Reanimated Residue: Science & Space

Our Orbital Space Junkyard

Sat, 07 Oct 2006 15:08:36 GMT

Orbital debris, more commonly known as ‘space junk’, is an unavoidable byproduct of human space exploration. Not only do we rubbish our Earthly environment with all sorts of crap, but since the dawn of orbital spaceflight in the 1950’s, humans have been littering the skies above as well.

On September 14th this year, astronauts of the space shuttle Atlantis, contributed a few bolts to Earth’s orbit while completing installation of new solar arrays for the International Space Station. These days NASA tries to tether everything used during a spacewalk – but accidents do happen. NASA and the US Air force track all space faring garbage larger than 10 centimetres and the addition of these few tidbits in September brought the count to 9,925.

Orbital debris consists of a wide menagerie of hazardous items, detrimental to astronauts, spacecraft, and expensive satellite equipment. Newer spacecraft, such as the International Space Station, are reinforced against orbital debris hazards but there are still many more at risk.

1996 is recorded as the first confirmed occurrence of a collision between cataloged space junk and Cerise – a French military reconnaissance satellite. The impact tore away some 4.2 metres of gravity gradient stabilisation boom from the craft. It is interesting to note that there are lawyers who track orbital debris – yes, there are expensive legal responsibilities resulting from your space junk damaging someone else’s satellite.

There are believed to be over 100,000 manmade objects zipping around the Earth at a speed of around 28,000 km/h, and the smaller items can be just as troublesome as larger ones – they’re just harder to track. Where NASA can warn astronauts and shuttle pilots to move out of the way of an impact with some of the larger pieces, it is almost impossible to avoid collisions with smaller debris. Fragments such as paint flakes can dent a craft or scratch the shuttle windshield, while clouds of smaller particles which can cause sandblasting.

Dumping waste from the space shuttle has urine, toothpaste, and shaving cream floating in the skies above us. After an Indonesian satellite was struck with urine and fecal matter, NASA decided that discarding human waste in space is probably not the greatest idea. Other hazards include trash thrown from the Russian space station Mir, rubble from explosions, spent booster rockets from launches since 1958, equipment discarded while repairing the Hubble Telescope, and some 2000 satellites no longer in use.

Not all space junk stays in orbit, with some returning to Earth or burning up on re-entry. To date, Lottie Williams is the only person to have been hit by space waste – a six inch metal shard from the fuel tank of a Delta II rocket from a 1996 US Air Force satellite launch. Hit in the shoulder while walking through an Oklahoma park on January 22^nd 1997, she was very lucky not to have been injured.

A $2700 spatula lost by spacewalker Piers Sellers in July this year was nicknamed “Spatsat” and is expected to return to Earth in a fireball some time this month. A stray spatula in space is a curious, but there have been all manner of unusual bits and pieces soaring about in the heavens above.

Ed White lost a glove on the first American spacewalk in 1965, cosmonaut Michael Collins misplaced his camera near the Gemini 10 spacecraft in 1966, while other astronauts are missing a toothbrush and a ham sandwich. In early February 2006 the crew of the International Space Station stuffed an old Russian spacesuit with clothes, attached a radio transmitter, and deliberately pushed it out into space. Known as Suitsat-1, the radio signal weakened unexpectedly after orbiting the Earth twice, and finally burned up in the atmosphere on September 2^nd.

Pluto Demoted - And Then There Were Eight

Fri, 25 Aug 2006 02:42:37 GMT

In an historic vote, the International Astronomical Union has finally agreed upon the definition of a “Planet”.

The International Astronomical Union (IAU), the internationally recognized organisation for naming and defining all things celestial, has closed their triennial General Assembly conference in Prague by deciding that there are only eight planets currently present in our solar system. Pluto has been demoted to “dwarf planet” status – albeit a new family of objects within its own right. The eight planets are (in order from the sun): Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The first “dwarf planets” to make the grade, consist of Ceres, Pluto, and 2003 UB313 (commonly referred to as “Xena”), with more to be added in the near future. The concluding vote took place on Thursday, August 24th, 2006.

It’s not all bad news for Pluto though, as it becomes the prototype for a yet-to-be named new class of objects that exist in the trans-Neptunian region. The IAU intends to set up a dedicated process for naming these bodies in the near future, which typically consists of large bodies within the Kuiper-belt region. Having visited all eight planets in the solar system, NASA's "New Horizons" spacecraft is currently enroute to Pluto and is expected to reach the dwarf planet in July of 2015. In June of 2007, NASA plans to launch off on the "Dawn" mission to fellow dwarf planet, Ceres. Though the chance to send your name to Pluto has passed, the opportunity is now available to be part of the Dawn mission by doing the same.

The passed IAU resolution reads:

RESOLUTION 5A

The IAU therefore resolves that "planets" and other bodies in our Solar System be defined into three distinct categories in the following way:

(1) A "planet"1 is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2 , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects3 except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".

1The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
2An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
3These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

RESOLUTION 6A
The IAU further resolves:

Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.1

The decision is exciting news for astronomers but it was not an easy task for the IAU to reach an agreement on the final definition. The furor began when it was found that Kuiper-belt object UB313, discovered in 2003 by astronomers Mike Brown (Caltech), Chad Trujillo (Gemini Observatory), and David Rabinowitz (Yale University), was slightly larger than Pluto, at approximately 2400km in diameter. This new discovery required a new planet (or several) be added to the list of “Planets” or a demotion of Pluto from the rank. Many were not happy with this idea, submitting a plethora of reasons, including historical relevance, astrological usage, text-book changes, and the confusion of children learning about our solar system. Then came about the problem of deciding what defining features actually made a planet a planet, without allowing other celestial objects to fall easily into this category either. A number of proposals were submitted and debated, settling on the final definition with more than 2500 astronomers voting on the resolution.

BOINC - Berkeley Open Infrastructure for Network Computing

Tue, 01 Aug 2006 12:12:01 GMT

BOINC is an open-source software platform for distributed computing which uses volunteer computer resources around the world for computationally-intensive tasks in scientific research. It was originally developed for the SETI@home project and is now used by many different grid computing network projects. The BOINC Manager allows participants to connect easily with several independent projects and decide how their computer resources are divided between each. When a project is offline or has no available work-units, BOINC distributes participant computer resources among other chosen projects.

Learn more about Distributed Computing
Learn more about BOINC
Download BOINC

My deviantART community of Scifi-Fans has a team at the SETI@home, Einstein@home, LHC@home, and QMC@home projects. Once you have an account at any of these projects, please feel welcome to join our team and have your credits counted toward our community total. You must join each team seperately and you can only be a member of one team for each project - we would love it if you could join the 'Scifi Fanatics' team when you participate in any, or all, of these projects.

Click on the logos below to join the Scifi Fanatics team
at your chosen projects

Earth’s Close Encounter with Large Asteroid on July 3rd 2006

Sun, 02 Jul 2006 16:02:19 GMT

Astronomers anticipate the approach of a prominent sized asteroid as it passes Earth just beyond the orbit of the moon.

Discovered by Lincoln Laboratory Near Earth Asteroid Research (LINEAR) on December 10th 2004, Asteroid 2004 XP14, is due to come uncomfortably close to Earth during the early hours of Monday July 3rd 2006.

The LINEAR project, funded by the United States Air Force and NASA, uses technology that was developed to monitor satellites orbiting the Earth, in an attempt to locate and record potential cosmic threats to our planet. To date, the LINEAR project has confirmed 1622 Near Earth Objects (NEOs), which also includes comets with a close approach orbit to the Earth. The greatest current potential impact risk, at an estimated diameter of 300 metres, is asteroid 99942 Apophis (2004 MN4) when it approaches Earth in April 2036. The probability of 99942 Apophis impacting the Earth is 0.0026% or 1 in 38,000.

Believed to be 600 metres or more in diameter, Asteroid 2004 XP14 was originally thought to be an impact threat, but further studies of its orbit later revealed the big rock is not an immediate danger to the Earth. Classed as a PHA (Potentially Hazardous Asteroid), 2004 XP14 is one of 796 within this classification, which is defined as an asteroid with a Minimum Orbit Intersection Distance (MOID) with the Earth of 0.05 AU or less, and an absolute magnitude of 22.0 or brighter.

The asteroid will pass just beyond the orbit of the moon at 1.1 LD (lunar distance from Earth) and is expected to reach an absolute magnitude of 12, so amateur and professional astronomers will be readying their telescopes in order to catch a glimpse of the fly-by. It will be traveling at a relative velocity of 17.41 kilometres per second.

At a distance of 1.7 LD, the most recent close approach by an NEO was only a few days ago on June 28th 2006, by 2006 MB14, but at an estimated diameter of 24-53 metres, it was a mere pebble compared to 2004 XP14. NEOs at such distances are somewhat rare. The next known asteroid expected to pass at a comparable distance of 1.4 LD, is 2005 YU55 in November of 2011; and then another, 1999 AN10, in August of 2027 at a distance of 1.0 LD. NASA reports that asteroid 1999 AN10 is at least 1 kilometre in diameter, and with the projected distance of this asteroid relative to the moon, we can certainly anticipate apocalyptic stories to accompany its approach.

Nix and Hydra: Naming Two Moons of Pluto

Sat, 24 Jun 2006 18:02:09 GMT

The official astronomical names of two newly discovered moons of Pluto have been revealed.

Photographed in May 2005 by NASA’s Hubble Space Telescope, and discovered by research teams in support of the New Horizons mission, the two moons found orbiting Pluto have been officially named Nix and Hydra by the International Astronomical Union (IAU). They join Pluto’s partner Charon, its largest and closest satellite, which was discovered in 1978.

Nix and Hydra orbit the small planet at about two to three times the distance of Charon, and are approximately 5000 times fainter than Pluto itself.

In accordance with traditional naming guidelines for celestial bodies, both moons were named after characters from stories of ancient mythology. The inner moon, Nix, was named after the Egyptian goddess of darkness and night, and in Greek Mythology is also the mother of Charon. Hydra, a serpent with nine heads, guarded Pluto’s realm in stories from ancient Greek mythology.

The names of the satellites, beginning with N and H, are also intended as an accolade to the New Horizons mission which left Earth on January 19 2006, bound for Pluto, the Kuiper Belt, and beyond. Traveling at 26.67 km/sec, the New Horizons spacecraft is currently 2.1 AU from Earth and 29.29 AU from Pluto. It is expected to reach the distant planet in July 2015, and carries a compact disc containing over 435,000 names of people who signed up to send their names to Pluto.

Lastly, astronomers from around the world eagerly await the IAU verdict on Pluto’s status as a “planet”. The decision will also determine the status of several “Trans Neptunian Objects”, including 2003 UB313 (commonly called Xena), and is expected in late August this year.

Deeply Impacted

Mon, 04 Jul 2005 10:57:00 GMT

At 3.52pm July 4th (Australian Eastern Stanadard Time) NASA successfully smashed their "Impactor" probe into Comet 9P/Tempel 1. Streamed live on NASA TV, the resulting impact was larger than most anticipated. The probe was released from the "Flyby" spacecraft into the path of the comet 24 hours prior to impact and proceeded to undertake a series of targeting maneuvers. The "Deep Impact" mission is the first of it's kind, and is expected to help scientists ascertain the interior material composition of a typical comet, amoungst other objectives, which include answering some basic questions which relate to the formation of the solar system.

Image Courtesy of NASA TV

Deep Impact Imminent

Fri, 10 Jun 2005 08:33:55 GMT

NASA announced on June 9th 2005 that it's mission to collide a 1 metre wide, 372 kilogram impact probe - deployed by the "Deep Impact" spacecraft - into the nucleus of Comet 9P/Tempel 1, is expected to occur at 5.52am +/- 3mins GMT on July 4th 2005 (10.52pm PST on July 3rd). Two or three days prior to impact they will know the exact time of impact within 30 secs.

Unfortunately, the strike will occur at approximately 3.52pm for Australian (Brisbane) observers, but was timed to allow for full coverage by NASA's Deep Space Network complexes in both Australia and California, and for observations by the Hubble Telescope during a 10-15 minute window before it moves behind the Earth on it's 90 minute orbit. Several other ground-based observatories will be monitoring the event, including Keck1 and Keck2 - the two largest telescopes in the world, which are located atop Hawaii's Mauna Kea.  Following dispatch of the probe, the "Deep Impact" spacecraft will maneuver to a safe distance and become a fly-by observer in the sky, along with numerous other "space-based" devices, including the Chandra X-Ray Observatory and the European Space Agency's "Rosetta" spacecraft.

The probe will be literally "run over" by the comet at a velocity of 10.3 kilometres per second, with the release of kinetic energy carving a crater approximately 2 to 14 stories deep, and ranging from the size of a large house up to a football stadium in diameter.  Occuring when the comet is nearing it's perihelion (closest point to the sun in it's orbit), the collision will decrease the comet's perihelion distance by 10 metres, slow it's velocity by 0.0001 millimetres p/sec, and reduce orbital period by far less than 1 second - "the astronomical equivalent of a mosquito running into a 767 airliner." Comparing this to when Comet 9P/Tempel 1 passes Jupiter in 2024, where perihelion distance will alter by 34 million kilometres, the orbital changes to perihelion distance caused by "Deep Impact" will be negligible.

This information possibly came about as a result of concerns that the mission could cause the Near Earth Object to change course, inducing a potential threat to our planet in the future. Another, was the curious report of Russian astrologist, Marina Bai, filing a lawsuit against NASA and asking for 8.7 billion rubles (US$311 million) in compensation for moral damages. She claimed the mission, which is operating under the 1967 United Nations treaty on "Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies" (also known as the "Outer Space Treaty") and has a Category 2 status under NASA's Planetary Protection policy, interfered with the natural life and balance of the Universe. The Russian high court ruled on May 6th 2005 that NASA's US embassy office in Moscow fell under it's jurisdiction and Ms Bai could sue the space agency. Russian scientists backed the case, claiming the project was an act of "vandalism that cannot be justified."

The "Deep Impact" spacecraft was successfully launched on January 12th 2005 from Cape Canaveral Airforce Station in Florida. The comet will be 133.6 million kilometres from Earth when the impact occurs. The "Deep Impact" craft will have travelled a total distance of 431 million kilometres when it reaches the target. The aim of the mission is to study the interior material composition of a typical comet, amoungst other objectives, which include answering some basic questions which relate to the formation of the solar system. The nucleus of Comet 9P/Tempel 1 is an irregular elongated shape, estimated to be 14 x 4.6 x 4.6 kilometres, about half the size of Manhatten Island NY. It is traveling through space at approximately 29.9 kilometres p/second. At this speed it would take 6.5 minutes to travel from east to west across North America.

Amateur observation of the comet from Earth requires large binoculars or a small telescope, and will be best from June 24th 2005.  It brightens as it continues it's approach towards the Sun and will appear in the constellation of Virgo in the evening sky. The impact itself could make the comet 15 to 40 times brighter than normal (which is about magnitude 9.5) - possibly making it viewable by the unaided human eye at magnitude 6 (larger numbers connote dimmer objects). The impactor probe is carrying a mini-compact disc containing the names of more than half a million space-enthusiasts from around the world, collected by the "Send Your Name to a Comet" internet campaign. The mini-CD and impactor will be totally obliterated on collision with Comet 9P/Tempel 1 on July 4th - America's Independence Day.

For more information visit NASA's Jet Propulsion Laboratory "Deep Impact" website, and the NASA "Deep Impact" site.