1999


From: Johns Hopkins University

FUSE Satellite Will Test Big Bang Theory

A space telescope designed to sort through the chemical muck and star-making stew of the cosmos will begin scouring for the fossil record of the origins of the universe when it is launched from Cape Canaveral in a few weeks.

The bold examination -- of objects from nearby planets to the extreme outskirts of the cosmos -- is expected to reveal the earliest relics of the Big Bang and provide a detailed picture of the immense galactic structure of the Milky Way. In the end, scientists say the satellite should help them make a huge leap towards understanding how the primordial chemical elements, out of which all life evolved, were created and distributed since the beginning of time. Among the questions:

  • What were conditions like moments after the Big Bang?
  • How do galaxies evolve?
  • Does the Milky Way have a vast galactic fountain that births stars, spews hot gas, circulates chemicals and churns cosmic material over and over again?
  • Will a fossil remnant of earliest times subvert the most fundamental suppositions of the Big Bang theory?
On May 20, a team led by The Johns Hopkins University is scheduled to launch a satellite named FUSE (Far Ultraviolet Spectroscopic Explorer) and begin a long-awaited quest to cull answers to some of these vexing questions about the origins of the universe.

"The big questions are these: Do we understand the origins of the universe, and do we understand how galaxies evolve?" said Ken Sembach, a Johns Hopkins scientist working on the project. "Because FUSE can observe wavelengths of light that aren't accessible to other telescopes, we will be able to test models of chemical evolution in unique ways and extrapolate back in time to determine the primordial abundance of an isotope called deuterium, which very well may test the limits of the Big Bang theory."

As one of the first missions in NASA's Origins Program, FUSE extends astronomy's reach much further into the ultraviolet wavelength region, allowing astronomers to test fundamental models of cosmic construction. The search begins like an archaeological dig around the first minutes of creation. In this case, however, the fossil remnant is not the outline of a leaf or a bone, but evidence of a hydrogen isotope created solely in the Big Bang called deuterium.

FUSE's instrument will conduct a kind of spectroscopic surgery into the past and present, sampling measures of deuterium and other elements in a variety of places, from the inner recesses of our solar system to the nether-reaches of the Milky Way. Relying on the telescope's finely tuned instrument, astronomers will be able to set an accurate benchmark for the amount of deuterium in the Milky Way. With that information, they can then "look back" into time and determine what conditions were like in the infant universe moments after the Big Bang.

Because star creation itself is thought to depend on the regular destruction of deuterium -- as it is essentially chewed up when hydrogen converts to helium -- a map of deuterium abundances in many regions of the Milky Way galaxy will give scientists a better understanding of how chemicals are mixed and distributed and destroyed.

By concentrating on the structure and galactic fountain of the Milky Way, astronomers may end up with a more trusted model of galactic processes in general.

"We will learn a lot about circulation and mixing of chemicals in galaxies and in the star-forming process," said William Blair, a research scientist at Johns Hopkins working on the project. "Are there great galactic fountains constantly cycling material through supernovae explosions and stellar winds, bursting out of the plane of their galaxies, squirting up into haloes, cooling and falling back into the mix? At some level, it must be happening. But we hope to quantify it in a way that has never been done before."

That such an ambitious program arises from one academic department on a small campus in Baltimore might once have seemed preposterous. But besides its commitment to bold astronomy, the FUSE team has made an equally bold commitment to a unique way of doing business, reflecting the desire of one federal agency's goal to do things differently.

In 1995, in an effort to save money, the National Aeronautics and Space Administration chose Johns Hopkins to be the first college campus ever to manage an aerospace project of such magnitude. Heading toward launch, the cost of the mission is about one-third what NASA estimated before inviting Johns Hopkins to take over the project. As another indication of the project's distinctiveness, after launch and for the next three years, FUSE will be controlled and operated by a team of scientists, engineers and students on the first floor of the Bloomberg Center for Physics and Astronomy on the Johns Hopkins campus.

RELATED LINKS: Photographs of satellite, mission overview, and launch status.




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