Archive | April 2008

Conference Proceedings Published

The conference proceedings for “From Planets to Dark Energy: the Modern Radio Universe” have been published, we presented a poster on radio emission from exoplanets and briefly mentioned what else can be achieved by the wide fields possible at low radio frequencies. For more on the conference see [pos.sissa.it] and our conference proceedings can be found on [astro-ph]. The abstract for the poster was: “We present results from new low frequency observations of two extrasolar planetary systems (Epsilon Eridani and HD128311) taken at 150 MHz with the Giant Metrewave Radio Telescope (GMRT). We do not detect either system, but are able to place tight upper limits on their low frequency radio emission.”

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How many moons does the Earth have?

A simple question, with an easy answer… well if you think it is as simple as 1 then you haven’t thought hard enough (seriously the answer is probably 1 but… ). Nothing new here but interesting nonetheless.
The near-Earth asteroid 3753 Cruithne is now known to be a companion, and an unusual one, of the Earth. This asteroid shares the Earth’s orbit, its motion “choreographed” in such a way as to remain stable and avoid colliding with our planet. It orbits around the Sun in 1:1 orbital resonance with that of the Earth. Due to its unusual orbit relative to that of the Earth, it is a periodic inclusion planetoid. From the Earth’s point of view Cruithne actually follows a kidney bean-shaped horseshoe orbit ahead of the Earth, taking slightly less than one year to complete a circuit (to see some diagrams of this take a look at [http://www.astro.uwo.ca/~wiegert]. Other examples of natural bodies known to be in horseshoe orbits include Janus and Epimetheus, natural satellites of Saturn. So maybe there is a case there?
It has been called “Earth’s second moon”. A term I find hard to agree with but I do like it, and in a way it could been deemed correct.
Cruithne is approximately 5 km in diameter, and its closest approach to Earth is approximately 30 times the separation between Earth and the Moon (12 million kilometres). Cruithne was discovered in 1986, so you have probably heard of it before… but if not this is some good trivia! A couple of others have been proposed in recent times including [http://www.astro.uwo.ca/~wiegert/]/
I would like to call 3753 Cruithne a moon, but it is not, it is a co-orbital asteroid, it shares our orbit. But what does this mean about the planet definition of an object clearing its path? biggrin.gif

Does the Sun Have a ‘Companion’?

A friend of mine mentioned the search for “Nemesis” the other day and I completely drew a blank. It seems that there are a bunch of people who think the Sun might have a ‘companion’ personally I’m not convinced but I do believe that there are probably some ultra cool stars in between us and Proxima Centauri (the closest stellar object we know of) that are yet to have been detected.
A good read can be found at: http://www.space.com/scienceastronomy/solarsystem/nemesis_010320-1.html and http://www.lbl.gov/Science-Articles/Archive/extinctions-nemesis.html – some interesting stuff but I wouldn’t believe all that you read!
If Nemesis exists, it may be detected by the planned Pan-STARRS or LSST astronomical surveys, or similar future projects. If Nemesis is a brown dwarf, then the upcoming WISE mission should find it (and it should be quite easy!).

The coolest brown dwarf

You may not know (you probably do if you come here often enough) but there are a class of objects that are too massive to be planets but not massive enough to have sustainable fusion – these are known as brown dwarfs (or ultra cool stars). This is one of the major aspects of my current research and the reason I went over to India earlier in the year… anyway some interesting stuff has been released about them – so I thought you might be interested in reading about it and seeing why I am so inspired to work on this stuff.. oh and for you UK taxpayers, don’t worry I didn’t waste too much time in India… biggrin.gif

An international team of astronomers has discovered the coldest brown dwarf ever observed, bringing scientists one step closer to bridging the gap between stars and planets.

Take a longer read at the full article at [astronomynow.com]

Best 404 ever…

yes, its a game… time to waste some time breaking blocks!!
[best 404].

How to get USB working for VirtualBox in Ubuntu

In Ubuntu Gusty some changes were made to the way it handles usb, anyway to get USB support for Virtual Box you need to edit `/etc/init.d/mountdevsubfs.sh and uncomment the 4 lines around line 40 (Magic to make /proc/bus/usb work). Then execute /etc/init.d/mountdevsubfs.sh start – this will then enable the use of USB in Virtual Box (oh you probably want to do the above as sudo).
Now there is a nice and geeky post biggrin.gif

10th talk in the Patrick Moore Series!!

I have to say I’m really proud to announce the 10th talk in the public lecture series that I’m one of the organizers of at the University of Birmingham…
Our next public talk is to take place on the 8th May at 7:30pm
The 10th “Patrick Moore” lecture
[www.talkandtelescope.org.uk]
Dr Mike Hapgood (Space Environment Group; Rutherford Appleton Laboratory)
“Space Weather and Lunar Exploration”
OPEN TO THE GENERAL PUBLIC
The talk starts at 7:30pm on Thursday 8th May
Poynting Physics S02 (LLT)
Snacks and tea in the Study lounge from 7pm before the talk
If clear, sky viewing with telescopes with the help of Astrosoc members after the talk
Talk synopsis:
The Moon is embedded in the space plasma environments that surround the Earth. As a result, it is exposed to a range of space weather effects including radiation, electrical charging and electromagnetic induction. These effects have profound implications for lunar exploration. Radiation is a health hazard to human explorers but also poses a risk to robots by disrupting and damaging electronic devices. Electrical charging of the lunar surface poses several problems. It is thought to be the primary process driving the transport of lunar dust above and across the lunar surface, so studies of charging underpin studies of the threat that dust poses to lunar exploration. Electrical charging is also a direct threat to systems deployed on the lunar surface since it may induce electrical discharges that can disrupt or damage electronic devices in those systems. Electromagnetic induction inside the Moon arises when it is exposed to large scale changes in the electric and magnetic fields embedded in the space plasma environment. It poses little or no immediate risk to exploration activities as the systems to be deployed on the Moon are fairly small, but it can be exploited as a tool for exporation of the lunar interior. The talk will review these effects and discuss how they change with the natural cycles of solar activity and the Moon’s orbital motion. It will also discuss the Apollo experience of these effects and show how it influences of our current understanding. Finally, the talk will look ahead and highlight some important lessons for future exploration.
Speaker Bio:
Mike Hapgood is Head of the Space Environment Group at the Rutherford Appleton Laboratory in Oxfordshire. He has a long involvement in solar-terrestrial physics and space weather. He has worked on the ESA Cluster project for many years and is lead scientist for the ESA-funded Cluster operations centre at RAL. He has also led several ESA studies on space weather projects and is current Chair of the ESA Space Weather Working Team. He also served on the recent BNSC Space Exploration Working Group. His current interests include the impact of space weather on lunar exploration and the application of space plasma concepts in other astrophysical environments.
This series of talks is funded by STFC http://www.scitech.ac.uk/, (Public
Understanding of Science grant), and is organised by the School of Physics
and Astronomy http://www.ph.bham.ac.uk and the Astronomical Society of UoB
AstroSoc http://www.astrosoc.org.uk)
For more information about our outreach activities visit:
http://www.talkandtelescope.org.uk