AfterTek

Following intense research, scientists have revealed some surprising facts about the origins and the formation of our solar system. A team of chemists and physicists studied the particles gathered by the Stardust spacecraft, which was launched in 1999. Stardust’s primary purpose was to investigate the makeup of the comet Wild 2 and its coma. It was launched on February 7, 1999 by NASA, traveled nearly 3 billion miles, and returned to Earth on January 15, 2006 to release a sample material capsule. It is the first sample return mission to collect cosmic dust and return the sample to Earth.

Stardust flew by the comet Wild 2 on January 2, 2004. During the flyby it collected dust samples from the comet’s coma and took detailed pictures of its icy nucleus. Additionally, the spacecraft accomplished several other goals. It passed within 3300 km of the asteroid 5535 Annefrank on November 2, 2002 and took several photographs.

The aerogel collector also acquired interstellar dust. In March-May 2000 and July-December 2002, the spacecraft angled itself into a dust stream believed to originate outside the solar system. The reverse side of the aerogel collector then caught a sample of such particles.

As mentioned before, comet and interstellar particles were collected in ultra low density aerogel. More than 1,000 square centimeters of collection area were provided for each type of particle, (cometary and interstellar). To analyze the aerogel for interstellar dust, about one million photographs were taken since January 2006, each one of a very small section of the gel. These photos were then processed by about 50 labs scattered around the globe.

Reporting their findings on Thursday, the international team of scientists who examined the cosmic particles retrieved by NASA’s spacecraft from comet Wild 2 (pronounced “vilt”) found the comet, as expected, contained material from outside the solar system. Using spectroscopy technology which does not damage the mineral content of the particles, the team found that the comet dust is made up of many different mineral compositions rather than a single dominant one.

This implies that the dust was formed in many different environments before coming together to make the comet, indicating a great deal of mixing in the early Solar System prior to the formation of planets.

Moreover, the scientists are reporting that elements that were usually found near the sun billion years ago were somehow propelled to the margins of our young solar system. “It was extremely exciting,” said University of Washington astronomer Donald Brownlee, who led the research published in the journal Science. “We expected the comet to be largely made out of interstellar grains, materials that formed before the solar system formed and were never really affected much by the solar system,” Brownlee said in a telephone interview.

“Comet dust seems to be a real zoo of things; we see all kinds of particles that are clearly formed at different places, possibly at different times and certainly under different conditions,” said Scott Sandford, lead author of the ‘organics’ paper and a scientist from NASA Ames Research Center in California’s Silicon Valley. His paper also revealed that scientists found a new class of organics in the comet dust.

“We weren’t expecting to find such widely-spread material in the sample of dust we were given to examine. The composition of minerals is all over the place, which tells us that the components that built this comet weren’t formed in one place at one time by one event. It seems that the Solar System was born in much more turbulent conditions than we previously thought.”

Phil Bland of Imperial College London, another scientist involved in the research, said the solar system apparently formed in much more turbulent conditions than previously believed. Apparently, as our solar system formed at the edge of the immense Milky Way galaxy, it mingled material from its “surroundings” with material from other regions of the space, possibly from different ages too.

What scientists also discovered is the fact that comets are not all the same. A comet is usually defined as a small body in the solar system that orbits the Sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail- both primarily from the effects of solar radiation upon the comet’s nucleus, which itself is a minor body composed of rock, dust, and ices. Stardust now proved that Wild 2 has no ice at all and that is has never interacted with water in the past.

“This is a very interesting mismatch, and it seems that comets are not all the same. Perhaps they vary as much in their evolution as in the composition of the dust from which they are made.” The importance of the Stardust mission is augmented simply by the fact that scientists now rely on physical evidence rather than distant observations in the study of comets. This gives them a lot of useful and new information about the early stages of our solar system because comets are the oldest cosmic objects that travel through it.

“Comets are likely to be the oldest objects in our Solar System and their components have remained largely unchanged, so discovering more about what they have experienced gives us a snapshot of the processes that formed the planets over four and a half billion years ago. Fundamentally we still don’t know how you make planets from a cloud of dust and gas. Hopefully the Wild-2 samples will help us towards an answer.”