Monthly Archives: February 2015

A History Of Planet Detection in 60 Seconds

Last week I gave my first proper talk to a conference of PhD students from nearby universities. Being an easily distracted man, rather than actually write my talk, I decided to spend the day before putting together an animation of the entire history of Planet Detection, from 1750 to 2015. It shows the orbital period (x-axis), planet mass (y-axis), radius (circle size)* and detection method (colour) of the 1800+ planets now known.

Made by Hugh Osborn
Made by Hugh Osborn

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The idea of this plot is to compare our own Solar System (with planets plotted in dark blue) against the newly-discovered extrasolar worlds. Think of this plot as a projection of all 1873 worlds onto our own solar system, with the Sun (and all other stars) at the far left. As you move out to the right, the orbital period of the planets increases, and correspondingly (thanks to Kepler’s Third Law), so does the distance from the star. Moving upwards means the mass of the worlds increase, from Moon-sized at the base to 10,000 times that of Earth at the top (30 Jupiter Masses).

The colours are also important – dark blue shows the solar system planets (which include Ceres and Pluto for a few deacades each); In light blue are RV planets, which began the gold rush in 1995 with the discovery of 51 Peg; In maroon are Direct Imaging planets; in orange the microlensing discoveries; and in green those planets found by the transit method.

You might see a few patterns beginning to emerge:

The top left has a dense cluster of large worlds. These are the Hot Jupiters. We know of loads of these, even though they’re pretty rare, simply because they are easiest to find. Being so close to their star they produce the biggest radial velocity signals (light blue) and are most likely to transit (green). Ground-based transit surveys like WASP cant find anything beyond ~15 days, causing the sparse region to the right of this group.

The top right cluster is a population of Jupiter-like worlds that Radial Velocity is best at finding – anything beyond 10 years is too long at the moment to have a full signal.

The bottom group is from the Kepler space telescope. This clustering is the only one that’s actually real and not just a systematic effect. This is because Kepler was capable of finding every type of planet down to ~1 Earth radius. So this clustering shows that there are more Earth and super-Earth sized planets than any other. Hopefully we can begin to probe below it’s limit and into the Earth-like regime, where thousands more worlds should await!

Hope you enjoy it, and feel free to borrow it for your own use!

*Where Mass or Radius were unavailable I used the Mass-radius relations of Weiss & Marcy. Information from, so it might be a bit wrong. Thanks to Matt Kenworthy for suggestions. Pulsar planets are not plotted.

Lunar Mission One – Can It Succeed?

10349900_1523807731203424_1290925223437780697_n[1]73%. That’s what former Minister for Science and Chairman of Lunar Missions Ltd Ian Taylor reckoned the chance of success of Lunar Mission One would be. This number, on the face of it, appears to be reasonably precise. Assembled from a detailed analysis of all the risks, you might think? No. In reality, like much of his talk this evening, it was a fudge – pieced together on the fly, with little scientific substance to back it up.

Lunar Mission One is a crowd-funded space mission. Started in late 2014 by a wide array of collaborating UK institutions which Ian Taylor listed with pride. It plans, in the early 2020s, to send a probe to the Moon and perform cutting-edge scientific research. They pitched the idea to the public via Kickstarter and, by the skin of their teeth, made it to the £600,000 goal needed to start developing the idea. Their ultimate goal is to produce a mission for everyone. (Where, as far as I can work out, ‘everyone’ is those who have donated sums of money to the cause).

lunar-mission-one_3110612k[1]Their scientific principle, at least, has merit. They will fly a large probe to the unexplored Shackleton Crater at the Lunar South Pole and use cutting-edge drilling tools to make a ~100m hole in the lunar ice and rock. The geology of this borehole could reveal untold secrets about the history of the Earth-Moon system and make literally dozens of British Lunar geologists quite happy.

The team will then fill in this hole with “Memory Boxes” – digitised containers that members of the public can, for a small fortune, fill with their most treasured memories and unwanted iTunes collections. These will then sit under the lunar crust for 4 billion years before either being fried by an expanding sun or rescued by some helpful intelligent alien species.

Lockheed build the Phoenix Lander
Lockheed build the Phoenix Lander

For those of you worried that there might be a limit to the market of moon-based hard-drive storage space, fear not – the Lunar Mission One team might have something else up their sleeve: Someone will take it over! Ian Taylor banded around a couple of names. Lockheed Martin for instance. For too long have these private contractors worked for contracts based on money – the time is right for them to start backing space missions for free…

Despite lots of long-winded answers-that-weren’t-quite-answers, Ian Taylor did not really fill us in on just how such a mission might be funded. The £600,000 raised so far is only 0.1% of the budget needed to get a space probe to the moon. He suggested international collaborations could easily get the funding necessary, but with most western countries already invested in their own agencies (eg ESA), where and why would any extra funding end up in a British company’s hands?

google-lunar-x-prize[1]The Google X-Prize contenders, who set to reap a $35million bonus for landing on the moon, tell a cautionary tale. Backed by a combination of crowd-funding and business investments, not one of the half-dozen teams involved made it to the Moon by the 2012 deadline. Twice this has been extended, and twice the teams have failed.

Even private investors such as Virgin Galactic or Space-X, who have a profitable business model, have struggled with the costs and timescales involved with spaceflight. And these, which Ian Taylor was so quick to draw comparisons to, are profitable ventures. Lunar Mission One has even less potential for generating income than Mars One, another independent space mission that looks destined for failure. Most would agree that crowd-funding has its limits, and £600million is above that limit. Way above.

Another question that springs to mind is why, if the scientific concept is so good, did the institutions involved go down a private route? Why not propose directly to ESA, and face the potential of €650million reward to build the space mission? I put this to Ian, and he tried to convince me that ESA (and NASA) was hell-bent on Mars and not on the Moon, whereas the scientists he had spoken to were adamant that lunar missions are more important. (NB: Well of course they were, Ian; you spoke to Lunar Scientists. If I only spoke to the dozen White Dwarf astronomers in my department then I’d probably get the idea that the only necessary mission was to send a craft to Sirius B!) And ESA missions to Jupiter, a comet, the Sun as well as two exoplanet satellites prove that is not really the case. The selection process is done by numerous committees that select programs based almost entirely on their scientific potential. That lunar geologists cannot get their missions selected in telling.

China's Moon Probe, Chang'e
China’s Moon Probe, Chang’e

In reality, most planetary scientists would agree that there are still other more interesting places in the solar to explore than the Moon. Many of these destinations, such as our planet’s near-twin Venus, are also relatively thin on the ground when it comes to future missions. The Moon, however, is an easy target for newly-emerging space agencies such as India and China. One can even imagine a manned mission before Lunar Mission One even launches.

I was cautionary optimistic when before hearing Ian Taylor and the Lunar Mission One concept. Now, after an hour of name-checking and avoiding difficult questions, I feel the opposite. The whole mission seems to lack any clear sense of direction. It seems like they caught their £600k target almost by surprise, like a dog chasing a car. Now, from that unlikely position, they must raise £599million more (£15 for every working adult in the UK) for a mission that, compared with the exploits of Rosetta, sounds uninspiring.  73% suggests Ian? My guess would be more like 0.7%.

An Open Letter to the RAS – The Writings of Adrian Berry

Dear Members of the RAS council,

I wish to bring to your attention the writings of RAS fellow Adrian Berry. You may know him as the Telegraph’s astronomy columnist, writing once a month in Britain’s most-read broadsheet and reaching a potential audience of more than half a million people.

However, his recent column seriously calls into question his scientific judgement, to the extent that I believe his membership to this esteemed society should be reviewed.


He states that Global Warming is a myth, that 500 million years of geological record have proved this to be so, that Carbon Dioxide has no effect on surface temperatures and that the un-peer reviewed writings of two authors (Svensmark and Calder) are somehow more credible than the tens of thousands of peer-reviewed science (see attached article).

As a society, we should be all for scientific debate and should not just discard unpopular hypotheses. However, an unbalanced piece in the Astronomy column of a national newspaper is neither the way nor the place to do it. Instead it is a reckless attempt to discredit climate change in the eyes of the public. For a public-facing astronomer with a huge audience and the credibility of this society behind him, stating these concepts as facts is disgraceful.

His article also completely disregards the charter and bye-laws of this society. This includes: “Act with skill and care in all scientific work”. “Take steps to prevent corrupt practices and professional misconduct.” “Declare conflicts of interest“. And, most pertinent of all: “Not knowingly mislead, or allow others to be misled, about scientific matters.”

Standing by such members damages the reputation of our society and I believe (along with many other fellows I have spoken to) that his membership should be reviewed and revoked.

Yours sincerely


Hugh P. Osborn
Fellow of the Royal Astronomical Society (FRAS)
Research Student (Ph.D)
Astronomy and Astrophysics Group,
Department of Physics,
University of Warwick

UPDATE 1: A copy of this letter was forwarded to the members of the RAS Council. I shall update this post with any decisions that are made.

UPDATE 2 (26/02/2015): The issue was extensively discussed at the most recent RAS general council. The final conclusion was that the specific case of Adrian Berry would not be taken any further. This was in part due to issues with free speech and the fact that, while being a member of the RAS, Berry did not specifically state his membership in the piece, so was not directly using it as credibility. The current process would also require a general vote of fellows to remove a member of the society.

However, with the RAS bye-laws being updated this year, a new Code of Conduct will be created that fellows will be expected to ratify on a yearly basis. This code, which can be viewed on the RAS website, will more easily allow the RAS to discipline fellows breaking this code and take action more easily.

I was not expecting the issue to even be discussed, so full credit to the RAS for listening, especially to President Martin Barstow who contacted me directly with the result. I understand the council’s decision in this case, especially as I feel any disciplinary action on Berry would probably serve to merely increase his (false) belief of a global warming conspiracy. But the new code of conduct is certainly a step in the right direction. Whether the RAS, which has never historically removed a member from it’s ranks despite worse cases than that of Berry, will actually discipline those breaking this code remains to be seen.