Nasa picks up emmy

Nasa TV has picked up an emmy for the Nasa 360 show – a half hour show that explores Nasa’s effect on everyday life. More details here.

Planetary pool

Anyone remember that episode of Dangermouse when a snooker cue shaped space ship threatened the Earth? No? Ok, well moving on.

The orbits of planets within the solar system are subject to change over time. The planets are pushed outward as the Sun loses mass and they are hit by the solar wind. Interactions with the gravity of other planets can also have an effect. Scientists Jacques Laskar and Mickael Gastineau of the Paris Observatory ran 2,501 scenarios of the evolution of the orbits of our solar system. In 25 cases, Mercury’s orbit was elongated by various interactions.

If this should happen, Mercury could end up colliding with Venus or burning in the Sun, in which case the matter is over and done with. However, concentrating on an elongated Mercury, it was seen that over about 3.3 billion years it was possible that Jupiter would tug Mercury out of its orbit, which in turn would affect Mars, which could then destabilise Venus and Earth.

The researchers modelled various scenarios of Mars being destabilised in this way. They found 200 scenarios of planetary collisions, including 48 involving the Earth and 5 in which Mars would be ejected from the solar system.

The real importance is not, however, any worry that the Spirit and Opportunity missions may be dramatically ended, but in the use of the calculations themselves, the most accurate equations used so far to test the stability of the solar system. These ones also include relativistic effects often left out due to their complexity.

Can Nasa go it alone anymore?

Not too long ago, I mentioned that Nasa were turning to funding private sector space missions to help create a source from which to buy tickets to space rather than continue with all the expensive research and development itself. Now it seems the agency plans to unite with ESA, the European Space Agency, to launch missions to Mars. Critics inside and out of Nasa complain that the competitive edge may be lost in a more consensual era of space flight and there are worries that in a world where Nasa outsources all it does, what will be left to keep the agency going?

Planets forming around twin stars

It has been seen as quite a controversial idea for some time – can planets form around double or triple star systems? Lots of stars are binary pairs and it is sometimes feared that the gravitational interaction between two stars and forming planets would either cast them out or drag them in.

Now observations made with the Smithsonian’s Submillimeter Array (SMA) by Joel Kastner of the Rochester (NY) Institute of Technology and colleagues of V4046 Sagittarii – a pair of solar mass stars separated by five solar radii – may have seen stable planet formation in action.

The 12 million year old system first started giving its secrets last year when the presence of molecules around the stars suggested something was afoot. However, images taken by the SMA radio telescope have confirmed what the astronomers hoped for – the binary system has a disc of planet forming material around it. The disc extends from a distance equivalent to the orbit of Neptune to ten times that distance.

As well as being the first disc confirmed around twin suns, the disc is four times the age it was believed gas giant planet formation would take. Additionally, at 240 light years away, which is half the distance of previous planet forming discs, this system is well placed for future observations of a possible newly forming solar system.

Kaguya hits the spot

The Kaguya Lunar probe of the Japanese space agency JAXA has impacted on the Moon. The probe has spent its operational life taking images of the Lunar surface in high definition. Once the main mission was completed, Kaguya moved to a lower orbit for an extended mission from February 1st, which included some extra high definition pictures. As the extended mission came to an end the decision was taken to crash the probe in a controlled descent rather than leave it to orbit the Moon at a decaying altitude and crash down later of its own accord.

The crash happened just on the dark side of the terminator at 19:25 BST. The ejecta plume was picked up by the Anglo-Australian telescope.

Credit: ESA AAT

Pictures of Orion

…the crew module of the Constellation program that is, not the constellation in the sky (yet).

There are a few Orion mock-ups being created for water-testing, abort system testing and an interior mock-up for astronaut training. A few pics of these can be seen here.

Win a Moon rock

To celebrate the upcoming fortieth anniversary of the Apollo 11 Lunar landing, New Scientist offers a little chunk of the Moon to call your own (a 1.4 gram fragment of a lunar sourced meteor to be precise). All they ask in return is the best answer (in 75 characters or less) to the question What should Armstrong have said when he first laid a foot on the Moon? Send your answers in via the comments section of this webpage.

Pulsars demure on their age

via Astronomy Now.

Like many an aging star of a certain vintage, Pulsars are known to still put on a show, but apparently they have been rather reticent about their ages. Normally, one would get this information through secondary sources – getting the age of the shell of the supernova that set them on the road to becoming neutron stars, or maybe by measuring the age of a companion white dwarf, a sister star who can be dated through seeing by how much she has cooled over the years.

For the more lonesome pulsars, things are a little more difficult. There’s no real corroboration of their age, but astrophysicists Bülent Kiziltan and Stephen Thorsett from the University of California, Santa Cruz believe they have found a way, as these aging stars (whisper it) do tend to get a little slower as they get older. By measuring how much they have slowed from their peak rotation rates an estimate can be got as to how long they have been pulsars.

The pulsars in question are milisecond pulsars – they produce pulses of radiowaves on the order of miliseconds between each pulse. The pulses are the result of the stars spinning and radiation being beamed to Earth like the light of a lighthouse from a magnetic pole. Pulsars are rotating neutron stars, the neutron stars having been formed as the remnant of a stellar core after a moderately sized star has gone supernova (lower mass stars produce white dwarfs, higher mass ones black holes). Most milisecond pulsars are formed by accretion of matter during a period as an X-ray binary. During this time, the gravity of the neutron star tears material off a companion star and it spins round the neutron star in an accretion disc until it falls onto the star’s surface. The angular momentum of the accretion disc is transferred to the neutron star as this happens, spinning them up. However, the time taken for this can only be guessed at and it may be that some pulsars have magnetic fields in such a configuration that accretion is too complicated for them to have formed like this.

It seems some ladies will keep their secrets.

Eccentric stars give clues to halo origin

via Universe Today.

In 2003 a new class of stars was announced – ultracool subdwarfs – so called because they are very cold, very low in elements other than hydrogen and helium and very small, some only just outside the range of brown dwarfs, the stage between star and gas giant planet. Because of their low temperatures and masses, these objects are pretty faint and so hard to detect amidst the brighter members of the stellar population of the galaxy, but several have been found and their orbits calculated. The results have been a bit of a surprise.

If stars are like planets, orbiting the centre of the Milky Way as Earth or Mars orbits the Sun, these cold stars are rather more like comets, with highly eccentric orbits taking them close into the centre and then far out from it again. In addition to this one has taken the appearance of a long period comet, stretching out 200,000 light years from the centre of the galaxy, ten times the distance we are from it and even farther out than some of the Milky Way’s closer neighbours.

2MASS 1227-0447 as the thing is romantically named presently lies in the constellation of Virgo. Adam Burgasser and colleagues of the Massachusetts Institute of Technology studied its motion and calculated its orbital parameters. Its highly eccentric billion year long orbit suggests that it might not be a local boy. The star may well have come in from another galaxy that either interacted with the Milky Way and had some of its matter torn off it as a result, or maybe the galaxy itself has merged with the Milky Way, leaving 2MASS 1227-0447 orphaned and adopted by our galaxy. Alternatively, 2MASS 1227-0447 may well have originated here and survived being torn away during a previous interaction. Either way, as these objects cut a dash through the galactic halo, learning more about them may teach us more about how the galaxy acquired that mysterious shell of Dark Matter.

Psst… look at our new rocket…

Former astronaut Jim Halsell of ATK Launch Systems takes Miles O’Brien on a tour through the various components of the Ares IX as NASA prepares to test fly the new rocket. From the youtube channel of SpaceFlightNow.