting the Sun beside our own to have a magnetic field.
Magnetic fields are generated by a liquid core but given its size, Mercury’s should have grown cold and solid by now, as did Mars.
This anomaly might be due to some feature of the core’s composition, something BepiColombo’s instruments will measure with much greater precision than has been possible so far.
On its surface, Mercury is a planet of extremes, vacillating between hot days of about 430 degrees Celsius to super-frosty nights of minus 180C.
Those days and nights last nearly three Earth months each. Earlier missions have detected evidence of ice in the deepest recesses of the planet’s polar craters.
Scientists speculate that this may have accumulated from comets crashing onto Mercury’s surface.
“If the presence of ice is confirmed, it means that some of those water samples date back nearly to the origin of the solar system,” Doressoundiram said.
Lashed by solar winds
Mercury is 58 million kilometres from the Sun, nearly three times closer than Earth.
“The planet is whipped by solar winds,” a constant torrent of ionised particles bombarding the surface at 500 kilometres per second, said Bousquet.
The scientists will be able to study the impact of these winds – 10 times stronger than the ones hitting Earth’s atmosphere – on Mercury’s magnetic field.
The BepiColombo mission will deploy two spacecraft. The Mercury Planet Orbiter, built by ESA, will investigate planet’s surface and interior composition.
The Mercury Magnetospheric Orbiter, made by the Japan Aerospace Exploration Agency, will study the region of space around the planet that is influenced by its magnetic field.
The mission will also look for tectonic activity, and seek to understand why spectroscopic observations show no iron even if it is thought to be one of the planet’s major component elements.
Compared to Mars, Venus, and Saturn, Mercury has barely been explored. Only two spacecraft have ever paid it a visit. NASA’s Mariner 10 did three flybys in 1974 and 1975, providing the first up-close images.
More than 30 years later, NASA’s Messenger did the same, before settling into orbit around Mercury in 2011.
The new mission is named after Giuseppe (Bepi) Colombo, a brilliant Italian mathematician and engineer who first understood the relationship between Mercury’s rotation and orbit.
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A side note, the Japanese are a wonderful people. The safest county on earth. Nice to see them involved in this, they have incredible ingenuity
It’s going to be an exciting few years for space with this, InSight, Mars 2020 and all of the Chinese missions.
I’m surprised nobody has complained about the mistake in the headline. I won’t. I like it.
What are all the staff, engineers, scientists going to do waiting around for the space ship to arrive in seven years ?
@Martin Sinnott:
Most of the people already involved won’t be involved when the orbiter reaches Mercury, they’ll have already moved onto other projects like Electra, ExoMarsrover and the Lunar Lander missions.
The ESA is doing loads over the next few years.
Travelling at 40.000 km per hour?
If it takes 7 years at that speed it will have travelled 2,452,800,000 km !
Yes ??No??
I don’t really care anyway.
I’m off for a pint .
Cant look after the people on this planet and throw money at this.
@Peter Coen: always one.
@Peter Coen: i bet you cycle to work, dont you?
@Peter Coen: You could kick of this new trend of not spending on technology and science and using the money to help people. Get rid of your internet connection and send the money saved to starving children in Leitrim. Win for everybody really.
@John: Always one, at least, who speaks out on behalf of the ‘Silent Majority’ and sparks an intelligent discussion about issues important to most of us of the Silent Majority.
There is no excuse for us earthlings to be exploring/researching space, spending trillions on it. We don’t belong in space.
The money could be better put to use in Medical research globally, looking for medical cures for various so-far incurables diseases and illnesses.
@Canny Jem: Please, go troll elsewhere
@Larissa Nikolaus: Well said. It was a very poor attempt also.
@Canny Jem:
Trillions?
U wot m8?
@Larissa Nikolaus: If offering honest opinions or stating facts in a discussion under a topic is “trolling”, then I plead guilty to your charge.
However, I do not engage in constant postings for divilment’s sake, which is what internet trolls do. Therefore your charge has no grounds.
The response you made under my post DOES qualify as ‘trolling’, per Internet Troll definitions.
@Canny Jem: So let’s just sit around and wait for the next big space rock to wipe us all out. Or let humans explore and expand out into the solar system where mankind can flourish with new discovery and tech. If we really always thought like you do. Just think and ponder on it a while as you read this on your smartphone.
@Seán J. Troy: Yep, countless space projects, each costing billions that amass to ‘Trillions’ over the years to date. I’m all for scientific research (I love science – esp Physics and Chemistry, almost went for a science career) but not for research on irrelevant, useless space projects that we have, really, no business pursuing.
1 Billion = 1,000,000,000 (a thousand million) and 1 Trillion = 1,000,000,000, 000 (a million million). There’s mindboggling noughts in those figures that have been wasted on many space projects that could have been/should be spent on human causes. Too many space projects come to naught, are littering our near outer-space with dying satellites and space debris that will fall to earth in time, perhaps even upon our human populated places with risk of many deaths. (We were very lucky with the falls of the giant Skylab, and the debris of the tragic ascending Challenger and descending Columbia Space Shuttles).
That’s money that could be better spent on medical research and development that could give tangible results all over our planet for our humankind – not wasted on far-flung space exploration where only non-tangible curiosity is served.
@Canny Jem: although the total cost for this project is close to 1.7 billions dollars, it is still a drop in the ocean of spending for weapons of war race. I think you should definitely complain about that one and not about space exploration. Look at the cost for development of the F35. Exceeding 150 billion dollars, and that’s just one type of war plane.
@Vincent: Totally agree. *Now where did I put my Pacifist Hat?*
@Canny Jem: space developments helped for example CT and MRI scans along with countless developments in manufacturing…
@Canny Jem:
We haven’t spent anything close to trillions on scientific programmes in space. You’re mad.
You clearly have no idea what ridiculous breakthroughs we’ve made through space programmes.
The vast majority of money spent on space now is getting commercial satellites up. I assume they’re a waste as well?
@SteoG: (Took me a while to write this response in between other stuf f I do) While I have a ‘Smartphone’, I rarely use it and never deliberately use it for internet purposes. My laptop is quite adequate for that, without the unnecessary expensive charges of Smartphone internet use. Sending a spacecraft carrying two satellites (one of which has Irish scientific input) to Mercury is not going to benefit me or any of us in our present or our future generations’ lives.
None of us has control of some big space rock hitting our planet. Our moon is said to have been formed by a large space rock colliding with what’s now Planet Earth and bouncing off it during the formation of our planet and was captured by our larger piece of piece of rock’s gravity. What few know is that bounce effect is still working – our moon is moving away from Planet Earth at the rate of some 3kms a year (check that out for yourself). Future moon visitors will have to travel further to reach it… and sometime in the distant future, lovers will gaze on a tiny star that was once a Lovers’ moon. Aah!… what a pity that is going to be.
Neither has anyone of us any control over the impending collapse of a mountainside on the Canarian island of La Palma that will create a mega-tsunami, at any moment, that will be disastrous for the densely populated east coast of America and for Ireland, Britain, mainland Europe and Africa.
But that’s not relevant to this discussion… We managed to live with terrestrial telephones for communication before big businesses decided that mobile phones would be good for us. In the Swiss Alps, people communicated by yodelling across the mountains, today replaced by mobile phones. In fact, mobile phones of any kind haven’t been good for us at all in the wider sociological sense. Visiting my son recently and having a family dinner, when another visitor answered a beep on his phone, his own 3yr old son shouted “No phones at the dinner table!” Shows how natural conversation over a dinner table can be unnecessarily intruded on by an artificial, satellite-controlled Smartphone, as in many other instances. It’s an intrusion that all of can do without in social intercourses. My 3yr old grandson even knew that.
I’d rather have chats with family, friends and others in my social life by using my own natural voice, by listening theirs and looking at human faces instead of Smartphone text messages, tinny-voiced phone and video calls controlled by big satellite businesses at our expense. What will life be like for people who live by such technology when the impending big sunburst of radiation destroys satellite waves? Probably we’ll have lost theart of conversation by then and just grunt at each other.
I fail to see how a $1.7 billion space project to Planet Mercury is going to benefit me or any of my fellow humans, now or in the future. I still maintain that the trillions of $’s wasted on space exploration (and armaments) over the years would be better spent on Science and Medical projects that benefit us and our fellow humans on Planet Earth.
@Canny Jem: there is just so much stupidity in this one post that I wouldn’t know where to start.
@Eamonn Kenny:
I agree, don’t know where to begin. It’s staggering.
It makes me depressed as a scientist.
@Seán J. Troy: No, we in Ireland haven’t spent trillions on space exploration but big wealthy conglomerate worldwide businesses do. Someome Irish-based scientists have contributed to development of some satellites, including this useless Planet Mercury project – at what cost to Irish taxpayers I don’t know. Ireland is a member of the European Space Agency (ESA) which has sent this Planet Mercury exploring spacecraft on its way.
Maybe some Irish TD might ask how much it cost taxpayers to fund space projects that, essentially, have failed to produce tangible results.
Overall, all the space exploration projects by different countries have collectively cost trillions in different currencies. My various calculators don’t have enough noughts to add up to show the sum of billions spent ending in trillions so far has come to naught. That shows how little we are capable of doing sums amounting to trillions that could be better spent in pursuit of medical cures for various ills among our humankind.
If we are incapable of collectively doing sums around world-wide expenditure on the costs of useless far-space exploration, what is the point of spending incalculable trillions that could be better put to earthly explorations of productive scientific and medical experiments that will (not ‘would’) benefit our humankind on Planet Earth – and not satisfy the curiosity of misdirected scientists whose talents would be better employed in service of their own humankind and humanity?
The multi-billion CERN Planet Earth-based project has still not delivered on the billions invested in it.
There is simply no human excuse for this kind of waste of rillions of money.
@Canny Jem:
“Big wealthy conglomerate worldwide businesses”
You forgot to add multi national to that verbal diarrhoea.
Trillions is still a ridiculous number. Not even a fraction of that has been spent on science projects in space.
@Canny Jem: Thanks you for the response. Had a few drinks so I will respond properly tomorrow.
@Seán J. Troy: I get your point and very much respect it.
If what I’ve truthfully said on expenditure of uselessly wasted trillions spent on space exploration gets your goat, then maybe you, as a self-declared earthling scientist could perhaps redirect and concentrate your scientific knowledge in pursuit of the sciences of eliminating the multitude of present-day incurable but curable diseases that some millions of our fellow-earthlings can be cured of by thorough exploratory scientific researches?
Like I’ve said before, I am fiercely in favour of scientific research, so long as it’s beneficial to our fellow-humankind and humanity first, even survival of some of our land- and sea-faring species that share Planet Earth with us.
No need to be feel depressed… Look forward to new scientific adventures that have nothing to do with wasteful expenditure on space things that have nothing to do with us humans and with what we live with on our Planet Earth.
It’s all you and me and all have got to live with, share and live with.
@themanwiththeplan: No, they didn’t… CT and MRI radiological scans were first developed by earthlings on our Planet Earth long before space explorations. They were tested by our fellow earthlings working for further developments in the weightlessness of space, which proved that earthling scientists got in right first-time.
There has been some interesting scientific experiments on earth-grown plants and vegetables taken up to space labs and grown in that alien environment that led to moderations in growing plants and vegetables that are now sold as “modified” stuff.
Give me honest Planet Earth earth-grown stuff all the time, none of this space-modified stuff.
@Eamonn Kenny: Oh please do elucidate for me and other readers on that allegation of yours. Start whenever it suits you. You’re free to do so…
@Canny Jem: very often findings from space programs actually help us develop treatments and better health care. There is a relationship between exploring space and understanding what we need here and now.
@Ciaran Leonard: I agree with that, out of some, very rare and exceptionally few, measures of near-space trillions-costing experiments being of some benefit to humankind on our own Planet earth, not on far-flung Planet Mercury or Planet Mars or, as has been proven by other expensive space programmes to our neighbouring moon, has not been worth it.
Quite simply, we humans of Planet Earth do not belong in space, should recognise that and stop trying to overcome what is frankly not ours to overcome.
Unfortunately, space exploration is not worth the trillions spent on non-productive endeavours like this Mercury project that could and should be spent on researches to solve so many existing human health and other ills happening all over our own world.
In overall contexts, there is no value added to space exploration enterprises that cost trillions of cash that could be more gainfully spent by scientists, governments and selfish profit-seeking business people in the causes of good humanity.
I’m all in favour of scientific exploration, so long as it is earth-based around our real fragile human or animal or sea-life world sicknesses
@Canny Jem:
Stop saying trillions. You’ve pulled that number completely out of nowhere. It’s pure fantasy.
@wzFbzPzf:
No, they haven’t. It’s about $600bn.
And that’s over 60 years. And a large amount of that wasn’t spent on science missions in space.
Most of the cost of the Saturn programme for example was in basic research such as developing new space and alloys (used in airplanes today) and new rocketry technology (used in commercial satellite launches).
You can’t just say trillions have been wasted. The number simply isn’t even a trillion and of that, most of it can be attributed to programmes which have produced a huge range of applications.
@Seán J. Troy: Erm, I think you need to check a few facts. NASA alone has spent over 1 trillion to date. You do the sums:
https://news.utexas.edu/2014/07/21/anniversary-shows-us-that-nasa-and-space-exploration-are-worth-their-costs
https://www.weforum.org/agenda/2016/01/which-countries-spend-the-most-on-space-exploration
@Canny Jem: *correcting mistypo* not 3kms/year… 3cms per year.
@Cany Jem I do agree with a lot of your sentiment, however, I think that you are being a little narrow minded in your outlook. It is true to say there is a lot of money spent unnecessarily on lavish projects, though I contend space exploration is not one of them. We live on a speck of dust in a massive universe. Why would we impose limitations on ourselves when there are endless possibilities. Yes, if you measure progress in your own lifetime then we are limited in what we can achieve. The future of mankind IMHO is at a crossroads either we evolve with technology, self-destruct by our own hand or are destroyed by a catastrophic event. If we remain solely on this planet we will most probably stagnate and die out. The best possible option is to explore and expand out into the solar system.
Expansion into the solar system will see mankind evolve and establish new colonies & habitats which will also advance science and technology to benefit all. The challenge of exploring and expansion will expand all our horizons taking the focus off the small planet we currently occupy. Investing in space is a long term investment and there have been many benefits to mankind https://science.howstuffworks.com/10-reasons-space-exploration-matters.htm So I think investing in space exploration is a positive thing.
@SteoG: Thanks for reply, good points, most of which, but not all, I agree with. Thanks also for the link you gave, which was interesting and had links to other sites, which basically confirm that trillions have been spent on space programme budgets over all the years by the USA, Russia, China, India and Europe. There have been some good developments from experiments in space but I still maintain that expenditure on space programmes, especially far-space exploration, have little true cost benefit and the money should be spent on other projects beneficial to humankind, not on space. However, it’s already happening and we all have to live with it.
Proponents of NASA’s space programmes claim that there’s been $8-$10 return for every dollar spent on space programs, without providing evidence to support that. NASA fights very hard for its funding, always trying to justify its cost in the face of much opposition in US Congress Budget debates, so some claims might deserve some doubting. Funding for NASA has been scaled back on fears of little real cost benefit.
The only cause of space exploration is to satisfy our curiosity and for mining purposes, highly unlikely to be for future preservation of our human species. Proponents of human colonies on other planets are scaremongering conspiritorialists. Gold and platinum on our planet arrived here from space in showers, though no one knows how they were formed in space. It is assumed that other planets will also have reserves of gold, platinum and other precious elements like our Planet Earth and it is sure that countries will want to mine them solely for profit.
Again I say that we humans don’t belong in space. The ideal maximum time an astronaut spends on the ISS for example is 6 months because human bone structure disintegrates pretty fast in space. Though this problem may be overcome in the future, I can’t see astronauts spending up to 16 months travelling to Mars and back, excluding time spent on it, without serious repercussions for their bodies. We humans really do not belong in space.
https://www.weforum.org/agenda/2016/01/which-countries-spend-the-most-on-space-exploration
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