Friday, December 14, 2012
Friday, December 7, 2012
The Near Earth Asteroid 4179 Toutatis will make a close approach to the Earth on Dec 12, 2012 at 6:40 am (UT) according to an ephemeris generated by JPL's HORIZONS website. A summary of the data in the ephemeris is given in the following table.
I loaded the orbital elements for Sep. 30, 2012 into Distant Suns and got the position indicated by the small white + for the time of close approach. The red marker shows the HORIZONS coordinates from the table above. The orbit may have been perturbed by the asteroid's proximity to the Earth. The perihelion longitude is ϖ=Ω+ω where Ω is the angle of the Ascending Node or the angular distance along the equator from the Vernal Equinox to the point where the orbit crosses the equator and ω is the argument of perihelion which is the angle from the equitorial plane to the asteroid's perihelion in the plane of its orbit. The asteroid's path is roughly parallel to the Ecliptic (the diagonal line through Pisces) but shows maximum deviation from it at the time of close approach. The apparent magnitude at close approach is given as 10.86 which means that one will need a telescope to see it.
Thursday, December 6, 2012
James Cameron spoke at AGU 2012 about his dives in the Deepsea Challenger in which he made a descent to a depth of nearly 36,000 ft. The videos shown in the talk were copyrighted and so part of the presentation was blocked. Here are some links to help fill in the gaps: steel sphere syntactic foam pelagic sea cucumber (holothurian)
The AGU 2012 Frontiers of Geophysics Lecture by Sir Robert Watson focused on gobal warming. He said that we will probably not make the 2°C goal for global warming but that a 5°C world would be more likely. Other conclusions were that reducing green house gases was a management issue. The world price for rice in a warmer world would increase due to reduced productivity and greater demand. We would have to depend more on renewable energy but that would not be enough and so we might have to rely more on nuclear energy but the damage to the Japanese reactor as a result of the tsunami would hinder progress in that direction. The current growth in CO2 emissions is primarily due to China's contribution while emissions in the US and Europe have been relatively constant but he also noted that the US has the highest contribution per person.
Wednesday, December 5, 2012
NASA is proposing a new rover similar to Curiosity to be sent to Mars in 2020. Plans include a camera with a telescopic lens [which might be used to do a little astronomy]. NASA administrator John Grunsfeld talked the new multi-year Mars program about the future of Mars exploration at yesterday's AGU 2012 conference.
Monday, December 3, 2012
Today's MSL Press Conference was held at a new venue, the AGU 2012 Fall Conference in San Francisco. It was a recap of Curiosity's progress on Mars to date and revealed a little more about recent SAM, Sample Analysis at Mars, results. Curiosity will stay in the Glenelg area for about another month and then she will start heading towards Mt Sharp and get started on the main science mission. One task remaining in her engineering checkout is the drill test which will be done a new location, Yellow Knife Bay. The major SAM result is the high ratio of deuterium to hydrogen, D/H, found in the evolved gases from the fifth Rocknest scoop and some simple chlorinated methane molecules. A high D/H ratio can be attributed to a loss of hydrogen in the Martian atmosphere over time either into space or through some surface process. The main gases detected by the SAM instrument are H20, CO2, O2 and SO2.
Supplemental (Dec 5): related press release with the AGU 2012 MSL press conference images.