Ewan's Corner

Archive for the ‘out there’ Category

A stunning view from Gough Island (40º20’57.7S 9º52’49.2W – Google Earth or Maps) during the partial solar eclipse this morning, from a live webcam.

We only saw 56% coverage in Durban (65% in Capetown) – thankfully the clouds were patchy so we had plenty of time for some great views.

Today also marked South Africa’s first formal day of the International Year of Astronomy 2009. I doesn’t matter how many eclipses I see, they are still awe-inspiring and somehow mystical events. I’ve seen two full eclipses before (one in Tshipise in Musina and the other from Lusaka, Zambia) and I plan to follow any others I can get to :-)

“Many people have no idea how many satellites orbit around the Earth. Now you can see the real-time positions of over 13,000 satellites updated every 30 seconds with Google Earth. The satellite positions come from a US government-sponsored database which Analytic Graphics, Inc., has interfaced with to make the data visible in 3D. Zoom around in space and pause to see the names of the satellites. Click on the satellite placemark icons to see more information on each one. Here is a YouTube video showing what the satellite visualization looks like. You can view the actual collection with AGI’s KML file in Google Earth. You can also watch it in your browser using the Earth plugin on this page by Google Earth Blog.”

~From the October 2008 issue of “The Sightseer” monthly newsletter for Google Earth.

“This KML network link visualizes all earth orbiting objects tracked by the United States Strategic Command (USSTRATCOM) using the satellite database processed by Analytical Graphics, Inc. using the Dynamic Geometry Library. All satellites are tracked in real-time and updated every 30 seconds.

USSTRATCOM has been tracking space objects since 1957 when the Soviets opened the space age with the launch of Sputnik I. Since then, they have recorded more than 26,000 space objects orbiting Earth. There are currently more than 12,000 man-made orbiting objects, the rest have re-entered Earth’s turbulent atmosphere and disintegrated, or survived re-entry and impacted the Earth. The space objects now orbiting Earth range from satellites weighing several tons to pieces of spent rocket bodies weighing under 10 pounds. About 3,000 space objects are operational satellites, the rest are space debris, retired satellites and rocket bodies left over from launches.

Analytical Graphics, Inc. (AGI) develops commercial off-the-shelf (COTS) analysis software for land, sea, air and space that is relied upon by the national security and space communities. With more than 32,000 worldwide installations, the main applications of AGI technologies focus on battlespace management, geospatial intelligence, space systems and national defense programs. In addition to the STK product suite, AGI produces the desktop software applications Navigation Tool Kit and Orbit Determination Tool Kit; interactive visualization AGI Viewer software; and the embedded technology development tool 4DX. For more information about AGI or its commercially available software technologies, e-mail info@agi.com or explore www.agi.com.”

From the excellent xkcd comic.

NASA’s Phoenix Mars Lander has just over 2 days left before touchdown in the Mars polar region. I’ll be following the touchdown as close to live as I can via NASA TV and the Launch Blog as well as twitter (finally, twitter usage I can relate to :-) and DSTV if a channel follows the landing.

The fun kicks off around 1:45am Monday (argh) South African time (4:46:33 p.m on Sunday – Pacific Daylight Time) when Phoenix enters the Martian atmosphere at over twenty thousand kilometres an hour (5.7 kilometres per second!) and hopefully touches down gently 7 minutes later. See below for links to landing guides and times – which take into account the 15 minutes 20 seconds it currently takes a radio signal from Mars to reach Earth.

The NASA press kit linked below gives the following mission overview:

NASA’s Mars Phoenix Lander mission is flying to a site in the far northern plains of Mars where it will analyze components of the surface, subsurface and atmosphere. It will use a trench-digging arm and a set of analytical tools to study water believed to be frozen into the soil just below the surface. It will check for the presence of organic compounds as part of an evaluation of whether the site has been a favorable environment for microbial life. The mission will place the stationary lander on the ground using descent engines all the way to the surface. The lander will have a prime mission of three months on Mars during late spring to mid-summer at the landing site.

This lander / landing is fascinating for several reasons:

• Of 13 attempts to land on the surface of Mars so far only *5* have succeeded
• Complex landing – no balloons this time, via descent engines all the way to the ground…. 5.7 km/s down to a soft landing in 7 minutes.
• Phoenix has a higher science instrument payload to total launch weight than any previous lander (thanks in part to using descent engines to touchdown safely rather than balloons to cushion the landing)
• Phoenix is an interplanetary laboratory – complete with a multi-talented robotic arm, multiple cameras (and for the first time one includes a motor adjusted focus), gas analyser with 8 tiny ovens, a wet chemical laboratory (which uses water from Earth), two microscopes, and a weather station.

I’ll also be recording the NASA TV coverage (using VLC) and can post that later, copyright permitting.

Links:

• NASA Landing Press Kit (3.2mb PDF, well worth the read!)
• Phoenix landing blog (although twitter may be a more up to date way to follow things)
• Landing events schedule
• 7 minutes of terror video
• space.com’s Phoenix Mars Lander: Step-by-Step Martian Landing Guide

Asteroid Apophis, a 350 metre wide chunk of rock due to make a worryingly close Earth flyby in April 2036, has been in the media for several years now – and I suppose a successful Apophis-based hoax was just a matter of time.

In a story straight out of Hollywood combining apocalyptic predictions, asteroid collisions with Earth, a cute kid showing up NASA scientists and dodgy science comes a successful hoax – Nico Marquardt, a 13-year-old from Germany, reportedly corrected the estimated chance of Apophis impacting Earth in 2036 down from a worrying 1 in 45000 to a downright scary 1 in 450 (i.e. 100 times more likely) based on the chance of Apophis hitting a geosynchronous satellite during its next Earth flyby on April 13, 2029.

Nico exists, but the story isn’t entirely true – see the NASA press release – and the chance remains 1 in 45000.
AFP (Agence France-Presse) started the global story rolling (although they weren’t the source – that honour apparently goes to Bild.de) and then it spread worldwide without anyone bothering to check the facts – today it made South African papers. Great journalism – not.
Links:

• Wikipedia Apophis topic
• Dedicated NASA Apophis site
• Slashdot coverage