Sonntag, 2. Januar 2011

Successful hunt for asteroids in the classroom

For the past few months, the Pan-STARRS 1 telescope, designed to become the world’s most powerful asteroid hunter, teamed up with school children from the USA and Germany to discover and study asteroids – clumps of rock, between a few and a few hundred kilometers in size, that cruise through our Solar System. At the close of the campaign, which was coordinated by the International Astronomical Search Collaboration, the students can look back on exciting eight weeks of asteroid search, which included the confirmation of four “Near-Earth Objects” (asteroids passing relatively close to Earth) and the discovery of what could turn out to be more than 170 previously undiscovered asteroids.
As the 1.8 meter (60 inch) Pan-STARRS 1 telescope (PS1), one of the most powerful current survey telescopes, scans the night sky, its 1400 Megapixel digital camera takes more than 500 exposures per night. Between October 25 and December 21, 2010, some of this data found its way into classrooms in the USA and in Germany, where high-school students have used it to track known asteroids, and also to discover candidate objects that could be previously unknown asteroids. When Hawaiian skies were overcast, schools also received data taken with a telescope operated by the Astronomical Research Institute (ARI) in Westfield, Illinois.

Over the Internet, the participating schools received series of astronomical images. Each series included images of one specific region of the sky, taken an hour apart. During this hour, the image of a main belt asteroid would have moved noticeably (in the images in question: about 100 pixels) relative to the distant background stars. The students examined the images for exactly this kind of position change, carefully sorting image artifacts from moving celestial objects, and reported back to the International Astronomical Search Collaboration, whose volunteers then checked the results and arranged for follow-up observations.

Some of the most interesting student observations during the project concerned “Near-Earth Objects” (NEO), asteroids or similar objects whose orbits bring them into the inner Solar System. Some NEOs might turn out to be potential “killer asteroids” that are bound to collide with our home planet; finding these is one main goal of the PS1 telescope. In order to keep track of NEOs, at least two separate observations at different times are required. Katharina Stöckler (age 17), an 11th grade student at Gymnasium Neckargemünd near Heidelberg, explains: “We obtained a ‘NEO confirmation’ for the asteroid 2010 UR7 – the second observation ever made of that object, which confirmed the asteroid’s existence and gave crucial information about its orbit.” Three additional such “NEO confirmations” were made during the project; in addition, 64 of the students' observations amounted to the third or fourth time a specific NEO had been observed. All these observations provide important additional data to scientists studying the motion of NEOs.

In the course of the project, the students also observed 151 candidate objects in the Pan-STARRS data (plus an additional 20 candidates in the ARI/Westfield telescope data) that could be newly discovered main belt asteroids, which orbit the Sun between the orbits of Mars and Jupiter. In one case, students from Benedikt Stattler Gymnasium, a high-school in Bavaria, Germany, discovered 7 such candidate objects in a single night! Before the students' finds are confirmed as discoveries, however, and assigned provisional designation numbers, they will need to be observed again – for a number of the candidates, this is going to prove impossible; on the other hand, some are likely to turn out to have been previously known, after all. Once a newly found object has been observed over at least a whole orbit (which typically lasts 3 to 6 years), it is assigned a definite numerical identifier, and can also be given a proper name.

via Informationsdienst Wissenschaft
Kommentar veröffentlichen
Research Blogging Awards 2010 Winner!
Creative Commons License
Amphibol Weblog von Gunnar Ries steht unter einer Creative Commons Namensnennung-Keine kommerzielle Nutzung-Weitergabe unter gleichen Bedingungen 3.0 Unported Lizenz.