Monday, November 25, 2013
What Remained to be Seen: NASA TV coverage less than stellar
Monday: A day of back to back launches
This Monday offers up two broadcasts of space launches for your viewing pleasure. A Soyuz ISS cargo resupply mission (Progress 53-P) launch will occur at about 3:53PM Eastern Standard Time. The launch will be broadcast live on nasa TV and on the Roscosmos video website here. That launch will be followed by a Space-X Falcon 9 (v1.1) launch at about 5PM Eastern Standard Time. It can be seen via the Space-X webcast here. The Falcon mission is Space-x's first geosynchronous orbit mission. In a strange twist, the Soyuz/Progress launch will occur at 53 minutes past midnight local time, while the Falcon will launch at around sunset time in Florida, thus the picture of the rockets at the head of this article have their day/night aspects completely reversed.
I would like to mention that much of the information I have posted here came from Space.com and from the Danspace77 blog. Please check out AstroDan's blog entries at your leisure. Also, the russian space agency, Roscosmos, has their own facebook page (in English) and their own website (in Russian). Their launch videos are all courtesy of this website..
Thursday, November 07, 2013
Reassessment of Air Burst Damage after Chelyabinsk Meteor Indicates Much Higher Risk
A new paper published in the November 6th electronic edition of Nature indicates that we are in greater danger of injury from asteroid "impact" than we have realized. The primary increased risk is due to the understanding that smaller objects can cause far more damage than we realized. The Chelyabinsk Meteor airburst caused an explosion that was equivalent to 500kt of TNT, it was a relatively small sized rock of 20 meters, and the primary explosion occurred about 30 km above the surface of the Earth, but the damage to the city of Chelyabinsk and its surrounds was extensive. Damage occured in an area 90 km to either side of the path of the meteor and more than 1,600 people were injured (mostly from flying glass).
Up until now, scientists at NASA have assumed that a rock less than 30 meters in diameter would harmlessly break up in the atmosphere, and while this may be true, it's now quite clear that an airburst actually can cause a fair amount of damage. There is somewhat of an inverse exponential relationship between the diameter of a space rock and the number of space rocks that fit that diameter in space. Tiny dust grains in space are innumerable, dwarf planets like Ceres are rare, but not as rare as planets. 30m diameter objects are much less prevalent than 20m objects. To make matters worse, it's much harder to find the smaller asteroids before they have a chance to cause us harm. The studies indicate that the increased risk of asteroid damage is now on the order of 10 times worse than expected. While this sounds shocking, please keep in mind that the overall risk of personal asteroid damage was quite small to begin with (almost trivial). Now we know the risk is not so trivial after all.
Links for this story:
Univ of Western Ontario CPSX Chelyabinsk Story
Older Paper on Chelyabinsk Meteor
In case you'd like to read the Nature paper at a cheaper price.
Video illustrating the delay between meteor and shockwave
Compilation of Russian Videos of the Airburst
Wednesday, November 06, 2013
New Study Shows Increased Presence of Goldilocks-Approved Earthlike Planets
A new study presented recently at the Kepler Science Conference contends that 1 out of every 5 sun-like stars in our galaxy are orbitted by an earth-like planet in the Goldilocks zone, an orbital distance from the parent star that allows liquid water to exist and thus is accomodating to life as we know it. The study was written by fourth year Berkeley graduate student, Erik Petigura.
India Launches Their First Mars Mission
On November 5, 2013 at 2:38PM IST (Indian Standard Time) the Indian Space Research Organization (ISRO) successfully launched the first Indian mission to the red planet. The spacecraft, named "Mangalyaan", successfully made it into orbit. From there, the spacecraft will go through a series of burns which will increase the eccentricity of its orbits around Earth until the final burn will send the craft into a hyperbolic trajectory away from Earth and towards Mars. The spacecraft should arrive at Mars on September 24, 2014. The objectives of the mission are fairly straightforward: (1) Provide a technology demonstration that highlights ISRO's ability to send craft to Mars. (2) Explore Martian land features and atmosphere from orbit. You can follow the mission on its web-page here.
Tuesday, November 05, 2013
ATV-4 Spectacular Re-Entry Coverage
This is just a short entry. The ESA's ATV-4 "Einstein" spacecraft re-entered the atmosphere on November 2nd and left behind an amazing series of photographs. Space.com did a good job of showing the pictures that were taken from the ISS as the ATV-4 re-entered, below it. Pictures were also posted by the folks at ESA on their Flickr Account, which is where I acquired the picture at the top of this blog entry. Pretty impressive fireworks!