Universe Today

This has taken awhile to filter into the Western press, but an asteroid exploded over the town of Bone,Indonesia on October 8th at around 11am local time. Initially, locals called the police to report that a plane had crashed, or that an earthquake shook the ground, as reported in the Jakarta Globe. The Jakarta Post quoted Thomas Djamaluddin, head of the Lapan Center for Climate and Atmosphere Science Implementation as saying that the explosion was due to a meteorite or bit of space junk that had entered the Earth's atmosphere. As it turns out after further analysis, the explosion was due to an asteroid about 5-10 meters (15-30 feet) in diameter exploding in the air between 15 and 20 km (nine to 12 miles) above sea level. Nobody was injured as a result of the explosion, but it evidently caused quite a scare with the local population! Read more…

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Earth asteroid tracking is done by several facilities around the world, with several in the United States. Many of the more prominent ones are done as a cooperative effort with NASA, the Air Force, and various universities. The LINEAR and NEAT programs are the main ones that the government helps to sponsor. Both look for new near Earth objects, track their orbits and suggest a Torino impact score based on their studies.

The Earth asteroid tracking system known as LINEAR stands for the Lincoln Near Earth Asteroid Research project. It is based out of MIT's training facility in Socorro, New Mexico. This project is a joint effort with the Air Force. The observations done at LINEAR are done using a one-meter aperture,Ground-based Electro-Optical Deep Space Surveillance(GEODSS) telescope. The system showed early promise. Between March and July 1997, a 1024 x 1024 CCD pixel detector was used in field tests and, while this CCD detector filled only about one fifth of the telescope's field of view, four NEOs were discovered. October, 1997 saw the addition of a large format CCD (1960 x 2560 pixels) that covered the telescope's 2 square degree field of view. The brought about the discovery of 9 new near Earth objects. In 1999 a second 1 m telescope was added. A third, but smaller telescope joined the program in 2002. It is mostly used to track known NEOs.

The NEAT project is another Earth asteroid tracking system. The Near Earth Asteroid Tracking project is a cooperative effort between the Air Force and NASA'a Jet Propulsion Lab. It utilizes a GEODSS telescope located at Haleakala, Maui, Hawaii. The format of the CCD camera is 4096 x 4096 pixels and the field of view is 1.2 x 1.6 degrees. Due to increased need for the telescope by the Air Force, NEAT's operations were transferred to the AMOS telescope which is 1.2m aperture. The switch allowed for more nights of observation and data collection per month. In 2001 a second 1.2 m telescope was added to the system at Palomar in California. A SkyMorph system was invented to compare pre-discovery photos with newly found NEOs to better predict their orbits. These photos are compiled and compared using the Digitized Sky Surveys 1 and 2(DSS and DSS2).

Earth asteroid tracking is done by many different agencies around the world, but the most prominent are the NEAT and LINEAR projects in the United States. There thought to be thousands of NEOs to observe and astronomers have found quite a few of them, but there are still areas of the sky that are not covered. These systems were instrumental in assessing the likelihood that Apophis would hit the Earth in its pass in 2004 and again in 2029 and 2036. Without these systems there would be no warning of an impending asteroid strike.

NASA has published an overview of the NEAT and LINEAR projects on their website. Here on Universe Today we have a couple of good articles on Earth asteroid tracking and the NEAT program.

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