Saturday, 11 August 2012
Astrophysics stuff from the fortnight 30/7 - 12/8/12
'The Milky Way Over Monument Valley'
"You don't have to be at Monument Valley to see the Milky Way arch across the sky like this -- but it helps"
I remember when Thunderf00t visited Monument Valley - it's getting ab it tourist-ridden, by the looks of hid vid, though.
3 big events in space exploration, this year:
- The Curiosity Lander arriving on Mars, on Sunday. Obviously!
- The Opportunity rover's 8th anniversary of scouting Mars
- The 8th anniversary of the MESSENGER spacecraft's launch
The MESSENGER craft has travelled 7.9 billion kilometres, in a mission that has seen it pass over the Sun 15 times, Venus twice, and Mercury, so far, 3 times!
It has now entered orbit around mercury, and earlier this year, lowered down to an 8-hour orbit, enabling us to peer even closer at Mercury's surface. So far, MESSENGER has sent back thousands of pictures of the Sun's closest planet.
MESSENGER main at NASA:
Another mission nearing an anniversary is Voyager - the Voyager 1 and Voyager 2 probes were launched almost 35 years ago, and their teams at NASA are currently awaiting data to confirm that Voyager 1 has escaped the heliosphere (the Sun's magnetic field) into inter-stellar space!
Voyager 2 turns 35 later this month.
'Astronomers crack mystery of the 'monster stars''
In 2010, observations of stars in the region R136 of the LMC (Large Magellanic Cloud) galaxy, led to the identification of four 'monster-sized' stars, which are ~300 times the mass of the Sun.
All previous observations of stars have led to the acceptance of a stellar-formation asymptote - a size limit of 150 stellar masses (150 times the mass of the Sun). So how did these stars get so big?
Well, some serious model-crunching has been done, and it seems that they formed from the merger of two smaller stars, which had previously been in close, binary orbits, around each other.
Maybe due to tugs from other stars, the binary systems fell in, towards each other, and formed the 300-stellar-mass monsters that the ESO's Very Large Telescope saw in 2010.
[images] It looks like the Sun's been vying for attention, with Mars - astronomers have photographed a huge, 800,000 km long filament, on the surface of the sun.
It reminds me a bit of Doctor Who, where there are cracks in walls, which are actually cracks in time itself. I'm scared. Someone hold me :D
[video] Here's something that sounds scary, but (hopefully) isn't... the increase in solar flares, as the Sun approaches solar maximum, which occurs every 11 years.
A recent flare has been named as the culprit for India's power outages, but most stellar radiation is caught and funnelled in towards the poles by the Van Allen Radiation Belt, which is held in place by the the magnetosphere - Earth's magnetic field.
It should be stressed (just in case) that this has nothing to do with the Mayan apocalypse rubbish - these happen all the time, but peak in frequency and strength every 11 years. In fact, this year's peak looks to be a low one.
Also, an 11-year cycle can not account for a 160-year trend in climate. Just saying...
[image] An incredible picture of the Sun's surface, swirling and emitting radiation into Space.