A light torch on the dark matter

The "dark matter" refers to this mysterious hidden mass that rules the Universe's gravity, and this term is a general name to store our ignorance on the subject, much like "terra incognita" was on the early maps.

Anyway, by combining numerical models and radio observations of some galaxies in the Hydra constellations, a friendly team of scientists managed to clear two tasks that would make me feel a hero if I was one of them.

First, they pointed out exactly where the dark matter should be (in red in the picture), so that it becomes suddenly brighter than expected.

Then they might have a serious idea about its composition : molecular hydrogen !

The "hidden" behavior of the dark matter was generally assumed to be due to its exotic composition : nice particles such as neutralinos, axions, or unknown "stuff".

Well in the studied galaxies, assuming that dark matter would be of this type would go against our best modern models about galaxy formation. these models tell that the dark matter should remain in the spherical halos that surround galaxies. But the numerical computations performed on the tide dwarves (forget about your Tolkien dreams, these are galaxies born because of giant intergalactic collisions - a bit freakier than the Moria), show that these galaxies simply stole matter from the discs of their mother-galaxy at their birth. The dark matter in those is obvious : their mass is 3 times what it should be, and it is also obviously not coming from the halos.

As a very cold molecular gas, hydrogen seems to be the number one suspect hiding behind the dark people...

credits : Ciel et Espace, CEA/CNRS,

NASA

slingshot mail delivery

Since SpaceDHL and starUPS didn't start to compete on the intergalactic fast shipping market, some students thought of a method to deliver a parcel to Earth using just gravity.
At an altitude of about 300 km, a half a millimeter thick, 30 km long tether will be released from the Russian research capsule Foton M3. From the tether will be attached the result of YES2 project, the "parcel", Fotino. Due to the gravity, the parcel will start swinging up and down. The parcel will be released and placed on a path towards Earth.

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picture credits: ESA

biggest boom

The brightest and most energetic stellar explosion was recorded by Chandra X-Ray Telescope and ground based space telescopes.

"The top panel of this graphic is an artist's illustration that shows what SN 2006gy may have looked like if viewed at a close distance. The fireworks-like material in white shows the explosion of an extremely massive star. This debris is pushing back two lobes of cool, red gas that were expelled in a large eruption from the star before it exploded. The green, blue and yellow regions in these lobes shows where gas is being heated in a shock front as the explosion material crashes into it and pushes it backwards. Most of the optical light generated by the supernova is thought to come from debris that has been heated by radioactivity, but some likely comes from the shocked gas."(http://chandra.harvard.edu)

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Image credit: Illustration: NASA/CXC/M.Weiss; X-ray: NASA/CXC/UC Berkeley/N.Smith et al.; IR: Lick/UC Berkeley/J.Bloom & C.Hansen

black hole eclipse

A black hole is not the first thing to come in one's mind in the list of eclipsable things. Nonetheless, Chandra X-Ray Telescope recorded such an "serendipitous" event. X-Ray photons released from the superheated material disk around the supermassive black hole were blocked by a passing dense cloud of gas. This allowed astronomers to measure the size of the material disk.

The X-Ray insert in the picture contains the Chandra image with the black hole appearing as a bright spot in the center, while the optical image was captured by the European Space Observatory Very Large Telescope.

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Image credit: X-ray: NASA/CXC/CfA/INAF/Risaliti Optical: ESO/VLT

training New Horizons

New Horizons is a NASA spacecraft launched in 2006. It's main mission is to visit Pluto and it's moon Charon and to reach the Kuiper Belt.
On February 28'th, New Horizons came to within 2.3 million kilometers from Jupiter, using the planet's gravity to trim 3 years from it's journey to Pluto. During it's approach to the Jupiter system, New Horizons stored more than 30Gb of pictures and information collected from Jupiter and it's moons. This proved to be a good occasion to test all instruments aboard New Horizons.

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photo: NASA, New Horizons Spacecraft, Jupiter's moon, Io, with a volcanic plume

rocket science games

Both NASA and ESA let you play a little with assembling their main launchers.

You can assemble Ariane 5 on ESA's webpage.

On NASA's webpage you can assemble one of the Delta, Atlas or Pegasus launchers.

milibots - nanonauts

A new breed of astronauts is born in Glasgow's laboratories. Taking advantage of miniaturization, the engineers there are cooking up robots not bigger than 1 mm. Despite their size, they can communicate, work in formation and take scientific measurements.
The most impressive part though, is their way of moving. They use small voltages to deform a polymer which is attached to the main chip. This allows them to change shape and increase or decrease the drag coefficient. Thus, they can use wind for moving towards a target. Actually they hop towards the target, taking advantage even of the swirling winds.
The nanonauts can be used to explore planets like Mars and Venus, but their size is limited by the density of the planet's atmosphere.

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