Astronomy Blog

What's in an exoplanet name?

Most 8 year olds can reel off the names of the planets with ease. These 8 names (they might have trouble remembering Laurele's 13 or 58) are easily recognised, even the ones of planets unknown in antiquity such as Uranus and Neptune. Since the first exoplanet - a planet orbiting a star other than our Sun - was discovered in 1990, we've found over 400 and the numbers are going up rapidly. These planets have names such as OGLE-TR-56 b, Gliese 876 d and 51 Peg b. These collections of letters and numbers make strong passwords for your email account but aren't the easiest thing to remember.

Over on the ArXiv, W. Lyra has written a rather long paper in which they advocate proper names for exoplanets. The paper goes on to suggest a naming system based largely on Roman-Greek mythology. Although I agree that there is a place for proper names for many of these discoveries (at least until Gaia starts churning them out by the Magrathean truckload), I have to disagree with the need to keep to Roman-Greek mythology. It is useful to have coherency though. I also question the need to use deities or mythological characters from ancient times. In fact, I would suggest not using them precisely because planets, moons (except the ones around Uranus which take Shakespearean names) and many stars already use those for names. Craters, asteroids and comets tend to take the names of their discoverers or other famous, real people so exoplanets could stay clear of those.

What's stopping us from using modern, fictional names for exoplanets? Modern names wouldn't preclude them having an association with the constellation they are in, the star they orbit or a nearby object of interest. Finding an association just requires some imagination and the Greeks and Romans didn't shy away from doing that.

Modern names (say, under 1000 years old) could come from the literature of all cultures and certainly shouldn't be limited to Anglo-Saxon origin. Planetary systems could be themed around a particular story much as moons often have an association with their host planet or neighbouring constellations sharing stories. Imagine planets found in Ursa Minor being named Zaphod, Dent, Trillian or Slarty Bartfast. Of course those are a little flippant but over on Twitter people have been coming up with plenty of great suggestions covering a range of literature.

Of course, as both the author of the paper and @cosmos4u point out, names may sound offensive in other languages or cultures. The most famous example in English is the snigger-fest that is Uranus but even that can be neutralised by pronouncing it in a different way i.e. without the "ay" sound in the middle and putting the emphasis on "ur". I suspect that this problem exists regardless of the source of the names so shouldn't stop the use of modern names but should be considered.

What do you think? Should exoplanets have proper names? Should we stick to the classics or start representing human imagination from more recent times? Comments welcome below.

Why are people L-CROSS?

While I wait for some code to run, I couldn't help notice the outcry on Twitter about the imminent impact of LCROSS with the Moon. People seem confused, angry and upset.

LCROSS is a relatively cheap mission that was launched along with LRO in June following design, development and construction over the previous few years. Today's impact with crater Cabeus, near the Moon's south pole, will give us definitive measurements of water within a permanently shadowed crater. There is great science to be done and we'll add to the recently announced results from India's Chandrayaan-1. So why are people upset?

A big reason people are upset seems to be a response to a particular choice of words being used on Twitter. LCROSS is being referred to as a "bomb" and NASA as "waging war on the Moon". It isn't a bomb as it isn't packed with explosives. Using the word "impactor" doesn't have the same emotional impact though. In reality, LCROSS and the Centaur rocket that took it to the Moon are not much different from the countless space rocks that have hit the Moon over the past 4 billion years creating the crater-pocked surface we see today. If anything, the Moon has been hit by many larger objects than LCROSS in the past and survived (update at 11:56 am: Chris North points out that impacts with the size and energy of LCROSS happen to the Moon about 4 times per month!). It takes a lot to have a large affect on something as big as the Moon and LCROSS is just too puny to do that. But the word "bomb" resonates with people and they rightly suggest that "waging war on the Moon" is a waste of money. That would be a waste of money and, thankfully, nobody is doing that.

With the perceived negative reason for the LCROSS impact, people have started to complain about the cost of the mission. This perceived "waste of money" in space is something I've written about before when pointing out that the money is actually spent down here on Earth. Spending money "on space" produces many things we rely on day-to-day and has some more suprising benefits too.

An interesting thing about the complaints is the comparisons people generally make. My experience in the past and today, is that people compare the cost of these missions to things such as starving children and finding cures for cancer. These are incredibly worthwhile causes and, in a strange way, show how far up people have to set the bar to give an example of a better use of our collective money. I'm not sure the last time I heard the excessive wages of a Premiership footballer held up against starving children or people demanding that the money spent on Hollywood action movies be diverted into cancer research.

Although the worthy comparisons are reassuring, this shouldn't make people who do astronomy or space science feel complacent. We should be justifying why we do this sort of research, and why it is important, to everyone. That includes the scared and confused people on Twitter as well as the people who already know why.

Europe isn't best placed to see the impact as the Moon is either set or too low. However, you can watch the impact on NASA TV.

First Light

First light. Those two words have been echoing around my head for the past few weeks but reached a crescendo today with the release of the first images from the European Space Agency's Planck spacecraft.

In astronomy, first light is that special moment in the life of a new instrument or telescope when it does its first observation of the Universe. It is like a moment of birth.

For Planck, astronomical photons have been entering the telescope since it was released from its Sylda cocoon shortly after launch. But at that point the instruments weren't turned on and the whole spacecraft had to be checked and cooled down over several weeks. Even after they were switched on, the instruments had to be tuned and tweaked to make sure that they were working as well as possible in this new environment of space. It was only on around August 13th that the instruments were declared ready and the first astronomical observations could truly begin. That date marks first light for Planck.

In the case of Planck though, first light has a pertinent second meaning. Planck's main aim is to observe the radiation of the cosmic microwave background. Back when the Universe was a baby - around 380,000 years after the Big Bang - it was much more compact and much hotter. It was so hot that the entire Universe was like the surface of the Sun - a plasma - in which photons of light were continuously bouncing off of free electrons and protons. As the Universe expanded and cooled those electrons and protons were able to stick together to make neutral atoms (mostly hydrogen). At this point the photons of light were free to go on their merry way in whatever direction they happened to be going*. When we look at the cosmic microwave background (CMB) we are finally ending the journey of those first photons that started to stream freely through the Universe. By looking at the CMB we are looking at the earliest light you can see.

Being cautious, Planck dedicated its first two weeks to a sort-of dress rehearsal for the two full-sky surveys that would take place over the following 15 months. This First Light Survey was completed at 14:49 CET on 27 August and the images are now online. The image getting most of the attention is the one showing the survey overlaid on an optical image of the sky by Axel Mellinger. As well as illustrating the way that Planck sweeps out rings on the sky (it spins once per minute) it beautifully shows the contrast of what Planck will observe. It includes 'local' things like our Milky Way galaxy (the red band across the middle) as well as the fluctuations in the cosmic microwave background. It is pretty but there is something quite important about the zoomed in images comparing observations at 70 and 100 GHz. Take a look.

Here you see a region of sky away from the plane of our Milky Way and therefore much less obscured by the gas and dust that occupies our galaxy. One thing you may have noticed is that the features in the two maps are very similar; the red blobs in one more or less match up with the red blobs in the other and likewise for the blue blobs. This is direct evidence that the blobs have an astronomical origin and are not just due to some kind of noise in the instrument itself. In fact the two frequencies seen here are from two different instruments that use two totally different types of technology to make their images: LFI uses radio amplifiers to boost the electromagnetic waves before turning them into a voltage at a detector; HFI uses bolometers which are basically a very sensitive type of thermometer. Despite the very different ways each technology captures the energy of the photons, what we see at the output is very similar. You can have confidence that you really are lookingat the tiny differences in the early Universe.

Over the coming 15 months or so the two instruments will work together to map the entire sky twice. At the same time, and for about a year after that, there will be the job of calibrating all the data, finding systematic errors, identifying all the 'foregrounds' (other astronomical things that have obscured our view of the cosmic microwave background) and calculating various properties of our Universe. It's a huge task but a tremendously exciting one and there's a great team of people working on it.

* Their 'merry way' would later be affected by heavy clusters of galaxies warping the space they were travelling through, huge patches of hot gas and, more recently, our messy Galactic neighbourhood.

Change

I'm not sure if I have any regular readers left. This blog certainly hasn't been regular over the past months so if you're still here then thanks for sticking it out (even if it is just because you couldn't be bothered to remove me from your RSS reader).

This blog was originally set up so that I could "write about astronomy and astrophysics related stuff". That was in 2003 and with everyone else doing such a great job of covering the latest astronomical happenings, it seems pointless me repeating it when you can get it from people such as Tom, Ian, Sarah, Phil, Stuart and Andy more quickly and in much more detail. That, combined with various IYA2009 events, podcasts and an increasingly busy real job (particularly since May!), has left me little time to write here. This situation isn't going to change any time soon.

My blogging days aren't over but the type of thing that I'll cover here is changing. I don't have the time to maintain a news blog or write long, insightful articles. This blog is, however, my base and it will continue to be where I put things of interest that aren't covered elsewhere and are too long to fit into 140 characters. I'll also use it to talk about astronomical things I've made and done. Talking of which, news of a new toy I've been developing coming soon.

LookUP Tweets

I know I seem to mention LookUP a lot but I'm quite proud of it and it keeps improving. I made it as a meta service which looks through Simbad, NED, Skybot etc. in an attempt to find any astronomical object by name rather than just a subset of the Universe.

Now Rob Simpson has made use of the XML output to add LookUP on Twitter. If you have a Twitter account you can send a message of the form: "@lookupastro Mars" and it will reply back to you with the coordinates (Right Ascension and Declination) and a link to more info. Of course it is probably quicker to just use LookUP online, on your iPhone or normal phone but what Rob has done is very neat.