Spitzer Finds Organics and Water Where New Planets May Grow

Mar 13, 2008
Spectrum AA Tauri
This plot of infrared data shows the signatures of water vapor and simple organic molecules in the disk of gas and dust surrounding a young star. Credit: NASA/JPL-Caltech/Naval Research Laboratory

Researchers using NASA's Spitzer Space Telescope have discovered large amounts of simple organic gases and water vapor in a possible planet-forming region around an infant star, along with evidence that these molecules were created there. They've also found water in the same zone around two other young stars.

By pushing the telescope's capabilities to a new level, astronomers now have a better view of the earliest stages of planetary formation, which may help shed light on the origins of our own solar system and the potential for life to develop in others. John Carr of the Naval Research Laboratory, Washington, and Joan Najita of the National Optical Astronomy Observatory, Tucson, Ariz., developed a new technique using Spitzer's infrared spectrograph to measure and analyze the chemical composition of the gases within protoplanetary disks. These are flattened disks of gas and dust that encircle young stars. Scientists believe they provide the building materials for planets and moons and eventually, over millions of years, evolve into orbiting planetary systems like our own.

"Most of the material within the disks is gas," said Carr, "but until now it has been difficult to study the gas composition in the regions where planets should form. Much more attention has been given to the solid dust particles, which are easier to observe." In their project, Carr and Najita took an in-depth look at the gases in the planet-forming region in the disk around the star AA Tauri. Less than a million years old, AA Tauri is a typical example of a young star with a protoplanetary disk.

With their new procedures, they were able to detect the minute spectral signatures for three simple organic molecules--hydrogen cyanide, acetylene and carbon dioxide--plus water vapor. In addition, they found more of these substances in the disk than are found in the dense interstellar gas called molecular clouds from which the disk originated. "Molecular clouds provide the raw material from which the protoplanetary disks are created," said Carr. "So this is evidence for an active organic chemistry going on within the disk, forming and enhancing these molecules."

Spitzer's infrared spectrograph detected these same organic gases in a protoplanetary disk once before. But the observation was dependent on the star's disk being oriented in just the right way. Now researchers have a new method for studying the primordial mix of gases in the disks of hundreds of young star systems.

Astronomers will be able to fill an important gap--they know that water and organics are abundant in the interstellar medium but not what happens to them after they are incorporated into a disk. "Are these molecules destroyed, preserved or enhanced in the disk?" said Carr. "Now that we can identify these molecules and inventory them, we will have a better understanding of the origins and evolution of the basic building blocks of life--where they come from and how they evolve." Carr and Najita's research results appear in the March 14 issue of Science.

Taking advantage of Spitzer's spectroscopic capabilities, another group of scientists looked for water molecules in the disks around young stars and found them--twice. "This is one of the very few times that water vapor has been directly shown to exist in the inner part of a protoplanetary disk--the most likely place for terrestrial planets to form," said Colette Salyk, a graduate student in geological and planetary sciences at the California Institute of Technology in Pasadena. She is the lead author on a paper about the results in the March 20 issue of Astrophysical Journal Letters.

Salyk and her colleagues used Spitzer to look at dozens of young stars with protoplanetary disks and found water in many. They honed in on two stars and followed up the initial detection of water with complementary high-resolution measurements from the Keck II Telescope in Hawaii. "While we don't detect nearly as much water as exists in the oceans on Earth, we see essentially only the disk's surface, so the implication is that the water is quite abundant," said Geoffrey Blake, professor of cosmochemistry and planetary sciences at Caltech and one of the paper's co-authors.

"This is a much larger story than just one or two disks," said Blake. "Spitzer can efficiently measure these water signatures in many objects, so this is just the beginning of what we will learn."

"With upcoming Spitzer observations and data in hand," Carr added, "we will develop a good understanding of the distribution and abundance of water and organics in planet-forming disks."

Source: NASA

Explore further: Quest for extraterrestrial life not over, experts say

add to favorites email to friend print save as pdf

Related Stories

Research group to study interstellar molecules

Apr 11, 2014

From April 2014, a new group will study interstellar molecules and use them to explore the entire star and planet formation process at the Max Planck Institute for Extraterrestrial Physics. Newly appointed ...

Astronomers looking for clues to water's origins

Mar 27, 2014

A gas and dust cloud collapses to form a star. Amid a whirling disc of debris, little bits of rock coated with liquid water and ice begin to stick together. It is this stage of a star's formation that astronomers ...

The dusty heart of an active galaxy

Mar 13, 2014

(Phys.org) —An international research team led by Konrad Tristram from the Max-Planck-Institute for Radio Astronomy in Bonn, Germany, obtained the most detailed view so far of the warm dust in the environment ...

Recommended for you

Quest for extraterrestrial life not over, experts say

19 hours ago

The discovery of an Earth-sized planet in the "habitable" zone of a distant star, though exciting, is still a long way from pointing to the existence of extraterrestrial life, experts said Friday. ...

Continents may be a key feature of Super-Earths

23 hours ago

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Exoplanets soon to gleam in the eye of NESSI

Apr 18, 2014

(Phys.org) —The New Mexico Exoplanet Spectroscopic Survey Instrument (NESSI) will soon get its first "taste" of exoplanets, helping astronomers decipher their chemical composition. Exoplanets are planets ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

zevkirsh
3 / 5 (2) Mar 13, 2008
spitzer...oy.
dev2000
3 / 5 (2) Mar 13, 2008
Headline should read "Former Governor Sentenced to Become Telescope"
superhuman
not rated yet Mar 14, 2008
nvm

More news stories

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...

The importance of plumes

The Hubble Space Telescope is famous for finding black holes. It can pick out thousands of galaxies in a patch of sky the size of a thumbprint. The most powerful space telescope ever built, the Hubble provided ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...