Skepticism, Medicine and Science News

Watch The Moon Tonight

Tonight, on Friday December 12th, the full moon will be bigger than it usually is. This is because its orbit will take it nearly as close to earth as is possible. The earth-moon distance is, on average, about 384,400 km, but tonight is is much closer, at about 356,567 km. Not since 1993 has the full moon been this close to earth, and it will take another 8 years before it happens again. Compared to the other full moons in 2008, this one will be 14% bigger and 30% brighter than any of them. So, get out and take a look. 


December 12, 2008 Posted by | Astronomy | , , , , , , , | Leave a comment

Teddies In Space

It sounds like a bad sci-fi movie from the 80s, but it is actually a really, really cool science project. Students at the University of Cambrige recently managed to put four teddy bears in space by using a weather balloon. The maximum altitude reached was about 30km, and to prevent the bears from freezing solid the students designed and built space suits for them to wear. This was really the main part of the project, and was an excellent way of teaching the students the principles of insulation, convection, conduction, radiation, pressure and loads of other exciting physics. Oh, and the students in question were actually aged about 11-12, and I think this is a wonderful way of getting young kids excited about science. I really hope other schools follow Cambridge’s example on this one. 

I mean, how cool is that!

December 8, 2008 Posted by | Astronomy, General Science | , , , , , , , , , , , , , , , , , | Leave a comment

Hubble Captures Two Ginormous Stars

A new picture from the Hubble Space Telescope shows two massive stars, WR 25 and Tr16-244, located in the open cluster Trumpler 16. This cluster lies within the Carina Nebula, approximately 7500 light years from earth. The nebula is home to many massive stars, including Eta Carinae, a supermassive luminous blue variable star with a luminosity four million times that of our sun, and a mass of 100-150 solar masses. WR 25 and Tr16-244 are not as big as Eta Carinae, but they are still pretty massive. 

WR 25 is located near the centre of the picture (the most blue of the big stars). It is binary star, and the largest of the two stars is a Wolf-Rayet star with a mass of about 50 solar masses. Wolf-Rayet stars are stars with a mass of >20 solar masses, and they loose their mass extremely rapidly due to a strong solar wind, typically about nine orders of magnitude more rapidly than our sun. The smaller star in the binary system is thought to have a mass of about half that of the other. 

Tr16-244 is located just to the left and up from WR 25, and is the third brightest star in the picture. The second brightest is a low-mass star much closer to earth (and thus it appears more luminous). This is a triple star, two of which are so close to each other that it took a while to determine they were in fact two separate stars. The third uses hundreds of thousands of years to orbit the first two. 

These new observations were made as part of a project led by Jesús Maíz Apellániz from the Instituto de Astrofísica de Andalucía in Spain, and consist of astronomers from the US, Argentina, Spain and Chile.

November 27, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Binary Star Explosion

For the first time in over 100 years, scientist have witnessed the explosion of a binary star inside a planetary nebula. Astronomers at University College London predict that the two stars eventually may spiral into each other and trigger a much larger supernova explosion. 

A planetary nebula is a glowing shell of gas and plasma formed by certain types of stars when they reach the red giant phase of their lives. During this phase, the outer layers of the star are expelled by strong pulsations and solar winds. The core of the star then emits ultraviolet radiation that ionises these ejected layers, and they radiate out as a planetary nebula. 

A nova, on the other hand, is nuclear explosion caused by accretion of hydrogen onto the surface of a nearly-dead white dwarf star.  In a closed binary system, the nova occurs as matter is transferred from one star to the other, which eventually causes a cataclysmic thermonuclear explosion. Novas are in themselves not uncommonly observed, but a nova inside a planetary nebula is rarely seen. The nova illuminates the surrounding gases and plasma as the light passes through it, and the UCL scientist say this could help us understand more about the life cycle of stars. 

The has been given the name V458 Vulpeculae, and it could turn out to provide researchers with an opportunity of observing how a nova might evolve into a supernova. 

The top image was taken in May 2008, and the bottom in September 2008. The changes that occur due to the ongoing nova are clearly visible. From University College London

November 25, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , , , , , , , | Leave a comment

Deep-Space Internet

NASA has successfully tested a new communication network that was modeled using the Internet as a basis. Researchers at NASA’s Jet Propulsion Lab (JPL) used software called Disruption-Tolerant Networking (DTN) to transmit data from a NASA space craft to earth. This new method for space communication could be the first step towards an interplanetary Internet, according to Adrian Hooke at NASA. 

Sending data through space has up until now been difficult, and each operations team has had to “manually schedule each link and generate all the commands to specify which data to send, when to send it, and where to send it” (Leigh Torgerson, manager of the DTN-project at JPL). The Internet uses TCP/IP (Transmission-Control Protocol/Internet Protocol) to send data, but DTN differs from this on key points. Unlike TCP/IP, DTN does not assume a end-to-end connection. If a destination path cannot be found, the data packets are not discarded, but rather stored in the network node until it can be safely sent to another node. As each node stores the information before it forwards it, the data will not be lost due to disruptions and disconnections. This means that the processes that now has to be done manually can be automated without fear of loosing data. 

This test is the first in a series of demonstrations intended to qualify the system for further use in future space missions. The researchers hope that over the next few years, this technology will enable new types of space exploration such as complex missions involving multiple landed, mobile and orbiting spacecraft. 

Artist concept of interplanetary internet. Image credit: NASA/JPL

November 20, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , | Leave a comment

First Pictures From the Moon Impact Probe

I previously blogged about Chandrayaan-1’s Moon Impact Probe (MIP), so for more information go here and here. Well, on last Friday (November 14th) at approximately 15:00 UTC the MIP was successfully embedded in the lunar surface. As of yet, no video has been released by ISRO, but they have released two pictures taken by the on-board camera: 

Credit: ISRO


Credit: ISRO

Still though, I’m looking forward to the video. Should be interesting.

November 16, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , , , | 1 Comment

Lunar Probe

As mentioned in a previous post, the Indian lunar satellite Chandrayaan-1 was launched on the 22nd of October and is now on its way to orbit the moon. One of the aspects i find most interesting about this satellite is that it carries a so-called moon impact probe. It is essentially what it sounds like, a mini-satellite (it’s only 375 mm x 375 mm x 470 mm and 35kg) that will separate from Chandrayaan-1 on Friday and then quickly de-orbit and bury itself in the lunar surface. The descent itself will only take about 25 minutes, but the probe will gather a lot of interesting data on its way down. It has a lot of different instrumentation on board, like a mass spectrometer, an altimeter etc, and the purpose of these are to analyse dust in the lunar atmosphere, and to gather data that will help test equipment that will later, hopefully, provide a soft landing for an eventual manned mission. All this is of course important and all, but what I find really exiting is the on-board CCD camera the probe carries. It will basically film the whole descent, and I really look forward to viewing that tape. Can’t wait! 

Read more about the mission and the probe in this NewScientist article.

Oh, and another cool thing is that the probe, when impacting the moon, will kick up a huge amount of dust that Chandrayaan will gather and analyse while orbiting. Yet another advantage of the low mass of the moon I guess…


A picture of Chandrayaan-1 from ISRO

November 12, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , , , , , , , , | 1 Comment

Going to Mars

One of the biggest problems with sending people to Mars is the radiation from the sun and cosmic rays. Cosmic rays consist mainly of highly energized protons capable of ionizing molecules such as DNA (which would be bad), causing cancer, neurological disorders etc. Solar flares are generally the main concern since they generate a huge amount of electromagnetic radiation and energized protons, and if a spacecraft travelling to the moon or mars were hit by one the effects would be really bad. Going to the moon doesn’t take that long, so if you plan ahead you can minimize the risks, but going to Mars would take a lot longer, so the astronauts would be exposed to large amounts of cosmic radiation and inevitably also solar flares. So, finding a way to shield the craft is one of the main challenges in putting humans on Mars, and recent research may have found a feasible way to do this.

The earth is protected from cosmic radiation by the magnetosphere, and the idea of generating a mini-magnetosphere around the ship has been around since the 1960s. It was, however, thought that this “magnetic bubble” would have to be more than 100km wide to have any real effect, but new computer simulations showed that a smaller bubble might in fact be adequate. A lab in the UK recently confirmed these findings my replecating a mini-solar wind with equipment used in fusion research, showing that the magnetic bubble might only need to be a few hundred meters wide. 

Image of a typical solar flare from the sun (Credit: NASA)

November 9, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Voyage Into Space

I stumbled upon this news item in Phil Plait’s blog, and it is extremely cool. The European Southern Observatory, or ESO, just released the deepest ultraviolet image of the Universe yet. It was taken by the Very Large Telescope (yes, that is it’s name, and it’s really a set of four telescopes working together, namely the Antu telescope, the Kueyen telescope, the Melipal telescope, and the Yepun telescope), and contains more than 27 million pixels.


This is a compressed version of the image, so for full resolution go here. When I first saw this picture i thought all the bright dots were stars, but no, they are in fact galaxies. Some of them are as far as 10 billion light years away, which means they are really, really young. I recommend you take a look at Phil Plait’s post about this picture. Being an astronomer he knows what he’s talking about, something I really don’t most of the time.

November 8, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Chandra X and the Crab Nebula

In 1999 NASA launched the Chandra X-Ray Observatory, which is part of NASA’s Great Observatories together with HubbleSpitzer, and Compton. Chandra X recently took a beautiful picture of the Crab Nebula

According to NASA, this is the first picture clearly showing the faint boundary of the nebula‘s X-ray emitting pulsar wind nebula. The white dot in the center is the neutron star (or pulsar) powering the nebula. Pulsars are essentially highly magnetized neutron stars that emit concentrated beams of electromagnetic radiation, which can only be observed when directed directly at earth. A pulsar will thus appear to pulsate (hence the name) when observed, and the regularity of this pulsing effect has been shown to be extremely precise, even to the level of an atomic clock. Anyhow, the rapid rotation of the pulsar in question combined with the intense electromagnetic field generated creates jets of matter and antimatter shooting out from the poles of the pulsar, and a strong wind flowing out in the equatorial direction. The inner ring surrounding the pulsar is possibly a shock wave serving as a boundary between the nebula and the matter/antimatter jets, and electrons and positrons flow outward from it, producing an extended X-ray glow. The shape of the nebula is related to the strong magnetic field, and the dark spots on the right and left is thought to be the result of a toroidal (doughnut) shaped magnetic field from a progenitor star.

November 7, 2008 Posted by | Astronomy | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment